Arquivo da tag: Evolucionismo

Computer Scientists Suggest New Spin On Origins of Evolvability: Competition to Survive Not Necessary? (Science Daily)

27/04/2013Uncategorizedciência, Computação, Evolução, Evolucionismo, Mediação tecnológicarenzotaddei

Apr. 26, 2013 — Scientists have long observed that species seem to have become increasingly capable of evolving in response to changes in the environment. But computer science researchers now say that the popular explanation of competition to survive in nature may not actually be necessary for evolvability to increase.

The average evolvability of organisms in each niche at the end of a simulation is shown. The lighter the color, the more evolvable individuals are within that niche. The overall result is that, as in the first model, evolvability increases with increasing distance from the starting niche in the center. (Credit: Joel Lehman, Kenneth O. Stanley. Evolvability Is Inevitable: Increasing Evolvability without the Pressure to Adapt. PLoS ONE, 2013; 8 (4): e62186 DOI: 10.1371/journal.pone.0062186)

In a paper published this week inPLOS ONE, the researchers report that evolvability can increase over generations regardless of whether species are competing for food, habitat or other factors.

Using a simulated model they designed to mimic how organisms evolve, the researchers saw increasing evolvability even without competitive pressure.

“The explanation is that evolvable organisms separate themselves naturally from less evolvable organisms over time simply by becoming increasingly diverse,” said Kenneth O. Stanley, an associate professor at the College of Engineering and Computer Science at the University of Central Florida. He co-wrote the paper about the study along with lead author Joel Lehman, a post-doctoral researcher at the University of Texas at Austin.

The finding could have implications for the origins of evolvability in many species.

“When new species appear in the future, they are most likely descendants of those that were evolvable in the past,” Lehman said. “The result is that evolvable species accumulate over time even without selective pressure.”

During the simulations, the team’s simulated organisms became more evolvable without any pressure from other organisms out-competing them. The simulations were based on a conceptual algorithm.

“The algorithms used for the simulations are abstractly based on how organisms are evolved, but not on any particular real-life organism,” explained Lehman.

The team’s hypothesis is unique and is in contrast to most popular theories for why evolvability increases.

“An important implication of this result is that traditional selective and adaptive explanations for phenomena such as increasing evolvability deserve more scrutiny and may turn out unnecessary in some cases,” Stanley said.

Stanley is an associate professor at UCF. He has a bachelor’s of science in engineering from the University of Pennsylvania and a doctorate in computer science from the University of Texas at Austin. He serves on the editorial boards of several journals. He has over 70 publications in competitive venues and has secured grants worth more than $1 million. His works in artificial intelligence and evolutionary computation have been cited more than 4,000 times.

Journal Reference:

Joel Lehman, Kenneth O. Stanley. Evolvability Is Inevitable: Increasing Evolvability without the Pressure to Adapt. PLoS ONE, 2013; 8 (4): e62186 DOI:10.1371/journal.pone.0062186

The Ethics of Resurrecting Extinct Species (Science Daily)

13/04/2013UncategorizedÉtica, Engenharia genética, Evolução, Evolucionismo, Extinção, Genéticarenzotaddei

Apr. 8, 2013 — At some point, scientists may be able to bring back extinct animals, and perhaps early humans, raising questions of ethics and environmental disruption.

Within a few decades, scientists may be able to bring back the dodo bird from extinction, a possibility that raises a host of ethical questions, says Stanford law Professor Hank Greely. (Credit: Frederick William Frohawk/Public domain image)

Within a few decades, scientists may be able to bring back the dodo bird from extinction, a possibility that raises a host of ethical questions, says Stanford law Professor Hank Greely.

Twenty years after the release ofJurassic Park, the dream of bringing back the dinosaurs remains science fiction. But scientists predict that within 15 years they will be able to revive some more recently extinct species, such as the dodo or the passenger pigeon, raising the question of whether or not they should — just because they can.

In the April 5 issue of Science, Stanford law Professor Hank Greely identifies the ethical landmines of this new concept of de-extinction.

“I view this piece as the first framing of the issues,” said Greely, director of the Stanford Center for Law and the Biosciences. “I don’t think it’s the end of the story, rather I think it’s the start of a discussion about how we should deal with de-extinction.”

In “What If Extinction Is Not Forever?” Greely lays out potential benefits of de-extinction, from creating new scientific knowledge to restoring lost ecosystems. But the biggest benefit, Greely believes, is the “wonder” factor.

“It would certainly be cool to see a living saber-toothed cat,” Greely said. “‘Wonder’ may not seem like a substantive benefit, but a lot of science — such as the Mars rover — is done because of it.”

Greely became interested in the ethics of de-extinction in 1999 when one of his students wrote a paper on the implications of bringing back wooly mammoths.

“He didn’t have his science right — which wasn’t his fault because approaches on how to do this have changed in the last 13 years — but it made me realize this was a really interesting topic,” Greely said.

Scientists are currently working on three different approaches to restore lost plants and animals. In cloning, scientists use genetic material from the extinct species to create an exact modern copy. Selective breeding tries to give a closely-related modern species the characteristics of its extinct relative. With genetic engineering, the DNA of a modern species is edited until it closely matches the extinct species.

All of these techniques would bring back only the physical animal or plant.

“If we bring the passenger pigeon back, there’s no reason to believe it will act the same way as it did in 1850,” said co-author Jacob Sherkow, a fellow at the Stanford Center for Law and the Biosciences. “Many traits are culturally learned. Migration patterns change when not taught from generation to generation.”

Many newly revived species could cause unexpected problems if brought into the modern world. A reintroduced species could become a carrier for a deadly disease or an unintentional threat to a nearby ecosystem, Greely says.

“It’s a little odd to consider these things ‘alien’ species because they were here before we were,” he said. “But the ‘here’ they were in is very different than it is now. They could turn out to be pests in this new environment.”

When asked whether government policies are keeping up with the new threat, Greely answers “no.”

“But that’s neither surprising nor particularly concerning,” he said. “It will be a while before any revised species is going to be present and able to be released into the environment.”

Greely and Sherkow recommend that the government leave de-extinction research to private companies and focus on drafting new regulations. Sherkow says the biggest legal and ethical challenge of de-extinction concerns our own long-lost ancestors.

“Bringing back a hominid raises the question, ‘Is it a person?’ If we bring back a mammoth or pigeon, there’s a very good existing ethical and legal framework for how to treat research animals. We don’t have very good ethical considerations of creating and keeping a person in a lab,” said Sherkow. “That’s a far cry from the type of de-extinction programs going on now, but it highlights the slippery slope problem that ethicists are famous for considering.”

Journal Reference:

J. S. Sherkow, H. T. Greely. What If Extinction Is Not Forever? Science, 2013; 340 (6128): 32 DOI:10.1126/science.1236965

Something Other Than Adaptation Could Be Driving Evolution (Wired)

01/04/2013UncategorizedAnimais, ciência, Darwinismo, Evolucionismorenzotaddei

BY BRANDON KEIM

03.28.13

A computational model of greenish warbler evolution (left) fits real-world patterns of the species (right). Color corresponds to degrees of genetic difference. Image: Martins et al./PNAS

What explains the incredible variety of life on Earth? It seems obvious. Evolution, of course! But perhaps not the evolution most people grew up with.

Some ecologists say the theory needs an update. They’ve proposed a new dynamic driving the emergence of new species, one that doesn’t involve adaptations or survival of the fittest.

Give evolution enough time and space, they say, and new species can just happen. Speciation might not only be an evolutionary consequence of fitness differences and natural selection, but a property intrinsic to evolution, just as all matter has gravity.

“Our work shows that evolution wants to be diverse,” said Yaneer Bar-Yam, president of the New England Complex Systems Institute. “It’s enough for organisms to be spread out in space and time.”

In a March 13 Proceedings of the National Academy of Sciences paper, Bar-Yam and his co-authors, Brazilian ecologists Ayana Martins at the University of Sao Paulo and Marcus Aguiar at the University of Campinas, modeled the evolution of greenish warblers living around the Tibetan plateau.

The warblers are what’s known as a ring species, a rare phenomenon that occurs when species inhabit a horseshoe-shaped range. Genes flow around the ring, passing between neighboring populations — yet at the ring’s tips, the animals no longer interbreed with one another.

By the usual standards, these end populations have become new species. According to the researchers’ model of the process, no special adaptations or differences in reproductive fitness are needed to explain — or at least to computationally replicate — the greenish warblers’ divergence.

‘An alternative hypothesis to adaptation and selection of new species.’

“This sounds kind of crazy, right? We normally think of species as being adapted for particular functions. They have their own role to play in a community. That’s the standard wisdom,” said theoretical ecologist James O’Dwyer of the Santa Fe Institute, who was not involved in the study.

Instead, over 2,000 modeled generations, a time frame that fits with the 10,000 years that greenish warblers have ringed the Tibetan plateau’s slopes since their exposure by retreating glaciers, random genetic mutations drifted through the birds’ populations, ultimately clustering in diversity patterns resembling what’s seen in reality.

Adaptation and natural selection certainly played a part in the warblers’ evolution, said Bar-Yam, but they weren’t necessarily the driving forces. And though geography is involved, it’s very different from the population-isolating physical separation created by mountain ranges or islands.

“The plateau plays an important role in the formation of the ring species, but it does not block gene flow,” said Aguiar. “No barriers and no specific selection processes are required.” Rather than adaptation, distance is the driver.

That notion falls under the umbrella of neutral biodiversity theory, a dry-sounding name for a dramatic challenge to the notion that adaptation is biological diversity’s wellspring. First articulated by University of California, Los Angeles ecologist Stephen Hubbell, who in 2001 published The Unified Neutral Theory of Biodiversity and Biogeography, it’s a challenge occasioned by the surprising difficulty of explaining biodiversity, or why life is arranged the way it is.

Neutral biodiversity doesn’t reject the usual evolutionary drivers of adaptation and geographic isolation, which are clearly at work in shaping species traits and generating diversity. But these drivers don’t seem to explain many big-picture patterns. It’s not just ring species that are perplexing. Tropical forests, which originally inspired Hubbell’s theory, seemingly have far more species than there are niches to adaptively inhabit. Common patterns of species distribution also occur in disparate places, such as rain forests and coral reefs. The usual evolutionary models didn’t fit these phenomena.

A greenish warbler in Taibai Shan, China. Image: Ron Knight/Flickr

Some under-appreciated forces seemed to be operating, which Hubbell identified as neutral genetic drift: the flow, at landscape-level scales, of random genetic variations that emerge in individuals and spread through populations, but are ‘neutral,’ having no biological function.

That most mutations are neutral isn’t a new idea. It was first proposed in the late 1960s by Japanese geneticist Mootoo Kimura, and is an established dynamic in population genetics. That it might actually drive diversity on its own, though, accounting for substantial differences between species, was new.

How exactly this might work and how important it could be has been hotly debated ever since, at least in ecological circles. Some ecologists reject the idea altogether. Other researchers, including Bar-Yam’s group, have built on Hubbell’s original ideas.

Their work “offers an alternative hypothesis to adaptation and selection of new species,” said O’Dwyer, but he warned that it’s hard to tell whether neutral processes really occur. Computational models of neutral biodiversity often seem to predict real-world patterns, as with the greenish warblers, but that doesn’t mean they’re right.

Datasets necessary to test neutral explanations need to span hundreds if not thousands of years, and should encompass not just a few species but entire ecosystems, said O’Dwyer. He thinks some combination of neutral and non-neutral processes likely shape biodiversity, and teasing their contributions apart will be difficult.

Ecologist Rampal Etienne of the University of Groningen, whose own research suggests that sexual reproduction makes evolution speed up, echoed O’Dwyer’s point. “The major question is what data will be able to distinguish neutral from non-neutral explanations,” said Etienne, who cautioned against jumping to conclusions with Bar-Yam’s model.

Like any model, it’s based on assumptions and only imperfectly imitates reality, he said. Its more fundamental value, as with other work on neutral biodiversity, is that it critically examines whether adaptation really explains the natural world’s richness.

In other words, the theory of evolution is still evolving.

Citation: “Evolution and stability of ring species.” By Ayana B. Martins, Marcus A. M. de Aguiar and Yaneer Bar-Yam. Proceedings of the National Academy of Sciences, March 11, 2013.

Update 3/28: Text modified to emphasize that neutral biodiversity theory does not exclude ‘traditional’ evolutionary mechanisms, but would be an addition to them.

Edward O. Wilson: The Riddle of the Human Species (N.Y.Times)

27/02/2013UncategorizedAntropologia, Biologia, ciência, discurso ambiental, Ecologia, Evolução, Evolucionismo, Formigas, Política, Socialidade animal, Sociobiologiarenzotaddei

THE STONEFebruary 24, 2013, 7:30 pm

By EDWARD O. WILSON

The task of understanding humanity is too important and too daunting to leave to the humanities. Their many branches, from philosophy to law to history and the creative arts, have described the particularities of human nature with genius and exquisite detail, back and forth in endless permutations. But they have not explained why we possess our special nature and not some other out of a vast number of conceivable possibilities. In that sense, the humanities have not accounted for a full understanding of our species’ existence.

So, just what are we? The key to the great riddle lies in the circumstance and process that created our species. The human condition is a product of history, not just the six millenniums of civilization but very much further back, across hundreds of millenniums. The whole of it, biological and cultural evolution, in seamless unity, must be explored for an answer to the mystery. When thus viewed across its entire traverse, the history of humanity also becomes the key to learning how and why our species survived.

A majority of people prefer to interpret history as the unfolding of a supernatural design, to whose author we owe obedience. But that comforting interpretation has grown less supportable as knowledge of the real world has expanded. Scientific knowledge (measured by numbers of scientists and scientific journals) in particular has been doubling every 10 to 20 years for over a century. In traditional explanations of the past, religious creation stories have been blended with the humanities to attribute meaning to our species’s existence. It is time to consider what science might give to the humanities and the humanities to science in a common search for a more solidly grounded answer to the great riddle.

To begin, biologists have found that the biological origin of advanced social behavior in humans was similar to that occurring elsewhere in the animal kingdom. Using comparative studies of thousands of animal species, from insects to mammals, they have concluded that the most complex societies have arisen through eusociality — roughly, “true” social condition. The members of a eusocial group cooperatively rear the young across multiple generations. They also divide labor through the surrender by some members of at least some of their personal reproduction in a way that increases the “reproductive success” (lifetime reproduction) of other members.

