Arquivo da tag: Evolução

Interdisciplinary approach yields new insights into human evolution (Vanderbilt University)

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Vanderbilt biologist Nicole Creanza Nicole Creanza takes interdisciplinary approach to human evolution as guest editor of Royal Society journal

The evolution of human biology should be considered part and parcel with the evolution of humanity itself, proposes Nicole Creanza, assistant professor of biological sciences. She is the guest editor of a new themed issue of the Philosophical Transactions of the Royal Society B, the oldest scientific journal in the world, that focuses on an interdisciplinary approach to human evolution.

Stanford professor Marc Feldman and Stanford postdoc Oren Kolodny collaborated with Creanza on the special issue.

“Within the blink of an eye on a geological timescale, humans advanced from using basic stone tools to examining the rocks on Mars; however, our exact evolutionary path and the relative importance of genetic and cultural evolution remain a mystery,” said Creanza, who specializes in the application of computational and theoretical approaches to human and cultural evolution, particularly language development. “Our cultural capacities-to create new ideas, to communicate and learn from one another, and to form vast social networks-together make us uniquely human, but the origins, the mechanisms, and the evolutionary impact of these capacities remain unknown.”

The special issue brings together researchers in biology, anthropology, archaeology, economics, psychology, computer science and more to explore the cultural forces affecting human evolution from a wider perspective than is usually taken.

“Researchers have begun to recognize that understanding non-genetic inheritance, including culture, ecology, the microbiome, and regulation of gene expression, is fundamental to fully comprehending evolution,” said Creanza. “It is essential to understand the dynamics of cultural inheritance at different temporal and spatial scales, to uncover the underlying mechanisms that drive these dynamics, and to shed light on their implications for our current theory of evolution as well as for our interpretation and predictions regarding human behavior.”

In addition to an essay discussing the need for an interdisciplinary approach to human evolution, Creanza included an interdisciplinary study of her own, examining the origins of English’s contribution to Sranan, a creole that emerged in Suriname following an influx of indentured servants from England in the 17th century.

Creanza, along with linguists Andre Sherriah and Hubert Devonish of the University of the West Indes and psychologist Ewart Thomas from Stanford, sought to determine the geographic origins of the English speakers whose regional dialects formed the backbone of Sranan. Their work combined linguistic, historical and genetic approaches to determine that the English speakers who influenced Sranan the most originated largely from two counties on opposite sides of southern England: Bristol, in the west, and Essex, in the east.

“Thus, analyzing the features of modern-day languages might give us new information about events in human history that left few other traces,” Creanza said.

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

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GEORGETOWN UNIVERSITY MEDICAL CENTER

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Human societies evolve along similar paths (University of Exeter)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Scientists Seek to Update Evolution (Quanta Magazine)

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

By Carl Zimmer. November 22, 2016

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

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

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

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

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

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

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

But no fisticuffs. At least not yet.

Making Evolution as We Know It

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

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

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

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

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

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

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

Adding to Darwin

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The Return of Natural Selection

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

This article was reprinted on TheAtlantic.com.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


Journal Reference:

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

O bichinho que desafia Deus (El País)

Organismo marinho mostra por que o ser humano não está no topo da evolução

MANUEL ANSEDE

Barcelona 13 JUN 2016 – 21:07 CEST

Os biólogos Ricard Albalat e Cristian Cañestro, com exemplares do 'Oikopleura'.

Os biólogos Ricard Albalat e Cristian Cañestro, com exemplares do ‘Oikopleura’. JUAN BARBOSA 

“Só o acaso pode ser interpretado como uma mensagem. Aquilo que acontece por necessidade, aquilo que é esperado e que se repete todos os dias, não é senão uma coisa muda. Somente o acaso tem voz”, escreveu Milan Kundera em A Insustentável Leveza do Ser. E tem algo que fala, ou melhor, grita, numa praia de Badalona, perto de Barcelona: a que é dominada pela Ponte do Petróleo. Por esse dique de 250 metros, que penetra no mar Mediterrâneo, eram descarregados produtos petrolíferos até o final do século XX. E a seus pés se levanta desde 1870 a fábrica do Anís del Mono, o licor em cujo rótulo aparece um símio com cara de Charles Darwin em referência à teoria da evolução, que gerava polêmica na época.

Hoje, a Ponte do Petróleo é um belo mirante com uma estátua de bronze dedicada ao macaco com rosto darwinista. E, por um acaso que fala, entre seus frequentadores se encontra uma equipe de biólogos evolutivos do departamento de Genética da Universidade de Barcelona. Os cientistas caminham pela passarela sobre o oceano e lançam um cubo para fisgar um animal marinho, o Oikopleura dioica, de apenas três centímetros, mas que possui boca, ânus, cérebro e coração. Parece insignificante, mas, como Darwin, faz estremecer o discurso das religiões. Coloca o ser humano no lugar que lhe corresponde: com o resto dos animais.

“Temos sido mal influenciados pela religião, pensando que estávamos no topo da evolução. Na verdade, estamos no mesmo nível que o dos outros animais”, diz o biólogo Cristian Cañestro. Ele e o colega Ricard Albalat dirigem um dos únicos três centros científicos do mundo dedicados ao estudo do Oikopleura dioica. Os outros dois estão na Noruega e no Japão. O centro espanhol é uma salinha fria, com centenas de exemplares praticamente invisíveis colocados em recipientes de água, num canto da Faculdade de Biologia da Universidade de Barcelona.

O organismo marinho ‘Oikopleura dioica’ indica que a perda de genes ancestrais, compartilhados com os humanos, seria o motor da evolução

“A visão até agora era que, ao evoluir, ganhávamos em complexidade, adquirindo genes. Era o que se pensava quando os primeiros genomas foram sequenciados: de mosca, de minhoca e do ser humano. Mas vimos que não é assim. A maioria de nossos genes está também nas medusas. Nosso ancestral comum os possuía. Não que tenhamos ganhado genes; eles é que perderam. A complexidade genética é ancestral”, diz Cañestro.

Em 2006, o biólogo pesquisava o papel de um derivado da vitamina A, o ácido retinoico, no desenvolvimento embrionário. Essa substância indica às células de um embrião o que têm que fazer para se transformar num corpo adulto. O ácido retinoico ativa os genes necessários, por exemplo, para formar as extremidades, o coração, os olhos e as orelhas dos animais. Cañestro estudava esse processo no Oikopleura. E ficou de boca aberta.

Uma fêmea de 'Oikopleura dioica' cheia de ovos.

Uma fêmea de ‘Oikopleura dioica’ cheia de ovos. CAÑESTRO & ALBALAT LAB

“Os animais utilizam uma grande quantidade de genes para sintetizar o ácido retinoico. Percebi que no Oikopleura dioica faltava um desses genes. Depois vi que faltavam outros. Não encontramos nenhum”, recorda. Esse animal de três milímetros fabrica seu coração, de maneira inexplicável, sem ácido retinoico. “Se você vê um carro se mover sem rodas, nesse dia sua percepção sobre as rodas muda”, diz Cañestro.

