Arquivo da tag: Evolucionismo

The Six Legacies of Edward O. Wilson (This View of Life)

By David Sloan Wilson – Published On: January 5, 2022

Note: An abbreviated version of this article is published in Nautilus Magazine.

Edward O. Wilson, who passed away at the age of 92 on December 26, 2021, is widely recognized as a giant of the Arts and Sciences. I include the Arts because Wilson regarded the creative dimension of science as an artistic endeavor, worked toward unifying the Arts and Sciences, and wrote beautifully for the general public, resulting in two Pulitzer prizes for nonfiction and one novel.

Wilson’s stature is so great, and reflections on his legacy upon his death are so numerous, that another reflection might seem unnecessary. The purpose of my reflection, however, is to make a novel point: Wilson left at least six legacies, which need to be combined to fully realize his vision. Combining the legacies of Edward O. Wilson requires first identifying them separately and then integrating them with each other.

The six legacies are:

1) His contributions to evolutionary biology.

2) His contributions to the conservation of biodiversity.

3) His contributions to a sociobiology that includes humans.

4) His contributions to the unification of knowledge.

5) His encouraging stance toward young scientists and other learners.

6) The new frontier that he was working on at the time of his death was ecosystems.   

My relationship with Edward O. Wilson

Before turning to these legacies and their integration, I will briefly recount my own relationship with Ed. I am 20 years younger so that he was already famous as a Harvard professor when I entered graduate school at Michigan State University in 1971. I first met him during the summer of that year. I was a student in an ecology course at the Marine Biological Laboratory in Woods Hole, Massachusetts. He was sitting in on the student project reports. After I reported my experiments on food size selection in zooplankton, Ed remarked “That’s new, isn’t it?” I was so proud to have impressed the great E.O. Wilson and contributed to the vast storehouse of scientific knowledge that I have remembered his comment ever since!

My graduate education was shaped in part by Ed’s influence on evolutionary biology, as I will elaborate below. My next personal interaction came near the end of my graduate career. I had constructed a mathematical model that provided support for the theory of group selection, which had been almost universally rejected by evolutionary biologists, as I will also elaborate below. Convinced of its importance, I wrote Ed asking if he would consider sponsoring it for the Proceedings of the National Academy of Sciences. Ed invited me to visit him at Harvard’s Museum of Comparative Zoology. As with my first encounter, I have a vivid memory of the visit, which began with a tour of his ant laboratory. Then he stood me in front of a blackboard, sat down in a chair, and said “you have 30 minutes until my next appointment.”

I talked like an auctioneer, filling the board with my equations. Ed was sufficiently intrigued to sponsor my article for PNAS after sending it out for review by two experts in theoretical biology. The article became my Ph.D. thesis, which is probably the shortest in the history of evolutionary science (four pages).

In the years that followed, I became one of the main advocates of group selection without directly crossing paths with Ed. I also took part in most of the other initiatives associated with Ed’s legacies without directly interacting with him. We were both involved in the formation of the Human Behavior and Evolution Society (HBES) and I hosted its third annual conference in 1993. On the theme of consilience, I started the first campus-wide program for teaching evolution across the curriculum and wrote one of the first book-length accounts of religion from an evolutionary perspective. It might seem strange that Ed and I shared so many interests without directly interacting, but just about everything associated with Ed’s legacies are in fact broad developments in the history of science involving many protagonists, a point to which I will return.

My next and by far most substantive interaction with Ed began at the 2006 annual conference of HBES. Ed was a plenary speaker and I was in the audience. Even though HBES members were in the avant-garde of studying human behavior from an evolutionary perspective, most of them were doctrinaire in their rejection of group selection. On his own, Ed had embraced group selection, converging on my own advocacy, and chose to break the news to the unsuspecting audience in his plenary. You could have heard a pin drop. Afterward, we found a corner of the lobby to talk alone.

“Did you like the grenade that I tossed in their midst?” Ed asked with a conspiratorial smile. On the spot, I suggested that we write a major article together, which became “Rethinking the Theoretical Foundation of Sociobiology”, published in the Quarterly Review of Biology in 2007. To reach a larger audience, we also wrote “Evolution for the Good of the Group”, which was published in the American Scientist in 2008. These were written by trading drafts and discussing them by email and phone. I still remember his voicemails, which sometimes went on for several minutes and were spoken in flawless extemporaneous prose.

At the end of our “Rethinking” article, we summarized our argument for group selection as the theoretical foundation of sociobiology by stealing from Rabbi Hillel, who was reputedly asked to explain the meaning of the Torah while standing on one foot and replied “What is hateful to you, do not do to your neighbor. Everything else is commentary.” Our one-foot version of sociobiology was: “Selfishness beats altruism within groups. Altruistic groups beat selfish groups. Everything else is commentary.” This meme has become widely known and Ed repeated it all the way up to his final publications and interviews.

After this intense collaboration, Ed and I went our separate ways to continue pursuing our largely overlapping interests. The last time I saw him was at a conference at MIT, which was close enough to his home that he could attend without arduous travel. In the few minutes that we spoke together, he told me excitedly about ecosystems as the next big topic that he planned to synthesize. He retained his youthful spirit of exploration right up to the end.

I have one more story about Ed to tell before turning to his six legacies. In 2014, the evolutionary psychologist Barry X. Kuhle recorded a series of interviews with pioneers of HBES, including both Ed and myself. Ed must have relished the opportunity to talk at a professional level with someone as well informed as Barry because his interview lasted two hours. I was president of the newly founded Evolution Institute and Editor in Chief of its online magazine This View of Life (TVOL), which was named after the final passage of Darwin’s On the Origin of Species (“There is grandeur in this view of life…”). I was eager to feature a print version of Barry’s interview with Ed on TVOL, so I offered to transcribe it myself. There is something about transcribing a recording, word by word, that burns it into your memory more than merely listening to the recording or reading the transcription. This experience adds to my knowledge of Ed and his legacies, along with his published work and my personal relationship with him.

The Six Legacies

History—including the history of science–is a complex systemic process involving many actors and environmental (including cultural) contingencies. Attention often becomes focused on a few key people, such Albert Einstein, Sigmund Freud, and B.F. Skinner, which under-represents the contributions of many dozens of others. Iconic status is thrust upon a person as much as actively sought by the person. There seems to be a need to personify ideas as a form of simplification, among the general public and even, to a degree, among the experts.  

A few evolutionary biologists such as Ed Wilson, Richard Dawkins, and the late Stephen Jay Gould have achieved this iconic status. Yes, they made outsized contributions as individuals, but they also represent something larger than themselves. I think that Ed would agree. In his book Sociobiology: The New Synthesis, for example, he was relying upon the work of many hundreds of scientists to support his claim that there can be a single theory of social behavior informed by evolution.

The world “catalyst” also bears examination. In chemistry, a catalyst is a substance that increases the rate of a chemical reaction without being used up in the process. The way a catalytic molecule works is by holding other molecules in an orientation that binds them to each other and releases the catalytic molecule to repeat the operation. A person can play a catalytic role in cultural change in much the same way. As we will see, Ed was a catalyst par excellence. He made things happen that otherwise would have occurred much more slowly or not at all.

Against this background, calling Ed an “icon” and a “catalyst” honors the individual while also going beyond the individual to examine systemic trends in the history of science. It is in this spirit that I will review his six legacies.     

1) His contributions to evolutionary biology.

Here is how Ed described his contribution to evolutionary biology in his interview with Barry Khule:

We have to go back to the 1950’s. In the 1950’s, the molecular revolution had begun. It was clear that the golden age of modern biology was going to be molecular and would endure a long time. In fact, it did occupy the second half of the 20th century and beyond. We felt here at Harvard immediately the pressure to start giving up positions to molecular biology. The Dean of the faculty and the President at that time were entirely in accord. We found—I say we, the organismic and evolutionary biologists here, comparative anatomists, comparative zoologists and so on–realized that we would not to be given much additional space anymore, that we probably would not get many if any new positions for a long time. They would be reserved to build up Harvard’s strength in molecular and cellular biology. What this did was have a tremendous impact on me personally because I realized…that those of us, my generation of what we came to call evolutionary biologists and organismic biologists, were not going to get anywhere by complaining by any means but we were going to have to—and we should be tremendously excited to plan this—develop an equivalent to molecular biology on our own. 

Ed then set about trying to modernize the biology of whole organisms, as part of a younger generation following the architects of the Modern Synthesis, which included names such as Ernst Mayr, Julian Huxley, and George Gaylord Simpson. This required finding and collaborating with people who had complementary expertise—especially the ability to build mathematical models of ecological and evolutionary processes. Names that Ed mentions as part of this younger generation include Robert MacArthur, Larry Slobodkin, and Richard Lewontin. These were some of the rock stars whose work I avidly read as a graduate student in the 1970s.

One of Ed’s most productive collaborations was with Robert MacArthur, an ecologist with mathematical training, leading to their landmark book The Theory of Island Biogeography, published by Princeton University Press in 1967 with Ed as the second author. What made the book so important was a theoretical framework that made sense of the great mass of natural history information on the distribution and abundance of species on islands—some of it collected by Ed for ant species around the world. The theory applied not only to actual islands but to all habitats that are island-like, such as mountains separated by valleys or patches of forest separated by deforested areas.  

While Ed played a prominent role in modernizing whole organism biology, he was by no means alone. Also during my time as a graduate student, a Nobel prize was awarded to Konrad Lorenz, Niko Tinbergen, and Carl von Frisch for pioneering the study of animal behavior and the geneticist Theodosius Dobzhansky titled an article for biology teachers “Nothing in biology makes sense except in the light of evolution”. Evolutionary theory was proving its explanatory scope and many people were taking part in the effort. What this meant to me as a graduate student was that I could choose any topic, begin asking intelligent questions based on evolutionary theory (often with the help of mathematical models), and then test my hypotheses on any appropriate organism. I didn’t need to become a taxonomic specialist and I could change topics at will. In short, I could become a polymath, based not on my personal attributes but on a theory that anyone can learn. This is the legacy of evolutionary biology, to which Ed made an outsized contribution.

2) His contributions to the conservation of biodiversity

As first and foremost a naturalist and ant taxonomic expert, Ed was passionate about the conservation of biological diversity and made room for it alongside his scientific career. His book Biophilia argued that we are genetically adapted to be surrounded by nature, with mental and physical health consequences if we are not. This bold conjecture has been largely supported by research. For example, hospital patients recover faster if their room has a window or is decorated with foliage and flowers.

Ed collaborated with Thomas Lovejoy, who coincidentally passed away just a day earlier at the age of 80, to preserve the biodiversity of the Amazon. According to a remembrance in the New Yorker magazine, it was they who coined the term biological diversity, which became shortened to biodiversity. They even drew upon the theory of Island Biogeography by studying the effect of the size of forest reserves on species loss.

With his gift for marketing whole disciplines and initiatives, Ed coined the term “Half Earth” for the goal of preserving half of the earth for nature and the other half for humankind—not in separation, but in a way that is interdigitated, so that humans can live within nature and nature can flow along corridors. Anyone who values nature should want to continue this legacy but doing so requires changing the minds and hearts of people, along with their cultural practices, in the real world.

3) His contributions to a sociobiology that includes humans

Ed’s 1975 book, Sociobiology: The New Synthesis, was in the same mold as Darwin’s “there is grandeur in his view of life” and Dobzhansky’s “nothing in biology makes sense except in the light of evolution”. Ed’s claim was that evolutionary theory provides a single conceptual toolkit for studying the social behaviors of all creatures great and small. Thanks to Ed’s gift for identifying whole fields of inquiry and writing for non-specialists, Sociobiology combined the authority of an academic tome with the look and feel of a coffee table book, complete with over 200 illustrations by the artist Sarah Landry. Thanks to his stature and gift for promotion, its publication was noted on the front page of the New York Times.

It was the last chapter on human social behavior that landed Ed in trouble and a systemic view of the history of science is needed to understand why. For all its explanatory scope, the study of evolution was restricted to genetic evolution for most of the 20th century, as if the only way that offspring can resemble their parents is by sharing the same genes. This is patently false when stated directly since it ignores the cultural transmission of traits entirely, but it essentially describes what became known as the modern synthesis and was consolidated by the molecular biology revolution described by Ed in his interview with Barry Kuhle.

What became of the study of cultural evolution? It was ceded to other disciplines in the human social sciences and humanities. Each discipline developed into a sophisticated body of knowledge, but not in reference and sometimes in perceived opposition to evolutionary theory. And all of those disciplines did not remotely become integrated with each other. Instead, they became an archipelago of knowledge with little communication among the islands. The lack of consilience for human-related knowledge stands in stark contrast with the consilience of biological knowledge, at least when it comes to genetic evolution.

Darwin’s theory is often said to have earned a bad reputation for itself in the human-related disciplines by providing a moral justification for inequality (Social Darwinism). The real history of Darwinism in relation to human affairs is more complex and interesting. Socialists such as Peter Kropotkin and progressive thinkers such as William James and John Dewey were inspired by Darwin along with “nature red and truth in claw” types. The bottom line is that any powerful tool can also be used as a weapon and Darwin’s theory is no different than any other theory in this regard.1

Returning to the reception to Sociobiology, when critics accused Ed of genetic determinism, they were absolutely right. The entire field of evolutionary biology was gene-centric and Ed was no exception. Yet, critics from the human social sciences and humanities had no synthesis of their own.

Only after the publication of Sociobiology did evolutionary thinkers begin to take cultural evolution seriously. Ed was among them with books such as On Human NatureGenes, Mind, and Culture (with Charles J. Lumsden), Promethean Fire (also with Lumsden), and The Social Conquest of Earth. Other major thinkers included Richard Dawkins and his concept of memes, Luigi Luca Cavalli-Sforza and Marcus Feldman (Cultural Transmission and Evolution), and Robert Boyd and Peter Richerson (Culture and the Evolutionary Process, Not By Genes Alone). The importance of symbolic thought began to occupy center stage with books such as The Symbolic Species by Terrence Deacon and Evolution in Four Dimensions by Eva Jablonka and Marion Lamb.

Today, Darwinian evolution is widely defined as any process that combines the three ingredients of variation, selection, and replication, no matter what the mechanism of replication. This definition is true to Darwin’s thought (since he knew nothing about genes) and can accommodate a plurality of inheritance mechanisms such as epigenetics (based on changes in gene expression rather than gene frequency), forms of social learning found in many species, and forms of symbolic thought that are distinctively human. While human cultural inheritance mechanisms evolved by genetic evolution, that doesn’t make them subordinate, as if genes hold cultures on a leash (one of Ed’s metaphors). On the contrary, as the faster evolutionary process, cultural evolution often takes the lead in adapting humans to their environments, with genetic evolution playing a following role (gene-culture co-evolution).

Part of the maturation of human cultural evolutionary theory is the recognition of group selection as an exceptionally strong force in human evolution—something else that Ed got right. According to Harvard evolutionary anthropologist Richard Wrangham in his book The Goodness Paradox, naked aggression is over 100 times more frequent in a chimpanzee community than in small-scale human communities. This is due largely to social control mechanisms in human communities that suppress bullying and other forms of disruptive self-serving behaviors so that cooperation becomes the primary social strategy (this is called a major evolutionary transition). Nearly everything distinctive about our species is a form of cooperation, including our ability to maintain an inventory of symbols with shared meaning that is transmitted across generations. Our capacity for symbolic thought became a full-blown inheritance system that operates alongside genetic inheritance (dual inheritance theory). Cultural evolution is a multilevel process, no less than genetic evolution, and the increasing scale of cooperation over the course of human history can be seen as a process of multilevel cultural evolution.

While the critique of genetic determinism was accurate for Sociobiology and evolutionary biology as a whole in 1975, this is no longer the case for the modern study of humans from an evolutionary perspective—which brings us to Ed’s next legacy.

4) His contributions to the unification of knowledge.

Something that can be said about Ed’s books is that they are all visionary—imagining whole new fields of inquiry—but vary in the degree to which Ed has made progress carrying out the vision. He made the most progress for ants and other social insects, of course, and Sociobiology reflected a thorough reading of the literature on animal social behaviors. A book such as Consilience, however, is long on vision and short on execution.

I do not intend this observation as a criticism. Ed had only 24 hours in a day, like the rest of us, and his visionary gaze is worthwhile even if the execution is left to others. In Consilience, the vision is “a conviction, far deeper than a mere working proposition, that the world is orderly and can be explained by a small number of natural laws (p4)”. While this vision stretches back to antiquity and includes knowledge of the physical world in addition to the living world, there is something about evolutionary theory that fulfills the vision for the living world in an extraordinary way. Here is how Ed describes his first encounter with evolutionary theory in the opening pages of Consilience. He’s an 18-year old kid newly arrived at the University of Alabama, with a passion for identifying plants and animals using field guides.

Then I discovered evolution. Suddenly—that is not too strong a word—I saw the world in a wholly new way. This epiphany I owed to my mentor Ralph Chermock, an intense, chain-smoking young assistant professor newly arrived in the provinces with a Ph.D. in entomology from Cornell University. After listening to me natter for a while about my lofty goal of classifying all the ants of Alabama, he handed me a copy of Ernst Mayr’s 1942 Systematics and the Origin of Species. Read it, he said, if you want to become a real biologist.

The thin volume in the plain blue cover was one of the New Synthesis works, uniting the nineteenth-century Darwinian theory of evolution and modern genetics. By giving a theoretical structure to natural history, it vastly expanded the Linnaean enterprise. A tumbler fell somewhere in my mind, and a door opened to a new world. I was enthralled, couldn’t stop thinking about the implications evolution has for classification and for the rest of biology. And for philosophy. And for just about everything. Static pattern slid into fluid process…A new enthusiasm surged through me. The animals and plants I loved so dearly reentered the stage as lead players in a grand drama. Natural history was validated as real science.

Coincidentally, Ernst Mayr’s Animal Species and Evolution was one of the first evolution books that I read as an undergraduate student. While it was not thin (811 pp!), I was similarly enthralled. Compare Ed’s epiphany with passages from Charles Darwin, such as “I can remember the very spot on the road…” and “he who understands the baboon would do more toward metaphysics than Locke”, which was scribbled in his notebook in 1838. There is something about the simplicity and generality of evolutionary theory that starts working at the very beginning, for Darwin as the originator and Ed Wilson as an unschooled kid. Now recall what I said about being a graduate student in the 1970s—that I could become a polymath, based not on my personal attributes but on a theory that anyone can learn. What this means is that by the 1970s, what Darwin and Ed glimpsed from the start was now proving itself for the length and breadth of the biological sciences. Every time an evolutionary biologist decides to switch to a new topic and/or organism–which happens all the time—consilience is being demonstrated in action.

The prospect that human-related knowledge can become unified in this way is both old and new. It was how Darwin thought and he originated group selection theory as much to explain human morality as “for the good of the group” traits in nonhuman species. But you can’t make sense of humanity without acknowledging its groupish nature and the importance of culturally transmitted symbolic meaning systems. As Emile Durkheim wisely put it: “Social life, then, in every aspect and throughout its history, is only possible thanks to a vast body of symbolism.” Only now are we in a position to synthesize human-related knowledge in the same way as biological knowledge, thanks to an expanded definition of Darwinism as any variation/selection/replication process. Ed’s vision in Consilience is right on and its fulfillment is now in progress.

5) His encouraging stance toward young scientists and other learners.

No remembrance of Ed would be complete without noting the way that he encouraged people to become scientists, to follow their hearts, and to cultivate a reverence for nature. Visit #eowilson on Twitter and you’ll find quotes such as these offered by those whose lives he touched.

“Adults . . . are prone to undervalue the mental growth that occurs during daydreaming and aimless wandering.” — The late great Edward O. Wilson

“Nature first, then theory. Love the organisms for themselves first, then strain for general explanations, and with good fortunes discoveries will follow.”

“You are capable of more than you know. Choose a goal that seems right for you and strive to be the best, however hard the path. Aim high. Behave honorably. Prepare to be alone at times, and to endure failure. Persist! The world needs all you can give.”

“Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction.

“There can be no purpose more enspiriting than to begin the age of restoration, reweaving the wondrous diversity of life that still surrounds us.”

“The evolutionary epic is the best myth we will ever have.”

“You teach me, I forget. You show me, I remember. You involve me, I understand.”

“Humanity is part of nature, a species that evolved among other species. The more closely we identify ourselves with the rest of life, the more quickly we will be able to discover the sources of human sensibility and acquire the knowledge on which an enduring ethic, a sense of preferred direction, can be built.”

Passages such as these spell the difference between science and a science-based worldview. By itself, science merely tells us what is. A worldview provides a sense of values and motivates action. A science-based worldview does this based on reverence of the natural world rather than a supernatural agency. Ed is remembered at least as much for the science-based worldview that he offered as his scientific discoveries.

6) Ecosystems as Ed’s final frontier

Ed’s next book was to be titled “Ecosystems and the Harmony of Nature”. I don’t know if it will be published posthumously but we can get a glimpse of what he had in mind from its title, a brief article on the E.O. Wilson Biodiversity Foundation website,2 and a short lecture on YouTube.3

In the article, Ed is quoted as saying: “We know that ecosystems, which are really what we are trying to protect–not just single species but ensembles of species that have come together and have reached the ability—sometimes over thousands or even in some places millions of years—have formed ecosystems that equilibrate. And we don’t really know how equilibration comes about.” Ed also encourages young people to join “the coming development of a new biological science, one of the next big things, which is ecosystem studies.”