Leif Parsons

Eusociality stands out as an oddity in a couple of ways. One is its extreme rarity. Out of hundreds of thousands of evolving lines of animals on the land during the past 400 million years, the condition, so far as we can determine, has arisen only about two dozen times. This is likely to be an underestimate, due to sampling error. Nevertheless, we can be certain that the number of originations was very small.

Furthermore, the known eusocial species arose very late in the history of life. It appears to have occurred not at all during the great Paleozoic diversification of insects, 350 to 250 million years before the present, during which the variety of insects approached that of today. Nor is there as yet any evidence of eusocial species during the Mesozoic Era until the appearance of the earliest termites and ants between 200 and 150 million years ago. Humans at the Homo level appeared only very recently, following tens of millions of years of evolution among the primates.

Once attained, advanced social behavior at the eusocial grade has proved a major ecological success. Of the two dozen independent lines, just two within the insects — ants and termites — globally dominate invertebrates on the land. Although they are represented by fewer than 20 thousand of the million known living insect species, ants and termites compose more than half of the world’s insect body weight.

The history of eusociality raises a question: given the enormous advantage it confers, why was this advanced form of social behavior so rare and long delayed? The answer appears to be the special sequence of preliminary evolutionary changes that must occur before the final step to eusociality can be taken. In all of the eusocial species analyzed to date, the final step before eusociality is the construction of a protected nest, from which foraging trips begin and within which the young are raised to maturity. The original nest builders can be a lone female, a mated pair, or a small and weakly organized group. When this final preliminary step is attained, all that is needed to create a eusocial colony is for the parents and offspring to stay at the nest and cooperate in raising additional generations of young. Such primitive assemblages then divide easily into risk-prone foragers and risk-averse parents and nurses.

Leif Parsons

What brought one primate line to the rare level of eusociality? Paleontologists have found that the circumstances were humble. In Africa about two million years ago, one species of the primarily vegetarian australopithecine evidently shifted its diet to include a much higher reliance on meat. For a group to harvest such a high-energy, widely dispersed source of food, it did not pay to roam about as a loosely organized pack of adults and young like present-day chimpanzees and bonobos. It was more efficient to occupy a campsite (thus, the nest) and send out hunters who could bring home meat, either killed or scavenged, to share with others. In exchange, the hunters received protection of the campsite and their own young offspring kept there.

From studies of modern humans, including hunter-gatherers, whose lives tell us so much about human origins, social psychologists have deduced the mental growth that began with hunting and campsites. A premium was placed on personal relationships geared to both competition and cooperation among the members. The process was ceaselessly dynamic and demanding. It far exceeded in intensity anything similar experienced by the roaming, loosely organized bands of most animal societies. It required a memory good enough to assess the intentions of fellow members, to predict their responses, from one moment to the next; and it resulted in the ability to invent and inwardly rehearse competing scenarios of future interactions.

The social intelligence of the campsite-anchored prehumans evolved as a kind of non-stop game of chess. Today, at the terminus of this evolutionary process, our immense memory banks are smoothly activated across the past, present, and future. They allow us to evaluate the prospects and consequences variously of alliances, bonding, sexual contact, rivalries, domination, deception, loyalty and betrayal. We instinctively delight in the telling of countless stories about others as players upon the inner stage. The best of it is expressed in the creative arts, political theory, and other higher-level activities we have come to call the humanities.

The definitive part of the long creation story evidently began with the primitive Homo habilis (or a species closely related to it) two million years ago. Prior to the habilines the prehumans had been animals. Largely vegetarians, they had human-like bodies, but their cranial capacity remained chimpanzee-size, at or below 500 cubic centimeters. Starting with the habiline period the capacity grew precipitously: to 680 cubic centimeters in Homo habilis, 900 in Homo erectus, and about 1,400 in Homo sapiens. The expansion of the human brain was one of the most rapid episodes of evolution of complex organs in the history of life.

Still, to recognize the rare coming together of cooperating primates is not enough to account for the full potential of modern humans that brain capacity provides. Evolutionary biologists have searched for the grandmaster of advanced social evolution, the combination of forces and environmental circumstances that bestowed greater longevity and more successful reproduction on the possession of high social intelligence. At present there are two competing theories of the principal force. The first is kin selection: individuals favor collateral kin (relatives other than offspring) making it easier for altruism to evolve among members of the same group. Altruism in turn engenders complex social organization, and, in the one case that involves big mammals, human-level intelligence.

The second, more recently argued theory (full disclosure: I am one of the modern version’s authors), the grandmaster is multilevel selection. This formulation recognizes two levels at which natural selection operates: individual selection based on competition and cooperation among members of the same group, and group selection, which arises from competition and cooperation between groups. Multilevel selection is gaining in favor among evolutionary biologists because of a recent mathematical proof that kin selection can arise only under special conditions that demonstrably do not exist, and the better fit of multilevel selection to all of the two dozen known animal cases of eusocial evolution.

The roles of both individual and group selection are indelibly stamped (to borrow a phrase from Charles Darwin) upon our social behavior. As expected, we are intensely interested in the minutiae of behavior of those around us. Gossip is a prevailing subject of conversation, everywhere from hunter-gatherer campsites to royal courts. The mind is a kaleidoscopically shifting map of others, each of whom is drawn emotionally in shades of trust, love, hatred, suspicion, admiration, envy and sociability. We are compulsively driven to create and belong to groups, variously nested, overlapping or separate, and large or small. Almost all groups compete with those of similar kind in some manner or other. We tend to think of our own as superior, and we find our identity within them.

The existence of competition and conflict, the latter often violent, has been a hallmark of societies as far back as archaeological evidence is able to offer. These and other traits we call human nature are so deeply resident in our emotions and habits of thought as to seem just part of some greater nature, like the air we all breathe, and the molecular machinery that drives all of life. But they are not. Instead, they are among the idiosyncratic hereditary traits that define our species.

The major features of the biological origins of our species are coming into focus, and with this clarification the potential of a more fruitful contact between science and the humanities. The convergence between these two great branches of learning will matter hugely when enough people have thought it through. On the science side, genetics, the brain sciences, evolutionary biology, and paleontology will be seen in a different light. Students will be taught prehistory as well as conventional history, the whole presented as the living world’s greatest epic.

We will also, I believe, take a more serious look at our place in nature. Exalted we are indeed, risen to be the mind of the biosphere without a doubt, our spirits capable of awe and ever more breathtaking leaps of imagination. But we are still part of earth’s fauna and flora. We are bound to it by emotion, physiology, and not least, deep history. It is dangerous to think of this planet as a way station to a better world, or continue to convert it into a literal, human-engineered spaceship. Contrary to general opinion, demons and gods do not vie for our allegiance. We are self-made, independent, alone and fragile. Self-understanding is what counts for long-term survival, both for individuals and for the species.

Edward O. Wilson is Honorary Curator in Entomology and University Research Professor Emeritus, Harvard University. He has received more than 100 awards for his research and writing, including the U. S. National Medal of Science, the Crafoord Prize and two Pulitzer Prizes in non-fiction. His most recent book is “The Social Conquest of Earth.”

* * *

Interview with Edward O. Wilson: The Origin of Morals (Spiegel)

February 26, 2013 – 01:23 PM

By Philip Bethge and Johann Grolle

American sociobiologist Edward O. Wilson is championing a controversial new approach for explaining the origins of virtue and sin. In an interview, the world-famous ant reseacher explains why he believes the inner struggle is the characteristic trait of human nature.

Edward O. Wilson doesn’t come across as the kind of man who’s looking to pick a fight. With his shoulders upright and his head tilting slightly to the side, he shuffles through the halls of Harvard University. His right eye, which has given him trouble since his childhood, is halfway closed. The other is fixed on the ground. As an ant researcher, Wilson has made a career out of things that live on the earth’s surface.

There’s also much more to Wilson. Some consider him to be the world’s most important living biologist, with some placing him on a level with Charles Darwin.

In addition to discovering and describing hundreds of species of ants, Wilson’s book on this incomparably successful group of insects is the only non-fiction biology tome ever to win a Pulitzer Prize. Another achievement was decoding the chemical communication of ants, whose vocabulary is composed of pheromones. His study of the ant colonization of islands helped to establish one of the most fruitful branches of ecology. And when it comes to the battle against the loss of biodiversity, Wilson is one of the movement’s most eloquent voices.

‘Blessed with Brilliant Enemies’

But Wilson’s fame isn’t solely the product of his scientific achievements. His enemies have also helped him to establish a name. “I have been blessed with brilliant enemies,” he says. In fact, the multitude of scholars with whom Wilson has skirmished academically is illustrious. James Watson, one of the discoverers of the double helix in DNA is among them, as is essayist Stephen Jay Gould.

At 83 years of age, Wilson is still at work making a few new enemies. The latest source of uproar is a book, “The Social Conquest of Earth,” published last April in the United States and this month in a German-language edition. In the tome, Wilson attempts to describe the triumphal advance of humans in evolutionary terms.

It is not uncommon for Wilson to look to ants for inspiration in his writings — and that proves true here, as well. When, for example, he recalls beholding two 90-million-year-old worker ants that were trapped in a piece of fossil metasequoia amber as being “among the most exciting moments in my life,” a discovery that “ranked in scientific importance withArchaeopteryx, the first fossil intermediary between birds and dinosaurs, and Australopithecus, the first ‘missing link’ discovered between modern humans and the ancestral apes.”

But that’s all just foreplay to the real controversy at the book’s core. Ultimately, Wilson uses ants to explain humans’ social behavior and, by doing so, breaks with current convention. The key question is the level at which Darwinian selection of human characteristics takes place. Did individuals enter into a fight for survival against each other, or did groups battle it out against competing groups?

Prior to this book, Wilson had been an influential champion of the theory of kin selection. He has now rejected his previous teachings, literally demolishing them. “The beautiful theory never worked well anyway, and now it has collapsed,” he writes. Today, he argues that human nature can only be understood if it is perceived as being the product of “group selection” — a view that Wilson’s fellow academics equate with sacrilege. They literally lined up to express their scientific dissent in a joint letter.

Some of the most vociferous criticism has come from Richard Dawkins, whose bestselling 1976 book “The Selfish Gene” first introduced the theory of kin selection to a mass audience. In a withering review of Wilson’s book in Britain’s Prospect magazine, Dawkins accuses a man he describes as his “lifelong hero” of “wanton arrogance” and “perverse misunderstandings”. “To borrow from Dorothy Parker,” he writes, “this is not a book to be tossed lightly aside. It should be thrown with great force.”

SPIEGEL recently sat down with sociobiologist Wilson to discuss his book and the controversy surrounding it.

SPIEGEL: Professor Wilson, lets assume that 10 million years ago some alien spacecraft had landed on this planet. Which organisms would they find particularly intriguing?

Wilson: Their interest, I believe, would not have been our ancestors. Primarily, they would have focused on ants, bees, wasps, and termites. Their discovery is what the aliens would report back to headquarters.

SPIEGEL: And you think those insects would be more interesting to them than, for example, elephants, flocks of birds or intelligent primates?

Wilson: They would be, because, at that time, ants and termites would be the most abundant creatures on the land and the most highly social creatures with very advanced division of labor and caste. We call them “eusocial,” and this phenomenon seems to be extremely rare.

SPIEGEL: What else might the aliens consider particularly interesting about ants?

Wilson: Ants engage in farming and animal husbandry. For example, some of them cultivate fungi. Others herd aphids and literally milk them by stroking them with their antennae. And the other thing the aliens would find extremely interesting would be the degree to which these insects organize their societies by pheromones, by chemical communication. Ants and termites have taken this form of communication to extremes.

SPIEGEL: So the aliens would cable back home: “We have found ants. They are the most promising candidates for a future evolution towards intelligent beings on earth?”

Wilson: No, they wouldn’t. They would see that these creatures were encased in exoskeletons and therefore had to remain very small. They would conclude that there was little chance for individual ants or termites to develop much reasoning power, nor, as a result, the capacity for culture. But at least on this planet, you have to be big in order to have sufficient cerebral cortex. And you probably have to be bipedal and develop hands with pulpy fingers, because those give you the capacity to start creating objects and to manipulate the environment.

SPIEGEL: Would our ancestors not have caught their eye?

Wilson: Ten million years ago, our ancestors indeed had developed a somewhat larger brain and versatile hands already. But the crucial step had yet to come.

SPIEGEL: What do you mean?

Wilson: Let me go back to the social insects for a moment. Why did social insects start to form colonies? Across hundreds of millions of years, insects had been proliferating as solitary forms. Some of them stayed with their young for a while, guided them and protected them. You find that widespread but far from universal in the animal kingdom. However, out of those species came a much smaller number of species who didn’t just protect their young, but started building nests that they defended …

SPIEGEL: … similar to birds.

Wilson: Yes. And I think that birds are right at the threshold of eusocial behaviour. But looking at the evolution of ants and termites again, there is another crucial step. In an even smaller group, the young don’t only grow up in their nest, but they also stay and care for the next generation. Now you have a group staying together with a division of labor. That is evidently the narrow channel of evolution that you have to pass through in order to become eusocial.

SPIEGEL: And our ancestors followed the same path?

Wilson: Yes. I argue that Homo habilis, the first humans, also went through these stages. In particular, Homo habilis was unique in that they already had shifted to eating meat.

SPIEGEL: What difference would that make?

Wilson: When animals start eating meat, they tend to form packs and to divide labor. We know that the immediate descendants of Homo habilis, Homo erectus, gathered around camp sites and that they actually had begun to use fire. These camp sites are equivalent to nests. That’s where they gathered in a tightly knit group, and then individuals went out searching for food.

SPIEGEL: And this development of groups drives evolution even further?

Wilson: Exactly. And, for example, if it now comes to staking out the hunting grounds, then group stands against group.

SPIEGEL: Meaning that this is the origin of warfare?

Wilson: Yes. But it doesn’t take necessarily the forming of an army or a battalion and meeting on the field and fighting. It was mostly what you call “vengeance raids”. One group attacks another, maybe captures a female or kills one or two males. The other group then counterraids, and this will go back and forth, group against group.

SPIEGEL: You say that this so called group selection is vital for the evolution of humans. Yet traditionally, scientists explain the emergence of social behavior in humans by kin selection.

Wilson: That, for a number of reasons, isn’t much good as an explanation.

SPIEGEL: But you yourself have long been a proponent of this theory. Why did you change your mind?