O último ancestral comum entre nós e esse minúsculo habitante do oceano viveu há cerca de 500 milhões de anos. Desde então, o Oikopleura perdeu 30% dos genes que nos uniam. E fez isso com sucesso. Se você entrar em qualquer praia do mundo, ali estará ele rodeando o seu corpo. Na batalha da seleção natural, os Oikopleura ganharam. Sua densidade atinge 20.000 indivíduos por metro cúbico de água em alguns ecossistemas marinhos. São perdedores, mas só de genes.

Nosso último ancestral comum viveu há 500 milhões de anos. Desde então, o ‘Oikopleura’ perdeu 30% dos genes que nos uniam

Albalat e Cañestro acabam de publicar na revista especializada Nature Reviews Genetics um artigo que analisa a perda de genes como motor da evolução. Seu texto despertou interesse mundial. Foi recomendado pela F1000Prime, uma publicação internacional que aponta os melhores artigos sobre biologia e medicina. O trabalho começa com uma frase do imperador romano Marco Aurelio, filósofo estoico: “A perda nada mais é do que mudança, e a mudança é um prazer da natureza”.

Os dois biólogos afirmam que a perda de genes pode inclusive ter sido essencial para a origem da espécie humana. “O chimpanzé e o ser humano compartilham mais de 98% do seu genoma. Talvez tenhamos que procurar as diferenças nos genes que foram perdidos de maneira diferente durante a evolução dos humanos e dos demais primatas. Alguns estudos sugerem que a perda de um gene fez com que a musculatura de nossa mandíbula ficasse menor, o que permitiu aumentar o volume do nosso crânio”, diz Albalat. Talvez, perder genes nos tornou mais inteligentes que o resto dos mortais.

Pesquisadores do laboratório de Cristian Cañestro e Ricard Albalat.Pesquisadores do laboratório de Cristian Cañestro e Ricard Albalat. UB

 Em 2012, um estudo do geneticista norte-americano Daniel MacArthur mostrou que, em média, qualquer pessoa saudável tem 20 genes desativados. E isso aparentemente não importa. Albalat e Cañestro, do Instituto de Pesquisa da Biodiversidade (IRBio) da Universidade de Barcelona, citam dois exemplos muito estudados. Em algumas pessoas, os genes que codificam as proteínas CCR5 e DUFFY foram anulados por mutações. São as proteínas usadas, respectivamente, pelo vírus HIV e o parasita causador da malária para entrar nas células. A perda desses genes torna os humanos resistentes a essas doenças.

No laboratório de Cañestro e Albalat, há um cartaz que imita o do filme Cães de Aluguel (“Reservoir Dogs”, em inglês), de Quentin Tarantino: os cientistas e outros membros de sua equipe aparecem vestidos com camisa branca e gravata preta. A montagem se chama Reservoir Oiks, em alusão ao Oikopleura. Os dois biólogos acreditam que o organismo marinho permitirá formular e responder perguntas novas sobre nosso manual de instruções comum: o genoma.

O ‘Oikopleura’ permite estudar quais genes são essenciais: por que algumas mutações são irrelevantes e outras provocam efeitos devastadores em nossa saúde

O cérebro do Oikopleura tem cerca de 100 neurônios e o dos humanos, 86 bilhões. Mas somos muito mais semelhantes do que à primeira vista. Entre 60% e 80% das famílias de genes humanos têm um claro representante no genoma do Oikopleura. “Esse animal nos permite estudar quais genes humanos são essenciais”, diz Albalat. Em outras palavras: por que algumas mutações são irrelevantes e outras provocam efeitos terríveis em nossa saúde.

Os seres vivos possuem um sistema celular que repara as mutações surgidas no DNA. O Oikopleura doica perdeu 16 dos 83 genes ancestrais que regulam esse processo. Essa incapacidade para a autorreparação poderia explicar sua perda extrema de genes, segundo o artigo da Nature Reviews Genetics.

O olhar de Cañestro se ilumina quando ele fala dessas ausências. Os genes costumam atuar em grupo para levar a cabo uma função. Se de um grupo conhecido de oito genes faltam sete no Oikopleura, pois a função foi perdida, a permanência do oitavo gene pode revelar uma segunda função essencial que teria passado despercebida. Esse gene seria como um cruzamento de estradas. Desmantelada uma rodovia, ele sobrevive porque é fundamental em outra. “Essa segunda função já estava no ancestral comum e pode ser importante nos humanos”, diz Cañestro.

“Não existem animais superiores ou inferiores. Nossas peças de Lego são basicamente as mesmas, embora com elas possamos construir coisas diferentes”, afirma. Pense no seu lugar no mundo da próxima vez que mergulhar no mar. Essa neve branca que flutua na água e pode ser vista contra a luz são os excrementos do Oikopleura.

Ancestors of Modern Humans Interbred With Extinct Hominins, Study Finds (N.Y.Times)

Carl Zimmer

Skulls of the Neanderthal man. Credit: European Press photo Agency 

The ancestors of modern humans interbred with Neanderthals and another extinct line of humans known as the Denisovans at least four times in the course of prehistory, according to an analysis of global genomes published Thursday in the journal Science. 

The interbreeding may have given modern humans genes that bolstered immunity to pathogens, the authors concluded.“This is yet another genetic nail in the coffin of our oversimplistic models of human evolution,” said Carles Lalueza-Fox, a research scientist at the Institute of Evolutionary Biology in Barcelona, Spain, who was not involved in the study. 

The new study expands on a series of findings in recent years showing that the ancestors of modern humans once shared the planet with a surprising number of near relatives — lineages like the Neanderthals and Denisovans that became extinct tens of thousands of years ago.

Before disappearing, however, they interbred with our forebears on at least several occasions. Today, we carry DNA from these encounters.

The first clues to ancient interbreeding surfaced in 2010, when scientists discovered that some modern humans — mostly Europeans — carried DNA that matched material recovered from Neanderthal fossils.

Later studies showed that the forebears of modern humans first encountered Neanderthals after expanding out of Africa more than 50,000 years ago.

But the Neanderthals were not the only extinct humans that our own ancestors found. A finger bone discovered in a Siberian cave, called Denisova, yielded DNA from yet another group of humans.

Research later indicated that all three groups — modern humans, Neanderthals and Denisovans — shared a common ancestor who lived roughly 600,000 years ago. And, perhaps no surprise, some ancestors of modern humans also interbred with Denisovans.

Some of their DNA has survived in people in Melanesia, a region of the Pacific that includes New Guinea and the islands around it.

Those initial discoveries left major questions unanswered, such as how often our ancestors interbred with Neanderthals and Denisovans. Scientists have developed new ways to study the DNA of living people to tackle these mysteries.

Joshua M. Akey, a geneticist at the University of Washington, and his colleagues analyzed a database of 1,488 genomes from people around the world. The scientists added 35 genomes from people in New Britain and other Melanesian islands in an effort to learn more about Denisovans in particular.

The researchers found that all of the non-Africans in their study had Neanderthal DNA, while the Africans had very little or none. That finding supported previous studies.

But when Dr. Akey and his colleagues compared DNA from modern Europeans, East Asians and Melanesians, they found that each population carried its own distinctive mix of Neanderthal genes.

The best explanation for these patterns, the scientists concluded, was that the ancestors of modern humans acquired Neanderthal DNA on three occasions.