I must confess that I am puzzled by these statements since the study of whole ecosystems dates back to the beginning of the 20th century and has become increasingly integrated with evolutionary ecology over the last 50 years. It turns out that multilevel selection theory is essential for understanding the nature of ecosystems, no less than single species societies. I will be fascinated to know if Ed has converged upon this conclusion.

To explain what I mean, a critical distinction needs to be made between two meanings of the term “complex adaptive system (CAS)”: A complex system that is adaptive as a system (CAS1), and a complex system composed of agents following their respective adaptive strategies (CAS2). A human society in the grip of civil war is an example of CAS2. It can be understood in terms of the conflicting interests of the warring factions, but it does not function well at the level of the whole society (CAS1) and no one would expect it to.

Many single-species societies in nature are like my human civil war example. Members of social groups are largely in conflict with each other and at most cooperate in specific contexts. We need look no further than chimpanzee communities for an example, where naked aggression is over 100 times more frequent than in small-scale human communities and the main context for community-wide cooperation is aggression against neighboring communities. Social strife in chimpanzee communities is stable—there is no reason to expect it to change, given the selection pressures that are operating—but that doesn’t make them harmonious or desirable from a human perspective.

Many multispecies ecosystems are also like this. For example, if you want to understand the nature of beaver ecosystems, ask the question “what’s in it for the beavers?” They are modifying the environment for their own benefit, flooding it to protect themselves from predators and eating the most palatable plants. Consequences for biodiversity and ecosystem processes such as nutrient cycling are collateral effects of beavers pursuing their interests. There is no reason to expect the whole ecosystem to be functionally organized and harmonious, any more than a chimpanzee community or a human society in the grip of civil war.

This is a hard lesson to learn about nature. We want it to be harmonious. Religious cosmologies often portray nature as harmonious (e.g., the Garden of Eden) except when disturbed by humans. The early study of ecosystems often treated them axiomatically as harmonious.  But Darwin’s theory of evolution tells a different story. It tells us that functional organization for any given system, at any given scale, requires a process of selection at that scale. That is the only way to achieve the status of CAS1 rather than merely CAS2, where functionally organized agents impose suffering on each other in the course of pursuing their respective adaptive strategies. That statement goes for human society, single-species animal societies, and multispecies ecosystems.   

Are there examples of whole ecosystems that have evolved into superorganisms? Yes! Microbiomes are an example. Every multicellular organism is not only a collection of mostly identical genes but also an ecosystem composed of trillions of microbes comprising thousands of species. When the host organisms differentially survive and reproduce, this is due in part to variation in their microbiomes along with variation in their genes. Thanks to selection at this level, microbiomes have evolved to be largely mutualistic with their hosts. There is also potential for selection among microbes within each host, however, leading to the evolution of pathogenic strains. It all depends on the level of selection.

Nowadays, whole forests are being imagined as mutualistic networks, with trees connected into a network by mycorrhizal fungi. Is such a thing possible? Yes, but only if selection has operated at the scale of whole forests with sufficient strength to counteract selection at lower scales. Otherwise, forests become merely CAS2 systems, composed of species that interact at cross purposes, rather than CAS1 systems.

Above all, it is important to avoid confusing “harmony” with “equilibrium”. Ecologists have started to use the word “regime” to describe stable assemblages of species. This is a well-chosen word because it evokes what we already know about human political regimes. All political regimes have a degree of stability, or we wouldn’t call them regimes, but they span the range from despotic (benefitting a few elites at the expense of everyone else) to inclusive (sharing their benefits with all citizens). Some of the worst regimes are also depressingly the most stable. Using the language of complex systems theory, there are multiple local stable equilibria and positive change requires escaping the gravitational pull of one local equilibrium to enter another local equilibrium. This requires active management and will not necessarily happen by itself. The management of ecosystems must itself be a human cultural evolutionary process informed by multilevel selection theory.

Combining the legacies

In this remembrance of Ed Wilson, I have tried to honor the person while also placing him in the context of broad trends in the history of science. Without mentioning Ed, we can say that Darwin’s theory of evolution has an amazing explanatory scope, that this scope was largely restricted to the study of genetic evolution for most of the 20th century, but now is rapidly expanding to include all aspects of humanity in addition to the rest of life. As I put it in my own book This View of Life: Completing the Darwinian Revolution, Dobzhansky’s statement “nothing in biology makes sense except in the light of evolution” can be extended to include everything associated with the words “human”, “culture”, and “policy”.

Without mentioning Ed, we can also say that evolutionary theory is capable of functioning as a worldview in addition to a body of scientific knowledge. Science only tells us what is, whereas a worldview inspires us psychologically and moves us to action. Creating a worldview informed entirely by science, as opposed to supernatural belief, is part of the enlightenment project that led to humanism as a philosophical worldview and social movement. While humanists accept Darwin’s theory as a matter of course, the recent developments that I have recounted have not been incorporated into the humanist movement for the most part. Thus, humanism and what it stands for is due for a renaissance, along with a renaissance of basic scientific knowledge.

Some simple calculations will help to put Ed’s career into historical perspective. Starting from when he received his Ph.D. in 1955 to his death in 2021, his career lasted for 66 years. If we mark the beginning of evolutionary science with the publication of Darwin’s On the Origin of Species in 1859, then Ed was present for 40% of the history of evolutionary thought. If we mark the beginning of the scientific revolution with the publication of Copernicus’s On the Revolution of the Heavenly Spheres in 1543, then Ed was present for 14% of the scientific revolution. As 20 years Ed’s junior, my numbers work out to 28% and 10% respectively.

These numbers remind us that evolutionary science and the scientific revolution are still works in progress. If science in general and evolutionary science, in particular, have revolutionized the way we see and therefore act upon the world, then we can look forward to further improvements in the near future. This leads to a form of hope and optimism, even in the darkest of times, that is part of Ed’s legacy.

For me, the next frontier is not just ecosystems but becoming wise stewards of evolution in all its forms. Variation/selection/replication processes are taking place all around us at different time scales, including genetic evolution, cultural evolution, and intra-generational personal evolution. Without wise stewardship, these evolutionary processes result merely in CAS2—complex systems composed of agents following their respective adaptive strategies, often inflicting harm on each other and on the entire system over the long term. Work is required to transform CAS2 into CAS1—systems that are adaptive as whole systems. This work will be required for all forms of positive change—individual, cultural, and ecosystemic. The ability to see this clearly and to act upon it has only become available during the last few decades and is currently shared by only a tiny fraction of those who need to know about it. Catalysis is needed, so that positive evolution can take place in a matter of years rather than decades or not at all. The best way to honor Ed’s combined legacies is to join in this catalysis.


[1] For more, see the TVOL special edition titled “Truth and Reconciliation for Social Darwinism”.



Game theory and economics show how to steer evolution in a better direction (Science Daily)

Date: November 16, 2021

Source: PLOS

Summary: Human behavior drives the evolution of biological organisms in ways that can profoundly adversely impact human welfare. Understanding people’s incentives when they do so is essential to identify policies and other strategies to improve evolutionary outcomes. In a new study, researchers bring the tools of economics and game theory to evolution management.

Human behavior drives the evolution of biological organisms in ways that can profoundly adversely impact human welfare. Understanding people’s incentives when they do so is essential to identify policies and other strategies to improve evolutionary outcomes. In a new study publishing November 16thin the open access journal, PLOS Biology, researchers led by Troy Day at Queens University and David McAdams at Duke University bring the tools of economics and game theory to evolution management.

From antibiotic-resistant bacteria that endanger our health to control-resistant crop pests that threaten to undermine global food production, we are now facing the harmful consequences of our failure to efficiently manage the evolution of the biological world. As Day explains, “By modelling the joint economic and evolutionary consequences of people’s actions we can determine how best to incentivize behavior that is evolutionarily desirable.”

The centerpiece of the new analysis is a simple mathematical formula that determines when physicians, farmers, and other “evolution managers” will have sufficient incentive to steward the biological resources that are under their control, trading off the short-term costs of stewardship against the long-term benefits of delaying adverse evolution.

For instance, when a patient arrives in an urgent-care facility, screening them to determine if they are colonized by a dangerous superbug is costly, but protects future patients by allowing superbug carriers to be isolated from others. Whether the facility itself gains from screening patients depends on how it weighs these costs and benefits.

The researchers take the mathematical model further by implementing game theory, which analyzes how individuals’ decisions are interconnected and can impact each other — such as physicians in the same facility whose patients can infect each other or corn farmers with neighboring fields. Their game-theoretic analysis identifies conditions under which outcomes can be improved through policies that change incentives or facilitate coordination.

“In the example of antibiotic-resistant bacteria, hospitals could go above and beyond to control the spread of superbugs through methods like community contact tracing,” McAdams says. “This would entail additional costs and, alone, a hospital would likely not have an incentive to do so. But if every hospital took this additional step, they might all collectively benefit from slowing the spread of these bacteria. Game theory gives you a systematic way to think through those possibilities and maximize overall welfare.”

“Evolutionary change in response to human interventions, such as the evolution of resistance in response to drug treatment or evolutionary change in response to harvesting, can have significant economic repercussions,” Day adds. “We determine the conditions under which it is economically beneficial to employ costly strategies that limit evolution and thereby preserve the value of biological resources for longer.”

Journal Reference:

  1. Troy Day, David A. Kennedy, Andrew F. Read, David McAdams. The economics of managing evolution. PLOS Biology, 2021; 19 (11): e3001409 DOI: 10.1371/journal.pbio.3001409

Opinião – Reinaldo José Lopes: Periódico científico da USP dá palco para negacionista da crise climática (Folha de S.Paulo)

Não existe multipartidarismo sobre a lei da gravidade ou pluralismo ideológico acerca da teoria da evolução

30.out.2021 às 7h00

O veterano meteorologista Luiz Carlos Molion é uma espécie de pregador itinerante do evangelho da pseudociência. Alguns anos atrás, andou rodando o interiorzão do país, a soldo de uma concessionária de tratores, oferecendo sua bênção pontifícia às 12 tribos do agro. Em suas palestras, garantia às tropas de choque da fronteira agrícola brasileira que desmatar não interfere nas chuvas (errado), que as emissões de gás carbônico não esquentam a Terra (errado) e que, na verdade, estamos caminhando para uma fase de resfriamento global (errado).

Existem formas menos esquálidas de terminar uma carreira que se supunha científica, mas parece que Molion realmente acredita no que fala. O que realmente me parece inacreditável, no entanto, é que um periódico científico editado pela maior universidade da América Latina abra suas portas para as invectivas de um ex-pesquisador como ele.

Foi o que aconteceu na última edição da revista Khronos, editada pelo Centro Interunidade de História da Ciência da USP. Numa seção intitulada “Debates”, Molion publicou o artigo “Aquecimento global antropogênico: uma história controversa”. Nele, Molion requenta (perdoai, Senhor, a volúpia dos trocadilhos) sua mofada marmita de negacionista, atacando a suposta incapacidade do IPCC, o painel do clima da ONU, de prever com acurácia o clima futuro deste planetinha usando modelos computacionais (errado).

O desplante era tamanho que provocou protestos formais de diversos pesquisadores de prestígio da universidade, membros do conselho do centro uspiano. Na carta assinada por eles e outros colegas, lembram que Molion não tem quaisquer publicações relevantes em revistas científicas sobre o tema das mudanças climáticas há décadas e que, para cúmulo da sandice, o artigo nem faz referência… à história da ciência, que é o tema da publicação, para começo de conversa.

A resposta do editor do periódico Khronos e diretor do centro, Gildo Magalhães, não poderia ser mais desanimadora. Diante do protesto dos professores, eis o que ele disse: “Não cabe no ambiente acadêmico fazer censura a ideias. Na universidade não deveria haver partido único. Quem acompanha os debates nos congressos climatológicos internacionais sabe que fora da grande mídia o aquecimento global antropogênico é matéria cientificamente controversa. Igualar sumariamente uma opinião diversa da ortodoxa com o reles negacionismo científico, como foi o caso no Brasil com a vacina contra a Covid, prejudica o entendimento e em nada ajuda o diálogo”.

Não sei se Magalhães está mentindo deliberadamente ou é apenas muito mal informado, mas a afirmação de que o aquecimento causado pelo homem é matéria controversa nos congressos da área é falsa. O acompanhamento dos periódicos científicos mostra de forma inequívoca que questionamentos como os de Molion não são levados a sério por praticamente ninguém. A controvérsia citada por Magalhães inexiste.

É meio constrangedor ter de explicar isso para um professor da USP, mas as referências a debate de “ideias” e “partido único” não têm lugar na ciência. Se as suas ideias não são baseadas em experimentos e observações feitos com rigor e submetidos ao crivo de outros membros da comunidade científica, elas não deveriam ter lugar num periódico acadêmico. Não existe multipartidarismo sobre a lei da gravidade ou pluralismo ideológico acerca da teoria da evolução. Negar isso é abrir a porteira para retrocessos históricos.

Out of Savannastan by Tim Flannery (New York Review of Books)

New York Review of Books, November 4, 2021

By Tim Flannery

Ancient Bones: Unearthing the Astonishing New Story of How We Became Human by Madelaine Böhme, Rüdiger Braun, and Florian Breier, translated from the German by Jane Billinghurst and with a foreword by David R. Begun. Greystone, 337 pp., $34.95

In 1863 the biologist T.H. Huxley proposed an African origin for humanity. Known as “Darwin’s bulldog” for his ferocious defense of Darwin’s evolutionary theory, he had been struck by the distribution in Africa of our nearest living relatives, the common chimpanzee and the gorilla. (The latter had first been described by Europeans just sixteen years earlier, in 1847.) Darwin himself, however, demurred. Aware of the discovery of fossils of apes in Europe dating to the Miocene Epoch (around 23 to 5 million years ago), he opined that “since so remote a period the Earth has certainly undergone many great revolutions, and there has been ample time for migration on the largest scale.”

It was the pioneering and indefatigable Leakey family who found evidence for Huxley’s narrowly supported hypothesis. Louis and Mary Leakey began their search for fossils of human ancestors in Olduvai Gorge, in what is now Tanzania, in the 1930s. Amid the dust, sweat, and inconvenience of remote field camps, they simultaneously dug for fossils and raised three boys, often finding nothing of significance for years at a time. Then, in 1959, Mary discovered a fossilized skull that made headlines around the world. Paranthropus boisei, as it became known, belonged to a male upright ape who had stood around five feet high, weighed 110 pounds, and lived 1.8 million years ago. With powerful teeth and a prominent crest atop his braincase to anchor prodigious chewing muscles, he was an archetypal “ape man.” I recall as a child staring awestruck at a painting of Paranthropus that combined the features of gorillas, chimps, and humans, and that powerfully cemented in my mind the idea that Africa had been humanity’s cradle.

A few months after this discovery, the Leakeys made a second, even more significant find—a jaw attributable to an early member of our own genus. Homo habilis, or “Handy Man,” was a toolmaker hailed as the oldest “true” human ever discovered. After that, the discoveries just kept coming. In 1974 an international team in Ethiopia led by the paleoanthropologist Donald Johanson unearthed the skeleton of the three-foot-tall bipedal ape Australopithecus afarensis, who became popularly known as Lucy. With a catchy name and providing powerful, easy-to-understand support for an African origin, Lucy soon became a household name. Four years later Mary Leakey found 3.6-million-year-old hominin footprints at Laetoli, Tanzania, providing the earliest evidence of bipedalism.

In 1984 a team led by Louis and Mary Leakey’s son Richard unearthed a skeleton of Homo erectus at Lake Turkana in northern Kenya that was 90 percent complete. It seemed as if these astonishing African fossils illustrated most of the important steps in the human evolutionary story. When, beginning in the 1980s, genetic evidence suggested that our species (Homo sapiens) originated in Africa, the case seemed settled: Huxley, rather than Darwin, had been right about our origins. Some researchers began elaborating an all-encompassing Out of Africa theory, which had three components: (1) our hominin lineage (which split from chimpanzees between 13 and 7 million years ago) arose in Africa; (2) our genus, Homo, arose in Africa about 2.3 million years ago, and (3) our species originated in Africa about 300,000 years ago.

But there were always a few dissenters who, like Darwin, felt that the significance of fossilized fragments from Europe and Asia had been overlooked. They pointed to a suspicious gap in the African fossil record between 12 and 6 million years ago, just when the human and chimpanzee lineages were diverging. And some worried that the Leakeys and others had found fossils only where they looked for them—in Africa. If equivalent effort was put in elsewhere, skeptics argued, important finds might be made.

These objections had long been ignored, but now, in her splendid and important new book Ancient Bones, Madelaine Böhme and her collaborators Rüdiger Braun and Florian Breier have taken them up. Scientifically rigorous and written with a clarity and candor that create a gripping tale, it presents a powerful challenge to proponents of the Out of Africa hypothesis. The book begins with a foreword by one of the earliest and most prominent objectors to the hypothesis, the University of Toronto professor David R. Begun. Begun believes that apes became extinct in Africa around 12 million years ago and that our earliest direct ancestors evolved in Europe, which is rich in ape fossils from 12 to 6 million years old. Böhme, a terrestrial paleoclimatologist and paleoanthropologist at the University of Tübingen, has excavated and researched many specimens of European apes herself, and her account of the history of Europe’s lost apes is imbued with the sweat, grime, and triumph that is the lot of the fieldworker, and carries great authority.

As Böhme illustrates, the evolution of the human lineage is complex. A crucial event occurred around 25 million years ago, when the apes and Old World monkeys originated from a common ancestor in East Africa. The monkeys flourished in Africa, but as time went on the apes dwindled, until around 16 million years ago some reached Europe, where they thrived. Climatic changes in Europe, including increased seasonality, seem to have favored their diversification, and twelve genera are now known from the European Miocene, varying from gibbon-like creatures that swung through the forest canopy to gorilla-sized, presumably terrestrial ramblers.

As oak and beech trees started to crowd out the tropical vegetation that had dominated Europe till then, the apes were forced to alter their diet. Depending on which part of Europe they lived in, they had to go for between two and four months without fresh leaves, fruits, or nuts. Around 15 million years ago, a genetic mutation occurred that resulted in their inability to produce uricase, the enzyme used by mammals to break down uric acid so that it can be excreted in urine. This mutation led to high levels of uric acid in the apes’ blood, allowing them to rapidly convert fructose into fat. And fat, stored in the liver and other tissues, is an energy reserve that made it possible for the apes to survive lean seasons.

I often curse this adaptation, for I’m a victim of that singularly painful condition, gout, which is caused by a buildup of uric acid in the blood. Were it not for the availability of uricase in pill form (thank God for modern medicine!), I’d be a bedridden old grouch by now. But gout is just one of the many “diseases of civilization” inflicted on us by this adaptation in our ape ancestors. Diabetes, obesity, high blood pressure, and heart disease are all related to some degree to the loss, in some long-extinct European ape, of the ability to remove uric acid from the blood.

One of Böhme’s most important fossil finds was made near Kaufbeuren, in southern Germany. There, while visiting a lignite pit, she examined small black lumps of what was supposedly coal, only to discover that they were ancient bones. The deposit was about to be mined and destroyed, and, with no alternative, Böhme asked that twenty-five tons of fossil-rich sediment be scooped up and dumped where paleontologists could sort through it without interrupting the quarrying. After two field seasons of arduous work, she recovered 15 percent of the skeleton of a single great ape, along with fragments from three others. Named Danuvius guggenmosi, the creature had lived 11.62 million years ago, in a subtropical environment. At just three feet tall and weighing around sixty-five pounds, Danuvius had big, powerful thumbs and toes and an elongated lower back that permitted an upright stance. Böhme quips that “from the waist up he looked like an ape and from the waist down he looked like an early hominin.” Danuvius is in fact one of the candidates for the last common ancestor of chimps and humans.

As the climate cooled later in the Miocene, savanna replaced forest in some parts of Europe, and this had a big impact on the continent’s apes. According to Böhme, a crucial piece of evidence indicating what happened was unearthed in June 1944, when besieged German soldiers dug a bunker near Athens. Bruno von Freyberg, a geology professor from Erlangen who was then serving in the German army, asked his workers to alert him to any fossils they encountered. Despite having lost an arm in World War I, Freyberg personally unearthed the finds, including the jaw of an ape, then sent his fossils to the Natural History Museum in Berlin for safekeeping. But the museum was bombed on February 3, 1945, and the priceless jawbone was severely damaged, losing most of its teeth.

In 1969 the great paleoanthropologist Gustav Heinrich Ralph von Koenigswald examined the damaged bone and named it Graecopithecus freybergi—Freyberg’s Greek ape. But it was so extensively mangled that other researchers concluded it was not identifiable, and so sought to suppress Koenigswald’s name. The jawbone might have been forgotten altogether but for Böhme, who tracked it down to a long-forgotten safe in a university department. When she had the jaw x-rayed, she saw that the roots of the teeth shared unique features with those of the subfamily Homininae, to which humans belong. She also redated the find, establishing that it was 7.175 million years old.

Her conclusion that the oldest human ancestor had lived in Greece around six to seven million years ago was so inconsistent with the dominant Out of Africa hypothesis that the paleoanthropological community largely reacted with stunned silence. But then, within months of Böhme’s analysis of Graecopithecus being published in 2017, a second, even more stunning and unexpected discovery was announced.