Wilson: You are right. During the 1970s, I was one of the main proponents of kin selection theory. And at first the idea sounds very reasonable. So for example, if I favored you because you were my brother and therefore we share one half of our genes, then I could sacrifice a lot for you. I could give up my chance to have children in order to get you through college and have a big family. The problem is: If you think it through, kin selection doesn’t explain anything. Instead, I came to the conclusion that selection operates on multiple levels. On one hand, you have normal Darwinian selection going on all the time, where individuals compete with each other. In addition, however, these individuals now form groups. They are staying together, and consequently it is group versus group.

SPIEGEL: Turning away from kin selection provoked a rather fierce reaction from many of your colleagues.

Wilson: No, it didn’t. The reaction was strong, but it came from a relatively small group of people whose careers are based upon studies of kin selection.

SPIEGEL: Isn’t that too easy? After all, 137 scientists signed a response to your claims. They accuse you of a “misunderstanding of evolutionary theory”.

Wilson: You know, most scientists are tribalists. Their lives are so tied up in certain theories that they can’t let go.

SPIEGEL: Does it even make a substantial difference if humans evolved through kin selection or group selection?

Wilson: Oh, it changes everything. Only the understanding of evolution offers a chance to get a real understanding of the human species. We are determined by the interplay between individual and group selection where individual selection is responsible for much of what we call sin, while group selection is responsible for the greater part of virtue. We’re all in constant conflict between self-sacrifice for the group on the one hand and egoism and selfishness on the other. I go so far as to say that all the subjects of humanities, from law to the creative arts are based upon this play of individual versus group selection.

SPIEGEL: Is this Janus-faced nature of humans our greatest strength at the end of the day?

Wilson: Exactly. This inner conflict between altruism and selfishness is the human condition. And it is very creative and probably the source of our striving, our inventiveness and imagination. It’s that eternal conflict that makes us unique.

SPIEGEL: So how do we negotiate this conflict?

Wilson: We don’t. We have to live with it.

SPIEGEL: Which element of this human condition is stronger?

Wilson: Let’s put it this way: If we would be mainly influenced by group selection, we would be living in kind of an ant society.

SPIEGEL: … the ultimate form of communism?

Wilson: Yes. Once in a while, humans form societies that emphasize the group, for example societies with Marxist ideology. But the opposite is also true. In other societies the individual is everything. Politically, that would be the Republican far right.

SPIEGEL: What determines which ideology is predominant in a society?

Wilson: If your territory is invaded, then cooperation within the group will be extreme. That’s a human instinct. If you are in a frontier area, however, then we tend to move towards the extreme individual level. That seems to be a good part of the problem still with America. We still think we’re on the frontier, so we constantly try to put forward individual initiative and individual rights and rewards based upon individual achievement.

SPIEGEL: Earlier, you differentiated between the “virtue” of altruism and the “sin” of individualism. In your book you talk about the “poorer and the better angels” of human nature. Is it helpful to use this kind of terminology?

Wilson: I will admit that using the terminology of “virtue” and “sin” is what poets call a “trope”. That is to say, I wanted the idea in crude form to take hold. Still, a lot of what we call “virtue” has to do with propensities to behave well toward others. What we call “sin” are things that people do mainly out of self-interest.

SPIEGEL: However, our virtues towards others go only so far. Outside groups are mainly greeted with hostility.

Wilson: You are right. People have to belong to a group. That’s one of the strongest propensities in the human psyche and you won’t be able to change that. However, I think we are evolving, so as to avoid war — but without giving up the joy of competition between groups. Take soccer …

SPIEGEL: … or American football.

Wilson: Oh, yes, American football, it’s a blood sport. And people live by team sports and national or regional pride connected with team sports. And that’s what we should be aiming for, because, again, that spirit is one of the most creative. It landed us on the moon, and people get so much pleasure from it. I don’t want to see any of that disturbed. That is a part of being human. We need our big games, our team sports, our competition, our Olympics.

SPIEGEL: “Humans,” the saying goes, “have Paleolithic emotions” …

Wilson: … “Medieval institutions and god-like technology”. That’s our situation, yeah. And we really have to handle that.

SPIEGEL: How?

Wilson: So often it happens that we don’t know how, also in situations of public policy and governance, because we don’t have enough understanding of human nature. We simply haven’t looked at human nature in the best way that science might provide. I think what we need is a new Enlightenment. During the 18th century, when the original Enlightenment took place, science wasn’t up to the job. But I think science is now up to the job. We need to be harnessing our scientific knowledge now to get a better, science-based self-understanding.

SPIEGEL: It seems that, in this process, you would like to throw religions overboard altogether?

Wilson: No. That’s a misunderstanding. I don’t want to see the Catholic Church with all of its magnificent art and rituals and music disappear. I just want to have them give up their creation stories, including especially the resurrection of Christ.

SPIEGEL: That might well be a futile endeavour …

Wilson: There was this American physiologist who was asked if Mary’s bodily ascent from Earth to Heaven was possible. He said, “I wasn’t there; therefore, I’m not positive that it happened or didn’t happen; but of one thing I’m certain: She passed out at 10,000 meters.” That’s where science comes in. Seriously, I think we’re better off with no creation stories.

SPIEGEL: With this new Enlightenment, will we reach a higher state of humanity?

Wilson: Do we really want to improve ourselves? Humans are a very young species, in geologic terms, and that’s probably why we’re such a mess. We’re still living with all this aggression and ability to go to war. But do we really want to change ourselves? We’re right on the edge of an era of being able to actually alter the human genome. But do we want that? Do we want to create a race that’s more rational and free of many of these emotions? My response is no, because the only thing that distinguishes us from super-intelligent robots are our imperfect, sloppy, maybe even dangerous emotions. They are what makes us human.

SPIEGEL: Mr. Wilson, we thank you for this conversation.

Interview conducted by Philip Bethge and Johann Grolle

Cultural Evolution Changes Bird Song (Science Daily)

30/01/2013UncategorizedAnimais, Cultura, Evolucionismo, Inteligência animal, Socialidade animalrenzotaddei

Jan. 29, 2013 — Thanks to cultural evolution, male Savannah sparrows are changing their tune, partly to attract “the ladies.”

Savannah sparrow. (Credit: Image courtesy of University of Guelph)

According to a study of more than 30 years of Savannah sparrows recordings, the birds are singing distinctly different songs today than their ancestors did 30 years ago — changes passed along generation to generation, according to a new study by University of Guelph researchers.

Integrative biology professors Ryan Norris and Amy Newman, in collaboration with researchers at Bowdoin College and Williams College in the U.S., analyzed the songs of male Savannah sparrows (Passerculus sandwichiensis) recorded over three decades, and found that the songs had changed distinctly from 1980 to 2011.

“The change is the result of cultural transmission of different song elements through many generations,” said Norris.

Norris added that the change in tune resembles changes in word choice and language among humans.

“If you listen to how people used to talk in the 1890s and how we talk today, you would notice major differences, and this is the result of shifts in culture or the popularity of certain forms,” he said. “The change in sparrow songs over time has occurred much the same way”

The sparrows, which live on Kent Island, N.B., in the Bay of Fundy, can generally sing only one song type that consists of several parts. Male sparrows learn that song early in their first year and continue to sing the same tune for the rest of their lives.

“Young male sparrows learn their songs from the birds around them,” said Norris. “It may be their fathers, or it could be other older male birds that live nearby.”

Each male sparrow has his own unique sound, added Newman.

“While the island’s sparrows all sing a characteristic ‘savannah sparrow song,’ with the same verses and sound similar, there are distinct differences between each bird,” she said. “Essentially, it is like karaoke versions of popular songs. It is the rise and fall in popular cover versions that has changed over time.”

The research team found that, in general, each song has three primary elements. The first identifies the bird as a Savannah sparrow, the second identifies which individual is singing, and the third component is used by females to assess males.

Using sonograms recorded from singing males each breeding season, the researchers determined that, while the introductory notes had stayed generally consistent for the last 30 years, the sparrows had added a series of clicks to the middle of their songs. The birds had also changed the ending trill: once long and high-frequency, it is now shorter and low-frequency.

“We found that the ending trill of the song has become shorter, likely because female sparrows preferred this, because males with shorter trills had higher reproductive success,” Norris said.

Kent Island has been home to the Bowdoin Scientific Station since it was donated by J. Sterling Rockefeller in 1932, and the birds have been recorded since the 1980s. Individual birds are also monitored throughout their lifetime.

“We know the identity and history of every single sparrow in the study population” said Norris, who has led the project with Newman since 2009. “To have 30 years of recordings is very rare, and it was definitely surprising to see such drastic changes.”

Journal Reference:

Heather Williams, Iris I. Levin, D. Ryan Norris, Amy E.M. Newman, Nathaniel T. Wheelwright. Three decades of cultural evolution in Savannah sparrow songs. Animal Behaviour, 2013; 85 (1): 213 DOI:10.1016/j.anbehav.2012.10.028

Fluctuating Environment May Have Driven Human Evolution (Science Daily)

27/12/2012UncategorizedAntropologia física, Evolução, Evolucionismo, Mudanças climáticasrenzotaddei

Dec. 24, 2012 — A series of rapid environmental changes in East Africa roughly 2 million years ago may be responsible for driving human evolution, according to researchers at Penn State and Rutgers University.

“The landscape early humans were inhabiting transitioned rapidly back and forth between a closed woodland and an open grassland about five to six times during a period of 200,000 years,” said Clayton Magill, graduate student in geosciences at Penn State. “These changes happened very abruptly, with each transition occurring over hundreds to just a few thousand years.”

According to Katherine Freeman, professor of geosciences, Penn State, the current leading hypothesis suggests that evolutionary changes among humans during the period the team investigated were related to a long, steady environmental change or even one big change in climate.

“There is a view this time in Africa was the ‘Great Drying,’ when the environment slowly dried out over 3 million years,” she said. “But our data show that it was not a grand progression towards dry; the environment was highly variable.”

According to Magill, many anthropologists believe that variability of experience can trigger cognitive development.

“Early humans went from having trees available to having only grasses available in just 10 to 100 generations, and their diets would have had to change in response,” he said. “Changes in food availability, food type, or the way you get food can trigger evolutionary mechanisms to deal with those changes. The result can be increased brain size and cognition, changes in locomotion and even social changes — how you interact with others in a group. Our data are consistent with these hypotheses. We show that the environment changed dramatically over a short time, and this variability coincides with an important period in our human evolution when the genus Homo was first established and when there was first evidence of tool use.”

The researchers — including Gail Ashley, professor of earth and planetary sciences, Rutgers University — examined lake sediments from Olduvai Gorge in northern Tanzania. They removed the organic matter that had either washed or was blown into the lake from the surrounding vegetation, microbes and other organisms 2 million years ago from the sediments. In particular, they looked at biomarkers — fossil molecules from ancient organisms — from the waxy coating on plant leaves.

“We looked at leaf waxes because they’re tough, they survive well in the sediment,” said Freeman.

The team used gas chromatography and mass spectrometry to determine the relative abundances of different leaf waxes and the abundance of carbon isotopes for different leaf waxes. The data enabled them to reconstruct the types of vegetation present in the Olduvai Gorge area at very specific time intervals.

The results showed that the environment transitioned rapidly back and forth between a closed woodland and an open grassland.

To find out what caused this rapid transitioning, the researchers used statistical and mathematical models to correlate the changes they saw in the environment with other things that may have been happening at the time, including changes in the Earth’s movement and changes in sea-surface temperatures.

“The orbit of the Earth around the sun slowly changes with time,” said Freeman. “These changes were tied to the local climate at Olduvai Gorge through changes in the monsoon system in Africa. Slight changes in the amount of sunshine changed the intensity of atmospheric circulation and the supply of water. The rain patterns that drive the plant patterns follow this monsoon circulation. We found a correlation between changes in the environment and planetary movement.”

The team also found a correlation between changes in the environment and sea-surface temperature in the tropics.

“We find complementary forcing mechanisms: one is the way Earth orbits, and the other is variation in ocean temperatures surrounding Africa,” Freeman said. The researchers recently published their results in the Proceedings of the National Academy of Sciences along with another paper in the same issue that builds on these findings. The second paper shows that rainfall was greater when there were trees around and less when there was a grassland.

“The research points to the importance of water in an arid landscape like Africa,” said Magill. “The plants are so intimately tied to the water that if you have water shortages, they usually lead to food insecurity.

“Together, these two papers shine light on human evolution because we now have an adaptive perspective. We understand, at least to a first approximation, what kinds of conditions were prevalent in that area and we show that changes in food and water were linked to major evolutionary changes.”

The National Science Foundation funded this research.

* * *

How climate shifts in Africa sparked human evolution (MSNBC)

Scientists say landscape transitions may have forced early humans to think on their feet

Image: Nutcracker Man

Nicolle Rager Fuller / NSF. The first specimen of Paranthropus boisei, also called Nutcracker Man, was reported by Mary and Louis Leakey in 1959 from a site in Olduvai Gorge, Tanzania.

By Charles Choi – LiveScience Contributor

updated 12/26/2012 2:16:27 PM ET

At Olduvai Gorge, where excavations helped to confirm Africa was the cradle of humanity, scientists now find the landscape once fluctuated rapidly, likely guiding early human evolution.

These findings suggest that key mental developments within the human lineage may have been linked with a highly variable environment, researchers added.

Olduvai Gorge is a ravine cut into the eastern margin of the Serengeti Plain in northern Tanzania that holds fossils of hominins — members of the human lineage. Excavations at Olduvai Gorge by Louis and Mary Leakey in the mid-1950s helped to establish the African origin of humanity.

The Great Drying?

To learn more about the roots of humanity, scientists analyzed samples of leaf waxes preserved in lake sediments at Olduvai Gorge, identifying which plants dominated the local environment around 2 million years ago. This was about when Homo erectus, a direct ancestor of modern humans who used relatively advanced stone tools, appeared.

“We looked at leaf waxes, because they’re tough, they survive well in the sediment,” researcher Katherine Freeman, a biogeochemist at Pennsylvania State University, said in a statement.

After four years of work, the researchers focused on carbon isotopes — atoms of the same element with different numbers of neutrons — in the samples, which can reveal what plants reigned over an area. The grasses that dominate savannas engage in a kind of photosynthesis that involves both normal carbon-12 and heavier carbon-13, while trees and shrubs rely on a kind of photosynthesis that prefers carbon-12. (Atoms of carbon-12 each possess six neutrons, while atoms of carbon-13 have seven.)