The first encounter happened when the common ancestor of all non-Africans interbred with Neanderthals.

The second occurred among the ancestors of East Asians and Europeans, after the ancestors of Melanesians split off. Later, the ancestors of East Asians — but not Europeans — interbred a third time with Neanderthals.

Earlier studies had hinted at the possibility that the forebears of modern humans had multiple encounters with Neanderthals, but hard data had been lacking.

“A lot of people have been arguing for that, but now they’re really providing the evidence for it,” said Rasmus Nielsen, a geneticist at the University of California, Berkeley, who was not involved in the new study.

The Melanesians took a different course. After a single interbreeding with Neanderthals, Dr. Akey found, their ancestors went on to interbreed just once with Denisovans as well.

Where that encounter could have taken place remains an enigma. The only place Denisovan remains have been found is Siberia, a long way from New Guinea.

It is possible that Denisovans ranged down to Southeast Asia, Dr. Akey said, crossing paths with modern humans who later settled in Melanesia.

Dr. Akey and his colleagues also identified some regions of Neanderthal and Denisovan DNA that became more common in modern humans as generations passed, suggesting that they provided some kind of a survival advantage.

Many of the regions contain immune system genes, Dr. Akey noted.

“As modern humans are spreading out across the world, they’re encountering pathogens they haven’t experienced before,” he said. Neanderthals and Denisovans may have had genes that were adapted to fight those enemies.

“Maybe they really helped us survive and thrive in these new environments,” he said.

Dr. Akey and his colleagues found that Neanderthal and Denisovan DNA was glaringly absent from four regions of the modern human genome.

That absence may signal that these stretches of the genome are instrumental in making modern humans unique. Intriguingly, one of those regions includes a gene called FOXP2, which is involved in speech.

Scientists suspect that Neanderthals and Denisovans were not the only extinct races our ancestors interbred with.

PingHsun Hsieh, a biologist at the University of Arizona, and his colleagues reported last month that the genomes of African pygmies contained pieces of DNA that came from an unknown source within the last 30,000 years.

Dr. Akey and his colleagues are now following up with an analysis of African populations. “This potentially allows us to find new twigs on the human family tree,” he said.

Fossil analysis pushes back human split from other primates by 2 million years (Los Alamos National Laboratory)

16-FEB-2016

Nature paper places human evolution in Africa, not Eurasia

DOE/Los Alamos National Laboratory

IMAGEIMAGE: TEAM ANALYSIS OF THESE 8-MILLION-YEAR-OLD CHORORAPITHECUS TEETH FOSSILS PROVIDED INSIGHTS INTO THE HUMAN-GORILLA EVOLUTIONARY SPLIT. CREDIT: GEN SUWA

LOS ALAMOS, N.M., February 16, 2015–A paper in the latest issue of the journal Nature suggests a common ancestor of apes and humans, Chororapithecus abyssinicus, evolved in Africa, not Eurasia, two million years earlier than previously thought.

“Our new research supports early divergence: 10 million years ago for the human-gorilla split and 8 million years ago for our split from chimpanzees,” said Los Alamos National Laboratory geologist and senior team member Giday WoldeGabriel. “That’s at least 2 million years earlier than previous estimates, which were based on genetic science that lacked fossil evidence.”

“Our analysis of C. abyssinicus fossils reveals the ape to be only 8 million years old, younger than previously thought. This is the time period when human and African ape lines were thought to have split, but no fossils from this period had been found until now,” WoldeGabriel said.

Chimpanzees, gorillas, orangutans and humans compose the biological family Hominidae. Our knowledge of hominid evolution–that is, when and how humans evolved away from the great ape family tree–has significantly increased in recent years, aided by unearthed fossils from Ethiopia, including the C. abyssinicus, a species of great ape.

The renowned international team that discovered the extinct gorilla-like species C. abyssinicus(reported in the journal Nature in 2007) reports new field observations and geological techniques that the authors say revise the age-constraint of the human split from their brethren.

The authors’ new paper, “New geological and palaeontological age constraint for the gorilla-human lineage split,” was published this week in Nature. WoldeGabriel coauthored the paper and his role was to characterize the volcanic ash and provide chemistry for local and regional correlation of the ashes sandwiching the fossils from Ethiopia’s Chorora area, a region where copious volcanic eruptions and earthquakes entombed fossils recently uplifted via ground motion and erosion.

Filling Gaps in the Fossil Record

Most of the senior members of the Chorora research team also belong to the Middle Awash project team that has recovered the fossil remains of at least eight hominid species, including some of the earliest hominids, spanning nearly 6 million years.

In the 1990s, before this team excavated the gorilla-like C. abyssinicus, they discovered the nearly intact skeleton of the 4.4-million-year-old species Ardipithecus ramidus (nicknamed “Ardi”) and its relative, the million-year-older species Ardipithecus kadabba. These Ardipithecusfossils were the earliest ancestor of humans after they diverged from the main ape lineage of the primate family tree, neither ape-like nor chimp-like, yet not human either. Notably, both were bipedal–they walked upright.

While the team was still investigating Ardi and Kadabba, they published their results about C. abyssinicus. From the collection of nine fossilized teeth from multiple C. abyssinicus individuals, the team surmised that these teeth were gorilla-like, adapted for a fibrous diet. Based on their research from the Chorora, Kadabba and Ardi finds, the team says the common ancestor of chimps and humans lived earlier than had been evidenced by genetic and molecular studies, which placed the split about 5 million years ago.

According to the paper, C. abyssinicus revealed answers about gorilla lineage but also provided fossil evidence that our common ancestor migrated from Africa, not Eurasia, where fossils were more prolific prior to this discovery of multiple skeletons. While some skeptics say that more fossil evidence is needed before they accept this team’s conclusions, many agree that the discovery of a fossil ape from this time period is important since only one other had been found.

Extensive Analysis Provides New Evidence

WoldeGabriel and the research team used a variety of methods to determine the age of teeth they found at the Chorora Formation. They estimated the age of the volcanic rocks and sediments that encased the fossils with argon-dating and paleomagnetic methods. The team investigated patterns of magnetic reversals–another method to determine age based on knowledge about an era’s magnetic orientation–and calibrated the sediments containing the fossils using Geomagnetic Polarity Time Scale (GPTS).

Through fieldwork, volcanic ash chemistry and geochronology, WoldeGabriel helped nail down the age of the fossils to approximately 8 million years old. Based on this new fossil evidence and analysis, the team suggests that the human branch of the tree (shared with chimpanzees) split away from gorillas about 10 million years ago–at least 2 million years earlier than previously claimed.

New appreciation for human micro biome leads to greater understanding of human health (Science Daily)

Date: February 14, 2016

Source: University of Oklahoma

Summary: Anthropologists are studying the ancient and modern human micro biome and the role it plays in human health and disease. By applying genomic and proteomic sequencing technologies to ancient human microbiomes, such as coprolites and dental calculus, as well as to contemporary microbiomes in traditional and industrialized societies, Researchers are advancing the understanding of the evolutionary history of our microbial self and its impact on human health today.