In 2002 the Polish paleontologist Gerard Gierliński had been vacationing with his girlfriend near Trachilos, Crete. On a slab of rock by the water he saw oblong marks that he recognized as fossilized footprints. But he didn’t follow up until 2010, when he mentioned them to a colleague; the two scientists hypothesized that the footprints might have been made by a bipedal ape. Analysis revealed that the feet that had left the tracks were small (between 4 and 8.5 inches long) and had five toes, a pronounced ball of the foot, and a big toe aligned with the other toes. The feet that left the prints undeniably resembled humans’ feet but lacked some features, such as an arch. Astonishingly, dating revealed that the prints were made more than six million years ago, when Crete was a long, southward-projecting peninsula of Europe.

I recall my own skepticism upon reading of this find: the discovery of six-million-year-old humanlike footprints on a Greek island seemed too outlandish. And evidently the paleoanthropological community felt similarly, for Gierliński and his colleagues had tried in vain for six and a half years to get their results published. According to Böhme, the manuscript was repeatedly rejected by anonymous reviewers whose reasoning was often difficult to decipher. But following the publication of Böhme’s reanalysis of Graecopithecus, Gierliński’s paper on the Trachilos footprints finally made it to press.

Böhme thinks that the tracks could have been left by Graecopithecus around the time upright apes migrated from Europe back to Africa, allowing them to repopulate a continent that they had been absent from for six million years. Whatever the case, there is no doubt that Graecopithecus and the Trachilos footprints present a strong challenge to the first part of the Out of Africa theory.

To most proponents of the Out of Africa theory, many of whom have invested lifetimes excavating sites in Africa, claims about human origins in Europe are heretical. A sense of just how high the stakes are can be gained from the controversy surrounding the discovery at the turn of the twenty-first century of the skull of Sahelanthropus tchadensis, a hominid species. The skull—which was found in the desert in Chad and studied by Professor Michel Brunet, then at the University of Poitiers—is thought to be six million years old and has been used to support the theory that the oldest human ancestor lived in North Africa six to seven million years ago. This finding has been widely accepted and celebrated: there is a street on the campus in Poitiers named for Brunet, and a parking garage named for Toumaï, as the skull is popularly known.

The skull is horribly fractured, and the area where it articulated with the spinal column is heavily damaged. The reconstruction by Brunet’s team made it appear that the skull sat atop the vertebral column, as it does in bipedal apes. But others disagreed, saying that the articulation was farther back, as in gorillas. Indeed, critics say, the skull has a number of gorilla-like features and may belong to an ancestral gorilla.

There matters might have remained, if not for the publication of a photograph of the skull as it was upon discovery. It lay in sand, surrounded by a scatter of other bones including a thighbone that was possibly part of the same individual as the Sahelanthropus skull. While Brunet was doing fieldwork, Aude Bergeret, a Ph.D. student who was studying the bones in her lab, concluded that the thighbone belonged to a great ape and that Sahelanthropus was not bipedal. According to Böhme, when Bergeret’s assertion became known, “the thighbone disappeared without a trace and the doctoral student lost her position at the university.”

In 2018 Bergeret and a colleague offered to give a presentation on the thighbone at the annual meeting of the Société d’Anthropologie de Paris, but they were refused. “Could it be,” Böhme asks, “that Michel Brunet, one of the icons of French science, Knight of the Légion d’honneur, recipient of the Ordre national du Mérite, did not want to be challenged?”

Questions about Sahelanthropus continue to pile up. Because the bones were found not in the sediments that preserved them but in sand drifts, it is unclear how old they are. And is Sahelanthropus an early gorilla or a member of the human lineage? The fossil record of gorillas is almost entirely unknown, so the discovery of an ancestral gorilla would be of huge significance. But it’s hard to imagine a street in a university being named for the discoverer of such a fossil.

The second part of the Out of Africa hypothesis states that the genus Homo evolved in Africa. Böhme strongly challenges this, arguing instead that our genus evolved in a great, now fragmented grassy woodland known as Savannastan, which covered parts of Europe, Asia, and Africa 2.6 million years ago. In support of the idea, she cites 1.8-million-year-old Homo skeletons from Georgia and, more intriguingly, a jaw and a few isolated teeth found in cave sediments in Longgupo Cave, in Wushan County in China’s Sichuan Province. The Chinese fossils were named as a new species, Homo wushanensis, by researchers in 1991, and according to Böhme the remains are between 2.6 and 2.48 million years old. As the oldest Homo habilis remains from Africa are only 2.3 million years old, the dating of the Chinese finds, if verified, would pose a direct challenge to part two of the Out of Africa hypothesis.

But interpretation of the fragmented remains of Homo wushanensis is complicated. In 2009 Russell Ciochon, an American researcher who described Homo wushanensis, declared that he had made a mistake. The jaw and some of the teeth did not belong to an early human, he said, but to one or more “mystery apes.”

 His retraction was acclaimed by some as a welcome act of intellectual honesty in a field characterized by fierce rivalry. Yet it has hardly settled matters. Böhme, for example, notes that stone tools were also found in Longgupo Cave, suggesting the presence of early humans. Others have speculated that the tools (along with some of the teeth) may have found their way into the deposit from more recent sediments, but Böhme is not satisfied by this explanation. Instead, she asks of Ciochon’s retraction, “Why the spectacular retreat? Was it to avoid jeopardizing the Out of Africa…hypothesis?”

Böhme, it seems, is just as determined to defend her hypothesis as the Out of Africanistas are to defend theirs.

Ancient Bones makes clear that Graecopithecus and the Trachilos footprints provide convincing evidence that our earliest direct ancestors evolved in Europe, and that they were walking upright as early as six million years ago. But the book, I think, is overly confident in its challenge to the idea that the genus Homo arose in Africa. That’s because, while there are intriguing clues that Homo may have been present in Europe or Asia before the oldest African finds (which date to around 2.3 million years ago), the evidence is far from conclusive. And of course the third part of the Out of Africa hypothesis, that Homo sapiens evolved in Africa, remains unchallenged—though the recent discovery that all living people carry genes from other hominin lineages, such as Neanderthals and Denisovans, which appear to have evolved in Europe and Asia, respectively, adds an intriguing twist to the tale.

What Ancient Bones does make clear, however, is that we place far too much emphasis on rewarding the discovery of our ancestors. In science, a discovery that leads in an unexpected direction, or even to a dead end, is often as productive as a lucky find. If we could only get past the great egos that swell in the field of paleoanthropology and reward the search as much as we do the discovery! But that, perhaps, would require an objectivity and generosity that aren’t entirely human.

Por que somos a única espécie humana do planeta (El País)

Nuño Domínguez, 04 jul 2021 – 12:48 BRT

Três grandes descobertas feitas nos últimos dias nos obrigam a repensar as origens da humanidade

Três descobertas nos últimos dias acabam de mudar o que sabíamos sobre a origem da raça humana e da nossa própria espécie, Homo sapiens. Talvez − dizem alguns especialistas − precisemos abandonar esse conceito para nos referir a nós mesmos, pois as novas descobertas sugerem que somos uma criatura de Frankenstein com partes de outras espécies humanas com as quais, não muito tempo atrás, compartilhamos planeta, sexo e filhos.

As descobertas da última semana indicam que cerca de 200.000 anos atrás havia até oito espécies ou grupos humanos diferentes. Todos faziam parte do gênero Homo, que nos engloba. Os recém-chegados apresentam uma interessante mistura de traços primitivos − arcos enormes acima das sobrancelhas, cabeça achatada − e modernos. O “homem dragão” da China tinha uma capacidade craniana tão grande quanto a dos humanos atuais, ou até superior. O Homo de Nesher Ramla, encontrado em Israel, pode ter sido o que deu origem aos neandertais e aos denisovanos que ocuparam, respectivamente, a Europa e a Ásia e com quem nossa espécie teve repetidos encontros sexuais, dos quais nasceram filhos mestiços que foram aceitos em suas respectivas tribos como mais um.

Agora sabemos que devido àqueles cruzamentos todas as pessoas de fora da África têm 3% de DNA neandertal, ou que os habitantes do Tibete têm genes transmitidos pelos denisovanos para poder viver em grandes altitudes. Algo muito mais inquietante foi revelado pela análise genética das populações atuais da Nova Guiné: é possível que os denisovanos − um ramo irmão dos neandertais − tenham vivido até apenas 15.000 anos atrás, uma distância muito pequena em termos evolutivos.

A terceira grande descoberta dos últimos dias é quase detetivesca. Na análise de DNA conservado no solo da caverna de Denisova, na Sibéria, foi encontrado material genético dos humanos autóctones, os denisovanos, de neandertais e de sapiens em períodos tão próximos que poderiam até se sobrepor. Lá foram encontrados há três anos os restos do primeiro híbrido entre espécies humanas que se conhece: uma menina filha de uma neandertal e de um denisovano.

O paleoantropólogo Florent Detroit descobriu para a ciência outra dessas novas espécies humanas: o Homo luzonensis, que viveu em uma ilha das Filipinas há 67.000 anos e que apresenta uma estranha mistura de traços que poderiam ser o resultado de sua longa evolução em isolamento durante mais de um milhão de anos. É um pouco parecido com o que experimentou seu contemporâneo Homo floresiensis, ou “homem de Flores”, um humano de um metro e meio que viveu em uma ilha indonésia. Tinha um cérebro do tamanho do de um chimpanzé, mas se for aplicado a ele o teste de inteligência mais usado pelos paleoantropólogos, podemos dizer que era tão avançado quanto o sapiens, pois suas ferramentas de pedra eram igualmente evoluídas.

Imagem radiográfica da mandíbula do ‘Homo’ de Nesher Ramla descoberta em Israel.
Imagem radiográfica da mandíbula do ‘Homo’ de Nesher Ramla descoberta em Israel.Ariel Pokhojaev

A esses dois habitantes insulares se soma o Homo erectus, o primeiro Homo viajante que saiu da África há cerca de dois milhões de anos. Ele conquistou a Ásia e lá viveu até pelo menos 100.000 anos atrás. O oitavo passageiro desta história seria o Homo daliensis, um fóssil encontrado na China com uma mistura de erectus e sapiens, embora seja possível que acabe sendo incluído na nova linhagem do Homo longi.

“Não me surpreende que houvesse várias espécies humanas vivas ao mesmo tempo”, afirma Detroit. “Se considerarmos o último período geológico que começou há 2,5 milhões de anos, sempre houve diferentes gêneros e espécies de hominídeos compartilhando o planeta. A grande exceção é a atualidade, nunca havia existido apenas uma espécie humana na Terra”, reconhece. Por que nós, os sapiens, somos os únicos sobreviventes?

Para Juan Luis Arsuaga, paleoantropólogo do sítio arqueológico de Atapuerca, no norte da Espanha, a resposta é que “somos uma espécie hipersocial, os únicos capazes de construir laços além do parentesco, ao contrário dos demais mamíferos”. “Compartilhamos ficções consensuais como pátria, religião, língua, times de futebol; e chegamos a sacrificar muitas coisas por elas”, assinala. Nem mesmo a espécie humana mais próxima de nós, os neandertais, que criavam adornos, símbolos e arte, tinham esse comportamento. Arsuaga resume assim: “Os neandertais não tinham bandeira”. Por razões ainda desconhecidas, essa espécie se extinguiu há cerca de 40.000 anos.

Os sapiens não eram “estritamente superiores” a seus congêneres, opina Antonio Rosas, paleoantropólogo do Conselho Superior de Pesquisas Científicas da Espanha. “Agora sabemos que somos o resultado de hibridações com outras espécies, e o conjunto de características que temos foi o perfeito para aquele momento”, explica. Uma possível vantagem adicional é que os grupos sapiens eram mais numerosos que os neandertais, o que significa menos endogamia e melhor saúde das populações.

Detroit acredita que parte da explicação está na própria essência da nossa espécie sapiens, “sábio” em latim. “Temos um cérebro enorme que devemos alimentar, por isso precisamos de muitos recursos e, portanto, de muito território”, assinala. “O Homo sapiens teve uma expansão demográfica enorme e é bem possível que a disputa pelo território fosse muito dura para as demais espécies”, acrescenta.

María Martinón-Torres, diretora do Centro Nacional de Pesquisa sobre Evolução Humana, com sede em Burgos, acredita que o segredo seja a “hiperadaptabilidade”. “A nossa é uma espécie invasiva, não necessariamente mal-intencionada, mas somos como o cavalo de Átila da evolução”, compara. “Por onde passamos, e com nosso estilo de vida, diminui a diversidade biológica, incluindo a humana. Somos uma das forças ecológicas de maior impacto do planeta e essa história, a nossa, começou a se delinear no Pleistoceno [o período que começou há 2,5 milhões de anos e terminou há cerca de 10.000, quando o sapiens já era a única espécie humana que restava no planeta]”, acrescenta.

As descobertas dos últimos dias voltam a expor um problema crescente: os cientistas estão denominando cada vez mais espécies humanas. Tem sentido fazer isso? Para o paleoantropólogo israelense Israel Hershkovitz, autor da descoberta do Homo de Nesher Ramla, não. “Há muitas espécies”, afirma. “A definição clássica diz que duas espécies diferentes não podem ter filhos férteis. O DNA nos diz que sapiens, neandertais e denisovanos tiveram, por isso deveriam ser considerados a mesma espécie”, aponta.

“Se somos sapiens, então essas espécies que são nossos ancestrais por meio da miscigenação também são”, reforça João Zilhão, professor da Instituição Catalã de Pesquisa e Estudos Avançados na Universidade de Barcelona.

Essa questão é objeto de discórdia entre especialistas. “A hibridação é muito comum em espécies atuais, especialmente no mundo vegetal”, lembra José María Bermúdez de Castro, codiretor das pesquisas em Atapuerca. “Pode-se matizar o conceito de espécie, mas acho que não podemos abandoná-lo, porque é muito útil para podermos nos entender”, ressalta.

Escavações no sítio arqueológico de Nesher Ramla.
Escavações no sítio arqueológico de Nesher Ramla. Zaidner

Muitas nuances entram em jogo nessa questão. A evidente diferença entre sapiens e neandertais não é a mesma coisa que a identidade como espécie do Homo luzonensis, do qual só conhecemos alguns poucos ossos e dentes, ou dos denisovanos, dos quais a maioria das informações vem do DNA extraído de fósseis minúsculos.

“Curiosamente, apesar dos cruzamentos frequentes, tanto os sapiens como os neandertais foram espécies perfeitamente reconhecíveis e distinguíveis até o fim”, destaca Martinón-Torres. “Os traços do neandertal tardio são mais marcados que os dos anteriores, em vez de terem se apagado como consequência do cruzamento. Houve trocas biológicas, e talvez culturais também, mas nenhuma das espécies deixou de ser ela, distintiva, reconhecível em sua biologia, seu aspecto, suas adaptações específicas, seu nicho ecológico ao longo de sua história evolutiva. Acredito que esse é o melhor exemplo de que a hibridação não colide necessariamente com o conceito de espécie”, conclui. Seu colega Hershkovitz alerta que o debate continuará: “Estamos fazendo escavações em outras três cavernas em Israel onde encontramos fósseis humanos que nos darão uma nova perspectiva sobre a evolução humana”.

Humans Are Evolving Faster Than Ever. The Reason Is Not Genetic, Study Claims (Science Alert)

Cameron Duke, Live Science – 15 JUNE 2021

At the mercy of natural selection since the dawn of life, our ancestors adapted, mated and died, passing on tiny genetic mutations that eventually made humans what we are today. 

But evolution isn’t bound strictly to genes anymore, a new study suggests. Instead, human culture may be driving evolution faster than genetic mutations can work.

In this conception, evolution no longer requires genetic mutations that confer a survival advantage being passed on and becoming widespread. Instead, learned behaviors passed on through culture are the “mutations” that provide survival advantages.

This so-called cultural evolution may now shape humanity’s fate more strongly than natural selection, the researchers argue.

“When a virus attacks a species, it typically becomes immune to that virus through genetic evolution,” study co-author Zach Wood, a postdoctoral researcher in the School of Biology and Ecology at the University of Maine, told Live Science.

Such evolution works slowly, as those who are more susceptible die off and only those who survive pass on their genes. 

But nowadays, humans mostly don’t need to adapt to such threats genetically. Instead, we adapt by developing vaccines and other medical interventions, which are not the results of one person’s work but rather of many people building on the accumulated “mutations” of cultural knowledge.

By developing vaccines, human culture improves its collective “immune system,” said study co-author Tim Waring, an associate professor of social-ecological systems modeling at the University of Maine.

And sometimes, cultural evolution can lead to genetic evolution. “The classic example is lactose tolerance,” Waring told Live Science. “Drinking cow’s milk began as a cultural trait that then drove the [genetic] evolution of a group of humans.”

In that case, cultural change preceded genetic change, not the other way around. 

The concept of cultural evolution began with the father of evolution himself, Waring said. Charles Darwin understood that behaviors could evolve and be passed to offspring just as physical traits are, but scientists in his day believed that changes in behaviors were inherited. For example, if a mother had a trait that inclined her to teach a daughter to forage for food, she would pass on this inherited trait to her daughter. In turn, her daughter might be more likely to survive, and as a result, that trait would become more common in the population. 

Waring and Wood argue in their new study, published June 2 in the journal Proceedings of the Royal Society B, that at some point in human history, culture began to wrest evolutionary control from our DNA. And now, they say, cultural change is allowing us to evolve in ways biological change alone could not.

Here’s why: Culture is group-oriented, and people in those groups talk to, learn from and imitate one another. These group behaviors allow people to pass on adaptations they learned through culture faster than genes can transmit similar survival benefits.

An individual can learn skills and information from a nearly unlimited number of people in a small amount of time and, in turn, spread that information to many others. And the more people available to learn from, the better. Large groups solve problems faster than smaller groups, and intergroup competition stimulates adaptations that might help those groups survive.

As ideas spread, cultures develop new traits.

In contrast, a person only inherits genetic information from two parents and racks up relatively few random mutations in their eggs or sperm, which takes about 20 years to be passed on to their small handful of children. That’s just a much slower pace of change.

“This theory has been a long time coming,” said Paul Smaldino, an associate professor of cognitive and information sciences at the University of California, Merced who was not affiliated with this study. “People have been working for a long time to describe how evolutionary biology interacts with culture.”

It’s possible, the researchers suggest, that the appearance of human culture represents a key evolutionary milestone.

“Their big argument is that culture is the next evolutionary transition state,” Smaldino told Live Science.

Throughout the history of life, key transition states have had huge effects on the pace and direction of evolution. The evolution of cells with DNA was a big transitional state, and then when larger cells with organelles and complex internal structures arrived, it changed the game again. Cells coalescing into plants and animals was another big sea change, as was the evolution of sex, the transition to life on land and so on.

Each of these events changed the way evolution acted, and now humans might be in the midst of yet another evolutionary transformation. We might still evolve genetically, but that may not control human survival very much anymore.

“In the very long term, we suggest that humans are evolving from individual genetic organisms to cultural groups which function as superorganisms, similar to ant colonies and beehives,” Waring said in a statement.

But genetics drives bee colonies, while the human superorganism will exist in a category all its own. What that superorganism looks like in the distant future is unclear, but it will likely take a village to figure it out. 

UMaine researchers: Culture drives human evolution more than genetics (Eureka Alert!)

News Release 2-Jun-2021

University of Maine

Research News

In a new study, University of Maine researchers found that culture helps humans adapt to their environment and overcome challenges better and faster than genetics.

After conducting an extensive review of the literature and evidence of long-term human evolution, scientists Tim Waring and Zach Wood concluded that humans are experiencing a “special evolutionary transition” in which the importance of culture, such as learned knowledge, practices and skills, is surpassing the value of genes as the primary driver of human evolution.

Culture is an under-appreciated factor in human evolution, Waring says. Like genes, culture helps people adjust to their environment and meet the challenges of survival and reproduction. Culture, however, does so more effectively than genes because the transfer of knowledge is faster and more flexible than the inheritance of genes, according to Waring and Wood.

Culture is a stronger mechanism of adaptation for a couple of reasons, Waring says. It’s faster: gene transfer occurs only once a generation, while cultural practices can be rapidly learned and frequently updated. Culture is also more flexible than genes: gene transfer is rigid and limited to the genetic information of two parents, while cultural transmission is based on flexible human learning and effectively unlimited with the ability to make use of information from peers and experts far beyond parents. As a result, cultural evolution is a stronger type of adaptation than old genetics.

Waring, an associate professor of social-ecological systems modeling, and Wood, a postdoctoral research associate with the School of Biology and Ecology, have just published their findings in a literature review in the Proceedings of the Royal Society B, the flagship biological research journal of The Royal Society in London.

“This research explains why humans are such a unique species. We evolve both genetically and culturally over time, but we are slowly becoming ever more cultural and ever less genetic,” Waring says.

Culture has influenced how humans survive and evolve for millenia. According to Waring and Wood, the combination of both culture and genes has fueled several key adaptations in humans such as reduced aggression, cooperative inclinations, collaborative abilities and the capacity for social learning. Increasingly, the researchers suggest, human adaptations are steered by culture, and require genes to accommodate.