Scientists had long thought Africa went through a period of gradually increasing dryness — called the Great Drying — over 3 million years, or perhaps one big change in climate that favored the expansion of grasslands across the continent, influencing human evolution. However, the new research instead revealed “strong evidence for dramatic ecosystem changes across the African savanna, in which open grassland landscapes transitioned to closed forests over just hundreds to several thousands of years,” researcher Clayton Magill, a biogeochemist at Pennsylvania State University, told LiveScience. [Know Your Roots? Take Our Human Evolution Quiz]

The researchers discovered that Olduvai Gorge abruptly and routinely fluctuated between dry grasslands and damp forests about five or six times during a period of 200,000 years.

“I was surprised by the magnitude of changes and the rapid pace of the changes we found,” Freeman told LiveScience. “There was a complete restructuring of the ecosystem from grassland to forest and back again, at least based on how we interpret the data. I’ve worked on carbon isotopes my whole career, and I’ve never seen anything like this before.”

Losing water

The investigators also constructed a highly detailed record of water history in Olduvai Gorge by analyzing hydrogen isotope ratios in plant waxes and other compounds in nearby lake sediments. These findings support the carbon isotope data, suggesting the region experienced fluctuations in aridity, with dry periods dominated by grasslands and wet periods characterized by expanses of woody cover.

“The research points to the importance of water in an arid landscape like Africa,” Magill said in a statement. “The plants are so intimately tied to the water that if you have water shortages, they usually lead to food insecurity.”

The research team’s statistical and mathematical models link the changes they see with other events at the time, such as alterations in the planet’s movement. [50 Amazing Facts About Earth]

“The orbit of the Earth around the sun slowly changes with time,” Freeman said in statement. “These changes were tied to the local climate at Olduvai Gorge through changes in the monsoon system in Africa.”

Earth’s orbit around the sun can vary over time in a number of ways — for instance,Earth’s orbit around the sun can grow more or less circular over time, and Earth’s axis of spin relative to the sun’s equatorial plane can also tilt back and forth. This alters the amount of sunlight Earth receives, energy that drives Earth’s atmosphere.

“Slight changes in the amount of sunshine changed the intensity of atmospheric circulation and the supply of water,” Freeman said. “The rain patterns that drive the plant patterns follow this monsoon circulation. We found a correlation between changes in the environment and planetary movement.”

The team also found links between changes at Olduvai Gorge and sea-surface temperatures in the tropics.

“We find complementary forcing mechanisms — one is the way Earth orbits, and the other is variation in ocean temperatures surrounding Africa,” Freeman said.

These findings now shed light on the environmental shifts the ancestors of modern humans might have had to adapt to in order to survive and thrive.

“Early humans went from having trees available to having only grasses available in just 10 to 100 generations, and their diets would have had to change in response,” Magill said in a statement. “Changes in food availability, food type, or the way you get food can trigger evolutionary mechanisms to deal with those changes. The result can be increased brain size and cognition, changes in locomotion and even social changes — how you interact with others in a group.”

This variability in the environment coincided with a key period in human evolution, “when the genus Homo was first established and when there was first evidence of tool use,” Magill said.

The researchers now hope to examine changes at Olduvai Gorge not just across time but space, which could help shed light on aspects of early human evolution such as foraging patterns.

Magill, Freeman and their colleague Gail Ashley detailed their findings online Dec. 24 in two papers in the Proceedings of the National Academy of Sciences.

Human hands evolved for punching (Discovery News)

20/12/2012UncategorizedAntropologia física, ciência, Corpo, Evolucionismo, Reducionismo, Teleologia, Violênciarenzotaddei

Analysis by Jennifer Viegas

Wed Dec 19, 2012 06:16 PM ET

Credit: iStockPhoto

Human hands evolved so that men could make fists and fight, and not just for manual dexterity, new research finds.

The study, published in the Journal of Experimental Biology, adds to a growing body of evidence that humans are among the most aggressive and violent animals on the planet.

“With the notable exception of bonobos, great apes are a relatively aggressive group of mammals,” lead author David Carrier told Discovery News. “Although some primatologists may argue that chimpanzees are the most aggressive apes, I think the evidence suggests that humans are substantially more violent.”

Carrier points out that while chimpanzees physically batter each other more frequently than humans, rape appears to be less common in chimpanzees, and torture and group-against-group forms of violence, such as slavery, are not documented in the animals.

“Chimpanzees are also known to engage in raiding welfare in which one group largely eliminates a neighboring group, but this is not comparable in scope to the genocide that has characterized human history,” added Carrier, a University of Utah biology professor.

For this latest study, he and co-author Michael Morgan, a medical student, conducted three experiments. First, they analyzed what happened when men, aged from 22 to 50, hit a punching bag as hard as they could. The peak stress delivered to the bag — the force per area — was 1.7 to 3 times greater with a fist strike compared with a slap.

“Because you have higher pressure when hitting with a fist, you are more likely to cause injury to tissue, bones, teeth, eyes and the jaw,” Carrier said.

The second and third experiments determined that buttressing provided by the human fist increases the stiffness of the knuckle joint fourfold. It also doubles the ability of the fingers to transmit punching force, mainly due to the force transferred from the fingers to the thumb when the fist is clenched.

In terms of the size and shape of hand anatomy, the scientists point out that humans could have evolved manual dexterity with longer thumbs, but without the fingers and palms getting shorter.

Gorilla hands are closer in proportion to human hands than are other apes’ hands, but they and no other ape — aside from us — hits with a clenched fist.

The researchers additionally point out that humans use fists during threat displays. There is also a difference in body size between males and females, particularly evident with hands and arms. This, Carrier said, is “consistent with the hand being a weapon.”

Human males tend to be more physically violent than women, with men being ten times more likely to commit homicide than females in the U.S., Carrier said. But the research, nonetheless, applies to women as well.

“The bottom line is that women need to fight and defend themselves too,” Morgan told Discovery News. “Women need to fight off attackers and defend themselves from rape.”

Defending children may even help to explain human hand anatomy, since both men and women are often driven to protect their offspring, in addition to fighting with others over territory, resources and for other reasons.

“It can be argued that modern man exists in a world devoid of the evolutionary and selective pressures to which aggression was a beneficial trait,” Morgan said. “Our aggressive behavior remains, but no longer serves an evolutionary purpose.”

Dead Guts Spill History of Extinct Microbes: Fecal Samples from Archeological Sites Reveal Evolution of Human Gut Microbes (Science Daily)

17/12/2012UncategorizedEvolucionismo, Víscerasrenzotaddei

This shows microbiomes across time and populations. (Credit: Tito RY, Knights D, Metcalf J, Obregon-Tito AJ, Cleeland L, et al. (2012) Insights from Characterizing Extinct Human Gut Microbiomes. PLoS ONE 7(12):e51146.doi:10.1371/journal.pone.0051146)

Dec. 12, 2012 — Extinct microbes in fecal samples from archaeological sites across the world resemble those found in present-day rural African communities more than they resemble the microbes found in the gut of cosmopolitan US adults, according to research published December 12 in the open access journalPLOS ONE by Cecil Lewis and colleagues from the University of Oklahoma.

The researchers analyzed 1400-8000-year-old fecal samples preserved at three archaeological sites: natural mummies from Caserones in northern Chile, and samples from Hinds Cave in the southern US and Rio Zape in northern Mexico. They also used samples from Otzi the Iceman and a soldier frozen on a glacier for nearly a century. They compared the now-extinct microbes in these samples to microbes present in current-day soil and compost, as well as the microbes present in mouths, gut and skin of people in rural African communities and cosmopolitan US adults.

The authors discovered that the extinct human microbes from natural mummies closely resembled compost samples, while one sample from Mexico was found to match that from a rural African child. Overall, the extinct microbial communities were more similar to those from present rural populations than those from cosmopolitan ones. The study concludes, “These results suggest that the modern cosmopolitan lifestyle resulted in a dramatic change to the human gut microbiome.”

As Lewis explains, “It is becoming accepted that modern aseptic and antibiotic practices, are often beneficial but come with a price, such as compromising the natural development of our immune system through changing the relationship we had with microbes ancestrally. What is unclear is what that ancestral state looked like. This paper demonstrates that we can use ancient human biological samples to learn about these ancestral relationships, despite the challenges of subsequent events like degradation and contamination.”

Journal Reference:

Raul Y. Tito, Dan Knights, Jessica Metcalf, Alexandra J. Obregon-Tito, Lauren Cleeland, Fares Najar, Bruce Roe, Karl Reinhard, Kristin Sobolik, Samuel Belknap, Morris Foster, Paul Spicer, Rob Knight, Cecil M. Lewis. Insights from Characterizing Extinct Human Gut Microbiomes.PLoS ONE, 2012; 7 (12): e51146 DOI:10.1371/journal.pone.0051146

Origin of intelligence and mental illness linked to ancient genetic accident (University of Edinburgh)

03/12/2012UncategorizedCognição, Evolução, Evolucionismo, Inteligência animal, Interação humanos-animais, Mediação tecnológica, Previsão, Saúde mentalrenzotaddei

2-Dec-2012 – By Tara Womersley, University of Edinburgh

Scientists have discovered for the first time how humans – and other mammals – have evolved to have intelligence

Scientists have discovered for the first time how humans – and other mammals – have evolved to have intelligence.

Researchers have identified the moment in history when the genes that enabled us to think and reason evolved.

This point 500 million years ago provided our ability to learn complex skills, analyse situations and have flexibility in the way in which we think.

Professor Seth Grant, of the University of Edinburgh, who led the research, said: “One of the greatest scientific problems is to explain how intelligence and complex behaviours arose during evolution.”

The research, which is detailed in two papers in Nature Neuroscience, also shows a direct link between the evolution of behaviour and the origins of brain diseases.

Scientists believe that the same genes that improved our mental capacity are also responsible for a number of brain disorders.

“This ground breaking work has implications for how we understand the emergence of psychiatric disorders and will offer new avenues for the development of new treatments,” said John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, one of the study funders.

The study shows that intelligence in humans developed as the result of an increase in the number of brain genes in our evolutionary ancestors.

The researchers suggest that a simple invertebrate animal living in the sea 500 million years ago experienced a ‘genetic accident’, which resulted in extra copies of these genes being made.

This animal’s descendants benefited from these extra genes, leading to behaviourally sophisticated vertebrates – including humans.

The research team studied the mental abilities of mice and humans, using comparative tasks that involved identifying objects on touch-screen computers.

Researchers then combined results of these behavioural tests with information from the genetic codes of various species to work out when different behaviours evolved.

They found that higher mental functions in humans and mice were controlled by the same genes.

The study also showed that when these genes were mutated or damaged, they impaired higher mental functions.

“Our work shows that the price of higher intelligence and more complex behaviours is more mental illness,” said Professor Grant.

The researchers had previously shown that more than 100 childhood and adult brain diseases are caused by gene mutations.

“We can now apply genetics and behavioural testing to help patients with these diseases”, said Dr Tim Bussey from Cambridge University, which was also involved in the study.

The study was funded by the Wellcome Trust, the Medical Research Council and European Union.

What do chimps and humans have in common? Gut bacteria (MSNBC)

14/11/2012UncategorizedEvolução, Evolucionismo, Intestinos, Macacos, Primatas, Primatologia, Saúde, Visceralidaderenzotaddei

It’s nearly identical, and suggests patterns evolved before the two split and went own ways

Chimpanzees at Gombe Stream National Park in Tanzania have a lot in common with humans. And they both like to eat, apparently. Photo: Ian Gilby

By Stephanie Pappas

updated 11/13/2012 3:30:35 PM ET

Humans share about 99 percent of our genomes with chimpanzees. Now, research finds we share something else: gut bacteria.

The bacterial colonies that populate the chimpanzee intestinal tract are mirror images of those found in the human gut, researchers report Tuesday in the journal Nature Communications. The findings suggest gut bacteria patterns evolved before chimps and humans split and went their evolutionarily separate ways.

Human gut bacteria are crucial to health, with infants relying on healthy microbe populations to influence the developing immune system. Problems with microbe populations may also contribute to obesity and inflammatory bowel diseases.

Three intestinal ecosystems

In 2011, researchers learned that everyone’s gut bacteria fall into one of three different types, almost analogous to blood types. In each type, certain bacteria dominate. These types weren’t linked to any personal characteristics such as geographic area, age or gender. Researchers dubbed these distinct bacterial ecosystems “enterotypes.” (“Entero” means gut or intestine.)

“No one really knows why these three enterotypes exist,” said study researcher Andrew Moeller, a doctoral student at Yale University.

Along with his adviser Howard Ochman and their colleagues, Moeller wants to understand how these enterotypes arose. They could be distinctly human, he told LiveScience, which would suggest they arose relatively recently, perhaps in response to the development of agriculture. Or they could be ancient, shared among our closest primate relatives.

The researchers analyzed gut bacteria samples from 35 chimpanzees from Gombe Stream National Park in Tanzania. The chimpanzees were all in the subspecies Pan troglodytes schweinfurthii, the eastern chimpanzee, which arose about the same time as Homo sapiens.

Shared bacteria

The researchers found that, just like humans, chimps’ guts harbor one of three distinct types of bacterial colonies. Even more intriguingly, these enterotypes matched humans’ precisely. In type 1, for example, both humans and chimps show a predominance of Bacteroides,Faecalibacterium and Parabacteroides.

There were some differences. For example, in humans and chimps, enterotype 2 is marked by an overabundance of bacteria called Lachnospiraceae. In humans, the bacteria Prevotellae is also prevalent in type 2. In chimps, Prevotellae appears in significant numbers in all three enterotypes, perhaps because it is associated with a high-carbohydrate diet.

Other differences could help explain certain human health issues. By comparing human and chimpanzee gut bacteria, the researchers found many of the bacteria present only in humans are linked to diseases such as inflammatory bowel diseases, conditions that cause pain, diarrhea and vomiting.

Seven of the chimps in the study were tested repeatedly over eight years, and their gut microbes were found to change from type to type over that time period. No one has ever tested humans for changes over a period longer than two weeks, Moeller said, but the results suggest our enterotypes may shift over time, too.

Our shared history

The similarities between chimp and human colonies suggest enterotypes predate our species, which in turn suggests that none of the three ecosystems are better than the others, Moeller said.

“Before we found this in chimpanzees, there was a possibility that enterotypes were a product of modernization, which could mean they have some negative effects on health,” he said. “I don’t think there’s any reason to think one enterotype is going to have an effect on health that’s going to be better” than the others.

Moeller and his colleagues are now examining gorilla fecal samples to find out where they stand as slightly more distant primate relatives to humans.