University of Oklahoma anthropologists are studying the ancient and modern human microbiome and the role it plays in human health and disease. By applying genomic and proteomic sequencing technologies to ancient human microbiomes, such as coprolites and dental calculus, as well as to contemporary microbiomes in traditional and industrialized societies, OU researchers are advancing the understanding of the evolutionary history of our microbial self and its impact on human health today.

Christina Warinner, professor in the Department of Anthropology, OU College of Arts and Sciences, will present, “The Evolution and Ecology of Our Microbial Self,” during the American Association for the Advancement of Science panel on Evolutionary Biology Impacts on Medicine and Public Health, at 1:30 pm, Sunday, Feb. 14, 2016 in the Marriott Marshall Ballroom West, Washington, DC. Warinner will discuss how major events, such as the invention of agriculture and the advent of industrialization, have affected the human microbiome.

“We don’t have a complete picture of the microbiome,” Warinner said. “OU research indicates human behavior over the past 2000 years has impacted the gut microbiome. Microbial communities have become disturbed, but before we can improve our health, we have to understand our ancestral microbiome. We cannot make targeted or informed interventions until we know that. Ancient samples allow us to directly measure changes in the human microbiome at specific times and places in the past.”

Warinner and colleague, Cecil M. Lewis, Jr., co-direct OU’s Laboratories of Molecular Anthropology and Microbiome Research and the research focused on reconstructing the ancestral human oral and gut microbiome, addressing questions concerning how the relationship between humans and microbes has changed through time and how our microbiomes influence health and disease in diverse populations, both today and in the past. Warinner and Lewis are leaders in the field of paleogenomics, and the OU laboratories house the largest ancient DNA laboratory in the United States.

Warinner is pioneering the study of ancient human microbiomes, and in 2014 she published the first detailed metagenomics and metaproteomic characterization of the ancient oral microbiome in the journal Nature Genetics. In 2015, she published a study on the identification of milk proteins in ancient dental calculus and the reconstruction of prehistoric European dairying practices. In the same year, she was part of an international team that published the first South American hunter-gatherer gut microbiome and identified Treponema as a key missing ancestral microbe in industrialized societies.

The Big Search to Find Out Where Dogs Come From (New York Times)

An ancient canine skull at the Royal Belgian Institute of Natural Sciences. Scientists are still debating exactly when and where the ancient human-canine bond originated. ANDREW TESTA FOR THE NEW YORK TIMES

By JAMES GORMAN

OXFORD, England — Before humans milked cows, herded goats or raised hogs, before they invented agriculture, or written language, before they had permanent homes, and most certainly before they had cats, they had dogs.

Or dogs had them, depending on how you view the human-canine arrangement. But scientists are still debating exactly when and where the ancient bond originated. And a large new study being run out of the University of Oxford here, with collaborators around the world, may soon provide some answers.

Scientists have come up with a broad picture of the origins of dogs. First off, researchers agree that they evolved from ancient wolves. Scientists once thought that some visionary hunter-gatherer nabbed a wolf puppy from its den one day and started raising tamer and tamer wolves, taking the first steps on the long road to leashes and flea collars. This is oversimplified, of course, but the essence of the idea is that people actively bred wolves to become dogs just the way they now breed dogs to be tiny or large, or to herd sheep.

The prevailing scientific opinion now, however, is that this origin story does not pass muster. Wolves are hard to tame, even as puppies, and many researchers find it much more plausible that dogs, in effect, invented themselves.

Arden Hulme-Beaman cutting a piece from an ancient skull for DNA testing at the Royal Belgian Institute of Natural Sciences in Brussels. ANDREW TESTA FOR THE NEW YORK TIMES

One reason for the conflicting theories, according to Greger Larson, a biologist in the archaeology department at the University of Oxford, is that dog genetics are a mess. In an interview at his office here in November, he noted that most dog breeds were invented in the 19th century during a period of dog obsession that he called “the giant whirlwind blender of the European crazy Victorian dog-breeding frenzy.”

That blender, as well as random breeding by dogs themselves, and interbreeding with wolves at different times over at least the last 15,000 years, created a “tomato soup” of dog genetics, for which the ingredients are very hard to identify, Dr. Larson said.

The way to find the recipe, Dr. Larson is convinced, is to create a large database of ancient DNA to add to the soup of modern canine genetics. And with a colleague, Keith Dobney at the University of Aberdeen, he has persuaded the Who’s Who of dog researchers to join a broad project, with about $2.5 million in funding from the Natural Environment Research Council in England and the European Research Council, to analyze ancient bones and their DNA.

Robert Wayne, an evolutionary biologist at U.C.L.A. who studies the origin of dogs and is part of the research, said, “There’s hardly a person working in canine genetics that’s not working on that project.”

A wolf on display at the Oxford Museum of Natural History. ANDREW TESTA FOR THE NEW YORK TIMES

That is something of a triumph, given the many competing theories in this field. “Almost every group has a different origination hypothesis,” he said.

But Dr. Larson has sold them all on the simple notion that the more data they have, the more cooperative the effort is, the better the answers are going to be. His personality has been crucial to promoting the team effort, said Dr. Wayne, who described Dr. Larson as “very outgoing, gregarious.” Also, Dr. Wayne added, “He has managed not to alienate anyone.”

Scientists at museums and universities who are part of the project are opening up their collections. So to gather data, Dr. Larson and his team at Oxford have traveled the world, collecting tiny samples of bone and measurements of teeth, jaws and occasionally nearly complete skulls from old and recent dogs, wolves and canids that could fall into either category. The collection phase is almost done, said Dr. Larson, who expects to end up with DNA from about 1,500 samples, and photographs and detailed measurements of several thousand.

Scientific papers will start to emerge this year from the work, some originating in Oxford, and some from other institutions, all the work of many collaborators.

Dr. Larson is gambling that the project will be able to determine whether the domestication process occurred closer to 15,000 or 30,000 years ago, and in what region it took place. That’s not quite the date, GPS location and name of the ancient hunter that some dog lovers might hope for.

But it would be a major achievement in the world of canine science, and a landmark in the analysis of ancient DNA to show evolution, migrations and descent, much as studies of ancient hominid DNA have shown how ancient humans populated the globe and interbred with Neanderthals.

And why care about the domestication of dogs, beyond the obsessive interest so many people have in their pets? The emergence of dogs may have been a watershed.

“Maybe dog domestication on some level kicks off this whole change in the way that humans are involved and responding to and interacting with their environment,” he added. “I don’t think that’s outlandish.”

Shepherding the Research

Dr. Larson is no stranger to widely varying points of view. He is an American, but recently became a British citizen as well. His parents are American and he visited the United States often as a child, but he was born in Bahrain and grew up in Turkey and Japan, places where his parents were teaching in schools on American military bases.

He graduated from Claremont McKenna College in California and received his Ph.D. at Oxford. In between college and graduate studies, he spent a year searching for the bed of an ancient river in Turkmenistan, and another couple of years setting up an environmental consulting office in Azerbaijan. He had an interest in science as an undergraduate, and some background from a college major in environment, economics and politics, but no set career plans. Instead, his career grew out of intense curiosity, a knack for making friends and a willingness to jump at an opportunity, like the time he managed to tag along on an archaeological dig.

He was staying in Ashgabat, Turkmenistan, and a local man who had helped him rent an old Soviet truck to explore the desert told him some Westerners were arriving to go on a dig, so he wangled his way onto one of the trucks.