Waring and Wood say culture is also special in one important way: it is strongly group-oriented. Factors like conformity, social identity and shared norms and institutions — factors that have no genetic equivalent — make cultural evolution very group-oriented, according to researchers. Therefore, competition between culturally organized groups propels adaptations such as new cooperative norms and social systems that help groups survive better together.

According to researchers, “culturally organized groups appear to solve adaptive problems more readily than individuals, through the compounding value of social learning and cultural transmission in groups.” Cultural adaptations may also occur faster in larger groups than in small ones.

With groups primarily driving culture and culture now fueling human evolution more than genetics, Waring and Wood found that evolution itself has become more group-oriented.

“In the very long term, we suggest that humans are evolving from individual genetic organisms to cultural groups which function as superorganisms, similar to ant colonies and beehives,” Waring says. “The ‘society as organism’ metaphor is not so metaphorical after all. This insight can help society better understand how individuals can fit into a well-organized and mutually beneficial system. Take the coronavirus pandemic, for example. An effective national epidemic response program is truly a national immune system, and we can therefore learn directly from how immune systems work to improve our COVID response.”


Waring is a member of the Cultural Evolution Society, an international research network that studies the evolution of culture in all species. He applies cultural evolution to the study of sustainability in social-ecological systems and cooperation in organizational evolution.

Wood works in the UMaine Evolutionary Applications Laboratory managed by Michael Kinnison, a professor of evolutionary applications. His research focuses on eco-evolutionary dynamics, particularly rapid evolution during trophic cascades.

Neanderthals carb loaded, helping grow their big brains (Science)

By Ann GibbonsMay. 10, 2021 , 3:00 PM 5-7 minutos

A reconstruction of Neanderthal mealtime Mauricio Anton/Science Source

Here’s another blow to the popular image of Neanderthals as brutish meat eaters: A new study of bacteria collected from Neanderthal teeth shows that our close cousins ate so many roots, nuts, or other starchy foods that they dramatically altered the type of bacteria in their mouths. The finding suggests our ancestors had adapted to eating lots of starch by at least 600,000 years ago—about the same time as they needed more sugars to fuel a big expansion of their brains.

The study is “groundbreaking,” says Harvard University evolutionary biologist Rachel Carmody, who was not part of the research. The work suggests the ancestors of both humans and Neanderthals were cooking lots of starchy foods at least 600,000 years ago. And they had already adapted to eating more starchy plants long before the invention of agriculture 10,000 years ago, she says.

The brains of our ancestors doubled in size between 2 million and 700,000 years ago. Researchers have long credited better stone tools and cooperative hunting: As early humans got better at killing animals and processing meat, they ate a higher quality diet, which gave them more energy more rapidly to fuel the growth of their hungrier brains.

Still, researchers have puzzled over how meat did the job. “For human ancestors to efficiently grow a bigger brain, they needed energy dense foods containing glucose”—a type of sugar—says molecular archaeologist Christina Warinner of Harvard and the Max Planck Institute for the Science of Human History. “Meat is not a good source of glucose.”

Researchers analyzed the bacterial DNA preserved in dental plaque of fossilized teeth, such as this one from a prehistoric human. Werner Siemens Foundation/Felix Wey

The starchy plants gathered by many living hunter-gatherers are an excellent source of glucose, however. To figure out whether oral bacteria track changes in diet or the environment, Warinner, Max Planck graduate student James Fellows Yates, and a large international team looked at the oral bacteria stuck to the teeth of Neanderthals, preagriculture modern humans that lived more than 10,000 years ago, chimps, gorillas, and howler monkeys. The researchers analyzed billions of DNA fragments from long-dead bacteria still preserved on the teeth of 124 individuals. One was a Neanderthal who lived 100,000 years ago at Pešturina Cave in Serbia, which produced the oldest oral microbiome genome reconstructed to date.

The communities of bacteria in the mouths of preagricultural humans and Neanderthals strongly resembled each other, the team reports today in the Proceedings of the National Academy of Sciences. In particular, humans and Neanderthals harbored an unusual group of Streptococcus bacteria in their mouths. These microbes had a special ability to bind to an abundant enzyme in human saliva called amylase, which frees sugars from starchy foods. The presence of the strep bacteria that consume sugar on the teeth of Neanderthals and ancient modern humans, but not chimps, shows they were eating more starchy foods, the researchers conclude.

Finding the streptococci on the teeth of both ancient humans and Neanderthals also suggests they inherited these microbes from their common ancestor, who lived more than 600,000 years ago. Although earlier studies found evidence that Neanderthals ate grasses and tubers and cooked barley, the new study indicates they ate so much starch that it dramatically altered the composition of their oral microbiomes.

“This pushes the importance of starch in the diet further back in time,” to when human brains were still expanding, Warinner says. Because the amylase enzyme is much more efficient at digesting cooked rather than raw starch, the finding also suggests cooking, too, was common by 600,000 years ago, Carmody says. Researchers have debated whether cooking became common when the big brain began to expand almost 2 million years ago or it spread later, during a second surge of growth.

The study offers a new way to detect major shifts in diet, says geneticist Ran Blekhman of the University of Minnesota, Twin Cities. In the case of Neanderthals, it reveals how much they depended on plants.

“We sometimes have given short shrift to the plant components of the diet,” says anthropological geneticist Anne Stone of Arizona State University, Tempe. “As we know from modern hunter-gatherers, it’s often the gathering that ends up providing a substantial portion of the calories.”

Humans were apex predators for two million years (Eureka Alert!)

News Release 5-Apr-2021

What did our ancestors eat during the stone age? Mostly meat

Tel-Aviv University

IMAGE: Human Brain. Credit: Dr. Miki Ben Dor

Researchers at Tel Aviv University were able to reconstruct the nutrition of stone age humans. In a paper published in the Yearbook of the American Physical Anthropology Association, Dr. Miki Ben-Dor and Prof. Ran Barkai of the Jacob M. Alkov Department of Archaeology at Tel Aviv University, together with Raphael Sirtoli of Portugal, show that humans were an apex predator for about two million years. Only the extinction of larger animals (megafauna) in various parts of the world, and the decline of animal food sources toward the end of the stone age, led humans to gradually increase the vegetable element in their nutrition, until finally they had no choice but to domesticate both plants and animals – and became farmers.

“So far, attempts to reconstruct the diet of stone-age humans were mostly based on comparisons to 20th century hunter-gatherer societies,” explains Dr. Ben-Dor. “This comparison is futile, however, because two million years ago hunter-gatherer societies could hunt and consume elephants and other large animals – while today’s hunter gatherers do not have access to such bounty. The entire ecosystem has changed, and conditions cannot be compared. We decided to use other methods to reconstruct the diet of stone-age humans: to examine the memory preserved in our own bodies, our metabolism, genetics and physical build. Human behavior changes rapidly, but evolution is slow. The body remembers.”

In a process unprecedented in its extent, Dr. Ben-Dor and his colleagues collected about 25 lines of evidence from about 400 scientific papers from different scientific disciplines, dealing with the focal question: Were stone-age humans specialized carnivores or were they generalist omnivores? Most evidence was found in research on current biology, namely genetics, metabolism, physiology and morphology.

“One prominent example is the acidity of the human stomach,” says Dr. Ben-Dor. “The acidity in our stomach is high when compared to omnivores and even to other predators. Producing and maintaining strong acidity require large amounts of energy, and its existence is evidence for consuming animal products. Strong acidity provides protection from harmful bacteria found in meat, and prehistoric humans, hunting large animals whose meat sufficed for days or even weeks, often consumed old meat containing large quantities of bacteria, and thus needed to maintain a high level of acidity. Another indication of being predators is the structure of the fat cells in our bodies. In the bodies of omnivores, fat is stored in a relatively small number of large fat cells, while in predators, including humans, it’s the other way around: we have a much larger number of smaller fat cells. Significant evidence for the evolution of humans as predators has also been found in our genome. For example, geneticists have concluded that “areas of the human genome were closed off to enable a fat-rich diet, while in chimpanzees, areas of the genome were opened to enable a sugar-rich diet.”

Evidence from human biology was supplemented by archaeological evidence. For instance, research on stable isotopes in the bones of prehistoric humans, as well as hunting practices unique to humans, show that humans specialized in hunting large and medium-sized animals with high fat content. Comparing humans to large social predators of today, all of whom hunt large animals and obtain more than 70% of their energy from animal sources, reinforced the conclusion that humans specialized in hunting large animals and were in fact hypercarnivores.

“Hunting large animals is not an afternoon hobby,” says Dr. Ben-Dor. “It requires a great deal of knowledge, and lions and hyenas attain these abilities after long years of learning. Clearly, the remains of large animals found in countless archaeological sites are the result of humans’ high expertise as hunters of large animals. Many researchers who study the extinction of the large animals agree that hunting by humans played a major role in this extinction – and there is no better proof of humans’ specialization in hunting large animals. Most probably, like in current-day predators, hunting itself was a focal human activity throughout most of human evolution. Other archaeological evidence – like the fact that specialized tools for obtaining and processing vegetable foods only appeared in the later stages of human evolution – also supports the centrality of large animals in the human diet, throughout most of human history.”

The multidisciplinary reconstruction conducted by TAU researchers for almost a decade proposes a complete change of paradigm in the understanding of human evolution. Contrary to the widespread hypothesis that humans owe their evolution and survival to their dietary flexibility, which allowed them to combine the hunting of animals with vegetable foods, the picture emerging here is of humans evolving mostly as predators of large animals.

“Archaeological evidence does not overlook the fact that stone-age humans also consumed plants,” adds Dr. Ben-Dor. “But according to the findings of this study plants only became a major component of the human diet toward the end of the era.”

Evidence of genetic changes and the appearance of unique stone tools for processing plants led the researchers to conclude that, starting about 85,000 years ago in Africa, and about 40,000 years ago in Europe and Asia, a gradual rise occurred in the consumption of plant foods as well as dietary diversity – in accordance with varying ecological conditions. This rise was accompanied by an increase in the local uniqueness of the stone tool culture, which is similar to the diversity of material cultures in 20th-century hunter-gatherer societies. In contrast, during the two million years when, according to the researchers, humans were apex predators, long periods of similarity and continuity were observed in stone tools, regardless of local ecological conditions.

“Our study addresses a very great current controversy – both scientific and non-scientific,” says Prof. Barkai. “For many people today, the Paleolithic diet is a critical issue, not only with regard to the past, but also concerning the present and future. It is hard to convince a devout vegetarian that his/her ancestors were not vegetarians, and people tend to confuse personal beliefs with scientific reality. Our study is both multidisciplinary and interdisciplinary. We propose a picture that is unprecedented in its inclusiveness and breadth, which clearly shows that humans were initially apex predators, who specialized in hunting large animals. As Darwin discovered, the adaptation of species to obtaining and digesting their food is the main source of evolutionary changes, and thus the claim that humans were apex predators throughout most of their development may provide a broad basis for fundamental insights on the biological and cultural evolution of humans.”

Can Evolution Explain All Dark Animal Behaviors? (Discovery)

Many actions that would be considered heinous to humans — cannibalism, eating offspring, torture and rape — have been observed in the animal kingdom. Most (but not all) eyebrow-raising behaviors among animals have an evolutionary underpinning.

By Tim Brinkhof, March 9, 2021 3:00 PM

evil looking chimp - shutterstock
(Credit: Sharon Morris/Shutterstock)

“In sober truth,” wrote the British philosopher John Stuart Mill, “nearly all the things which men are hanged or imprisoned for doing to one another, are nature’s everyday performances.” While it is true that rape, torture and murder are more commonplace in the animal kingdom than they are in human civilization, our fellow creatures almost always seem to have some kind of evolutionary justification for their actions — one that we Homo sapiens lack.

Cats, for instance, are known to toy with small birds and rodents before finally killing them. Although it is easy to conclude that this makes the popular pet a born sadist, some zoologists have proposed that exhausting prey is the safest way of catching them. Similarly, it’s tempting to describe the way African lions and bottlenose dolphins –– large, social mammals –– commit infanticide (the killing of young offspring), as possibly psychopathic. Interestingly, experts suspect that these creatures are in fact doing themselves a favor; by killing offspring, adult males are making their female partners available to mate again.

These behaviors, which initially may seem symptomatic of some sinister psychological defect, turn out to be nothing more than different examples of the kind of selfishness that evolution is full of. Well played, Mother Nature.

But what if harming others is of no benefit to the assailant? In the human world, senseless destruction features on virtually every evening news program. In the animal world, where the laws of nature –– so we’ve been taught –– don’t allow for moral crises, it’s a different story. By all accounts, such undermining behavior shouldn’t be able to occur. Yet it does, and it’s as puzzling to biologists as the existence of somebody like Ted Bundy or Adolf Hitler has been to theodicists –– those who follow a philosophy of religion that ponders why God permits evil.

Cains and Abels

According to Charles Darwin’s theory of evolution, genes that increase an organism’s ability to survive are passed down, while those that don’t are not. Although Darwin remains an important reference point for how humans interpret the natural world, he is not infallible. During the 1960s, biologist W.D. Hamilton proposed that On the Origins of Species failed to account for the persistency of traits that didn’t directly benefit the animal in question.

The first of these two patterns –– altruism –– was amalgamated into Darwin’s theory of evolution when researchers uncovered its evolutionary benefits. One would think that creatures are hardwired to avoid self-sacrifice, but this is not the case. The common vampire bat shares its food with roostmates whose hunt ended in failure. Recently, Antarctic plunder fish have been found to guard the nests of others if they are left unprotected. In both of these cases, altruistic behavior is put on display when the indirect benefit to relatives of the animal in question outweighs the direct cost incurred by that animal.

In Search of Spite

The second animal behavior –– spite –– continues to be difficult to make sense of. For humans, its concept is a familiar yet elusive one, perhaps understood best through the Biblical story of Cain and Abel or the writings of Fyodor Dostoevsky. Although a number of prominent evolutionary biologists –– from Frans de Waal to members of the West Group at the University of Oxford’s Department of Zoology –– have made entire careers out of studying the overlap between animal and human behavior, even they warn against the stubborn tendency to anthropomorphize nonhuman subjects.

As Edward O. Wilson put it in his study, “The Insect Societies,” spite refers to any “behavior that gains nothing or may even diminish the fitness of the individual performing the act, but is definitely harmful to the fitness of another.” Wilson’s definition, which is generally accepted by biologists, allows researchers to study its occurrence in an objective, non-anthropomorphized manner. It initially drew academic attention to species of fish and birds that destroyed the eggs (hatched or unhatched) of rival nests, all at no apparent benefit to them.

Emphasis on “apparent,” though, because –– as those lions and dolphins demonstrated earlier –– certain actions and consequences aren’t always what we think they are. In their research, biologists Andy Gardner and Stuart West maintain that many of the animal behaviors which were once thought spiteful are now understood as selfish. Not in the direct sense of the word (approaching another nest often leads to brutal clashes with its guardian), but an indirect one: With fewer generational competitors, the murderer’s own offspring are more likely to thrive.

For a specific action to be considered true spite, a few more conditions have to be met. The cost incurred by the party acting out the behavior must be “smaller than the product of the negative benefit to the recipient and negative relatedness of the recipient to the actor,” Gardner and West wrote in Current Biology. In other words, a creature can be considered spiteful if harming other creatures does them more bad than good. So far, true spite has only been observed rarely in the animal kingdom, and mostly occurs among smaller creatures.

The larvae of polyembryonic parasitoid wasps, which hatch from eggs that are laid on top of caterpillar eggs, occasionally develop into adults that are not just infertile but have a habit of eating other larvae. From an evolutionary perspective, developing into this infertile form is not a smart move for the wasp because it cannot pass on its genes to the next generation. Nor does it help the creature’s relatives survive, as they are then at risk of being eaten.

That doesn’t mean spite is relegated to the world of insects. It also pops up among monkeys, where it tends to manifest in more recognizable forms. In a 2016 study, Harvard University psychology researchers Kristin Leimgruber and Alexandra Rosati separated chimpanzees and capuchins from the rest of the group during feeding time and gave them the option take away everyone’s food. While the chimps only ever denied food to those who violated their group’s social norms, the capuchins often acted simply out of spite. As Leimgruber explains: “Our study provides the first evidence of a non-human primate choosing to punish others simply because they have more. This sort of ‘if I can’t have it, no one can’ response is consistent with psychological spite, a behavior previously believed unique to humans.”

Beyond the Dark Tetrad

Of course, spite isn’t the only type of complex and curiously human behavior for which the principles of evolution have not produced an easily discoverable (or digestible) answer. Just as confounding are the four components of the Dark Tetrad — a model for categorizing malevolent behaviors, assembled by personality psychologist Delroy Paulhus. The framework’s traits include narcissism, Machiavellianism, psychopathy and everyday sadism.

Traces of all four have been found inside the animal kingdom. The intertribal warfare among chimpanzees is, first and foremost, a means of controlling resources. At the same time, many appear to actively enjoy partaking in hyperviolent patrols. Elsewhere, primate researchers who have made advances in the assessment of great ape psychology suggest the existence of psychotic personality types. As for Machiavellianism, the willingness to hurt relatives in order to protect oneself has been observed in both rhesus macaques and Nile tilapia.

Although the reasons for certain types of animal behavior are still debated, the nature of these discussions tend to be markedly different from discourse around, say, the motivations of serial killers. And often, researchers have a solid understanding of the motivations and feelings of their own study subjects but not those outside of their purview. Regardless of whether the academic community is talking about humans or animals, however, the underlying conviction guiding the conversation — that every action, no matter how upsetting or implacable, must have a logical explanation — is one and the same. 

Israeli Archaeologists Present Groundbreaking Universal Theory of Human Evolution (Haaretz)

Tel Aviv University archaeologists Miki Ben-Dor and Ran Barkai proffer novel hypothesis, showing how the greed of Homo erectus set us careening down an anomalous evolutionary path

Ruth Schuster, Feb. 25, 2021

Why the human brain evolved as it did never has been plausibly explained. Apparently, not since the first life-form billions of years ago did a single species gain dominance over all others – until we came along. Now, in a groundbreaking paper, two Israeli researchers propose that our anomalous evolution was propelled by the very mass extinctions we helped cause. Or: As we sawed off the culinary branches from which we swung, we had to get ever more inventive in order to survive.

As ambling, slow-to-reproduce large animals diminished and gradually went extinct, we were forced to resort to smaller, nimbler animals that flee as a strategy to escape predation. To catch them, we had to get smarter, nimbler and faster, according to the universal theory of human evolution proposed by researchers Miki Ben-Dor and Prof. Ran Barkai of Tel Aviv University, in a paper published in the journal Quaternary.

In fact, the great African megafauna began to decline about 4.6 million years ago. But our story begins with Homo habilis, which lived about 2.6 million years ago and apparently used crude stone tools to help it eat flesh, and with Homo erectus, which thronged Africa and expanded to Eurasia about 2 million years ago. The thing is, erectus wasn’t an omnivore: it was a carnivore, Ben-Dor explains to Haaretz.

“Eighty percent of mammals are omnivores but still specialize in a narrow food range. If anything, it seems Homo erectus was a hyper-carnivore,” he observes.

And in the last couple of million years, our brains grew threefold to a maximum capacity of about 1,500 cranial capacity, a size achieved about 300,000 years ago. We also gradually but consistently ramped up in technology and culture – until the Neolithic revolution and advent of the sedentary lifestyle, when our brains shrank to about 1,400 to 1,300cc, but more on that anomaly later.

The hypothesis suggested by Ben-Dor and Barkai – that we ate our way to our present physical, cultural and ecological state – is an original unifying explanation for the behavioral, physiological and cultural evolution of the human species.

Out of chaos

Evolution is chaotic. Charles Darwin came up with the theory of the survival of the fittest, and nobody has a better suggestion yet, but mutations aren’t “planned.” Bodies aren’t “designed,” if we leave genetic engineering out of it. The point is, evolution isn’t linear but chaotic, and that should theoretically apply to humans too.

Hence, it is strange that certain changes in the course of millions of years of human history, including the expansion of our brain, tool manufacture techniques and use of fire, for example, were uncharacteristically progressive, say Ben-Dor and Barkai.

“Uncharacteristically progressive” means that certain traits such as brain size, or cultural developments such as fire usage, evolved in one direction over a long time, in the direction of escalation. That isn’t what chaos is expected to produce over vast spans of time, Barkai explains to Haaretz: it is bizarre. Very few parameters behave like that.

So, their discovery of correlation between contraction of the average weight of African animals, the extinction of megafauna and the development of the human brain is intriguing.

From mammoth marrow to joint of rat

To be clear, just this month a new paper posited that the late Quaternary extinction of megafauna, in the last few tens of thousands of years, wasn’t entirely the fault of humanity. In North America specifically, it was due primarily to climate change, with the late-arriving humans apparently providing the coup de grâce to some species.

In the Old World, however, a human role is clearer. African megafauna apparently began to decline 4.6 million years ago, but during the Pleistocene (2.6 million to 11,600 years ago) the size of African animals trended sharply down, in what the authors term an abrupt reversal from a continuous growth trend of 65 million years (i.e., since the dinosaurs almost died out).

When Homo erectus the carnivore began to roam Africa around 2 million years ago, land mammals averaged nearly 500 kilograms. Barkai’s team and others have demonstrated that hominins ate elephants and large animals when they could. In fact, originally Africa had six elephant species (today there are two: the bush elephant and forest elephant). By the end of the Pleistocene, by which time all hominins other than modern humans were extinct too, that average weight of the African animal had shrunk by more than 90 percent.