“The next step is to try to find out the processes and mechanisms responsible for producing these three community states,” Moeller said, “which is kind of a lofty goal, but I think more sampling will actually reveal why these communities exist.”

Far from random, evolution follows a predictable genetic pattern, Princeton researchers find (Princeton)

01/11/2012UncategorizedBiologia, ciência, Evolução, Evolucionismo, Incerteza, Mediação tecnológica, Previsão, Teleologiarenzotaddei

Posted October 25, 2012; 12:00 p.m.

by Morgan Kelly, Office of Communications

Evolution, often perceived as a series of random changes, might in fact be driven by a simple and repeated genetic solution to an environmental pressure that a broad range of species happen to share, according to new research.

Princeton University research published in the journal Science suggests that knowledge of a species’ genes — and how certain external conditions affect the proteins encoded by those genes — could be used to determine a predictable evolutionary pattern driven by outside factors. Scientists could then pinpoint how the diversity of adaptations seen in the natural world developed even in distantly related animals.

The Princeton researchers sequenced the expression of a poison-resistant protein in insect species that feed on plants such as milkweed and dogbane that produce a class of steroid-like cardiotoxins called cardenolides as a natural defense. The insects surveyed spanned three orders: butterflies and moths (Lepidoptera); beetles and weevils (Coleoptera); and aphids, bed bugs, milkweed bugs and other sucking insects (Hemiptera). Above: Dogbane beetle(Photo courtesy of Peter Andolfatto)

“Is evolution predictable? To a surprising extent the answer is yes,” said senior researcher Peter Andolfatto, an assistant professor in Princeton’s Department of Ecology and Evolutionary Biology and the Lewis-Sigler Institute for Integrative Genomics. He worked with lead author and postdoctoral research associate Ying Zhen, and graduate students Matthew Aardema and Molly Schumer, all from Princeton’s ecology and evolutionary biology department, as well as Edgar Medina, a biological sciences graduate student at the University of the Andes in Colombia.

The researchers carried out a survey of DNA sequences from 29 distantly related insect species, the largest sample of organisms yet examined for a single evolutionary trait. Fourteen of these species have evolved a nearly identical characteristic due to one external influence — they feed on plants that produce cardenolides, a class of steroid-like cardiotoxins that are a natural defense for plants such as milkweed and dogbane.

Though separated by 300 million years of evolution, these diverse insects — which include beetles, butterflies and aphids — experienced changes to a key protein called sodium-potassium adenosine triphosphatase, or the sodium-potassium pump, which regulates a cell’s crucial sodium-to-potassium ratio. The protein in these insects eventually evolved a resistance to cardenolides, which usually cripple the protein’s ability to “pump” potassium into cells and excess sodium out.

Lead author Ying Zhen (foreground), Andolfatto (far left), fourth author and graduate student Molly Schumer (near left), and their co-authors sequenced and assembled all the expressed genes in 29 distantly related insect species, the largest sample of organisms yet examined for a single evolutionary trait. They used these sequences to predict how a certain protein would be encoded in the genes of 14 distantly related species that evolved a similar resistance to toxic plants. Similar techniques could be used to trace protein changes in a species’ DNA to understand how many diverse organisms evolved as a result of environmental factors. At right is research assistant Ilona Ruhl, who was not involved in the research. (Photo by Denise Applewhite)

Andolfatto and his co-authors first sequenced and assembled all the expressed genes in the studied species. They used these sequences to predict how the sodium-potassium pump would be encoded in each of the species’ genes based on cardenolide exposure.

Scientists using similar techniques could trace protein changes in a species’ DNA to understand how many diverse organisms evolved as a result of environmental factors, Andolfatto said. “To apply this approach more generally a scientist would have to know something about the genetic underpinnings of a trait and investigate how that trait evolves in large groups of species facing a common evolutionary problem,” Andolfatto said.

“For instance, the sodium-potassium pump also is a candidate gene location related to salinity tolerance,” he said. “Looking at changes to this protein in the right organisms could reveal how organisms have or may respond to the increasing salinization of oceans and freshwater habitats.”

Milkweed tussock moth (Photo courtesy of Peter Andolfatto)

Jianzhi Zhang, a University of Michigan professor of ecology and evolutionary biology, said that the Princeton-based study shows that certain traits have a limited number of molecular mechanisms, and that numerous, distinct species can share the few mechanisms there are. As a result, it is likely that a cross-section of certain organisms can provide insight into the development of other creatures, he said.

“The finding of parallel evolution in not two, but numerous herbivorous insects increases the significance of the study because such frequent parallelism is extremely unlikely to have happened simply by chance,” said Zhang, who is familiar with the study but had no role in it.

“It shows that a common molecular mechanism is used by many different insects to defend themselves against the toxins in their food, suggesting that perhaps the number of potential mechanisms for achieving this goal is very limited,” he said. “That many different insects independently evolved the same molecular tricks to defend themselves against the same toxin suggests that studying a small number of well-chosen model organisms can teach us a lot about other species. Yes, evolution is predictable to a certain degree.”

Andolfatto and his co-authors examined the sodium-potassium pump protein because of its well-known sensitivity to cardenolides. In order to function properly in a wide variety of physiological contexts, cells must be able to control levels of potassium and sodium. Situated on the cell membrane, the protein generates a desired potassium to sodium ratio by “pumping” three sodium atoms out of the cell for every two potassium atoms it brings in.

Cardenolides disrupt the exchange of potassium and sodium, essentially shutting down the protein, Andolfatto said. The human genome contains four copies of the pump protein, and it is a candidate gene for a number of human genetic disorders, including salt-sensitive hypertension and migraines. In addition, humans have long used low doses of cardenolides medicinally for purposes such as controlling heart arrhythmia and congestive heart failure.

Large milkweed bugs (Photo courtesy of Peter Andolfatto)

The Princeton researchers used the DNA microarray facility in the University’s Lewis-Sigler Institute for Integrative Genomics to sequence the expression of the sodium-potassium pump protein in insect species spanning three orders: butterflies and moths (Lepidoptera); beetles and weevils (Coleoptera); and aphids, bed bugs, milkweed bugs and other sucking insects (Hemiptera).

The researchers found that the genes of cardenolide-resistant insects incorporated various mutations that allowed it to resist the toxin. During the evolutionary timeframe examined, the sodium-potassium pump of insects feeding on dogbane and milkweed underwent 33 mutations at sites known to affect sensitivity to cardenolides. These mutations often involved similar or identical amino-acid changes that reduced susceptibility to the toxin. On the other hand, the sodium-potassium pump mutated just once in insects that do not feed on these plants.

Significantly, the researchers found that multiple gene duplications occurred in the ancestors of several of the resistant species. These insects essentially wound up with one conventional sodium-potassium pump protein and one “experimental” version, Andolfatto said. In these insects, the newer, hardier versions of the sodium-potassium pump are mostly expressed in gut tissue where they are likely needed most.

“These gene duplications are an elegant solution to the problem of adapting to environmental changes,” Andolfatto said. “In species with these duplicates, the organism is free to experiment with one copy while keeping the other constant, avoiding the risk that the new version of the protein will not perform its primary job as well.”

The researchers’ findings unify the generally separate ideas of what predominately drives genetic evolution: protein evolution, the evolution of the elements that control protein expression or gene duplication. This study shows that all three mechanisms can be used to solve the same evolutionary problem, Andolfatto said.

Central to the work is the breadth of species the researchers were able to examine using modern gene sequencing equipment, Andolfatto said.

“Historically, studying genetic evolution at this level has been conducted on just a handful of ‘model’ organisms such as fruit flies,” Andolfatto said. “Modern sequencing methods allowed us to approach evolutionary questions in a different way and come up with more comprehensive answers than had we examined one trait in any one organism.

“The power of what we’ve done is to survey diverse organisms facing a similar problem and find striking evidence for a limited number of possible solutions,” he said. “The fact that many of these solutions are used over and over again by completely unrelated species suggests that the evolutionary path is repeatable and predictable.”

The paper, “Parallel Molecular Evolution in an Herbivore Community,” was published Sept. 28 by Science. The research was supported by grants from the Centre for Genetic Engineering and Biotechnology, the National Science Foundation and the National Institutes of Health.

When Leaving Your Wealth to Your Sister’s Sons Makes Sense (Science Daily)

18/10/2012UncategorizedEconomia experimental, Evolucionismo, Modelagem, Parentesco, Teoria dos jogosrenzotaddei

ScienceDaily (Oct. 16, 2012) — To whom a man’s possessions go when he dies is both a matter of cultural norm and evolutionary advantage.

In most human societies, men pass on their worldly goods to their wife’s children. But in about 10 percent of societies, men inexplicably transfer their wealth to their sister’s sons — what’s called “mother’s brother-sister’s son” inheritance. A new study on this unusual form of matrilineal inheritance by Santa Fe Institute reseacher Laura Fortunato has produced insights into this practice.

Her findings appear October 17 in the online edition of Proceedings of the Royal Society B.

“Matrilineal inheritance is puzzling for anthropologists because it causes tension for a man caught between his sisters and wife,” explains Fortunato, who has used game theory to study mother’s brother-sister’s son inheritance. “From an evolutionary perspective it’s also puzzling because you expect an individual to invest in his closest relatives — usually the individual’s own children.”

For decades research on the practice of matrilineal inheritance focused on the probabilities of a man being the biological father of his wife’s children — probabilities that lie on a sliding scale depending on the rate of promiscuity or whether polyandrous marriage (when a woman takes two or more husbands) is practiced.

Of special interest has been the probability value below which man is more closely related to his sister’s children than to his wife’s children. Below this “paternity threshold” a man is better off investing in his sister’s offspring, who are sure to be blood relatives, than his own wife’s children.

In her work modeling the evolutionary payoffs of marriage and inheritance strategies, Fortunato looked beyond the paternity threshold to see, among other things, what payoffs there were for men and women in different marital situations — including polygamy.

“What emerges is quite interesting,” says Fortunato. “Where inheritance is matrilineal, a man with multiple wives ‘wins’ over a man with a single wife.” That’s because wives have brothers, and those brothers will pass on their wealth to the husband’s sons. So more wives means more brothers-in-laws to invest in your sons.

The model also shows an effect for women with multiple husbands. The husband of a woman with multiple husbands is unsure of his paternity, so he may be better off investing in his sister’s offspring.

“A woman does not benefit from multiple husbands where inheritance is matrilineal, however,” Fortunato explains, “because her husbands will invest in their sisters’ kids.” Family structure determines how societies handle relatedness and reproduction issues, Fortunato says. Understanding these practices and their evolutionary implications is a prerequisite for a theory of human behavior.

Journal Reference:

Dr Laura Fortunato. The evolution of matrilineal kinship organization. Proceedings of the Royal Society B, October 17, 2012 DOI: 10.1098/rspb.2012.1926

Evolution mostly driven by brawn, not brains (University College London)

18/10/2012UncategorizedCorpo, Evolução, Evolucionismo, neurociências, Neurofisiologiarenzotaddei

Public release date: 15-Oct-2012
By Clare Ryan
University College London

The most common measure of intelligence in animals, brain size relative to body size, may not be as dependent on evolutionary selection on the brain as previously thought, according to a new analysis by scientists.

Brain size relative to body size has been used by generations of scientists to predict an animal’s intelligence. For example, although the human brain is not the largest in the animal kingdom in terms of volume or mass, it is exceptionally large considering our moderate body mass.

Now, a study by a team of scientists at UCL, the University of Konstanz, and the Max Planck Institute of Ornithology has found that the relationship between the two traits is driven by different evolutionary mechanisms in different animals.

Crucially, researchers have found that the most significant factor in determining relative brain size is often evolutionary pressure on body size, and not brain size. For example, the evolutionary history of bats reveals they decreased body size much faster than brain size, leading to an increase in relative brain size. As a result, small bats were able to evolve improved flying manoeuvrability while maintaining the brainpower to handle foraging in cluttered environments.

This shows that relative brain size can not be used unequivocally as evidence of selection for intelligence. The study is published today in the Proceedings of the National Academy of Sciences.

Dr Jeroen Smaers (UCL Anthropology and UCL Genetics, Evolution & Environment), lead author of the study said: “When using brain size relative to body size as a measure of intelligence, the assumption has always been that this measure is primarily driven by changes in brain size. It now appears that the relationship between changes in brain and body size in animals is more complex than has long been assumed.

“Changes in body size often occur independently of changes in brain size and vice versa. Moreover, the nature of these independent changes in brain and body size, are different in different groups of animals.”

Researchers at UCL gathered data on brain and body mass for hundreds of modern and extinct bats, carnivorans, and primates. They then charted brain and body size evolution over time for each species. Across millions of years, most animals increased body size faster than brain size, with the exception of bats.

In primate lineages decreases in brain size marginally outpaced those in body size. Carnivoran evolution has taken yet a different course, with changes generally more strongly associated with body size rather than selection on brain size and cognition.

Given such differences, the authors believe that the predominant interpretation of relative brain size as the consequence of selection on intelligence inherently masks the often more significant influence of selection on body size.

Developmental biologist proposes new theory of early animal evolution (New York Medical College)

18/10/2012UncategorizedBiologia, Evolução, Evolucionismorenzotaddei

Alternative model challenges a basic assumption of evolution

Public release date: 11-Oct-2012
By Donna E. Moriarty, MPH
New York Medical College

VALHALLA, October 11, 2012—A New York Medical College developmental biologist whose life’s work has supported the theory of evolution has developed a concept that dramatically alters one of its basic assumptions—that survival is based on a change’s functional advantage if it is to persist. Stuart A. Newman, Ph.D., professor of cell biology and anatomy, offers an alternative model in proposing that the origination of the structural motifs of animal form were actually predictable and relatively sudden, with abrupt morphological transformations favored during the early period of animal evolution.

Newman’s long view of evolution is fully explained in his perspective article, “Physico-Genetic Determinants in the Evolution of Development,” which is to be published in the October 12 issue of the journal Science, in a special section called Forces in Development. The paper has been selected for early online publication and a podcast interview with the scientist*.

Evolution is commonly thought to take place opportunistically, by small steps, with each change persisting, or not, based on its functional advantage. Newman’s alternative model is based on recent inferences about the genetics of the single-celled ancestors of the animals and, more surprisingly, the physics of “middle-scale” materials.