“I think everybody there thought I was with somebody else,” Dr. Larson said.

By the time the group stopped to rest and someone asked him who he was, it was too late to question whether he really belonged. “I was a complete stowaway,” he said.

But he could move dirt and speak Russian, and he had some recently acquired expertise — in college drinking games — that he said was in great demand at night. By luck, he said, the researchers on the dig turned out to be “the great and the good of British neolithic archaeology.” One of them was Chris Gosden, the chairman of European Archaeology at Oxford, who later invited him to do a one-year master’s degree in archaeology at Oxford. That eventually led to a Ph.D. program after he spent some time in graduate school in the United States.

The current project began when he became fed up with the lack of ancient DNA evidence in papers about the origin of dogs. He called Dr. Dobney, of the University of Aberdeen in 2011, and said, “We’re doing dogs.”

After receiving the grant from the council in England, he and Dr. Dobney organized a conference in Aberdeen, Scotland, to gather as many people involved in researching dog origins as they could. His pitch to the group was that despite their different points of view, everyone was interested in the best possible evidence, no matter where it led.

“If we have to eat crow, we eat crow,” he said. “It’s science.”

A 32,000-Year-Old Skull

Mietje Germonpré, a paleontologist at the Royal Belgian Institute of Natural Sciences, is one of the many scientists participating in the dog project. She was one of a number of authors on a 2013 paper in Science that identified a skull about 32,000 years old from a Belgian cave in Goyet as an early dog. Dr. Wayne at U.C.L.A. was the senior author on the paper and Olaf Thalmann from the University of Turku in Finland was the first author.

It is typical of Dr. Larson’s dog project that although he disagreed with the findings of the paper, arguing that the evidence just wasn’t there to call the Goyet skull a dog, all of the authors of the paper are working on the larger project with him.

In November in Brussels, holding the priceless fossil, Dr. Germonpré pointed out the wide skull, crowded teeth and short snout of the ancient skull — all indicators to her that it was not a wolf.

“To me, it’s a dog,” she said. Studies of mitochondrial DNA, passed down from females only, also indicated the skull was not a wolf, according to the 2013 paper.

Dr. Germonpré said she thinks dogs were domesticated some time before this animal died, and she leans toward the idea that humans intentionally bred them from wolves.

She holds up another piece of evidence, a reconstruction of a 30,000-year-old canid skull found near Predmostí, in the Czech Republic, with a bone in its mouth. She reported in 2014 that this was a dog. And she says the bone is part of evidence the animal was buried with care. “We think it was deliberately put there,” she said.

But she recognizes these claims are controversial and is willing, like the rest of the world of canine science, to risk damage to the fossils themselves to get more information on not just the mitochondrial DNA but also the nuclear DNA.

To minimize that risk, she talked with Ardern Hulme-Beaman, a postdoctoral researcher with the Oxford team, about where to cut into it. He was nearing the end of months of traveling to Russia, Turkey, the United States and all over Europe to take samples of canid jaws and skulls.

He and Allowyn Evin, now with the National Center for Scientific Research in Montpelier, France, also took many photographs of each jaw and skull to do geometric morphometrics. Software processes detailed photographs from every angle into 3-D recreations that provide much more information on the shape of a bone than length and width measurements.

Dr. Germonpré and Dr. Hulme-Beaman agreed on a spot in the interior of the skull to cut. In the laboratory, he used a small electric drill with a cutting blade to remove a chunk the size of a bit of chopped walnut. An acrid, burning smell indicated that organic material was intact within the bone — a good sign for the potential retrieval of DNA.

Back in Oxford, researchers will attempt to use the most current techniques to get as much DNA as possible out of the sample. There is no stretch of code that says “wolf” or “dog,” any more than there is a single skull feature that defines a category. What geneticists try to establish is how different the DNA of one animal is from another. Adding ancient DNA gives many more points of reference over a long time span.

Dr. Larson hopes that he and his collaborators will be able to identify a section of DNA in some ancient wolves that was passed on to more doglike descendants and eventually to modern dogs. And he hopes they will be able to identify changes in the skulls or jaws of those wolves that show shifts to more doglike shapes, helping to narrow the origins of domestication.

The usual assumption about domestic animals is that the process of taming and breeding them happened once. But that’s not necessarily so. Dr. Larson and Dr. Dobney showed that pigs were domesticated twice, once in Anatolia and once in China. The same could be true of dogs.

Only the Beginning

Although the gathering of old bones is almost done, Dr. Larson is still negotiating with Chinese researchers for samples from that part of the world, which he says are necessary. But he hopes they will come.

If all goes well, said Dr. Larson, the project will publish a flagship paper from all of the participants describing their general findings. And over the next couple of years, researchers, all using the common data, will continue to publish separate findings.

Other large collaborative efforts are brewing, as well. Dr. Wayne, at U.C.L.A., said that a group in China was forming with the goal of sequencing 10,000 dog genomes. He and Dr. Larson are part of that group.

Last fall, Dr. Larson was becoming more excited with each new bit of data, but not yet ready to tip his hand about what conclusions the data may warrant, or how significant they will be.

But he is growing increasingly confident that they will find what they want, and come close to settling the thorny question of when and where the tearing power of a wolf jaw first gave way to the persuasive force of a nudge from a dog’s cold nose.

“I’m starting to drink my own Kool-Aid,” he said.

Ancient viral molecules essential for human development (Science Daily)

Date: November 23, 2015

Source: Stanford University Medical Center

Summary: Genetic material from ancient viral infections is critical to human development, according to researchers.


Rendering of a virus among blood cells. Credit: © ysfylmz / Fotolia

Genetic material from ancient viral infections is critical to human development, according to researchers at the Stanford University School of Medicine.

They’ve identified several noncoding RNA molecules of viral origins that are necessary for a fertilized human egg to acquire the ability in early development to become all the cells and tissues of the body. Blocking the production of this RNA molecule stops development in its tracks, they found.

The discovery comes on the heels of a Stanford study earlier this year showing that early human embryos are packed full of what appear to be viral particles arising from similar left-behind genetic material.

“We’re starting to accumulate evidence that these viral sequences, which originally may have threatened the survival of our species, were co-opted by our genomes for their own benefit,” said Vittorio Sebastiano, PhD, an assistant professor of obstetrics and gynecology. “In this manner, they may even have contributed species-specific characteristics and fundamental cell processes, even in humans.”

Sebastiano is a co-lead and co-senior author of the study, which will be published online Nov. 23 in Nature Genetics. Postdoctoral scholar Jens Durruthy-Durruthy, PhD, is the other lead author. The other senior author of the paper is Renee Reijo Pera, PhD, a former professor of obstetrics and gynecology at Stanford who is now on the faculty of Montana State University.

Sebastiano and his colleagues were interested in learning how cells become pluripotent, or able to become any tissue in the body. A human egg becomes pluripotent after fertilization, for example. And scientists have learned how to induce other, fully developed human cells to become pluripotent by exposing them to proteins known to be present in the very early human embryo. But the nitty-gritty molecular details of this transformative process are not well understood in either case.