And during the Pleistocene, as the African animals shrank, the Homo genus grew taller and more gracile, and our stone tool technology improved (which in no way diminished our affection for archaic implements like the hand ax or chopper, both of which remained in use for more than a million years, even as more sophisticated technologies were developed).

If we started some 3.3 million years ago with large, crude stone hammers that may have been used to bang big animals on the head or break bones to get at the marrow, over the epochs we invented the spear for remote slaughter. By about 80,000 years ago, the bow and arrow was making its appearance, which was more suitable for bringing down small fry like small deer and birds. Over a million years ago, we began to use fire, and later achieved better control of it, meaning the ability to ignite it at will. Later we domesticated the dog from the wolf, and it would help us hunt smaller, fleet animals.

Why did the earliest humans hunt large animals anyway? Wouldn’t a peeved elephant be more dangerous than a rat? Arguably, but catching one elephant is easier than catching a large number of rats. And megafauna had more fat.

A modern human can only derive up to about 50 percent of calories from lean meat (protein): past a certain point, our livers can’t digest more protein. We need energy from carbs or fat, but before developing agriculture about 10,000 years ago, a key source of calories had to be animal fat.

Big animals have a lot of fat. Small animals don’t. In Africa and Europe, and in Israel too, the researchers found a significant decline in the prevalence of animals weighing over 200 kilograms correlated to an increase in the volume of the human brain. Thus, Ben-Dor and Barkai deduce that the declining availability of large prey seems to have been a key element in the natural selection from Homo erectus onward. Catching one elephant is more efficient than catching 1,000 rabbits, but if we must catch 1,000 rabbits, improved cunning, planning and tools are in order.

Say it with fat

Our changing hunting habits would have had cultural impacts too, Ben-Dor and Barkai posit. “Cultural evolution in archaeology usually refers to objects, such as stone tools,” Ben-Dor tells Haaretz. But cultural evolution also refers to learned behavior, such as our choice of which animals to hunt, and how.

Thus, they posit, our hunting conundrum may have also been a key element to that enigmatic human characteristic: complex language. When language began, with what ancestor of Homo sapiens, if any before us, is hotly debated.

Ben-Dor, an economist by training prior to obtaining a Ph.D. in archaeology, believes it began early. “We just need to follow the money. When speaking of evolution, one must follow the energy. Language is energetically costly. Speaking requires devotion of part of the brain, which is costly. Our brain consumes huge amounts of energy. It’s an investment, and language has to produce enough benefit to make it worthwhile. What did language bring us? It had to be more energetically efficient hunting.”

Domestication of the dog also requires resources and, therefore, also had to bring sufficient compensation in the form of more efficient hunting of smaller animals, he points out. That may help explain the fact that Neolithic humans not only embraced the dog but ate it too, going by archaeological evidence of butchered dogs.

At the end of the day, wherever we went, humans devastated the local ecologies, given enough time.

There is a lot of thinking about the Neolithic agricultural revolution. Some think grain farming was driven by the desire to make beer. Given residue analysis indicating that it’s been around for over 10,000 years, that theory isn’t as far-fetched as one might think. Ben-Dor and Barkai suggest that once we could grow our own food and husband herbivores, the megafauna almost entirely gone, hunting for them became too energy-costly. So we had to use our large brains to develop agriculture.

And as the hunter-gathering lifestyle gave way to permanent settlement, our brain size decreased.

Note, Ben-Dor adds, that the brains of wolves which have to hunt to survive are larger than the brain of the domesticated wolf, i.e., dogs. We did promise more on that. That was it. Also: The chimpanzee brain has remained stable for 7 million years, since the split with the Homo line, Barkai points out.

“Why does any of this matter?” Ben-Dor asks. “People think humans reached this condition because it was ‘meant to be.’ But in the Earth’s 4.5 billion years, there have been billions of species. They rose and fell. What’s the probability that we would take over the world? It’s an accident of nature. It never happened before that one species achieved dominance over all, and now it’s all over. How did that happen? This is the answer: A non-carnivore entered the niche of carnivore, and ate out its niche. We can’t eat that much protein: we need fat too. Because we needed the fat, we began with the big animals. We hunted the prime adult animals which have more fat than the kiddies and the old. We wiped out the prime adults who were crucial to survival of species. Because of our need for fat, we wiped out the animals we depended on. And this required us to keep getting smarter and smarter, and thus we took over the world.”

Study suggests environmental factors had a role in the evolution of human tolerance (Eureka Alert)

News Release 3-Feb-2021

Study suggests environmental factors had a role in the evolution of human tolerance and friendliness

University of York

Environmental pressures may have led humans to become more tolerant and friendly towards each other as the need to share food and raw materials became mutually beneficial, a new study suggests.

This behaviour was not an inevitable natural progression, but subject to ecological pressures, the University of York study concludes.

Humans have a remarkable capacity to care about people well outside their own kin or local group. Whilst most other animals tend to be defensive towards those in other groups our natural tolerance allows us to collaborate today on a global scale, as seen with trade or international relief efforts to provide aid for natural disasters.

Using computer simulations of many thousands of individuals gathering resources for their group and interacting with individuals from other groups, the research team attempted to establish what key evolutionary pressures may have prompted human intergroup tolerance.

The study suggests this may have begun when humans began to leave Africa and during a period of increasingly harsh and variable environments.

The study was concerned with the period 300,000 to 30,000 years ago where archaeological evidence indicated greater mobility and more frequent interactions between different groups. In particular, this is a time in which there is a movement of raw materials over much longer distances and between groups.

The researchers found that populations which shared resources were more likely to be more successful and more likely to survive harsh environments, where extinctions occur, than those populations which do not share across borders.

However, in resource rich environments sharing was less advantageous and in extremely harsh environments populations are too low for sharing to be feasible.

Penny Spikins, Professor in the Archaeology of Human Origins at the University of York, said: “That our study demonstrates the importance of tolerance to human success is perhaps surprising, especially when we often think of prehistory as a time of competition, however we have seen that in situations where people with surplus share across borders with those in need everyone benefits in the long term.”

Dr Jennifer C. French, lecturer in Palaeolithic Archaeology at the University of Liverpool added: “Our study’s findings also have important implications for wider debates about the increases in examples of innovation and greater rates of cultural evolution that occurred during this period.

“They help to explain previously enigmatic changes in the archaeological record between 300,000 and 30,000 years ago.”


The study is published in the Journal of Archaeological Method and Theory.

Intelligent Life Really Can’t Exist Anywhere Else (Popular Mechanics)

Hell, our own evolution on Earth was pure luck.

Caroline Delbert, Nov 24, 2020

LipowskiGetty Images

  • Cosmic statisticians say the likelihood of life evolving on Earth is even less than we thought.
  • Analysis suggests individual steps in evolution were more likely to take longer than Earth’s existence.
  • The scientists say this research is designed give future researchers a foundation.

In newly published research from Oxford University’s Future of Humanity Institute, scientists study the likelihood of key times for evolution of life on Earth and conclude that it would be virtually impossible for that life to evolve the same way somewhere else.

Life has come a very long way in a very short time on Earth, relatively speaking—and scientists say that represents even more improbable luck for intelligent life that is rare to begin with.

For decades, scientists and even philosophers have chased many explanations for the Fermi paradox. How, in an infinitely big universe, can we be the only intelligent life we’ve ever encountered? Even on Earth itself, they wonder, how are we the only species that ever has evolved advanced intelligence?

There are countless naturally occurring, but extremely lucky ways in which Earth is special, sheltered, protected, and encouraged to have evolved life. And some key moments of emerging life seem much more likely than others, based on what really did happen.

“The fact that eukaryotic life took over a billion years to emerge from prokaryotic precursors suggests it is a far less probable event than the development of multicellular life, which is thought to have originated independently over 40 times,” the researchers explain. They continue:

“The early emergence of abiogenesis is one example that is frequently cited as evidence that simple life must be fairly common throughout the Universe. By using the timing of evolutionary transitions to estimate the rates of transition, we can derive information about the likelihood of a given transition even if it occurred only once in Earth’s history.”

In this paper, researchers from Oxford University’s illustrious Future of Humanity Institute continue to wonder how all this can be and what it means. The researchers include mathematical ecologists, who do a kind of forensic mathematics of Earth’s history.

In this case, they’ve used a Bayesian model of factors related to evolutionary transitions, which are the key points where life on Earth has turned from ooze to eukaryotes, for example, and from fission and other asexual reproduction to sexual reproduction, which greatly accelerates the rate of mutation and development of species by mixing DNA as a matter of course.

Most of these “evolutionary transitions” are poorly understood and have not been very well studied by the scientists of likelihoods. And using their model, these scientists say that Earth’s series of Goldilocks lottery tickets are more likely to have taken far longer than they really did on Earth.

There’s an iconic scene in the 2001 movie Ocean’s Eleven where George Clooney explains the series of escalating improbabilities of his planned crime. After several hugely unlikely outcomes, he says, “Then it’s a piece of cake: just three more guards with Uzis, and the most elaborate vault door conceived by man.” In a way, the unlikely hurdles to the rapid flourishing of complex life on Earth are the same way.

First, we win the lottery for surface temperature and protection from spaceborne dangers. Second, we win the lottery for the presence of building blocks of life. Third, we win the lottery for the right location for the right building blocks. That’s before anything like the most primitive single cell has even emerged.

Using some information we do know, like the age of Earth and the expected end of its habitable lifetime due to the expanding heat radius of our sun, these researchers have turned evolutionary transitions into a series of existential scratch-off tickets. Read the whole fascinating study here.

Are Humans Still Evolving? Scientists Weigh In (Science Alert)

Eva Hamrud, Metafact – 20 Sept. 2020

As a species, humans have populated almost every corner of the earth. We have developed technologies and cultures which shape the world we live in.

The idea of ‘natural selection’ or ‘survival of the fittest’ seems to make sense in Stone Age times when we were fighting over scraps of meat, but does it still apply now?

We asked 12 experts whether humans are still evolving. The expert consensus is unanimously ‘yes’, however scientists say we might have the wrong idea of what evolution actually is.

Evolution is not the same as natural selection

Evolution is often used interchangeable with the phrases ‘survival of the fittest’ or ‘natural selection’. Actually, these are not quite the same thing.

‘Evolution’ simply means the gradual change of a population over time.

‘Natural selection’ is a mechanism by which evolution can occur. Our Stone Age ancestors who were faster runners avoided being trampled by mammoths and were more likely to have children. That is ‘natural selection’.

Overtime, the human population became faster at running. That’s evolution.

Evolution can happen without natural selection

That makes sense for Stone Age humans, but what about nowadays? We don’t need to outrun mammoths, we have medicines for when we’re sick and we can go to the shops to get food.

Natural selection needs a ‘selection pressure’ (e.g. dangerous trampling mammoths), so if we don’t have these anymore, does this mean we stop evolving?

Even with no selection pressures, experts say evolution still occurs by other mechanisms.

Professor Stanley Ambrose, an anthropologist from the University of Illinois, explains that “any change in the proportions of genes or gene variants over time is also considered evolution. The variants may be functionally equivalent, so evolution does not automatically equate with ‘improvement'”.

Whilst some genes can be affected by natural selection (e.g. genes that help us run faster), other changes in our DNA might have no obvious effect on us. ‘Neutral’ variations can also spread through a population by a different mechanism called ‘genetic drift’.

Genetic drift works by chance: some individuals might be unlucky and die for reasons which have nothing to do with their genes. Their unique gene variations will not be passed on to the next generation, and so the population will change.

Genetic drift doesn’t need any selection pressures, and it is still happening today.

Natural selection is still happening in humans

As much as we have made things easier for ourselves, there are still selection pressures around us, which mean that natural selection is still happening.

Like all mammals, humans lose the ability to digest milk when they stop breastfeeding. This is because we stop making an enzyme called lactase. In some countries, the population has acquired ‘lactase persistence’, meaning that people make lactase throughout their lives.

In European countries we can thank one specific gene variation for our lactase persistence, which is called ‘-13910*T’. By studying this specific gene variation in modern and ancient DNA samples, researchers suggest that it became common after humans started domesticated and milking animals.

This is an example of natural selection where we have actually made the selection pressure ourselves – we started drinking milk, so we evolved to digest it!

Another example of humans undergoing natural selection to adapt to a lifestyle is the Bajau people, who traditionally live in houseboats in the waters of South East Asia and spend much of their lives diving to hunt fish or collect shellfish.

Ultrasound imaging has found that Bajau people have larger spleens than their neighbours – an adaption which allows them to stay underwater for longer.

There are always selective pressures around us, even ones that we create ourselves.

As Dr Benjamin Hunt from the University of Birmingham puts it, “Our technological and cultural changes alter the strength and composition of the selection pressures within our environment, but selection pressures still exist.”

Evolution can’t be stopped

So, evolution can happen by different mechanisms like natural selection and genetic drift. As our environment is always changing, natural selection is always happening. And even if our environment was ‘just right’ for us, we would evolve anyway!

Dr Alywyn Scally, an expert in evolution and genetics from the University of Cambridge, explains: “As long as human reproduction involves randomness and genetic mutation (and the laws of the Universe pretty much guarantee that this will always be the case at some level), there will continue to be differences from one generation to the next, meaning that the process of evolution can never be truly halted.”

Takeaway: Evolution means change in a population. That includes both easy-to-spot changes to adapt to an environment as well as more subtle, genetic changes.

Humans are still evolving, and that is unlikely to change in the future.

Article based on 12 expert answers to this question: Are humans still evolving?

This expert response was published in partnership with independent fact-checking platform Subscribe to their weekly newsletter here.

Carlos Guerra Schrago: Teoria e prática da evolução (Pesquisa Fapesp)

Disciplina que busca reconstituir as histórias das espécies está, ela própria, em mutação, de acordo com biólogo da UFRJ

Fabrício Marques e Maria Guimarães

Edição 291
mai. 2020

Em companhia de Charles Darwin no Museu de História Natural de Londres, em 2018. Arquivo pessoal

O biólogo Carlos Guerra Schrago, do Departamento de Genética da Universidade Federal do Rio de Janeiro (UFRJ), faz extensas análises de dados no computador, usa estatística e sequências genéticas. Assentado na teoria evolutiva, seu trabalho ajuda a entender aspectos da realidade, como os caminhos da disseminação de uma doença (a epidemia de zika a partir de 2015) e a diversificação de mamíferos, especialmente roedores e primatas.

A variedade de objetos de estudo é reveladora de como a mesma teoria pode ser aplicada a todos os organismos, com uma diferença importante: com uma vida efêmera enquanto indivíduos, microrganismos são capazes de perpetuar-se por meio de uma rápida multiplicação. Aos olhos de um evolucionista, reconstituir a trilha de modificações genéticas resultante dessa replicação se transforma praticamente em um filme que relata sua história.

Graduado em biologia na UFRJ com especialização em bioinformática no Laboratório Nacional de Computação Científica (LNCC), em Petrópolis, Guerra concluiu seu doutorado na UFRJ em 2004 e, entre 2018 e 2019, fez estágio de pós-doutorado na Universidade Harvard, nos Estados Unidos. Na entrevista a seguir, concedida por videoconferência, ele fala de mudanças pelas quais a teoria evolutiva vem passando e de como reage quando estudantes contestam a disciplina. Para ele, os pesquisadores caem em uma armadilha quando reagem como se houvesse um embate entre religião e ciência.

 Seu campo de estudo é a evolução viral. Como você vê a pandemia do novo coronavírus?
Ainda não analisei o material bruto do coronavírus, mas chamou a minha atenção que talvez tenha sido a primeira vez que a biologia evolutiva lidou com um problema prático novo, que é avaliar se uma sequência, seja um genoma de vírus ou de bactéria, foi manipulada em laboratório ou não. O trabalho que mostrou que o vírus Sars-CoV-2 não passou por manipulação, publicado em março na revista Nature Medicine, foi assinado por um grupo de virologistas moleculares que trabalham com evolução e teve uma repercussão considerável. É inclusive um problema geopolítico, porque saber se uma sequência teve ou não origem natural implica avaliar se foi objeto de bioterrorismo.

Esse tipo de trabalho também permite analisar a evolução molecular do vírus para traçar como ele está circulando e tentar fazer previsões…
Certamente para a vigilância epidemiológica de qualquer país é relevante saber o ritmo, a taxa de crescimento e de expansão das infecções e tentar traçar de onde esses vírus e sequências vieram. Mas o trabalho feito até agora carece de uma amostragem de sequências maior. É difícil fazer inferências sobre a dinâmica espacial e temporal de uma epidemia quando a amostragem é incompleta. Em relação ao Sars-CoV-2 circulante no Brasil, mostrou-se que são sequências de vírus originadas da Europa e EUA, mas o esforço de obter amostras não foi homogêneo em todos os países.

Talvez a seleção natural não seja a única explicação, mas ainda é a melhor que temos para entender a complexidade dos seres vivos

Seu laboratório trabalha com zika. Qual o alvo dos estudos?
Nossos questionamentos são teóricos e relacionados à epidemia de zika, e o que se aplica à zika vale para qualquer epidemia. As metodologias de bioinformática ou de evolução molecular são as mesmas. Nosso interesse era saber como se comportam parâmetros relevantes para quem trabalha com saúde pública, como a idade da epidemia, de onde ela veio, sua taxa de crescimento. Há uma quantidade enorme de pressupostos teóricos que queríamos avaliar e isso requer simulações computacionais bastante realistas. Nosso trabalho tem sido desenhar simuladores de crescimento e de dinâmica da epidemia, tentando aproximá-los da realidade do vírus no espaço e no tempo. Isso para avaliar a robustez de métodos tradicionalmente usados, por exemplo, para a reconstrução da história evolutiva do vírus ou cálculos da dinâmica espacial. Concluímos que alguns desses métodos têm problemas. Obtivemos valores mais precisos quando usamos as mudanças silenciosas no genoma, ou seja, mudanças no nível do DNA que não são passadas para o que é aparente, o fenótipo. As mudanças não silenciosas, aquelas que acarretam mudança de fato em alguma proteína que afeta um fenótipo, estão submetidas a regimes de seleção e são mais suscetíveis.

O trabalho envolve estatística e bioinformática. É possível explicar para um leigo como isso funciona?
Em publicações de divulgação científica ou mesmo em filmes de ficção científica, sempre aparecem sequências de DNA com aquelas letrinhas: A, C, T e G. São as bases nitrogenadas que se combinam para formar o DNA. Um dos desafios de quem trabalha com evolução molecular e genética é olhar essas letras, com diversas combinações e possibilidades, e tentar desvendar a história por trás delas. É como chegar na sua casa, olhar os cômodos e tentar descobrir o que aconteceu enquanto você estava ausente. Às vezes, é simples. Se você tem um cachorro e encontra tudo rasgado na sala, conclui: foi o cachorro. Mas em muitos casos requer a aplicação de modelos avançados. É algo comum do pensamento humano fazer inferências históricas. Entretanto, em biologia evolutiva é preciso estar respaldado por algo mais quantitativo. Na busca por uma comunicação objetiva, recorremos a inferências estatísticas que permitem quantificar mudanças na natureza. Nessa história, tratamos de tudo, de tempo, de quem é parente de quem, de onde veio, como chegou até aqui. Essas perguntas podem ser aplicadas a vírus, plantas, animais.

Como tem sido a evolução dessa metodologia? Como ela contribui para avançar o conhecimento?
A disciplina evolução molecular e filogenética surgiu na década de 1960, embora os conceitos com que trabalhamos sejam mais antigos – de uma história evolutiva compartilhada, de como a diversidade genética responde a regimes de seleção. Mas eles careciam de métodos mais algorítmicos para serem estudados e só foi possível chegar a esse patamar com o crescimento da utilização de computadores nas ciências naturais. Isso também dependeu do conhecimento sobre as sequências de nucleotídeos – e a estrutura do DNA só foi desvendada nos anos 1950. Até o aparecimento da disciplina, não se tinha ideia de como os genomas evoluíam. Com ela, o tema se tornou objeto de pesquisa e, utilizando dados moleculares, tornou-se possível reconstruir relações evolutivas entre várias espécies e ampliar o conhecimento sobre a árvore da vida, presente nos livros técnicos de ecologia, zoologia, botânica ou qualquer área da biologia. Temos hoje uma biologia bastante unificada pelo discurso evolutivo.

Quando se fala de evolução e seleção natural, as pessoas costumam pensar em animais ou plantas. Você estuda evolução molecular de vírus. O objeto de estudo faz diferença?
Faz diferença porque, no caso dos vírus, a taxa de evolução é muito acelerada e é possível enxergar o processo evolutivo com mais detalhes. Nos grandes mamíferos, é possível enxergar fotografias espalhadas por milhões de anos e fazer inferências sobre o que aconteceu entre uma imagem e outra. No caso dos vírus o espaçamento é menor, mas há algumas complexidades também. O pesquisador precisa estar atento e escolher ferramentas apropriadas para não fazer uma análise enviesada, pois há metodologias para enxergar quadros muito afastados no tempo e outras para quadros muito próximos.