Animal bodies and the embryos that generate them exhibit an assortment of recurrent “morphological motifs” which, on the evidence of the fossil record, first appeared more than a half billion years ago. During embryonic development of present-day animals, cells arrange themselves into tissues having non-mixing layers and interior cavities. Embryos contain patterned arrangements of cell types with which they may form segments, exoskeletons and blood vessels. Developing bodies go on to fold, elongate, and extend appendages, and in some species, generate endoskeletons with repeating elements (e.g., the human hand).

These developmental motifs are strikingly similar to the forms assumed by nonliving condensed, chemically active, viscoelastic materials when they are organized by relevant physical forces and effects, although the mechanisms that generate the motifs in living embryos are typically much more complex. Newman proposes that the ancestors of the present-day animals acquired these forms when ancient single-celled organisms came to reside in multicellular clusters and physical processes relevant to matter at this new (for cellular life) spatial scale were immediately mobilized.

The unicellular progenitors are believed to have contained genes of the “developmental-genetic toolkit” with which all present-day animals orchestrate embryonic development, though they used the genes for single-cell functions. It was precisely these genes whose products enabled the ancestral clusters to harness the middle-scale physical effects that produced the characteristic motifs. And since not every ancestral cluster contained the same selection of toolkit genes, different body forms arose in parallel, giving rise to the modern morphologically distinct animal phyla.

Natural selection, acting over the hundreds of millions of years since the occurrence of these origination events led, according to Newman’s hypothesis, to more complex developmental processes which have made embryogenesis much less dependent on potentially inconsistent physical determinants, although the “physical” motifs were retained. As Newman describes in his article, this new perspective provides natural interpretations for puzzling aspects of the early evolution of the animals, including the “explosive” rise of complex body forms between 540 and 640 million years ago and the failure to add new motifs since that time. The model also helps us to understand the conserved use of the same set of genes to orchestrate development in all of the morphologically diverse phyla, and the “embryonic hourglass” of comparative developmental biology: the observation that the species of a phylum can have drastically different trajectories of early embryogenesis (e.g., frogs and mice), but still wind up with very similar “body plans.”

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This link will take you to the podcast segment featuring the interview with Dr. Newman: http://www.sciencemag.org/content/338/6104/217/suppl/DC1

Evolution could explain the placebo effect (New Scientist)

06/09/2012Uncategorizedciência, Enquadramento, Evolução, Evolucionismo, Incerteza, Matemática, Mediação tecnológica, Saúde, Teleologiarenzotaddei

06 September 2012 by Colin Barras

Magazine issue 2881

ON THE face of it, the placebo effect makes no sense. Someone suffering from a low-level infection will recover just as nicely whether they take an active drug or a simple sugar pill. This suggests people are able to heal themselves unaided – so why wait for a sugar pill to prompt recovery?

New evidence from a computer model offers a possible evolutionary explanation, and suggests that the immune system has an on-off switch controlled by the mind.

It all starts with the observation that something similar to the placebo effect occurs in many animals, says Peter Trimmer, a biologist at the University of Bristol, UK. For instance, Siberian hamsters do little to fight an infection if the lights above their lab cage mimic the short days and long nights of winter. But changing the lighting pattern to give the impression of summer causes them to mount a full immune response.

Likewise, those people who think they are taking a drug but are really receiving a placebo can have a response which is twice that of those who receive no pills (Annals of Family Medicine, doi.org/cckm8b). In Siberian hamsters and people, intervention creates a mental cue that kick-starts the immune response.

There is a simple explanation, says Trimmer: the immune system is costly to run – so costly that a strong and sustained response could dangerously drain an animal’s energy reserves. In other words, as long as the infection is not lethal, it pays to wait for a sign that fighting it will not endanger the animal in other ways.

Nicholas Humphrey, a retired psychologist formerly at the London School of Economics, first proposed this idea a decade ago, but only now has evidence to support it emerged from a computer model designed by Trimmer and his colleagues.

According to Humphrey’s picture, the Siberian hamster subconsciously acts on a cue that it is summer because food supplies to sustain an immune response are plentiful at that time of year. We subconsciously respond to treatment – even a sham one – because it comes with assurances that it will weaken the infection, allowing our immune response to succeed rapidly without straining the body’s resources.

Trimmer’s simulation is built on this assumption – that animals need to spend vital resources on fighting low-level infections. The model revealed that, in challenging environments, animals lived longer and sired more offspring if they endured infections without mounting an immune response. In more favourable environments, it was best for animals to mount an immune response and return to health as quickly as possible (Evolution and Human Behavior, doi.org/h8p). The results show a clear evolutionary benefit to switching the immune system on and off depending on environmental conditions.

“I’m pleased to see that my theory stands up to computational modelling,” says Humphrey. If the idea is right, he adds, it means we have misunderstood the nature of placebos. Farming and other innovations in the past 10,000 years mean that many people have a stable food supply and can safely mount a full immune response at any time – but our subconscious switch has not yet adapted to this. A placebo tricks the mind into thinking it is an ideal time to switch on an immune response, says Humphrey.

Paul Enck at the University of Tübingen in Germany says it is an intriguing idea, but points out that there are many different placebo responses, depending on the disease. It is unlikely that a single mechanism explains them all, he says.

To Bring Back the Extinct (Edge)

31/08/2012UncategorizedÉtica, Biotecnologias, Evolução, Evolucionismo, Extinção, Históriarenzotaddei

A Conversation with Ryan Phelan [8.28.12]

One of the fundamental questions here is, is extinction a good thing? Is it “nature’s way?” And if it’s nature’s way, who in the world says anyone should go about changing nature’s way? If something was meant to go extinct, then who are we to screw around with it and bring it back? I don’t think it’s really nature’s way. I think that the extinction that we’ve seen since man is 99.9 percent caused by man.

RYAN PHELAN is the Executive Director of Revive and Restore, a project within The Long Now Foundation, with a mission to provide deep ecological enrichment through extinct species revival.

[ ED. NOTE: The following conversation took place at the seventh annual Science Foo Camp (SciFoo), hosted by Nature, Digital Science, O’Reilly Media, and Google, August 3 – 5, 2012, at the Googleplex in Mountain View, California. Special thanks to Philip Campbell of Nature, Timo Hannay of Digital Science, Tim O’Reilly of O’Reilly Media (“Foo” stands for “friends of O’Reilly”), and Chris DiBona and Cat Allman of Google. —JB ]

TO BRING BACK THE EXTINCT

[RYAN PHELAN:] The big question that I’m asking right now is: If we could bring back an extinct species, should we? Could we? Should we? How does it benefit society? How does it advance the science? And the truth is, we’re just at the beginning of trying to figure all this out. I got inspired really thinking about this through my involvement with George Church, and I’ve been on the periphery of an organization that he started called The Personal Genome Project. Over the last seven years I’ve been working primarily in personalized medicine, keeping my eye on the application of genomic medicine in different areas, and the growth of genomics and the shockingly drop in the sequencing price, and the cost of sequencing, and what that means to all different areas of science.

One thing led to another and we started talking with George about what it would mean if we could actually apply this towards the de-extinction of species. It turns out, of course, that in George’s lab he’s pioneering in all these methods. Right now, George’s approach of basically editing the genome starts to make the concept of bringing something back really plausible.

Video

There are right now probably three different methods that are being used to contemplate bringing back species. The most traditional is what they refer to as back breeding, and we see that going on right now with the ancient cattle called aurochs. Basically, what they do is they start by taking the strains of cattle that are closest to the ancient aurochs and try to breed back in much the way they do with plant biology and hybridization.

The other area that is being done is in cloning, and the best example of that is with the Spanish Pyrenean ibex (a wild mountain goat). They actually were able to get some cellular matter from the last remaining ibex to clone. The Spanish scientists that did all that work feel that that cloning is completely viable. The truth is that when they did that ibex, it only lasted seven minutes, because of a particular lung frailty. That’s quite common in cloning anything. That is just something that cloning technology has to deal with, so he feels really confident if he had funding he could clone an extinct species now without a problem, and solve the lung issue.

The third concept is the one that we’re focused on right now: genome editing that George Church is pioneering. The way it would work (and again, I’m not the scientist here, George is better to explain it) the idea would be to take the most closely related extant living species and actually compare it genomically with the extinct species, and basically gene by gene match it, and edit it accordingly.

The species of choice right now that we’re looking at helping, aiding, and abetting, is the passenger pigeon, and the passenger pigeon, as you may know, is an iconic bird that had flocks in the billions just over a hundred years ago. A hundred and fifty years ago the passenger pigeon darkened the sky when it would pass. They say that these flocks were so thick in the sky that when they passed it could take a mile for a flock of birds to go by. They would darken the sky. It’s an amazing concept. We don’t have anything like that today. When that happened, it went from being the most prolific bird, and in just 30 years to being extinct. Why does that matter? Well, it matters for a lot of reasons. What was going on ecologically there? What did that bird bring to that whole eastern deciduous forest? God knows, it had a tremendous impact. I think we’re just now trying to figure out what would that impact might be like today if you were to reintroduce it.

The idea with the passenger pigeon is to take a closely related relative, which is the and-tailed pigeon, and sequence that genome. We’re sequencing that right now at Harvard, with an intern that we’re helping to fund, named Ben Novak. Right now we’re in the process of doing that work, and then they will basically edit the band-tail genome until the band-tail walks, and talks, and flies like a passenger pigeon. That’s how resurgence will occur.

We’re using the term “resurgence” because as you can imagine, there’s a lot of controversy over if you could bring back an extinct species, is it invasive? Would it become an invasive species? And is this a bad thing?

We’re in the process of starting a new organization. It’s called Revive and Restore. If we were to say it has a mission, it’s to help rethink extinction, to basically bring back extinct species if it’s the right thing to do. We’re contemplating the ethics involved in all this. This fall we’ll have a conference that we’re sponsoring in Washington DC, and I think it’s going to be thrilling. We’re bringing in 25 to 35 the scientists from all over the world that are actually doing extinction work— from the Korean team that’s working on the wooly mammoth, to the New Zealand and Australian teams that are de-extincting some species yet to be identified. They’re calling it the Lazarus Project. We don’t really know what it is. It could be the Moa. There are different theories about what it is. But, hopefully, in the fall we’ll learn more about that.

We’ll be talking with these scientists about the different technologies that they’re deploying, of which this genome hybridization technique that George is doing is going to be one and I’m sure there are others. We’ll be talking about the ethics of re-wilding. It’s one thing to actually bring back a species in the lab. It’s another to actually release it into the wild. And so we’ll be talking to scientists that are working in captive breeding, like the San Diego Zoo, with the California ondor. We’ll be talking with the frozen zoos that are doing this kind of banking of genetic material, and trying to figure out what kind of ethical framework we could create, so that when these scientists actually start to succeed in these fields we can somehow socialize this in the public discourse.

What I fear, quite honestly, is backlash that we’ve seen around genetically modified foods, that these organisms will be deemed genetically modified, which, of course, they are. This is genome engineering, and there may be way too much of a concern over what happens when they go into the wild.

One of the fundamental questions here is, is extinction a good thing? Is it “nature’s way”? And if it’s nature’s way, who in the world says anyone should go about changing nature’s way? If something was meant to go extinct, then who are we to screw around with it and bring it back? I don’t think it’s really nature’s way. I think that the extinction that we’ve seen since man is 99.9 percent caused by man.

I’m going to just take the passenger pigeon as an example, not because it’s my favorite bird, but because it’s so iconic. If we are the ones that are responsible for blasting it out of the sky, do we have a little bit of responsibility to think about bringing it back now that we have science that can easily allow for it? I say “easily,” but in the scheme of things, it’s still going to be a lot of heavy lifting to help make this happen.

What does all this mean to the average citizen? A good example of a reintroduction of a species is the peregrine falcon. The peregrine falcon had actually gone extinct as a species in the East. For many of us bird lovers, we love the peregrine falcon. We love seeing that bird fly and soar like it does. But, it was really only through captive breeding and a reintroduction of a sub-species from the Rocky Mountain area that we even have a peregrine now flourishing on the East Coast. Where the peregrine falcon really wants to nest is on bridges or on the sides of skyscrapers, and that bird is now evolving into a bird that is better adapted for working in an urban environment.

What’s going to happen is, even if we were to have a passenger pigeon, they’re not going to be in the flocks of the billions any more. Their impact with agriculture will be lessened, because of an obvious reduction in size. The truth is, if anything happened with that bird, we know it’s a tremendous game bird that people loved, and probably people would be shooting it for good meat, good game.

One question is: If you could actually bring back anything, would you bring back the California grizzly bear? A species that could eat people? Well, we recently were at the California Academy of Sciences, up front and personal with “Monarch”, the last California grizzly, a beautiful specimen there, and we were joking, and not really joking, saying, “Well, what if you could genome edit the California grizzly so that it didn’t like the taste of people?” That would be kind of interesting! Big megafauna, good for the land, but take the fear of it out for people. The truth is all of this could someday be possible.

Some people have said to us, “Well, are you one click away from “Jurassic Park” here?” The truth is, we’re not. “Jurassic Park” was a good movie, if that, but the science is not there at all today, and the reason for that is that we don’t have a close relative of the dinosaurs. We just don’t have it. The only reason that this concept of bringing back an extinct species works right now is if you can take those genomes and actually edit them based on either a close living relative, or you’ve got viable cell tissue, and we don’t have that. So right now that one is not a worry. But could it be someday? Sure.

The concept of Revive and Restore is an idea that might well blossom on the West Coast, here in Silicon Valley, but the truth is that the pressures that I think all these scientists who are working in de-extinction worldwide will feel will be around this whole question of: Who are you to play God and bring back an extinct species? Who are you to introduce something that could be “invasive”? Whether it’s in academia or it’s being done in industry, I think the science is going to be challenged around this really intriguing issue. That’s why I think an organization like Revive and Restore can actually help with the public discourse.

Somebody has to responsibly help the industry and academia think through these heady issues, and I think we’re going to start that dialogue this fall. But in the absence of it, what we’re going to see is the, “Oh, my God, we’re cloning this dangerous species again,” or we’re doing something horrific with our chicken to avoid the Avian flu. These things are going to happen.

Everyone wants to bring up the Neanderthals, and interestingly enough, anyone who’s working around the Neanderthal genome is reluctant to participate in our fall workshop, because they last thing they want is to be criticized or implicated in bringing back a Neanderthal. It’s just verboten.

I’ve been dealing with this whole genetic exceptionalism now for almost a decade with personalized medicine. There has always been a hypersensitivity to anything genetic and I’m looking forward to when we get over that.

The most interesting part of all this is going to be where the science goes, what we learn from doing this. It’s not going to be necessarily about bringing back something. It’s going to be about what we learn.