An ancient infection

The researchers knew that a type of RNA molecules called long-intergenic noncoding, or lincRNAs, have been implicated in many important biological processes, including the acquisition of pluripotency. These molecules are made from DNA in the genome, but they don’t go on to make proteins. Instead they function as RNA molecules to affect the expression of other genes.

Sebastiano and Durruthy-Durruthy used recently developed RNA sequencing techniques to examine which lincRNAs are highly expressed in human embryonic stem cells. Previously, this type of analysis was stymied by the fact that many of the molecules contain highly similar, very repetitive regions that are difficult to sequence accurately.

They identified more than 2,000 previously unknown RNA sequences, and found that 146 are specifically expressed in embryonic stem cells. They homed in on the 23 most highly expressed sequences, which they termed HPAT1-23, for further study. Thirteen of these, they found, were made up almost entirely of genetic material left behind after an eons-ago infection by a virus called HERV-H.

HERV-H is what’s known as a retrovirus. These viruses spread by inserting their genetic material into the genome of an infected cell. In this way, the virus can use the cell’s protein-making machinery to generate viral proteins for assembly into a new viral particle. That particle then goes on to infect other cells. If the infected cell is a sperm or an egg, the retroviral sequence can also be passed to future generations.

HIV is one common retrovirus that currently causes disease in humans. But our genomes are also littered with sequences left behind from long-ago retroviral infections. Unlike HIV, which can go on to infect new cells, these retroviral sequences are thought to be relatively inert; millions of years of evolution and accumulated mutations mean that few maintain the capacity to give instructions for functional proteins.

After identifying HPAT1-23 in embryonic stem cells, Sebastiano and his colleagues studied their expression in human blastocysts — the hollow clump of cells that arises from the egg in the first days after fertilization. They found that HPAT2, HPAT3 and HPAT5 were expressed only in the inner cell mass of the blastocyst, which becomes the developing fetus. Blocking their expression in one cell of a two-celled embryo stopped the affected cell from contributing to the embryo’s inner cell mass. Further studies showed that the expression of the three genes is also required for efficient reprogramming of adult cells into induced pluripotent stem cells.

Sequences found only in primates

“This is the first time that these virally derived RNA molecules have been shown to be directly involved with and necessary for vital steps of human development,” Sebastiano said. “What’s really interesting is that these sequences are found only in primates, raising the possibility that their function may have contributed to unique characteristics that distinguish humans from other animals.”

The researchers are continuing their studies of all the HPAT molecules. They’ve learned that HPAT-5 specifically affects pluripotency by interacting with and sequestering members of another family of RNAs involved in pluripotency called let-7.

“Previously retroviral elements were considered to be a class that all functioned in basically the same way,” said Durruthy-Durruthy. “Now we’re learning that they function as individual elements with very specific and important roles in our cells. It’s fascinating to imagine how, during the course of evolution, primates began to recycle these viral leftovers into something that’s beneficial and necessary to our development.”


Journal Reference:

  1. Jens Durruthy-Durruthy, Vittorio Sebastiano, Mark Wossidlo, Diana Cepeda, Jun Cui, Edward J Grow, Jonathan Davila, Moritz Mall, Wing H Wong, Joanna Wysocka, Kin Fai Au, Renee A Reijo Pera. The primate-specific noncoding RNA HPAT5 regulates pluripotency during human preimplantation development and nuclear reprogrammingNature Genetics, 2015; DOI: 10.1038/ng.3449

Borboletas estão encolhendo por causa das mudanças climáticas (O Globo)

Estudo mostra redução no tamanho de duas espécies na Groenlândia

POR O GLOBO

A Boloria chariclea foi uma das espécies analisadas pelos pesquisadores – Divulgação/Toke T. Hoye

RIO — As mudanças climáticas já provocam impactos sobre a Humanidade, mas também sobre algumas espécies animais. Um estudo publicado ontem na revista científica “Biology Letters” mostra que borboletas na Groenlândia se tornaram menores como resposta ao aumento das temperaturas. Para os pesquisadores, a mudança no tamanho corporal prejudica a mobilidade, que pode causar graves consequências à dinâmica populacional e distribuição geográfica das espécies.

Pesquisadores da Universidade de Aarhus, na Dinamarca, analisaram aproximadamente 4,5 mil borboletas de duas espécies diferentes capturadas entre 1996 e 2013. Os resultados apontaram para uma redução no tamanho das asas, na mesma taxa em ambas as espécies, provocada pelo aumento das temperaturas durante o verão. As espécies estudadas foram a Boloria chariclea e a Colias hecla.

— Nossos estudos mostram que machos e fêmeas seguem o mesmo padrão, que é similar em duas espécies diferentes, o que sugere que o clima exerce um papel importante na determinação do tamanho corporal das borboletas na Groenlândia — explicou Toke T. Hoye, pesquisador da Universidade de Aarhus.Esse é um dos primeiros estudos a acompanhar mudanças no tamanho corporal de uma espécie durante um período de mudanças climáticas, e corrobora pesquisas realizadas em laboratório, mas raramente demonstradas em campo.

A Colias hecla está ficando menor por causa dos verões mais quentes no Ártico – Divulgação/Toke T. Hoye

Experimentos apontam que a mudança no tamanho corporal é uma resposta antecipada às mudanças climáticas, que pode acontecer de duas maneiras. Para algumas espécies, uma temporada maior de alimentação pode resultar no aumento do tamanho, enquanto para outras, alterações metabólicas provocam a perda de energia e consequente redução das dimensões.

— Nós, humanos, usamos mais energia quando está frio, porque precisamos manter a temperatura corporal constante — disse Hoye. — Mas para a larva da borboleta e outros animais de sangue frio, que dependem do ambiente para manter a temperatura, o metabolismo aumenta em temperaturas maiores por causa dos processos bioquímicos que se tornam mais rápidos. Dessa maneira, a larva gasta mais energia do que é capaz de consumir. Nossos resultados indicam que essa mudança é tão significativa que a taxa de crescimento das larvas diminui. E quando as larvas são menores, as borboletas também se tornam menores.

As consequências para as borboletas do Ártico podem ser significativas. Com corpos menores, a mobilidade é reduzida. Como as duas espécies vivem apenas no Norte, a redução no tamanho pode ter graves consequências na dinâmica populacional, e prejudicar a dispersão dos insetos.

— Elas vivem tão ao Norte que não podem se mover para regiões mais frias, e elas provavelmente vão desaparecer da parte mais ao Sul da Groenlândia por causa do aumento da temperatura — disse Hoye. — Além disso, sua capacidade de dispersão está se deteriorando, e corpos menores devem resultar em menor taxa de fecundidade. Então, essas espécies do Ártico devem enfrentar desafios severos causados pela rápida mudança climática.

Leia mais sobre esse assunto em  http://oglobo.globo.com/sociedade/sustentabilidade/borboletas-estao-encolhendo-por-causa-das-mudancas-climaticas-17714284#ixzz3o0Y0gr6z
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Chimpanzés caçadores dão pistas sobre os primeiros humanos (El País)

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

 12 MAY 2015 – 18:14 BRT

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

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

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

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

Os machos mais fortes dessa comunidade respeitam as fêmeas na caça

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

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

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

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

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

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

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

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

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

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

Puppy-Dog Eyes of Science (Savage Minds)

April 24, 2015 – John Hartigan

“Scientists say…” It’s interesting what natural science research starts making the rounds on social media. Mostly on diet or health broadly, and increasingly concerning climate change. On rare occasion—as over the past few days—some reports surface that offer insight into the circulating clutter itself, as in “cute dog” photos. In this instance, they’re opportunities to glimpse changing understandings of big topics, like domestication and evolution.