Os vírus usam as células do hospedeiro para se multiplicar e deixam partes de seu material genético inseridos no genoma dos animais. Como os vírus se entrelaçam em nossa história evolutiva?
O que temos até agora são estudos de caso, alguns deles interessantíssimos, mostrando que o papel desses seres é muito mais complexo do que se imaginava. Não há como ponderar se ao longo da história dos mamíferos ou de qualquer outro grupo a contribuição dos vírus tenha sido mais positiva ou mais negativa. Tendemos a achar que é negativa, pois eles são parasitas celulares que utilizam a maquinaria da célula para se replicar e depois a célula morre. Mas nem sempre isso é verdade, e eles podem trazer novidades evolutivas. Isso era inimaginável até algum tempo atrás.

Quanto tempo?
Essas ideias começaram a aparecer por volta dos anos 1990. Depois do entendimento da natureza química do material genético, em 1953, criou-se um conceito de indivíduo muito associado a um único genoma. Entendia-se que, nas células de uma pessoa, o genoma poderia ter pequenas modificações criadas durante o processo de divisão celular. Assim, o genoma de uma célula do fígado poderia ser um pouco diferente do genoma de uma célula do pulmão. Mas ninguém admitiria que outros genomas presentes no organismo, originados de seres tão diferentes quanto bactérias e vírus, poderiam alterar fenótipos e chegar ao ponto de influenciar o comportamento de uma pessoa, como ansiedade e depressão. Chegamos a uma pergunta: afinal de contas, o que é um indivíduo? É apenas o seu genoma ou é o seu genoma e toda essa comunidade de genomas que está presente nesses microrganismos, incluindo os vírus?

Qual será a resposta, na sua avaliação?
O desenvolvimento das técnicas de sequenciamento permite uma análise muito mais detalhada do problema e acho que vamos nos surpreender nos próximos anos. É um desafio considerável inclusive para a bioinformática. A complexidade da informação é gigantesca, porque a variação não é apenas entre pessoas, mas também de uma mesma pessoa ao longo de sua vida. É impossível dar sentido a isso sem o auxílio de computadores. Minha impressão é de que, nos próximos anos, os cursos de biologia terão obrigatoriamente conteúdos de programação de computador para seus estudantes.

O discurso científico é limitado pelo naturalismo metodológico a agentes que devem ter relação mecânica de causa e efeito

Como essa contribuição da microbiologia influencia o conhecimento sobre a teoria da evolução?
O impacto está em andamento. A complexidade do genoma e de sua interação com os genomas de todos esses microrganismos não foi assimilada. Existe uma parcela de pesquisadores que considera a seleção natural a única explicação para a organização surpreendente que vemos nos seres vivos, enquanto outros acham que fenômenos além da seleção natural podem contribuir e defendem que a biologia evolutiva deveria ser reformulada para incorporar essas novidades, abandonando a concepção clássica que vem dos anos 1920. Talvez a seleção natural não seja a única explicação, mas ainda é a melhor que temos para entender a complexidade impressionante dos seres vivos.

Ainda se discute se os vírus são ou não vivos?
A pandemia do coronavírus mostrou que uma molécula de RNA consegue parar o mundo. Dentro das células, essas moléculas levam a uma rede hierárquica de reações em cadeia. Acaba sendo irrelevante perguntar se o vírus é vivo ou não. Esse debate quase virou uma disputa futebolística.

Estamos em um momento no qual se tornou frequente negar a evolução. Como você vive isso na docência?
É um problema real. Com frequência alunos fazem questionamentos de conteúdo religioso, mas raramente é um questionamento filosófico. O que chega em sala de aula é essa interpretação literal, simplista, em que o estudante argumenta: “Ah, não é isso que o capítulo tal do livro tal, do Gênesis, diz”. Acho que isso é bom tema de análise para os sociólogos. Devemos nos perguntar por que isso está aparecendo agora, pois é algo que eu não via 10 anos atrás. É preciso contextualizar o problema. Não se trata de uma disputa entre ciência e religião.

Por que não?
Muitos pesquisadores caem na armadilha e transformam algo que é local e específico em um problema filosófico que não tem solução. Na verdade, estamos lidando com algo muito menos sofisticado. O estudante nunca vem com um discurso teológico avançado. Tenho a impressão de que alguns estudantes entram na aula de evolução achando que é uma disciplina para ensinar ateísmo. Então, é natural que atuem de maneira hostil, porque cresceram em um ambiente familiar religioso e seu entendimento de moral está associado a princípios religiosos.

Como lidar com isso?
Combatendo a percepção de que o discurso científico é pregação ateísta. O professor precisa contextualizar quais são os limites e os agentes do discurso científico. Para o estudante tem que estar claro que o discurso científico é limitado pelo naturalismo metodológico a agentes que devem ter relação mecânica de causa e efeito. Qualquer tipo de agente não natural é incompatível com o universo que caracteriza o discurso científico. Uma vez eu tive de explicar: “Isto aqui é aula de biologia evolutiva, não de apologética ateísta. Eu não sou apologista de matérias do divino, sou biólogo”. Com isso, o aluno fica mais tranquilo e entende que, a partir daqui, fazer qualquer tipo de pulo metafísico é complicado. E isso inclui a aceitação ou rejeição de interpretações metafísicas do naturalismo. Quando alguém diz que hipóteses pseudocientíficas como a do “design inteligente” deveriam entrar nos livros de biologia evolutiva, deve-se indagar o seguinte: o que se propõe está envolto em naturalismo metodológico? Os agentes que estão atuando têm relação mecânica de causa e efeito? Não têm. Então, ótimo, pode-se fazer o que quiser com isso, mas no livro de evolução não entra. Criar essa proteção para o discurso científico evita o problema, mas também tem uma consequência que desagrada a alguns cientistas.

A consequência de apresentar o discurso da ciência como apenas um dos discursos possíveis do intelecto humano. Para o cientista, é muito complicado dissociar a relação de igualdade entre ciência e conhecimento. Quando se afirma que existem outras formas de conhecimento fora da proteção do naturalismo metodológico, o cientista tem dificuldade em compreender. Para ele, o mundo só é cognoscível pelo naturalismo metodológico.

Conspiracy theories: how belief is rooted in evolution – not ignorance (The Conversation)

December 13, 2019 9.33am EST – original article

Mikael Klintman PhD, Professor, Lund University

Despite creative efforts to tackle it, belief in conspiracy theories, alternative facts and fake news show no sign of abating. This is clearly a huge problem, as seen when it comes to climate change, vaccines and expertise in general – with anti-scientific attitudes increasingly influencing politics.

So why can’t we stop such views from spreading? My opinion is that we have failed to understand their root causes, often assuming it is down to ignorance. But new research, published in my book, Knowledge Resistance: How We Avoid Insight from Others, shows that the capacity to ignore valid facts has most likely had adaptive value throughout human evolution. Therefore, this capacity is in our genes today. Ultimately, realising this is our best bet to tackle the problem.

So far, public intellectuals have roughly made two core arguments about our post-truth world. The physician Hans Rosling and the psychologist Steven Pinker argue it has come about due to deficits in facts and reasoned thinking – and can therefore be sufficiently tackled with education.

Meanwhile, Nobel Prize winner Richard Thaler and other behavioural economists have shown how the mere provision of more and better facts often lead already polarised groups to become even more polarised in their beliefs.

Tyler Merbler/Flickr, CC BY-SA

The conclusion of Thaler is that humans are deeply irrational, operating with harmful biases. The best way to tackle it is therefore nudging – tricking our irrational brains – for instance by changing measles vaccination from an opt-in to a less burdensome opt-out choice.

Such arguments have often resonated well with frustrated climate scientists, public health experts and agri-scientists (complaining about GMO-opposers). Still, their solutions clearly remain insufficient for dealing with a fact-resisting, polarised society.

Evolutionary pressures

In my comprehensive study, I interviewed numerous eminent academics at the University of Oxford, London School of Economics and King’s College London, about their views. They were experts on social, economic and evolutionary sciences. I analysed their comments in the context of the latest findings on topics raging from the origin of humanity, climate change and vaccination to religion and gender differences.

It became evident that much of knowledge resistance is better understood as a manifestation of social rationality. Essentially, humans are social animals; fitting into a group is what’s most important to us. Often, objective knowledge-seeking can help strengthen group bonding – such as when you prepare a well-researched action plan for your colleagues at work.

But when knowledge and group bonding don’t converge, we often prioritise fitting in over pursuing the most valid knowledge. In one large experiment, it turned out that both liberals and conservatives actively avoided having conversations with people of the other side on issues of drug policy, death penalty and gun ownership. This was the case even when they were offered a chance of winning money if they discussed with the other group. Avoiding the insights from opposing groups helped people dodge having to criticise the view of their own community.

Similarly, if your community strongly opposes what an overwhelming part of science concludes about vaccination or climate change, you often unconsciously prioritise avoiding getting into conflicts about it.

This is further backed up by research showing that the climate deniers who score the highest on scientific literacy tests are more confident than the average in that group that climate change isn’t happening – despite the evidence showing this is the case. And those among the climate concerned who score the highest on the same tests are more confident than the average in that group that climate change is happening.

This logic of prioritising the means that get us accepted and secured in a group we respect is deep. Those among the earliest humans who weren’t prepared to share the beliefs of their community ran the risk of being distrusted and even excluded.

And social exclusion was an enormous increased threat against survival – making them vulnerable to being killed by other groups, animals or by having no one to cooperate with. These early humans therefore had much lower chances of reproducing. It therefore seems fair to conclude that being prepared to resist knowledge and facts is an evolutionary, genetic adaptation of humans to the socially challenging life in hunter-gatherer societies.

Today, we are part of many groups and internet networks, to be sure, and can in some sense “shop around” for new alliances if our old groups don’t like us. Still, humanity today shares the same binary mindset and strong drive to avoid being socially excluded as our ancestors who only knew about a few groups. The groups we are part of also help shape our identity, which can make it hard to change groups. Individuals who change groups and opinions constantly may also be less trusted, even among their new peers.

In my research, I show how this matters when it comes to dealing with fact resistance. Ultimately, we need to take social aspects into account when communicating facts and arguments with various groups. This could be through using role models, new ways of framing problems, new rules and routines in our organisations and new types of scientific narratives that resonate with the intuitions and interests of more groups than our own.

There are no quick fixes, of course. But if climate change were reframed from the liberal/leftist moral perspective of the need for global fairness to conservative perspectives of respect for the authority of the father land, the sacredness of God’s creation and the individual’s right not to have their life project jeopardised by climate change, this might resonate better with conservatives.

If we take social factors into account, this would help us create new and more powerful ways to fight belief in conspiracy theories and fake news. I hope my approach will stimulate joint efforts of moving beyond disputes disguised as controversies over facts and into conversations about what often matters more deeply to us as social beings.

Steven Pinker talks Donald Trump, the media, and how the world is better off today than ever before (ABC Australia)


“By many measures of human flourishing the state of humanity has been improving,” renowned cognitive scientist Steven Pinker says, a view often in contrast to the highlights of the 24-hour news cycle and the recent “counter-enlightenment” movement of Donald Trump.

“Fewer of us are dying of disease, fewer of us are dying of hunger, more of us are living in democracies, were more affluent, better educated … these are trends that you can’t easily appreciate from the news because they never happen all at once,” he says.

Canadian-American thinker Steven Pinker is the author of Bill Gates’s new favourite book — Enlightenment Now — in which he maintains that historically speaking the world is significantly better than ever before.

But he says the media’s narrow focus on negative anomalies can result in “systematically distorted” views of the world.

Speaking to the ABC’s The World program, Mr Pinker gave his views on Donald Trump, distorted perceptions and the simple arithmetic that proves the world is better than ever before.

Donald Trump’s ‘counter-enlightenment’

“Trumpism is of course part of a larger phenomenon of authoritarian populism. This is a backlash against the values responsible for the progress that we’ve enjoyed. It’s a kind of counter-enlightenment ideology that Trumpism promotes. Namely, instead of universal human wellbeing, it focusses on the glory of the nation, it assumes that nations are in zero-sum competition against each other as opposed to cooperating globally. It ignores the institutions of democracy which were specifically implemented to avoid a charismatic authoritarian leader from wielding power, but subjects him or her to the restraints of a governed system with checks and balances, which Donald Trump seems to think is rather a nuisance to his own ability to voice the greatness of the people directly. So in many ways all of the enlightenment forces we have enjoyed, are being pushed back by Trump. But this is a tension that has been in play for a couple of hundred years. No sooner did the enlightenment happen that a counter-enlightenment grew up to oppose it, and every once in a while it does make reappearances.”

News media can ‘systematically distort’ perceptions

“If your impression of the world is driven by journalism, then as long as various evils haven’t gone to zero there’ll always be enough of them to fill the news. And if journalism isn’t accompanied by a bit of historical context, that is not just what’s bad now but how bad it was in the past, and statistical context, namely how many wars? How many terrorist attacks? What is the rate of homicide? Then our intuitions, since they’re driven by images and narratives and anecdotes, can be systematically distorted by the news unless it’s presented in historical and statistical context.

‘Simple arithmetic’: The world is getting better

“It’s just a simple matter of arithmetic. You can’t look at how much there is right now and say that it is increasing or decreasing until you compare it with how much took place in the past. When you look at how much took place in the past you realise how much worse things were in the 50s, 60s, 70s and 80s. We don’t appreciate it now when we concentrate on the remaining horrors, but there were horrific wars such as the Iran-Iraq war, the Soviets in Afghanistan, the war in Vietnam, the partition of India, the Bangladesh war of independence, the Korean War, which killed far more people than even the brutal wars of today. And if we only focus on the present, we ought to be aware of the suffering that continues to exist, but we can’t take that as evidence that things have gotten worse unless we remember what happened in the past.”

Don’t equate inequality with poverty

“Globally, inequality is decreasing. That is, if you don’t look within a wealthy country like Britain or the United States, but look across the globe either comparing countries or comparing people worldwide. As best as we can tell, inequality is decreasing because so many poor countries are getting richer faster than rich countries are getting richer. Now within the wealthy countries of the anglosphere, inequality is increasing. And although inequality brings with it a number of serious problems such as disproportionate political power to the wealthy. But inequality itself is not a problem. What we have to focus on is the wellbeing of those at the bottom end of the scale, the poor and the lower middle class. And those have not actually been decreasing once you take into account government transfers and benefits. Now this is a reason we shouldn’t take for granted, the important role of government transfers and benefits. It’s one of the reasons why the non-English speaking wealthy democracies tend to have greater equality than the English speaking ones. But we shouldn’t confuse inequality with poverty.”

Language is learned in brain circuits that predate humans (Georgetown University)



WASHINGTON — It has often been claimed that humans learn language using brain components that are specifically dedicated to this purpose. Now, new evidence strongly suggests that language is in fact learned in brain systems that are also used for many other purposes and even pre-existed humans, say researchers in PNAS (Early Edition online Jan. 29).

The research combines results from multiple studies involving a total of 665 participants. It shows that children learn their native language and adults learn foreign languages in evolutionarily ancient brain circuits that also are used for tasks as diverse as remembering a shopping list and learning to drive.

“Our conclusion that language is learned in such ancient general-purpose systems contrasts with the long-standing theory that language depends on innately-specified language modules found only in humans,” says the study’s senior investigator, Michael T. Ullman, PhD, professor of neuroscience at Georgetown University School of Medicine.

“These brain systems are also found in animals – for example, rats use them when they learn to navigate a maze,” says co-author Phillip Hamrick, PhD, of Kent State University. “Whatever changes these systems might have undergone to support language, the fact that they play an important role in this critical human ability is quite remarkable.”

The study has important implications not only for understanding the biology and evolution of language and how it is learned, but also for how language learning can be improved, both for people learning a foreign language and for those with language disorders such as autism, dyslexia, or aphasia (language problems caused by brain damage such as stroke).

The research statistically synthesized findings from 16 studies that examined language learning in two well-studied brain systems: declarative and procedural memory.

The results showed that how good we are at remembering the words of a language correlates with how good we are at learning in declarative memory, which we use to memorize shopping lists or to remember the bus driver’s face or what we ate for dinner last night.

Grammar abilities, which allow us to combine words into sentences according to the rules of a language, showed a different pattern. The grammar abilities of children acquiring their native language correlated most strongly with learning in procedural memory, which we use to learn tasks such as driving, riding a bicycle, or playing a musical instrument. In adults learning a foreign language, however, grammar correlated with declarative memory at earlier stages of language learning, but with procedural memory at later stages.

The correlations were large, and were found consistently across languages (e.g., English, French, Finnish, and Japanese) and tasks (e.g., reading, listening, and speaking tasks), suggesting that the links between language and the brain systems are robust and reliable.

The findings have broad research, educational, and clinical implications, says co-author Jarrad Lum, PhD, of Deakin University in Australia.

“Researchers still know very little about the genetic and biological bases of language learning, and the new findings may lead to advances in these areas,” says Ullman. “We know much more about the genetics and biology of the brain systems than about these same aspects of language learning. Since our results suggest that language learning depends on the brain systems, the genetics, biology, and learning mechanisms of these systems may very well also hold for language.”

For example, though researchers know little about which genes underlie language, numerous genes playing particular roles in the two brain systems have been identified. The findings from this new study suggest that these genes may also play similar roles in language. Along the same lines, the evolution of these brain systems, and how they came to underlie language, should shed light on the evolution of language.

Additionally, the findings may lead to approaches that could improve foreign language learning and language problems in disorders, Ullman says.

For example, various pharmacological agents (e.g., the drug memantine) and behavioral strategies (e.g., spacing out the presentation of information) have been shown to enhance learning or retention of information in the brain systems, he says. These approaches may thus also be used to facilitate language learning, including in disorders such as aphasia, dyslexia, and autism.

“We hope and believe that this study will lead to exciting advances in our understanding of language, and in how both second language learning and language problems can be improved,” Ullman concludes.

Human societies evolve along similar paths (University of Exeter)


Societies ranging from ancient Rome and the Inca empire to modern Britain and China have evolved along similar paths, a huge new study shows.

Despite their many differences, societies tend to become more complex in “highly predictable” ways, researchers said.

These processes of development – often happening in societies with no knowledge of each other – include the emergence of writing systems and “specialised” government workers such as soldiers, judges and bureaucrats.The international research team, including researchers from the University of Exeter, created a new database of historical and archaeological information using data on 414 societies spanning the last 10,000 years. The database is larger and more systematic than anything that has gone before it.

“Societies evolve along a bumpy path – sometimes breaking apart – but the trend is towards larger, more complex arrangements,” said corresponding author Dr Thomas Currie, of the Human Behaviour and Cultural Evolution Group at the University of Exeter’s Penryn Campus in Cornwall.

“Researchers have long debated whether social complexity can be meaningfully compared across different parts of the world. Our research suggests that, despite surface differences, there are fundamental similarities in the way societies evolve.

“Although societies in places as distant as Mississippi and China evolved independently and followed their own trajectories, the structure of social organisation is broadly shared across all continents and historical eras.”

The measures of complexity examined by the researchers were divided into nine categories. These included:

  • Population size and territory
  • Number of control/decision levels in administrative, religious and military hierarchies
  • Information systems such as writing and record keeping
  • Literature on specialised topics such as history, philosophy and fiction
  • Economic development

The researchers found that these different features showed strong statistical relationships, meaning that variation in societies across space and time could be captured by a single measure of social complexity.

This measure can be thought of as “a composite measure of the various roles, institutions, and technologies that enable the coordination of large numbers of people to act in a politically unified manner”.

Dr Currie said learning lessons from human history could have practical uses.

“Understanding the ways in which societies evolve over time and in particular how humans are able to create large, cohesive groups is important when we think about state building and development,” he said.

“This study shows how the sciences and humanities, which have not always seen eye-to-eye, can actually work together effectively to uncover general rules that have shaped human history.”


The new database of historical and archaeological information is known as “Seshat: Global History Databank” and its construction was led by researchers from the University of Exeter, the University of Connecticut, the University of Oxford, Trinity College Dublin and the Evolution Institute. More than 70 expert historians and archaeologists have helped in the data collection process.

The paper, published in Proceedings of the National Academy of Sciences, is entitled: “Quantitative historical analysis uncovers a single dimension of complexity that structures global variation in human social organisation.”

Scientists Seek to Update Evolution (Quanta Magazine)

Recent discoveries have led some researchers to argue that the modern evolutionary synthesis needs to be amended. 

By Carl Zimmer. November 22, 2016

Douglas Futuyma, a biologist at Stony Brook University, defends the “Modern Synthesis” of evolution at the Royal Society earlier this month.  Kevin Laland looked out across the meeting room at a couple hundred people gathered for a conference on the future of evolutionary biology. A colleague sidled up next to him and asked how he thought things were going.

“I think it’s going quite well,” Laland said. “It hasn’t gone to fisticuffs yet.”

Laland is an evolutionary biologist who works at the University of St. Andrews in Scotland. On a chilly gray November day, he came down to London to co-host a meeting at the Royal Society called “New Trends in Evolutionary Biology.” A motley crew of biologists, anthropologists, doctors, computer scientists, and self-appointed visionaries packed the room. The Royal Society is housed in a stately building overlooking St. James’s Park. Today the only thing for Laland to see out of the tall meeting-room windows was scaffolding and gauzy tarps set up for renovation work. Inside, Laland hoped, another kind of renovation would be taking place.

In the mid-1900s, biologists updated Darwin’s theory of evolution with new insights from genetics and other fields. The result is often called the Modern Synthesis, and it has guided evolutionary biology for over 50 years. But in that time, scientists have learned a tremendous amount about how life works. They can sequence entire genomes. They can watch genes turn on and off in developing embryos. They can observe how animals and plants respond to changes in the environment.