Just like everything that we know that’s really innovative in science, you never know the unintended benefits or what the outcomes are going to be. Specifically, around the study of extinct species we’re going to probably learn what made them vulnerable to extinction. The implications for endangered species are tremendous. We don’t really know why things go extinct. We can surmise, but right now we could actually start to look at the genetic level, at what some of these contributory factors were, and I think that’s really exciting.

THE REALITY CLUB:

Jennifer Jacquet: To the question of who is Ryan Phelan, or anybody else, to bring an extinct species back I would counter: who was anyone to make these animals extinct to begin with? An estimated 869 species have gone officially and, so far, irreversibly extinct just since the 16th century, and 290 more species are considered critically endangered and possibly extinct — and in almost all cases the finger points to humans. Many of these disappearances, like the Tasmanian tiger, the Great auk, and the Steller’s sea cow, were precipitated by a relatively small group that never asked their fellow earthlings, let alone future generations, if they wanted these animals gone forever. Should the entire group have been queried, my guess is that its majority, certainly in the case of the large, delicate, and vegetarian Steller’s sea cow, would have answered in a resounding “No.” (Admittedly the response might be different in the case of the saber-toothed cat, for instance, which went extinct not long after the invention of farming.) To be in favor of human-induced extinction seems one of the pillars of myopia.

But what is a genome edited songbird brought back from extinction to do against the poachers in the Mediterranean? What happens when the reconstituted baby Yangtze River dolphin (last seen in 2005) is released into still sullied Chinese waters? We already have captive-bred tigers, but that hasn’t stopped the habitat fragmentation and human takeover that has led to fewer than 3500 wild tigers (there were 100,000 in 1900) today in India. In other words, does this technical solution, which is elegant and scientifically interesting, as Phelan points out, distract from old boring problems? Or does it necessitate more work on pollution, habitat loss, and human behavior because the species that would be the usual victims now have a shot at immortality?

Bonobo genius makes stone tools like early humans did (New Scientist)

30/08/2012UncategorizedCognição, Evolução, Evolucionismo, Macacos, Primatologia, Tecnologiarenzotaddei

13:09 21 August 2012 by Hannah Krakauer

Video: Watch this bonobo go to all ends to get food

Kanzi the bonobo continues to impress. Not content with learning sign language or making up “words” for things like banana or juice, he now seems capable of making stone tools on a par with the efforts of early humans.

Even a human could manage this <i>(Image: Elizabeth Rubert-Pugh (Great Ape Trust of Iowa/Bonobo Hope Sanctuary))</i>

Even a human could manage this (Image: Elizabeth Rubert-Pugh (Great Ape Trust of Iowa/Bonobo Hope Sanctuary))

Eviatar Nevo of the University of Haifa in Israel and his colleagues sealed food inside a log to mimic marrow locked inside long bones, and watched Kanzi, a 30-year-old male bonobo chimp, try to extract it. While a companion bonobo attempted the problem a handful of times, and succeeded only by smashing the log on the ground, Kanzi took a longer and arguably more sophisticated approach.

Both had been taught to knap flint flakes in the 1990s, holding a stone core in one hand and using another as a hammer. Kanzi used the tools he created to come at the log in a variety of ways: inserting sticks into seams in the log, throwing projectiles at it, and employing stone flints as choppers, drills, and scrapers. In the end, he got food out of 24 logs, while his companion managed just two.

Perhaps most remarkable about the tools Kanzi created is their resemblance to early hominid tools. Both bonobos made and used tools to obtain food – either by extracting it from logs or by digging it out of the ground. But only Kanzi’s met the criteria for both tool groups made by early Homo: wedges and choppers, and scrapers and drills.

Do Kanzi’s skills translate to all bonobos? It’s hard to say. The abilities of animals like Alex the parrot, who could purportedly count to six, and Betty the crow, who crafted a hook out of wire, sometimes prompt claims about the intelligence of an entire species. But since these animals are raised in unusual environments where they frequently interact with humans, their cases may be too singular to extrapolate their talents to their brethren.

The findings will fuel the ongoing debate over whether stone tools mark the beginning of modern human culture, or predate our Homo genus. They appear to suggest the latter – though critics will point out that Kanzi and his companion were taught how to make the tools. Whether the behaviour could arise in nature is unclear.

Journal reference: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1212855109

Populations Survive Despite Many Deleterious Mutations: Evolutionary Model of Muller’s Ratchet Explored (Science Daily)

17/08/2012UncategorizedBiologia, Caos, ciência, Evolução, Evolucionismo, Incerteza, Previsãorenzotaddei

ScienceDaily (Aug. 10, 2012) — From protozoans to mammals, evolution has created more and more complex structures and better-adapted organisms. This is all the more astonishing as most genetic mutations are deleterious. Especially in small asexual populations that do not recombine their genes, unfavourable mutations can accumulate. This process is known as Muller’s ratchet in evolutionary biology. The ratchet, proposed by the American geneticist Hermann Joseph Muller, predicts that the genome deteriorates irreversibly, leaving populations on a one-way street to extinction.

Equilibrium of mutation and selection processes: A population can be divided into groups of individuals that carry different numbers of deleterious mutations. Groups with few mutations are amplified by selection but loose members to other groups by mutation. Groups with many mutations don’t reproduce as much, but gain members by mutation. (Credit: © Richard Neher/MPI for Developmental Biology)

In collaboration with colleagues from the US, Richard Neher from the Max Planck Institute for Developmental Biology has shown mathematically how Muller’s ratchet operates and he has investigated why populations are not inevitably doomed to extinction despite the continuous influx of deleterious mutations.

The great majority of mutations are deleterious. “Due to selection individuals with more favourable genes reproduce more successfully and deleterious mutations disappear again,” explains the population geneticist Richard Neher, leader of an independent Max Planck research group at the Max Planck Institute for Developmental Biology in Tübingen, Germany. However, in small populations such as an asexually reproducing virus early during infection, the situation is not so clear-cut. “It can then happen by chance, by stochastic processes alone, that deleterious mutations in the viruses accumulate and the mutation-free group of individuals goes extinct,” says Richard Neher. This is known as a click of Muller’s ratchet, which is irreversible — at least in Muller’s model.

Muller published his model on the evolutionary significance of deleterious mutations in 1964. Yet to date a quantitative understanding of the ratchet’s processes was lacking. Richard Neher and Boris Shraiman from the University of California in Santa Barbara have now published a new theoretical study on Muller’s ratchet. They chose a comparably simple model with only deleterious mutations all having the same effect on fitness. The scientists assumed selection against those mutations and analysed how fluctuations in the group of the fittest individuals affected the less fit ones and the whole population. Richard Neher and Boris Shraiman discovered that the key to the understanding of Muller’s ratchet lies in a slow response: If the number of the fittest individuals is reduced, the mean fitness decreases only after a delay. “This delayed feedback accelerates Muller’s ratchet,” Richard Neher comments on the results. It clicks more and more frequently.

“Our results are valid for a broad range of conditions and parameter values — for a population of viruses as well as a population of tigers.” However, he does not expect to find the model’s conditions one-to-one in nature. “Models are made to understand the essential aspects, to identify the critical processes,” he explains.

In a second study Richard Neher, Boris Shraiman and several other US-scientists from the University of California in Santa Barbara and Harvard University in Cambridge investigated how a small asexual population could escape Muller’s ratchet. “Such a population can only stay in a steady state for a long time when beneficial mutations continually compensate for the negative ones that accumulate via Muller’s ratchet,” says Richard Neher. For their model the scientists assumed a steady environment and suggest that there can be a mutation-selection balance in every population. They have calculated the rate of favourable mutations required to maintain the balance. The result was surprising: Even under unfavourable conditions, a comparably small proportion in the range of several percent of positive mutations is sufficient to sustain a population.

These findings could explain the long-term maintenance of mitochondria, the so-called power plants of the cell that have their own genome and divide asexually. By and large, evolution is driven by random events or as Richard Neher says: “Evolutionary dynamics are very stochastic.”

Why Do Organisms Build Tissues They Seemingly Never Use? (Science Daily)

17/08/2012UncategorizedBiologia, Caos, Evolução, Evolucionismo, Teleologiarenzotaddei

ScienceDaily (Aug. 10, 2012) — Why, after millions of years of evolution, do organisms build structures that seemingly serve no purpose?

A study conducted at Michigan State University and published in the current issue of The American Naturalist investigates the evolutionary reasons why organisms go through developmental stages that appear unnecessary.

“Many animals build tissues and structures they don’t appear to use, and then they disappear,” said Jeff Clune, lead author and former doctoral student at MSU’s BEACON Center of Evolution in Action. “It’s comparable to building a roller coaster, razing it and building a skyscraper on the same ground. Why not just skip ahead to building the skyscraper?”

Why humans and other organisms retain seemingly unnecessary stages in their development has been debated between biologists since 1866. This study explains that organisms jump through these extra hoops to avoid disrupting a developmental process that works. Clune’s team called this concept the “developmental disruption force.” But Clune says it also could be described as “if the shoe fits, don’t change a thing.”

“In a developing embryo, each new structure is built in a delicate environment that consists of everything that has already developed,” said Clune, who is now a postdoctoral fellow at Cornell University. “Mutations that alter that environment, such as by eliminating a structure, can thus disrupt later stages of development. Even if a structure is not actually used, it may set the stage for other functional tissues to grow properly.”

Going back to the roller coaster metaphor, even though the roller coaster gets torn down, the organism needs the parts from that teardown to build the skyscraper, he added.

“An engineer would simply skip the roller coaster step, but evolution is more of a tinkerer and less of an engineer,” Clune said. “It uses whatever parts that are lying around, even if the process that generates those parts is inefficient.”

An interesting consequence is that newly evolved traits tend to get added at the end of development, because there is less risk of disrupting anything important. That, in turn, means that there is a similarity between the order things evolve and the order they develop.

A new technology called computational evolution allowed the team to conduct experiments that would be impossible to reproduce in nature.

Rather than observe embryos grow, the team of computer scientists and biologists used BEACON’s Avida software to perform experiments with evolution inside a computer. The Avidians — self-replicating computer programs — mutate, compete for resources and evolve, mimicking natural selection in real-life organisms. Using this software, Clune’s team observed as Avidians evolved to perform logic tasks. They recorded the order that those tasks evolved in a variety of lineages, and then looked at the order those tasks developed in the final, evolved organism.

They were able to help settle an age-old debate that developmental order does resemble evolutionary order, at least in this computationally evolving system. Because in a computer thousands of generations can happen overnight, the team was able to repeat this experiment many times to document that this similarity repeatedly occurs.

Additional MSU researchers contributing to the study included BEACON colleagues Richard Lenski, Robert Pennock and Charles Ofria. The research was funded by the National Science Foundation.

Why Are People Overconfident So Often? It’s All About Social Status (Science Daily)

17/08/2012UncategorizedClasses sociais, Discriminação, Evolucionismo, Previsão, Psicologia, Statusrenzotaddei

ScienceDaily (Aug. 13, 2012) — Researchers have long known that people are very frequently overconfident — that they tend to believe they are more physically talented, socially adept, and skilled at their job than they actually are. For example, 94% of college professors think they do above average work (which is nearly impossible, statistically speaking). But this overconfidence can also have detrimental effects on their performance and decision-making. So why, in light of these negative consequences, is overconfidence still so pervasive?

The lure of social status promotes overconfidence, explains Haas School Associate Professor Cameron Anderson. He co-authored a new study, “A Status-Enhancement Account of Overconfidence,” with Sebastien Brion, assistant professor of managing people in organizations, IESE Business School, University of Navarra, Haas School colleagues Don Moore, associate professor of management, and Jessica A. Kennedy, now a post-doctoral fellow at the Wharton School of Business. The study will be published in theJournal of Personality and Social Psychology (forthcoming).

“Our studies found that overconfidence helped people attain social status. People who believed they were better than others, even when they weren’t, were given a higher place in the social ladder. And the motive to attain higher social status thus spurred overconfidence,” says Anderson, the Lorraine Tyson Mitchell Chair in Leadership and Communication II at the Haas School.

Social status is the respect, prominence, and influence individuals enjoy in the eyes of others. Within work groups, for example, higher status individuals tend to be more admired, listened to, and have more sway over the group’s discussions and decisions. These “alphas” of the group have more clout and prestige than other members. Anderson says these research findings are important because they help shed light on a longstanding puzzle: why overconfidence is so common, in spite of its risks. His findings suggest that falsely believing one is better than others has profound social benefits for the individual.

Moreover, these findings suggest one reason why in organizational settings, incompetent people are so often promoted over their more competent peers. “In organizations, people are very easily swayed by others’ confidence even when that confidence is unjustified,” says Anderson. “Displays of confidence are given an inordinate amount of weight.”

The studies suggest that organizations would benefit from taking individuals’ confidence with a grain of salt. Yes, confidence can be a sign of a person’s actual abilities, but it is often not a very good sign. Many individuals are confident in their abilities even though they lack true skills or competence.

The authors conducted six experiments to measure why people become overconfident and how overconfidence equates to a rise in social stature. For example:

In Study 2, the researchers examined 242 MBA students in their project teams and asked them to look over a list of historical names, historical events, and books and poems, and then to identify which ones they knew or recognized. Terms included Maximilien Robespierre, Lusitania, Wounded Knee, Pygmalion, and Doctor Faustus. Unbeknownst to the participants, some of the names were made up. These so-called “foils” included Bonnie Prince Lorenzo, Queen Shaddock, Galileo Lovano, Murphy’s Last Ride, and Windemere Wild. The researchers deemed those who picked the most foils the most overly confident because they believed they were more knowledgeable than they actually were. In a survey at the end of the semester, those same overly confident individuals (who said they had recognized the most foils) achieved the highest social status within their groups.

It is important to note that group members did not think of their high status peers as overconfident, but simply that they were terrific. “This overconfidence did not come across as narcissistic,” explains Anderson. “The most overconfident people were considered the most beloved.”

Study 4 sought to discover the types of behaviors that make overconfident people appear to be so wonderful (even when they were not). Behaviors such as body language, vocal tone, rates of participation were captured on video as groups worked together in a laboratory setting. These videos revealed that overconfident individuals spoke more often, spoke with a confident vocal tone, provided more information and answers, and acted calmly and relaxed as they worked with their peers. In fact, overconfident individuals were more convincing in their displays of ability than individuals who were actually highly competent.