Links for two articles recently popped up in my Twitter feed: “The Science of Puppy-Dog Eyes” (NYTimes, 4/21/14) and “The Guilty Looking Companion,” Scientific American(4/20/15), both treating the gazing behavior of dogs and its various effects on humans. The first, by Jan Hoffman, reported on a study published in Science (in a themed-column on evolution), titled, “Dogs hijack the human bonding pathway.” The second, by Julie Hecht, “The Guilty Looking Companion,” builds off an article in Behavioral Processes, on a tangled question: “Are owners’ reports of their dogs’ ‘guilty look’ influenced by the dogs’ action and evidence of the misdeed?” Both suggest a far more agential companion species than many people might’ve suspected, but more importantly they each complicate stock domestication narratives suggesting it was something we simply did to them. They also suggest opportunities for extending social analysis beyond the human.

As the title of the Science article suggests, dogs were possibly canny drivers of domestication: “dogs became domesticated in part by adapting to human means of communication: eye contact.” In particular, the speculation is that dogs cleverly “utilized a natural system meant for bonding a parent with his or her child.” Evolutionarily, “the challenge for dogs may simply have been to express a behavioral (and morphological) repertoire that mimicked the cues that elicit caregiving toward our own young. Indeed, these juvenile characteristics of dogs are known to carry a selective advantage with respect to human preferences.” So dogs wile their way into our good graces by coopting the cuteness channel we have for children. To complicate agency a bit further, this seems to all hinge on a bidirectional hormonal mechanism: people and dogs both develop heightened, pleasurable levels of oxytocin from protracted gazing into each other’s eyes. “These findings suggest not only an interspecific effect of oxytocin, but also the exciting possibility of a feedback loop,” since “shifts in oxytocin concentration in a dog might elicit similar changes in a human and vice-versa—just as when a mother bonds with her infant.” Domestication just got a good deal more interesting.

“The guilty looking companion” takes up the theme of sociality and how social bonds are respectively maintained in various species, but also how humans might be duped by our tendency to anthropomorphize dogs as possessing a subjective state approximating shame. The reparative behaviors of appeasement and reconciliation that maintain relationships, practiced by many species, when manifested by dogs, reads easily, to us, as “guilt.” But through a fascinating series of experiments, researchers countered that these canine gestures are just “cohesive displays,” which operate “to reduce conflict, diffuse tension, and reinforce social bonds.” Dogs are not responding to ameliorating a subjective sense of shame at transgressing rules; they are instead “incredibly sensitive to environmental and social cues.” If there’s furniture torn or overturned, the owner is looking for someone to chastise—better grovel or cringe. These behavior are very effective, according to surveys of dog owners, who withhold punishments in the wake of such displays. But Hecht concludes with a caution: “It might just be that we’re anthropomorphizing,” in reference to the viral spew of “dog shamming” photos. “Which, in this case, might not be good for us or our dogs.” Indeed, but what is even more valuable here is the perspective opened up onto thinking about parallel and converging forms of species sociality, beyond the question of who is domesticating who.

On that topic, another recently published science article pursues just these openings, though unfortunately it does not seem to be circulating widely at all. “Testing the myth: Tolerant dogs and aggressive wolves,” in Proceedings B (Royal Society Publishing) reports on findings that indicate “a steeper dominance hierarchy in dogs than in wolves.” While “tolerance” is supposed to be the character trait “selected for,” dogs appear far more aggressive and uncooperative with conspecifics than wolves. The problem with “all domestication theories” to date is that they’ve ignored “apparently contradictory behaviours…observed in dogs and wolf packs.” There’s an enormous amount to this piece, but it may come down to “face,” as Erving Goffman developed the concept. “Visual communication in dogs is somewhat impaired due to their reduced visual (facial as well as bodily) expressions,” which “might lead to an inability to control conflicts in close quarters.” Wolves are far more articulate in reading both gaze and facial features in conspecific communications. Range et al write, “Although dogs and wolves seem to use the same signals overall, it is possible that dogs do not use them as appropriately as wolves”—i.e., they haven’t refined the etiquette of conspecific communications quite as well, though they’re very good at circumventing our conspecific gaze signaling tendencies.

But that “wolves appear tolerant, attentive, and at the same time cooperative towards pack members” is in stark “contrast to the starting point of several recent domestication hypotheses.” Free-ranging dogs—constituting about 76-83% of the global dog population!!—not so much. So the questions swirl as to dogs’ cognitive and emotional processes underlying their intraspecific sociality and how that variously aligns with ours, in the deep past and today.

“Nobres Selvagens” na Ilustríssima (Folha de S.Paulo) de domingo, 22 de fevereiro de 2015

Antropólogos, índios e outros selvagens

RICARDO MIOTO
ilustração ANA PRATA

22/02/2015  03h05

RESUMO Livro do antropólogo Napoleon Chagnon que aborda suas pesquisas entre os ianomâmis é lançado no Brasil. Em entrevista, autor, que direcionou sua carreira para uma interpretação evolutiva do comportamento indígena, fala sobre suas conclusões e comenta a recepção, muitas vezes negativa, de sua obra entre seus pares.

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Sobre Napoleon Chagnon, 76, há só uma unanimidade: trata-se do pesquisador mais polêmico da antropologia contemporânea.É

Nesta entrevista, o americano –que lança agora no Brasil o livro “Nobres Selvagens: Minha Vida entre Duas Tribos Perigosas: os Ianomâmis e os Antropólogos” pelo selo Três Estrelas, do Grupo Folha– afirma que a antropologia brasileira representa o que há de mais atrasado no pensamento anticientífico nessa área.

Chagnon critica ainda alguns brasileiros ligados à temática indígena, como o líder ianomâmi Davi Kopenawa, “manipulado por antropólogos e ONGs”, e o cineasta José Padilha, autor do documentário “Segredos da Tribo”, que “deveria se limitar a filmar Robocop”.

Ana Prata

Chagnon estudou os ianomâmis do Brasil e, principalmente, da Venezuela a partir de 1964 e ao longo de 35 anos, em 25 viagens que totalizaram 5 anos entre os índios. Foi o pioneiro no contato com várias tribos isoladas, que acredita serem uma janela para as sociedades pré-históricas nas quais o gênero Homo viveu por milhões de anos.

Foi visto com antipatia por diversos colegas antropólogos por propor explicações darwinianas para o comportamento dos índios –e dos humanos em geral– e ao escrever, em 1968, um livro em que tratava amplamente da violência entre os índios e no qual, desde o título, “Yanomamö: The Fierce People” (sem tradução no Brasil), chamava os ianomâmis de “o povo feroz”. Despertou inimizades ao se afastar dos colegas antropólogos, que acreditava mais interessados em fazer política do que ciência, e se aproximar de geneticistas.