As a result, Laland and a like-minded group of biologists argue that the Modern Synthesis needs an overhaul. It has to be recast as a new vision of evolution, which they’ve dubbed the Extended Evolutionary Synthesis. Other biologists have pushed back hard, saying there is little evidence that such a paradigm shift is warranted.

This meeting at the Royal Society was the first public conference where Laland and his colleagues could present their vision. But Laland had no interest in merely preaching to the converted, and so he and his fellow organizers also invited prominent evolutionary biologists who are skeptical about the Extended Evolutionary Synthesis.

Both sides offered their arguments and critiques in a civil way, but sometimes you could sense the tension in the room — the punctuations of tsk-tsks, eye-rolling, and partisan bursts of applause.

But no fisticuffs. At least not yet.

Making Evolution as We Know It

Every science passes through times of revolution and of business as usual. After Galileo and Newton dragged physics out of its ancient errors in the 1600s, it rolled forward from one modest advance to the next until the early 1900s. Then Einstein and other scientists established quantum physics, relativity and other new ways of understanding the universe. None of them claimed that Newton was wrong. But it turns out there’s much more to the universe than matter in motion.

Evolutionary biology has had revolutions of its own. The first, of course, was launched by Charles Darwin in 1859 with his book On the Origin of Species. Darwin wove together evidence from paleontology, embryology and other sciences to show that living things were related to one another by common descent. He also introduced a mechanism to drive that long-term change: natural selection. Each generation of a species was full of variations. Some variations helped organisms survive and reproduce, and those were passed down, thanks to heredity, to the next generation.

Darwin inspired biologists all over the world to study animals and plants in a new way, interpreting their biology as adaptations produced over many generations. But he succeeded in this despite having no idea what a gene was. It wasn’t until the 1930s that geneticists and evolutionary biologists came together and recast evolutionary theory. Heredity became the transmission of genes from generation to generation. Variations were due to mutations, which could be shuffled into new combinations. New species arose when populations built up mutations that made interbreeding impossible.

In 1942, the British biologist Julian Huxley described this emerging framework in a book called Evolution: The Modern Synthesis. Today, scientists still call it by that name. (Sometimes they refer to it instead as neo-Darwinism, although that’s actually a confusing misnomer. The term “neo-Darwinism” was actually coined in the late 1800s, to refer to biologists who were advancing Darwin’s ideas in Darwin’s own lifetime.)

The Modern Synthesis proved to be a powerful tool for asking questions about nature. Scientists used it to make a vast range of discoveries about the history of life, such as why some people are prone to genetic disorders like sickle-cell anemia and why pesticides sooner or later fail to keep farm pests in check. But starting not long after the formation of the Modern Synthesis, various biologists would complain from time to time that it was too rigid. It wasn’t until the past few years, however, that Laland and other researchers got organized and made a concerted effort to formulate an extended synthesis that might take its place.

The researchers don’t argue that the Modern Synthesis is wrong — just that it doesn’t capture the full richness of evolution. Organisms inherit more than just genes, for example: They can inherit other cellular molecules, as well as behaviors they learn and the environments altered by their ancestors. Laland and his colleagues also challenge the pre-eminent place that natural selection gets in explanations for how life got to be the way it is. Other processes can influence the course of evolution, too, from the rules of development to the environments in which organisms have to live.

“It’s not simply bolting more mechanisms on what we already have,” said Laland. “It requires you to think of causation in a different way.”

Adding to Darwin

Eva Jablonka, a biologist at Tel Aviv University, used her talk to explore the evidence for a form of heredity beyond genes.

Our cells use a number of special molecules to control which of their genes make proteins. In a process called methylation, for example, cells put caps on their DNA to keep certain genes shut down. When cells divide, they can reproduce the same caps and other controls on the new DNA. Certain signals from the environment can cause cells to change these so-called “epigenetic” controls, allowing organisms to adjust their behavior to new challenges.

Some studies indicate that — under certain circumstances — an epigenetic change in a parent may get passed down to its offspring. And those children may pass down this altered epigenetic profile to their children. This would be kind of heredity that’s beyond genes.

The evidence for this effect is strongest in plants. In one study, researchers were able to trace down altered methylation patterns for 31 generations in a plant called Arabidopsis. And this sort of inheritance can make a meaningful difference in how an organism works. In another study, researchers found that inherited methylation patterns could change the flowering time of Arabidopsis, as well as the size of its roots. The variation that these patterns created was even bigger than what ordinary mutations caused.

After presenting evidence like this, Jablonka argued that epigenetic differences could determine which organisms survived long enough to reproduce. “Natural selection could work on this system,” she said.

While natural selection is an important force in evolution, the speakers at the meeting presented evidence for how it could be constrained, or biased in a particular direction. Gerd Müller, a University of Vienna biologist, offered an example from his own research on lizards. A number of species of lizards have evolved feet that have lost some toes. Some have only four toes, while others have just one, and some have lost their feet altogether.

The Modern Synthesis, Müller argued, leads scientists to look at these arrangements as simply the product of natural selection, which favors one variant over others because it has a survival advantage. But that approach doesn’t work if you ask what the advantage was for a particular species to lose the first toe and last toe in its foot, instead of some other pair of toes.

“The answer is, there is no real selective advantage,” said Müller.

The key to understanding why lizards lose particular toes is found in the way that lizard embryos develop toes in the first place. A bud sprouts off the side of the body, and then five digits emerge. But the toes always appear in the same sequence. And when lizards lose their toes through evolution, they lose them in the reverse order. Müller suspects this constraint is because mutations can’t create every possible variation. Some combinations of toes are thus off-limits, and natural selection can never select them in the first place.

Development may constrain evolution. On the other hand, it also provides animals and plants with remarkable flexibility. Sonia Sultan, an evolutionary ecologist from Wesleyan University, offered a spectacular case in point during her talk, describing a plant she studies in the genus Polygonum that takes the common name “smartweed.”

The Modern Synthesis, Sultan said, would lead you to look at the adaptations in a smartweed plant as the fine-tuned product of natural selection. If plants grow in low sunlight, then natural selection will favor plants with genetic variants that let them thrive in that environment — for example, by growing broader leaves to catch more photons. Plants that grow in bright sunlight, on the other hand, will evolve adaptations that let them thrive in those different conditions.

“It’s a commitment to that view that we’re here to confront,” Sultan said.

If you raise genetically identical smartweed plants under different conditions, Sultan showed, you’ll end up with plants that may look like they belong to different species.

For one thing, smartweed plants adjust the size of their leaves to the amount of sunlight they get. In bright light, the plants grow narrow, thick leaves, but in low light, the leaves become broad and thin. In dry soil, the plants send roots down deep in search of water, while in flood soil, they grow shallow hairlike roots that that stay near the surface.

Scientists at the meeting argued that this flexibility — known as plasticity — can itself help drive evolution. It allows plants to spread into a range of habitats, for example, where natural selection can then adapt their genes. And in another talk, Susan Antón, a paleoanthropologist at New York University, said that plasticity may play a significant role in human evolution that’s gone underappreciated till now. That’s because the Modern Synthesis has strongly influenced the study of human evolution for the past half century.

Paleoanthropologists tended to treat differences in fossils as the result of genetic differences. That allowed them to draw an evolutionary tree of humans and their extinct relatives. This approach has a lot to show for it, Antón acknowledged. By the 1980s, scientists had figured out that our early ancient relatives were short and small-brained up to about two million years ago. Then one lineage got tall and evolved big brains. That transition marked the origin of our genus, Homo.

But sometimes paleoanthropologists would find variations that were harder to make sense of. Two fossils might look in some ways like they should be in the same species but look too different in other respects. Scientists would usually dismiss those variations as being caused by the environment. “We wanted to get rid of all that stuff and get down to their essence,” Antón said.

But that stuff is now too abundant to ignore. Scientists have found a dizzying variety of humanlike fossils dating back to 1.5 to 2.5 million years ago. Some are tall, and some are short. Some have big brains and some have small ones. They all have some features of Homo in their skeletonbut each has a confusing mix-and-match assortment.

Antón thinks that the Extended Evolutionary Synthesis can help scientists make sense of this profound mystery. In particular, she thinks that her colleagues should take plasticity seriously as an explanation for the weird diversity of early Homo fossils.

To support this idea, Antón pointed out that living humans have their own kinds of plasticity. The quality of food a woman gets while she’s pregnant can influence the size and health of her baby, and those influences can last until adulthood. What’s more, the size of a woman — influenced in part by her own mother’s diet — can influence her own children. Biologists have found that women with longer legs tend to have larger children, for example.

Antón proposed that the weird variations in the fossil record might be even more dramatic examples of plasticity. All these fossils date to when Africa’s climate fell into a period of wild climate swings. Droughts and abundant rains would have changed the food supply in different parts of the world, perhaps causing early Homo to develop differently.

The Extended Evolutionary Synthesis may also help make sense of another chapter in our history: the dawn of agriculture. In Asia, Africa and the Americas, people domesticated crops and livestock. Melinda Zeder, an archaeologist at the Smithsonian Institution, gave a talk at the meeting about the long struggle to understand how this transformation unfolded.

Before people farmed, they foraged for food and hunted wild game. Zeder explained how many scientists treat the behavior of the foragers in a very Modern Synthesis way: as finely tuned by natural selection to deliver the biggest payoff for their effort to find food.

The trouble is that it’s hard to see how such a forager would ever switch to farming. “You don’t get the immediate gratification of grabbing some food and putting it in your mouth,” Zeder told me.

Some researchers suggested that the switch to agriculture might have occurred during a climate shift, when it got harder to find wild plants. But Zeder and other researchers have actually found no evidence of such a crisis when agriculture arose.

Zeder argues that there’s a better way of thinking about this transition. Humans are not passive zombies trying to survive in a fixed environment. They are creative thinkers who can change the environment itself. And in the process, they can steer evolution in a new direction.

Scientists call this process niche construction, and many species do it. The classic case is a beaver. It cuts down trees and makes a dam, creating a pond. In this new environment, some species of plants and animals will do better than others. And they will adapt to their environment in new ways. That’s true not just for the plants and animals that live around a beaver pond, but for the beaver itself.

When Zeder first learned about niche construction, she says, it was a revelation. “Little explosions were going off in my head,” she told me. The archaeological evidence she and others had gathered made sense as a record of how humans changed their own environment.

Early foragers show signs of having moved wild plants away from their native habitats to have them close at hand, for example. As they watered the plants and protected them from herbivores, the plants adapted to their new environment. Weedy species also moved in and became crops of their own. Certain animals adapted to the environment as well, becoming dogs, cats and other domesticated species.

Gradually, the environment changed from sparse patches of wild plants to dense farm fields. That environment didn’t just drive the evolution of the plants. It also began to drive the cultural evolution of the farmers, too. Instead of wandering as nomads, they settled down in villages so that they could work the land around them. Society became more stable because children received an ecological inheritance from their parents. And so civilization began.

Niche construction is just one of many concepts from the Extended Evolutionary Synthesis that can help make sense of domestication, Zeder said. During her talk, she presented slide after slide of predictions it provides, about everything from the movements of early foragers to the pace of plant evolution.

“It felt like an infomercial for the Extended Evolutionary Synthesis,” Zeder told me later with a laugh. “But wait! You can get steak knives!”

The Return of Natural Selection

Among the members of the audience was a biologist named David Shuker. After listening quietly for a day and a half, the University of St Andrews researcher had had enough. At the end of a talk, he shot up his hand.

The talk had been given by Denis Noble, a physiologist with a mop of white hair and a blue blazer. Noble, who has spent most of his career at Oxford, said he started out as a traditional biologist, seeing genes as the ultimate cause of everything in the body. But in recent years he had switched his thinking. He spoke of the genome not as a blueprint for life but as a sensitive organ, detecting stress and rearranging itself to cope with challenges. “I’ve been on a long journey to this view,” Noble said.

To illustrate this new view, Noble discussed an assortment of recent experiments. One of them was published last year by a team at the University of Reading. They did an experiment on bacteria that swim by spinning their long tails.

First, the scientists cut a gene out of the bacteria’s DNA that’s essential for building tails. The researchers then dropped these tailless bacteria into a petri dish with a meager supply of food. Before long, the bacteria ate all the food in their immediate surroundings. If they couldn’t move, they died. In less than four days in these dire conditions, the bacteria were swimming again. On close inspection, the team found they were growing new tails.

“This strategy is to produce rapid evolutionary genome change in response to the unfavorable environment,” Noble declared to the audience. “It’s a self-maintaining system that enables a particular characteristic to occur independent of the DNA.”

That didn’t sound right to Shuker, and he was determined to challenge Noble after the applause died down.

“Could you comment at all on the mechanism underlying that discovery?” Shuker asked.

Noble stammered in reply. “The mechanism in general terms, I can, yes…” he said, and then started talking about networks and regulation and a desperate search for a solution to a crisis. “You’d have to go back to the original paper,” he then said.

While Noble was struggling to respond, Shuker went back to the paper on an iPad. And now he read the abstract in a booming voice.

“‘Our results demonstrate that natural selection can rapidly rewire regulatory networks,’” Shuker said. He put down the iPad. “So it’s a perfect, beautiful example of rapid neo-Darwinian evolution,” he declared.

Shuker distilled the feelings of a lot of skeptics I talked to at the conference. The high-flying rhetoric about a paradigm shift was, for the most part, unwarranted, they said. Nor were these skeptics limited to the peanut gallery. Several of them gave talks of their own.

“I think I’m expected to represent the Jurassic view of evolution,” said Douglas Futuyma when he got up to the podium. Futuyma is a soft-spoken biologist at Stony Brook University in New York and the author of a leading textbook on evolution. In other words, he was the target of many complaints during the meeting that textbooks paid little heed to things like epigenetics and plasticity. In effect, Futuyma had been invited to tell his colleagues why those concepts were ignored.

“We must recognize that the core principles of the Modern Synthesis are strong and well-supported,” Futuyma declared. Not only that, he added, but the kinds of biology being discussed at the Royal Society weren’t actually all that new. The architects of the Modern Synthesis were already talking about them over 50 years ago. And there’s been a lot of research guided by the Modern Synthesis to make sense of them.

Take plasticity. The genetic variations in an animal or a plant govern the range of forms into which organism can develop. Mutations can alter that range. And mathematical models of natural selection show how it can favor some kinds of plasticity over others.

If the Extended Evolutionary Synthesis was so superfluous, then why was it gaining enough attention to warrant a meeting at the Royal Society? Futuyma suggested that its appeal was emotional rather than scientific. It made life an active force rather than the passive vehicle of mutations.

“I think what we find emotionally or aesthetically more appealing is not the basis for science,” Futuyma said.

Still, he went out of his way to say that the kind of research described at the meeting could lead to some interesting insights about evolution. But those insights would only arise with some hard work that leads to hard data. “There have been enough essays and position papers,” he said.

Some members in the audience harangued Futuyma a bit. Other skeptical speakers sometimes got exasperated by arguments they felt didn’t make sense. But the meeting managed to reach its end on the third afternoon without fisticuffs.

“This is likely the first of many, many meetings,” Laland told me. In September, a consortium of scientists in Europe and the United States received $11 million in funding (including $8 million from the John Templeton Foundation) to run 22 studies on the Extended Evolutionary Synthesis.

Many of these studies will test predictions that have emerged from the synthesis in recent years. They will see, for example, if species that build their own environments — spider webs, wasp nests and so on — evolve into more species than ones that don’t. They will look at whether more plasticity allows species to adapt faster to new environments.

“It’s doing the research, which is what our critics are telling us to do,” said Laland. “Go find the evidence.”

Correction: An earlier version of this article misidentified the photograph of Andy Whiten as Gerd Müller.

This article was reprinted on

Large human brain evolved as a result of ‘sizing each other up’ (Science Daily)

August 12, 2016
Cardiff University
Humans have evolved a disproportionately large brain as a result of sizing each other up in large cooperative social groups, researchers have proposed.

The brains of humans enlarged over time thanks to our sizing up the competition, say scientists. Credit: © danheighton / Fotolia

Humans have evolved a disproportionately large brain as a result of sizing each other up in large cooperative social groups, researchers have proposed.

A team led by computer scientists at Cardiff University suggest that the challenge of judging a person’s relative standing and deciding whether or not to cooperate with them has promoted the rapid expansion of human brain size over the last 2 million years.

In a study published in Scientific Reports, the team, which also includes leading evolutionary psychologist Professor Robin Dunbar from the University of Oxford, specifically found that evolution favors those who prefer to help out others who are at least as successful as themselves.

Lead author of the study Professor Roger Whitaker, from Cardiff University’s School of Computer Science and Informatics, said: “Our results suggest that the evolution of cooperation, which is key to a prosperous society, is intrinsically linked to the idea of social comparison — constantly sizing each up and making decisions as to whether we want to help them or not.

“We’ve shown that over time, evolution favors strategies to help those who are at least as successful as themselves.”

In their study, the team used computer modelling to run hundreds of thousands of simulations, or ‘donation games’, to unravel the complexities of decision-making strategies for simplified humans and to establish why certain types of behaviour among individuals begins to strengthen over time.

In each round of the donation game, two simulated players were randomly selected from the population. The first player then made a decision on whether or not they wanted to donate to the other player, based on how they judged their reputation. If the player chose to donate, they incurred a cost and the receiver was given a benefit. Each player’s reputation was then updated in light of their action, and another game was initiated.

Compared to other species, including our closest relatives, chimpanzees, the brain takes up much more body weight in human beings. Humans also have the largest cerebral cortex of all mammals, relative to the size of their brains. This area houses the cerebral hemispheres, which are responsible for higher functions like memory, communication and thinking.

The research team propose that making relative judgements through helping others has been influential for human survival, and that the complexity of constantly assessing individuals has been a sufficiently difficult task to promote the expansion of the brain over many generations of human reproduction.

Professor Robin Dunbar, who previously proposed the social brain hypothesis, said: “According to the social brain hypothesis, the disproportionately large brain size in humans exists as a consequence of humans evolving in large and complex social groups.

“Our new research reinforces this hypothesis and offers an insight into the way cooperation and reward may have been instrumental in driving brain evolution, suggesting that the challenge of assessing others could have contributed to the large brain size in humans.”

According to the team, the research could also have future implications in engineering, specifically where intelligent and autonomous machines need to decide how generous they should be towards each other during one-off interactions.

“The models we use can be executed as short algorithms called heuristics, allowing devices to make quick decisions about their cooperative behaviour,” Professor Whitaker said.

“New autonomous technologies, such as distributed wireless networks or driverless cars, will need to self-manage their behaviour but at the same time cooperate with others in their environment.”

Journal Reference:

  1. Roger M. Whitaker, Gualtiero B. Colombo, Stuart M. Allen, Robin I. M. Dunbar. A Dominant Social Comparison Heuristic Unites Alternative Mechanisms for the Evolution of Indirect ReciprocityScientific Reports, 2016; 6: 31459 DOI: 10.1038/srep31459

Is human behavior controlled by our genes? Richard Levins reviews ‘The Social Conquest of Earth’ (Climate & Capitalism)

“Failing to take class division into account is not simply a political bias. It also distorts how we look at human evolution as intrinsically bio-social and human biology as socialized biology.”


August 1, 2012

Edward O. Wilson. The Social Conquest of Earth. Liverwright Publishing, New York, 2012

reviewed by Richard Levins

In the 1970s, Edward O. Wilson, Richard Lewontin, Stephen Jay Gould and I were colleagues in Harvard’s new department of Organismic and Evolutionary Biology. In spite of our later divergences, I retain grateful memories of working in the field with Ed, turning over rocks, sharing beer, breaking open twigs, putting out bait (canned tuna fish) to attract the ants we were studying..

We were part of a group that hoped to jointly write and publish articles offering a common view of evolutionary science, but that collaboration was brief, largely because Lewontin and I strongly disagreed with Wilson’s Sociobiology.

Reductionism and Sociobiology

Although Wilson fought hard against the reduction of biology to the study of molecules, his holism stopped there. He came to promote the reduction of social and behavioral science to biology. In his view:

“Our lives are restrained by two laws of biology: all of life’s entities and processes are obedient to the laws of physics and chemistry; and all of life’s entities and processes have arisen through evolution and natural selection.” [Social Conquest, p. 287]

This is true as far as it goes but fails in two important ways.

First, it ignores the reciprocal feedback between levels. The biological creates the ensemble of molecules in the cell; the social alters the spectrum of molecules in the biosphere; biological activity creates the biosphere itself and the conditions for the maintenance of life.

Second, it doesn’t consider how the social level alters the biological: our biology is a socialized biology.

Higher (more inclusive) levels are indeed constrained by the laws at lower levels of organization, but they also have their own laws that emerge from the lower level yet are distinct and that also determine which chemical and physical entities are present in the organisms. In new contexts they operate differently.

Thus for example we, like a few other animals including bears, are omnivores. For some purposes such as comparing digestive systems that’s an adequate label. But we are omnivores of a special kind: we not only acquire food by predation, but we also producefood, turning the inedible into edible, the transitory into stored food. This has had such a profound effect on our lives that it is also legitimate to refer to us as something new, productivores.