“These big participators were not obnoxious, they didn’t say, ‘I’m really good at this.’ Instead, their behavior was much more subtle. They simply participated more and exhibited more comfort with the task — even though they were no more competent than anyone else,” says Anderson.

Two final studies found that it is the “desire” for status that encourages people to be more overconfident. For example, in Study 6, participants read one of two stories and were asked to imagine themselves as the protagonist in the story. The first story was a simple, bland narrative of losing then finding one’s keys. The second story asked the reader to imagine him/herself getting a new job with a prestigious company. The job had many opportunities to obtain higher status, including a promotion, a bonus, and a fast track to the top. Those participants who read the new job scenario rated their desire for status much higher than those who read the story of the lost keys.

After they were finished reading, participants were asked to rate themselves on a number of competencies such as critical thinking skills, intelligence, and the ability to work in teams. Those who had read the new job story (which stimulated their desire for status) rated their skills and talent much higher than did the first group. Their desire for status amplified their overconfidence.

De-emphasizing the natural tendency toward overconfidence may prove difficult but Prof. Anderson hopes this research will give people the incentive to look for more objective indices of ability and merit in others, instead of overvaluing unsubstantiated confidence.

Programa de computador mimetiza evolução humana (Fapesp)

17/08/2012Uncategorizedciência, Enquadramento, Evolução, Evolucionismo, Incerteza, Mediação tecnológica, Previsão, Teleologia, Visualidaderenzotaddei

Software desenvolvido na USP de São Carlos cria e seleciona programas geradores de Árvores de Decisão, ferramentas capazes de fazer previsões. Pesquisa foi premiada nos Estados Unidos, no maior evento de computação evolutiva (Wikimedia)

16/08/2012

Por Karina Toledo

Agência FAPESP – Árvores de Decisão são ferramentas computacionais que conferem às máquinas a capacidade de fazer previsões com base na análise de dados históricos. A técnica pode, por exemplo, auxiliar o diagnóstico médico ou a análise de risco de aplicações financeiras.

Mas, para ter a melhor previsão, é necessário o melhor programa gerador de Árvores de Decisão. Para alcançar esse objetivo, pesquisadores do Instituto de Ciências Matemáticas e de Computação (ICMC) da Universidade de São Paulo (USP), em São Carlos, se inspiraram na teoria evolucionista de Charles Darwin.

“Desenvolvemos um algoritmo evolutivo, ou seja, que mimetiza o processo de evolução humana para gerar soluções”, disse Rodrigo Coelho Barros, doutorando do Laboratório de Computação Bioinspirada (BioCom) do ICMC e bolsista da FAPESP.

A computação evolutiva, explicou Barros, é uma das várias técnicas bioinspiradas, ou seja, que buscam na natureza soluções para problemas computacionais. “É notável como a natureza encontra soluções para problemas extremamente complicados. Não há dúvidas de que precisamos aprender com ela”, disse Barros.

Segundo Barros, o software desenvolvido em seu doutorado é capaz de criar automaticamente programas geradores de Árvores de Decisão. Para isso, faz cruzamentos aleatórios entre os códigos de programas já existentes gerando “filhos”.

“Esses ‘filhos’ podem eventualmente sofrer mutações e evoluir. Após um tempo, é esperado que os programas de geração de Árvores de Decisão evoluídos sejam cada vez melhores e nosso algoritmo seleciona o melhor de todos”, afirmou Barros.

Mas enquanto o processo de seleção natural na espécie humana leva centenas ou até milhares de anos, na computação dura apenas algumas horas, dependendo do problema a ser resolvido. “Estabelecemos cem gerações como limite do processo evolutivo”, contou Barros.

Inteligência artificial

Em Ciência da Computação, é denominada heurística a capacidade de um sistema fazer inovações e desenvolver técnicas para alcançar um determinado fim.

O software desenvolvido por Barros se insere na área de hiper-heurísticas, tópico recente na área de computação evolutiva que tem como objetivo a geração automática de heurísticas personalizadas para uma determinada aplicação ou conjunto de aplicações.

“É um passo preliminar em direção ao grande objetivo da inteligência artificial: o de criar máquinas capazes de desenvolver soluções para problemas sem que sejam explicitamente programadas para tal”, detalhou Barros.

O trabalho deu origem ao artigo A Hyper-Heuristic Evolutionary Algorithm for Automatically Designing Decision-Tree Algorithms, premiado em três categorias na Genetic and Evolutionary Computation Conference (GECCO), maior evento da área de computação evolutiva do mundo, realizado em julho na Filadélfia, Estados Unidos.

Além de Barros, também são autores do artigo os professores André Carlos Ponce de Leon Ferreira de Carvalho, orientador da pesquisa no ICMC, Márcio Porto Basgalupp, da Universidade Federal de São Paulo (Unifesp), e Alex Freitas, da University of Kent, no Reino Unido, que assumiu a co-orientação.

Os autores foram convidados a submeter o artigo para a revista Evolutionary Computation Journal, publicada pelo Instituto de Tecnologia de Massachusetts (MIT). “O trabalho ainda passará por revisão, mas, como foi submetido a convite, tem grande chance de ser aceito”, disse Barros.

A pesquisa, que deve ser concluída somente em 2013, também deu origem a um artigo publicado a convite no Journal of the Brazilian Computer Society, após ser eleito como melhor trabalho no Encontro Nacional de Inteligência Artificial de 2011.

Outro artigo, apresentado na 11ª International Conference on Intelligent Systems Design and Applications, realizada na Espanha em 2011, rendeu convite para publicação na revistaNeurocomputing.

Organisms Cope With Environmental Uncertainty by Guessing the Future (Science Daily)

17/08/2012UncategorizedBiologia, Caos, Evolução, Evolucionismo, Incerteza, Previsãorenzotaddei

ScienceDaily (Aug. 16, 2012) — In uncertain environments, organisms not only react to signals, but also use molecular processes to make guesses about the future, according to a study by Markus Arnoldini et al. from ETH Zurich and Eawag, the Swiss Federal Institute of Aquatic Science and Technology. The authors report in PLoS Computational Biology that if environmental signals are unreliable, organisms are expected to evolve the ability to take random decisions about adapting to cope with adverse situations.

Most organisms live in ever-changing environments, and are at times exposed to adverse conditions that are not preceded by any signal. Examples for such conditions include exposure to chemicals or UV light, sudden weather changes or infections by pathogens. Organisms can adapt to withstand the harmful effects of these stresses. Previous experimental work with microorganisms has reported variability in stress responses between genetically identical individuals. The results of the present study suggest that this variation emerges because individual organisms take random decisions, and such variation is beneficial because it helps organisms to reduce the metabolic costs of protection without compromising the overall benefits.

The theoretical results of this study can help to understand why genetically identical organisms often express different traits, an observation that is not explained by the conventional notion of nature and nurture. Future experiments will reveal whether the predictions made by the mathematical model are met in natural systems.

Modern culture emerged in Africa 20,000 years earlier than thought (L.A.Times)

30/07/2012UncategorizedAntropologia, Cultura, Evolução, Evolucionismo, História, Incerteza, Mediação tecnológica, Tecnologiarenzotaddei

By Thomas H. Maugh II

July 30, 2012, 1:54 p.m.

Objects found in the archaeological site called Border Cave include a) a wooden digging stick; b) a wooden poison applicator; c) a bone arrow point decorated with a spiral incision filled with red pigment; d) a bone object with four sets of notches; e) a lump of beeswax; and f) ostrich eggshell beads and marine shell beads used as personal ornaments. (Francesco d’Errico and Lucinda Backwell/ July 30, 2012)

Modern culture emerged in southern Africa at least 44,000 years ago, more than 20,000 years earlier than anthropologists had previously believed, researchers reported Monday.

That blossoming of technology and art occurred at roughly the same time that modern humans were migrating fromAfrica to Europe, where they soon displaced Neanderthals. Many of the characteristics of the ancient culture identified by anthropologists are still present in hunter-gatherer cultures of Africa today, such as the San culture of southern Africa, the researchers said.

The new evidence was provided by an international team of researchers excavating at an archaeological site called Border Cave in the foothills of the Lebombo Mountains on the border of KwaZulu-Natal in South Africa and Swaziland. The cave shows evidence of occupation by human ancestors going back more than 200,000 years, but the team reported in two papers in the Proceedings of the National Academy of Sciences that they were able to accurately date their discoveries to 42,000 to 44,000 years ago, a period known as the Later Stone Age or the Upper Paleolithic Period in Europe.

Among the organic — and thus datable — artifacts the team found in the cave were ostrich eggshell beads, thin bone arrowhead points, wooden digging sticks, a gummy substance called pitch that was used to attach bone and stone blades to wooden shafts, a lump of beeswax likely used for the same purpose, worked pig tusks that were probably use for planing wood, and notched bones used for counting.

“They adorned themselves with ostrich egg and marine shell beads, and notched bones for notational purposes,” said paleoanthropologist Lucinda Blackwell of the University of Witwatersrand in South Africa, a member of the team. “They fashioned fine bone points for use as awls and poisoned arrowheads. One point is decorated with a spiral groove filled with red ochre, which closely parallels similar marks that San make to identify their arrowheads when hunting.”

The very thin bone points are “very good evidence” for the use of bows and arrows, said co-author Paola Villa, a curator at the University of Colorado Museum of Natural History. Some of the bone points were apparently coated with ricinoleic acid, a poison made from the castor bean. “Such bone points could have penetrated thick hides, but the lack of ‘knock-down’ power means the use of poison probably was a requirement for successful kills,” she said.

The discovery also represents the first time pitch-making has been documented in South Africa, Villa said. The process requires burning peeled bark in the absence of air. The Stone Age residents probably dug holes in the ground, inserted the bark, lit it on fire, and covered the holes with stones, she said.

Hunter-gatherers, Westerners use same amount of energy, contrary to theory (PLoS)

26/07/2012UncategorizedAntropologia, Índios, Caçadores-coletores, ciência, Discriminação, Economia, Enquadramento, Evolucionismorenzotaddei

Lindsay Morton
Public Library of Science

25-Jul-2012

Results contradict previously held idea that rising obesity is due to lowered energy expenditure

Modern lifestyles are generally quite different from those of our hunter-gatherer ancestors, a fact that some claim as the cause of the current rise in global obesity, but new results published July 25 in the open access journal PLoS ONE find that there is no difference between the energy expenditure of modern hunter-gatherers and Westerners, casting doubt on this theory.

The research team behind the study, led by Herman Pontzer of Hunter College in New York City, along with David Raichlen of the University of Arizona and Brian M. Wood of Stanford measured daily energy expenditure (calories per day) among the Hadza, a population of traditional hunter-gatherers living in the open savannah of northern Tanzania. Despite spending their days trekking long distances to forage for wild plants and game, the Hadza burned no more calories each day than adults in the U.S. and Europe. The team ran several analyses accounting for the effects of body weight, body fat percentage, age, and gender. In all analyses, daily energy expenditure among the Hadza hunter-gatherers was indistinguishable from that of Westerners. The study was the first to measure energy expenditure in hunter-gatherers directly; previous studies had relied entirely on estimates.

These findings upend the long-held assumption that our hunter-gatherer ancestors expended more energy than modern populations, and challenge the view that obesity in Western populations results from decreased energy expenditure. Instead, the similarity in daily energy expenditure across a broad range of lifestyles suggests that habitual metabolic rates are relatively constant among human populations. This in turn supports the view that the current rise in obesity is due to increased food consumption, not decreased energy expenditure.

The authors emphasize that physical exercise is nonetheless important for maintaining good health. In fact, the Hadza spend a greater percentage of their daily energy budget on physical activity than Westerners do, which may contribute to the health and vitality evident among older Hadza. Still, the similarity in daily energy expenditure between Hadza hunter-gatherers and Westerners suggests that we have more to learn about human physiology and health, particularly in non-Western settings.

“These results highlight the complexity of energy expenditure. It’s not simply a function of physical activity,” says Pontzer. “Our metabolic rates may be more a reflection of our shared evolutionary past than our diverse modern lifestyles.”

Citation: Pontzer H, Raichlen DA, Wood BM, Mabulla AZP, Racette SB, et al. (2012) Hunter-Gatherer Energetics and Human Obesity. PLoS ONE7(7): e40503. doi:10.1371/journal.pone.0040503

Uma (in)certa antropologia

An (un)certain anthropology

Arquivo da tag: Evolucionismo

Computer Scientists Suggest New Spin On Origins of Evolvability: Competition to Survive Not Necessary? (Science Daily)

The Ethics of Resurrecting Extinct Species (Science Daily)

Something Other Than Adaptation Could Be Driving Evolution (Wired)

Edward O. Wilson: The Riddle of the Human Species (N.Y.Times)

Interview with Edward O. Wilson: The Origin of Morals (Spiegel)

Cultural Evolution Changes Bird Song (Science Daily)

Fluctuating Environment May Have Driven Human Evolution (Science Daily)

How climate shifts in Africa sparked human evolution (MSNBC)

Scientists say landscape transitions may have forced early humans to think on their feet

Human hands evolved for punching (Discovery News)

Dead Guts Spill History of Extinct Microbes: Fecal Samples from Archeological Sites Reveal Evolution of Human Gut Microbes (Science Daily)

Origin of intelligence and mental illness linked to ancient genetic accident (University of Edinburgh)

Scientists have discovered for the first time how humans – and other mammals – have evolved to have intelligence

What do chimps and humans have in common? Gut bacteria (MSNBC)

Far from random, evolution follows a predictable genetic pattern, Princeton researchers find (Princeton)

When Leaving Your Wealth to Your Sister’s Sons Makes Sense (Science Daily)

Evolution mostly driven by brawn, not brains (University College London)

Developmental biologist proposes new theory of early animal evolution (New York Medical College)

Evolution could explain the placebo effect (New Scientist)

To Bring Back the Extinct (Edge)

Bonobo genius makes stone tools like early humans did (New Scientist)

Populations Survive Despite Many Deleterious Mutations: Evolutionary Model of Muller’s Ratchet Explored (Science Daily)

Why Do Organisms Build Tissues They Seemingly Never Use? (Science Daily)

Why Are People Overconfident So Often? It’s All About Social Status (Science Daily)

Programa de computador mimetiza evolução humana (Fapesp)

Organisms Cope With Environmental Uncertainty by Guessing the Future (Science Daily)

Modern culture emerged in Africa 20,000 years earlier than thought (L.A.Times)

Hunter-gatherers, Westerners use same amount of energy, contrary to theory (PLoS)