The productivore mode of sustenance opens a whole new domain: the mode of production. Human societies have experienced different modes of production and ways to organize reproduction, each with its own dynamics, relations with the rest of nature, division into classes, and processes which restore or change it when it is disturbed.

The division of society into classes changes how natural selection works, who is exposed to what diseases, who eats and who doesn’t eat, who does the dishes, who must do physical work, how long we can expect to live. It is no longer possible to prescribe the direction of natural selection for the whole species.

So failing to take class division into account is not simply a political bias. It also distorts how we look at human evolution as intrinsically bio-social and human biology as socialized biology.

The opposite of the genetic determinism of sociobiology is not “the blank slate” view that claims that our biological natures were irrelevant to behavior and society. The question is, what about our animal heritage was relevant?

We all agree that we are animals; that as animals we need food; that we are terrestrial rather than aquatic animals; that we are mammals and therefore need a lot of food to support our high metabolic rates that maintain body temperature; that for part of our history we lived in trees and acquired characteristics adapted to that habitat, but came down from the trees with a dependence on vision, hands with padded fingers, and so on. We have big brains, with regions that have different major functions such as emotions, color vision, and language.

But beyond these general capacities, there is widespread disagreement about which behaviors or attitudes are expressions of brain structure. The amygdala is a locus of emotion, but does it tell us what to be angry or rejoice about? It is an ancient part of our brains, but has it not evolved in response to what the rest of the brain is doing? There is higher intellectual function in the cortex, but does it tell us what to think about?

Every part of an organism is the environment for the rest of the organism, setting the context for natural selection. In contrast to this fluid viewpoint, phrases such as “hard-wired” have become part of the pop vocabulary, applied promiscuously to all sorts of behaviors.

In a deeper sense, asking if something is heritable is a nonsense question. Heritability is always a comparison: how much of the difference between humans and chimps is heritable? What about the differences between ourselves and Neanderthals? Between nomads and farmers?

Social Conquest of Earth

The Social Conquest of Earth, Ed Wilson’s latest book, continues his interest in the “eusocial” animals – ants, bees and others that live in groups with overlapping generations and a division of labor that includes altruistic behavior. As the title shows. he also continues to use the terminology of conquest and domination, so that social animals “conquer” the earth, their abundance makes them “dominate.”

The problem that Wilson poses in this book is first, why did eusociality arise at all, and second, why is it so rare?

Wilson is at his best when discussing the more remote past, the origins of social behavior 220 million years ago for termites, 150 million years for ants, 70-80 million years for humble bees and honey bees.

But as he gets closer to humanity the reductionist biases that informed Sociobiology reassert themselves. Once again Wilson argues that brain architecture determines what people do socially – that war, aggression, morality, honor and hierarchy are part of “human nature.”

Rejecting kin selection

A major change, and one of the most satisfying parts of the book, is his rejection of kin selection as a motive force of social evolution, a theory he once defended strongly.

Kin selection assumed that natural selection acts on genes. A gene will be favored if it results in enhancing its own survival and reproduction, but it is not enough to look at the survival of the individual. If my brother and I each have 2 offspring, a shared gene would be doubled in the next generation. But if my brother sacrifices himself so that I might leave 5 offspring while he leaves none, our shared gene will increase 250%.

Therefore, argued the promoters of this theory, the fitness that natural selection increases has to be calculated over a whole set of kin, weighted by the closeness of their relationship. Mathematical formulations were developed to support this theory. Wilson found it attractive because it appeared to support sociobiology.

However, plausible inference is not enough to prove a theory. Empirical studies comparing different species or traits did not confirm the kin selection hypothesis, and a reexamination of its mathematical structure (such as the fuzziness of defining relatedness) showed that it could not account for the observed natural world. Wilson devotes a lot of space to refuting kin selection because of his previous support of it: it is a great example of scientific self-correction.

Does group selection explain social behaviour?

Wilson has now adopted another model in which the evolution of sociality is the result of opposing processes of ordinary individual selection acting within populations, and group selection acting between populations. He invokes this model account to for religion, morality, honor and other human behaviors.

He argues that individual selection promotes “selfishness” (that is, behavior that enhances individual survival) while group selection favors cooperative and “altruistic” behavior. The two forms of selection oppose each other, and that results in our mixed behaviors.

“We are an evolutionary chimera living on intelligence steered by the demands of animal instinct. This is the reason we are mindlessly dismantling the biosphere and with it, our own prospects for permanent existence.” [p.13]

But this simplistic reduction of environmental destruction to biology will not stand. Contrary to Wilson, the destruction of the biosphere is not “mindless.” It is the outcome of interactions in the noxious triad of greed, poverty, and ignorance, all produced by a socio-economic system that must expand to survive.

For Wilson, as for many environmentalists, the driver of ecological destruction is some generic “we,” who are all in the same boat. But since the emergence of classes after the adoption of agriculture some 8-10,000 years ago it is no longer appropriate to talk of a collective “we.”

The owners of the economy are willing to use up resources, pollute the environment, debase the quality of products, and undermine the health of the producers out of a kind of perverse economic rationality. They support their policies with theories such as climate change denial or doubting the toxicity of pesticides, and buttress it with legislation and court decisions.

Evolution and religion

The beginning and end of the book, a spirited critique of religion as possibly explaining human nature, is more straightforwardly materialist than the view supported by Stephen J. Gould, who argued that religion and science are separate magisteria that play equal roles in human wellbeing.

But Wilson’s use of evidence is selective.

For example, he argues that religion demands absolute belief from its followers – but this is true only of Christianity and Islam. Judaism lets you think what you want as long as you practice the prescribed rituals, Buddhism doesn’t care about deities or the afterlife.

Similarly he argues that creation myths are a product of evolution:

“Since paleolithic times … each tribe invented its own creation myths… No tribe could long survive without a creation myth… The creation myth is a Darwinian device for survival.” [p. 8]

But the ancient Israelites did not have an origin myth when they emerged as a people in the hills of Judea around 1250 B.C.E. Although it appears at the beginning of the Bible, the Israelites did not adapt the Book of Genesis from Babylonian mythology until four centuries after Deuteronomy was written, after they had survived 200 years as a tribal confederation, two kingdoms and the Assyrian and Babylonian conquests— by then the writing of scripture was a political act, not a “Darwinian device for survival.”

Biologizing war

In support of his biologizing of “traits,” Wilson reviews recent research that appears to a show a biological basis for the way people see and interpret color, for the incest taboo, and for the startle response – and then asserts that inherited traits include war, hierarchy, honor and such. Ignoring the role of social class, he views these as universal traits of human nature.

Consider war. Wilson claims that war reflects genes for group selection. “A soldier going into battle will benefit his country but he runs a higher risk of death than one who does not.” [p. 165]

But soldiers don’t initiate conflict. We know in our own times that those who decide to make war are not those who fight the wars – but, perhaps unfortunately, sterilizing the general staff of the Pentagon and of the CIA would not produce a more peaceful America.

The evidence against war as a biological imperative is strong. Willingness to fight is situational.

Group selection can’t explain why soldiers have to be coerced into fighting, why desertion is a major problem for generals and is severely punished, or why resistance to recruitment is a major problem of armies. In the present militarist USA, soldiers are driven to join up through unemployment and the promises of benefits such as learning skills and getting an education and self-improvement. No recruitment posters offer the opportunity to kill people as an inducement for signing up.

The high rates of surrender and desertion of Italian soldiers in World War II did not reflect any innate cowardice among Italians but a lack of fascist conviction. The very rarity of surrender by Japanese soldiers in the same war was not a testimony to greater bravery on the part of the Japanese but of the inculcated combination of nationalism and religion.

As the American people turned against the Vietnam war, increased desertions and the killing of officers by the soldiers reflected their rejection of the war.

The terrifying assaults of the Vikings during the middle ages bear no resemblance to the mellow Scandinavian culture of today, too short a time for natural selection to transform national character.

The attempt to make war an inherited trait favored by natural selection reflects the sexism that has been endemic in sociobiology. It assumes that local groups differed in their propensity for aggression and prowess in war. The victorious men carry off the women of the conquered settlements and incorporate them into their own communities. Therefore the new generation has been selected for greater military success among the men. But the women, coming from a defeated, weaker group, would bring with them their genes for lack of prowess, a selection for military weakness! Such a selection process would be self-negating.


Wilson also considers ethnocentrism to be an inherited trait: group selection leads people to favor members of their own group and reject outsiders.

The problem is that the lines between groups vary under different circumstances. For example, in Spanish America, laws governing marriage included a large number of graded racial categories, while in North America there were usually just two. What’s more, the category definitions are far from permanent: at one time, the Irish were regarded as Black, and the whiteness of Jews was questioned.

Adoption, immigration, mergers of clans also confound any possible genetic basis for exclusion.


Wilson draws on the work of Herbert Simon to argue that hierarchy is a result of human nature: there will always be rulers and ruled. His argument fails to distinguish between hierarchy and leadership.

There are other forms of organization possible besides hierarchy and chaos, including democratic control by the workers who elect the operational leadership. In some labor unions, leaders’ salaries are pegged to the median wage of the members. In University departments the chairmanship is often a rotating task that nobody really wants. When Argentine factory owners closed their plants during the recession, workers in fact seized control and ran them profitably despite police sieges.

Darwinian behavior?

Wilson argues that “social traits” evolved through Darwinian natural selection. Genes that promoted behaviors that helped the individual or group to survive were passed on; genes that weakened the individual or group were not. The tension between individual and group selection decided which traits would be part of our human nature.

But a plausible claim that a trait might be good for people is not enough to explain its origin and survival. A gene may become fixed in a population even if it is harmful, just by the random genetic changes that we know occur. Or a gene may be harmful but be dragged along by an advantageous gene close to it on the same chromosome.

Selection may act in different directions in different subpopulations, or in different habitats, or in differing environmental. Or the adaptive value of a gene may change with its prevalence or the distribution of ages in the population, itself a consequence of the environment and population heterogeneity.

For instance, Afro-Americans have a higher death rate from cancer than Euro-Americans. In part this reflects the carcinogenic environments they have been subjected to, but there is also a genetic factor. It is the combination of living conditions and genetics that causes higher mortality rates.

* * *

Obviously I am not arguing that evolution doesn’t happen. The point is that we need a much better argument than just a claim that some genotype might be beneficial. And we need a much more rigorous understanding of the differences and linkages between the biological and social components of humanity’s nature. Just calling some social behavior a “trait” does not make it heritable.

In a book that attempts such a wide-ranging panorama of human evolution, there are bound to be errors. But the errors in The Social Conquest of Earth form a pattern: they reduce social issues to biology, and they insist on our evolutionary continuity with other animals while ignoring the radical discontinuity that made us productivores and divided us into classes.

The surprising links between faith and evolution and climate denial — charted (The Washington Post)

 May 20, 2015

For a long time, we’ve been having a pretty confused discussion about the relationship between religious beliefs and the rejection of science — and especially its two most prominent U.S. incarnations, evolution denial and climate change denial.

At one extreme is the position that science denial is somehow deeply or fundamentally religion’s fault. But this neglects the wide diversity of views about science across faiths and denominations — and even across individuals of the same faith or denomination — not all of which are anti-climate science, or anti-evolution.

At the other extreme, meanwhile, is the view that religion has no conflict with science at all. But that can’t be right either: Though the conflict between the two may not be fundamental or necessary in all cases, it is pretty clear that the main motive for evolution denial is, indeed, a perceived conflict with faith (not to mention various aspects of human cognition that just make accepting evolution very hard for many people).

The main driver of climate science rejection, however, appears to be a free market ideology — which is tough to characterize as religious in nature. Nonetheless, it has often been observed (including by me) that evolution denial and climate science rejection often seem to overlap, at least to an extent.

[Pope Francis has given the climate movement just what it needed: faith]

And there does seem to be at least some tie between faith and climate science doubt. Research by Yale’s Dan Kahan, for instance, found a modest correlation between religiosity and less worry about climate change. Meanwhile, a 2013 study in Political Science Quarterly found that “believers in Christian end-times theology are less likely to support policies designed to curb global warming than are other Americans.”

So how do we make sense of this complex brew?

Josh Rosenau, an evolutionary biologist who works for the National Center for Science Education — which champions both evolutionary science and climate science teaching in schools — has just created a chart that, no matter what you think of the relationship between science and religion, will give you plenty to talk about.

Crunching data from the 2007 incarnation of a massive Pew survey of American religious beliefs, Rosenau plotted different U.S. faiths and denominations based on their members’ views about both the reality of specifically human evolution, and also how much they favor “stricter environmental laws and regulations.” And this was the result (click to enlarge):

As Rosenau notes, in the figure above, “The circle sizes are scaled so that their areas are in proportion to the relative population sizes in Pew’s massive sample (nearly 36,000 people!).” And as you can see, while at the top right atheists, agnostics, Buddhists, non-Orthodox Jews and others strongly accept evolution and environmental rules, at the bottom left Southern Baptists, Pentecostals and other more conservative leaning faiths are just as skeptical of both.

Obviously, it is important to emphasize that a given individual, of any faith, could be anywhere on the chart above — it’s just that this is where the denominations as a whole seemed to fall out, based on Rosenau’s analysis (which itself mirrors prior analyses of the political alignments of U.S. faiths and denominations by political scientist and Religion News Service blogger Tobin Grant).

Reached by phone Tuesday, Rosenau (whom I’ve known for a long time from the community of bloggers about science and the environment) seemed to be still trying to fully understand the implications of the figure he’d created. “People seemed to like it,” he said. “I think some people are finding hope in it” — hope, specifically, that there is a way out of seemingly unending science versus religion spats.

Here are some of Rosenau’s other conclusions from the exercise, from his blog post introducing the chart:

First, look at all those groups whose members support evolution. There are way more of them than there are of the creationist groups, and those circles are bigger. We need to get more of the pro-evolution religious out of the closet.

Second, look at all those religious groups whose members support climate change action. Catholics fall a bit below the zero line on average, but I have to suspect that the forthcoming papal encyclical on the environment will shake that up.

[Our new pro-science pontiff: Pope Francis on climate change, evolution, and the Big Bang]

Rosenau also remarks on the striking fact that for the large bulk of religions and religious denominations, as support for evolution increases, so does support for tougher environmental rules (and vice versa). The two appear to be closely related.

So what can that mean?

Rosenau told me he was still trying to work that out — still playing with the data and new analyses to try to understand it.

One possible way of interpreting the figure is that as with political parties themselves, people at least partially self-sort into faiths or denominations that seem more consonant with their own worldviews. And thus, a cluster of issue stances may travel alongside these choices of affiliation. “People are choosing what religion they want to associate with,” suggested Rosenau. “If people feel alienated from a church, they’re switching.”

There may also be a substantive point here that links together the ideas. A view of the world that thinks of human beings as having evolved, as being part of the natural world and having emerged through the same process as other organisms, may also be related to a manner of thinking that puts great overall emphasis on the value of nature and one’s connectedness with it.

In any case, while the pattern above may require more analysis, one clear punchline of the figure is that it really doesn’t make sense to say that religion is at war with science. You can say that for some people, religion is clearly linked to less science acceptance — especially on evolution. But for others, clearly, religion presents no hurdle at all.

I would also agree that these data reinforce the idea that the pope’s coming encyclical on the environment could really shake matters up. Catholics are the biggest bubble in the chart above, and they’re right in the middle of the pack on the environment.

The pope, incidentally, also appears to accept evolution.

Chimpanzés caçadores dão pistas sobre os primeiros humanos (El País)

Primatas que usam lanças podem fornecer indícios sobre origem das sociedades humanas

 12 MAY 2015 – 18:14 BRT

Um velho chimpanzé bebe água em um lago, em Fongoli, no Senegal. / FRANS LANTING

Na quente savana senegalesa se encontra o único grupo de chimpanzés que usa lanças para caçar animais com os quais se alimenta. Um ou outro grupo de chimpanzés foi visto portando ferramentas para a captura de pequenos mamíferos, mas esses, na comunidade de Fongoli, caçam regularmente usando ramos afiados. Esse modo de conseguir alimento é um uso cultural consolidado para esse grupo de chimpanzés.

Além dessa inovação tecnológica, em Fongoli ocorre também uma novidade social que os distingue dos demais chimpanzés estudados na África: há mais tolerância, maior paridade dos sexos na caça e os machos mais corpulentos não passam com tanta frequência por cima dos interesses dos demais, valendo-se de sua força. Para os pesquisadores que vêm observando esse comportamento há uma década esses usos poderiam, além disso, oferecer pistas sobre a evolução dos ancestrais humanos.

“São a única população não humana conhecida que caça vertebrados com ferramentas de forma sistemática, por isso constituem uma fonte importante para a hipótese sobre o comportamento dos primeiros hominídeos, com base na analogia”, explicam os pesquisadores do estudo no qual formularam suas conclusões depois de dez anos observando as caçadas de Fongoli. Esse grupo, liderado pela antropóloga Jill Pruetz, considera que esses animais são um bom exemplo do que pode ser a origem dos primeiros primatas eretos sobre duas patas.

Os machos mais fortes dessa comunidade respeitam as fêmeas na caça

Na sociedade Fongoli as fêmeas realizam exatamente a metade das caçadas com lança. Graças à inovação tecnológica que representa a conversão de galhos em pequenas lanças com as quais se ajudam para caçar galagos – pequenos macacos muito comuns nesse entorno –, as fêmeas conseguem certa independência alimentar. Na comunidade de Gombe, que durante muitos anos foi estudada por Jane Goodall, os machos arcam com cerca de 90% do total das presas; em Fongoli, somente 70%. Além disso, em outros grupos de chimpanzés os machos mais fortes roubam uma de cada quatro presas caçadas pelas fêmeas (sem ferramentas): em Fongoli, apenas 5%.

Uma fêmea de chimpanzé apanha e examina um galho que usará para capturar sua presa. / J. PRUETZ

“Em Fongoli, quando uma fêmea ou um macho de baixo escalão captura uma presa, permitem que ele fique com ela e a coma. Em outros lugares, o macho alfa ou outro macho dominante costuma tomar-lhe a presa. Assim, as fêmeas obtêm pouco benefício da caça, se outro chimpanzé lhe tira sua presa”, afirma Pruetz. Ou seja, o respeito dos machos de Fongoli pelas presas obtidas por suas companheiras serviria de incentivo para que elas se decidam a ir à caça com mais frequência do que as de outras comunidades. Durante esses anos de observação, praticamente todos os chimpanzés do grupo – cerca de 30 indivíduos – caçaram com ferramentas,

O clima seco faz com que os macacos mais acessíveis em Fongoli sejam os pequenos galagos, e não os colobos vermelhos – os preferidos dos chimpanzés em outros lugares da África –, que são maiores e difíceis de capturar por outros que não sejam os machos mais rápidos e corpulentos. Quase todos os episódios de caça com lanças observados (três centenas) se deram nos meses úmidos, nos quais outras fontes de alimento são escassas.

A savana senegalesa, com poucas árvores, é um ecossistema que tem uma importante semelhança com o cenário em que evoluíram os ancestrais humanos. Ao contrário de outras comunidades africanas, os chimpanzés de Fongoli passam a maior parte do tempo no chão, e não entre os galhos. A excepcional forma de caça de Fongoli leva os pesquisadores a sugerir em seu estudo que os primeiros hominídeos provavelmente intensificaram o uso de ferramentas tecnológicas para superar as pressões ambientais, e que eram até mesmo “suficientemente sofisticados a ponto de aperfeiçoar ferramentas de caça”.

“Sabemos que o entorno tem um impacto importante no comportamento dos chimpanzés”, afirma o primatólogo Joseph Call, do Instituto Max Planck. “A distribuição das árvores determina o tipo de caça: onde a vegetação é mais frondosa, a caçada é mais cooperativa em relação a outros entornos nos quais é mais fácil seguir a presa, e eles são mais individualistas”, assinala Call.

No entanto, Call põe em dúvida que essas práticas de Fongoli possam ser consideradas caçadas com lança propriamente ditas, já que para ele lembram mais a captura de formigas e cupins usando palitos, algo mais comum entre os primatas. “A definição de caça que os pesquisadores estabelecem em seu estudo não se distingue muito do que fazem colocando um raminho em um orifício para conseguir insetos para comer”, diz Call. Os chimpanzés de Fongoli cutucam com paus os galagos quando eles se escondem em cavidades das árvores para forçá-los a sair e, uma vez fora, lhes arrancam a cabeça com uma mordida. “É algo que fica entre uma coisa e a outra”, argumenta.

Esses antropólogos acreditam que o achado permite pensar que os primeiros hominídeos eretos também usavam lanças

Pruetz responde a esse tipo de crítica dizendo que se trata de uma estratégia para evitar que o macaco os morda ou escape, uma situação muito diferente daquela de colocar um galho em um orifício para capturar bichos. Se for o mesmo, argumentam Pruetz e seus colegas, a pergunta é “por que os chimpanzés de outros grupos não caçam mais”.

Além do caso particular, nem sequer está encerrado o debate sobre se os chimpanzés devem ser considerados modelos do que foram os ancestrais humanos. “Temos de levar em conta que o bonobo não faz nada disso e é tão próximo de nós como o chimpanzé”, defende Call. “Pegamos o chimpanzé por que nos cai bem para assinalar determinadas influências comuns. É preciso ter muito cuidado e não pesquisar a espécie dependendo do que queiramos encontrar”, propõe.