Foi em 1988, porém, que causou a fúria dos colegas, ao publicar na revista “Science” um estudo mostrando que os homens ianomâmis com assassinatos no currículo eram justamente os que tinham mais mulheres e descendentes. Em termos biológicos, a violência masculina e certo egoísmo humano seriam estratégias reprodutivas bem-sucedidas, ideia que desagradou fortemente seus colegas das humanidades.

O antropólogo sempre defendeu que os índios que estudou guerreavam movidos por uma insaciável vontade de capturar mulheres, enquanto os livros tradicionais de antropologia diziam que a guerra primitiva tinha motivos como a escassez de alimentos ou de terra.

Chagnon diz que seus críticos são marxistas movidos pela ideologia de que os conflitos humanos se explicam pela luta de classes ou por disputas materiais, e não por motivos mais animalescos, como a busca por sucesso sexual.

Ele afirma que nenhum colega pôde apontar falhas nos dados publicados na “Science”. No entanto, antropólogos questionam seu procedimento não só nesse caso como em outros trabalhos (leia ao lado).

Em 2000, o jornalista Patrick Tierney publicou o livro “Trevas no Eldorado” (lançado no Brasil em 2002, pela Ediouro), acusando Chagnon e colegas, entre outras coisas, de terem espalhado sarampo deliberadamente entre os índios. As acusações foram investigadas pela Associação Americana de Antropologia, que inocentou os pesquisadores da grave acusação.

Na entrevista abaixo, feita por telefone, Chagnon trata ainda de temas como a higiene dos índios e os riscos da selva.

*

Folha – O antropólogo Eduardo Viveiros de Castro criticou na internet a publicação do seu livro no Brasil, dizendo que o sr. está ligado à “direita boçalmente cientificista”.

Napoleon Chagnon – A ideia de que o comportamento humano tem uma natureza biológica, moldada pela evolução, além da cultura, sofreu muita oposição nas últimas décadas de quem tem uma visão marxista. Está havendo uma mudança de paradigma, mas os antropólogos brasileiros são o último reduto dessa oposição e sempre tentaram impedir meu trabalho.

Marxistas não gostam de explicações que não envolvam a luta por recursos materiais. Para eles, isso explica tudo. Eles diziam, por exemplo, que a causa da guerra entre os ianomâmis era a escassez de proteína –uma tribo atacaria a outra em busca de carne. Nossas observações mostraram, porém, que não havia correlação. Eles tinham abundância de proteína; lutavam, na verdade, por mulheres.

Nos EUA, cientistas importantes, como meu grande amigo Steven Pinker e o professor Jared Diamond, escreveram recentemente livros demonstrando a relevância crescente da psicologia evolutiva.

Os antropólogos latino-americanos me atacam, mas não têm dados para rebater as conclusões que proponho, porque não gostam de trabalho de campo. Eles gostam de argumentos teóricos, de ficar sentados nas suas cadeiras na universidade fazendo ativismo. No entanto, para entender o mundo, você tem de coletar informações a fim de testar suas previsões e teorias. Essa é a base do método científico. A tendência pós-modernista é dizer que não há verdade, que tudo é social ou político. Isso é a morte da ciência.

Esses críticos dizem que sua visão dos ianomâmis é muito negativa. Citam trechos do seu livro em que o sr. descreve criticamente os hábitos de higiene dos índios, dizendo que eles espalhavam muco em tudo.

Tenho muitas críticas à minha própria civilização também, como o excesso de filas. Os ianomâmis não têm uma teoria da transmissão de doenças via germes. Então assoam o nariz na mão e passam no cabelo, nos outros, até na minha bermuda [risos]. A primeira coisa que quis aprender na língua deles foi “não encoste em mim, suas mãos estão sujas”, mas não adiantou. Você se acostuma.

Na verdade, você percebe que há coisas mais sérias com que se preocupar. A vida na tribo é perigosa. Há muitas cobras. Um bebê de uma tribo ianomâmi em que vivi sumiu, e os pais concluíram que a única explicação era que tivesse sido comido por uma anaconda. Há ainda muitos insetos, há onças, muitos outros incômodos.

Como é a sua relação com o líder ianomâmi Davi Kopenawa?

Ele é manipulado pelos seus mentores, seus conselheiros políticos, a maioria antropólogos e ONGs, que dizem a ele o que ele deve declarar. Ouço que muitos jornalistas brasileiros têm essa percepção, mas sabem que é impopular dizer isso em público.

As entrevistas com ele costumam ser mediadas por antropólogos.

Pois é. Veja, em uma das minhas visitas aos ianomâmis no Brasil, Kopenawa proibiu o piloto do meu avião de utilizar o combustível que tinha guardado perto de uma das tribos em que ele tinha influência. Ele queria a todo custo que eu ficasse isolado na floresta, fez isso deliberadamente. O piloto teve de conseguir combustível com outros colegas. Essa é uma das razões que me levaram a não ter uma opinião muito positiva a respeito dele.

Kopenawa critica vocês por não devolverem amostras de sangue que coletaram entre os índios em 1967 para estudos científicos na área de genética e que foram parar em bancos de universidades dos EUA.

Sou simpático a esse pedido. Mas essas amostras são 99% de tribos venezuelanas, não brasileiras. Seria horrível se entregássemos tal sangue para os ianomâmis brasileiros, como Kopenawa. Uma tribo ficaria muito assustada de saber que seus vizinhos têm o sangue de seus ancestrais, eles acreditam que isso poderia ser utilizado para fazer magia negra, por exemplo.

É importante dizer que, influenciadas por antropólogos, lideranças ianomâmis tornaram impossível hoje, para qualquer pesquisador, ir a suas tribos e coletar amostras de sangue; foram convencidos de que isso foi um crime terrível que cometemos. Dessa forma, nenhum pesquisador da área biomédica pode agora fazer estudos que envolvam coleta de amostras. Os ianomâmis vetaram para sempre qualquer pesquisa que possa beneficiar a sua saúde e dependa de exames de sangue.

Eu gosto muito dos ianomâmis. Fiquei muitos anos com eles. Eles merecem ser mais bem representados. É nítido que eles precisam de instituições que permitam acesso à medicina moderna, por exemplo. Eles precisam de ajuda.

De qualquer forma, eu não coletei amostras de sangue. Eu só ajudei os médicos a fazê-lo. Eu sou antropólogo. Não estou nem aí para o que acontecerá com as amostras de sangue congeladas nos EUA. Mas seria irresponsável se fossem entregues aos índios errados.

O sr. assistiu ao documentário “Os Segredos da Tribo” (2010), do brasileiro José Padilha?

Padilha mentiu para mim, foi muito desonesto. Ele disse que faria um filme equilibrado, mas nunca mencionou que as acusações feitas contra mim foram completamente desmentidas [pela Associação Americana de Antropologia]. Ele contratou um missionário que falava a língua ianomâmi para fazer as entrevistas com os índios. Esse missionário, amigo meu, depois veio me avisar que Padilha direcionava as entrevistas contra mim, que tudo era feito para criar a impressão de que os ianomâmis me odiavam. O filme é ridículo.

Além disso, Padilha lançou o filme e desapareceu, nunca respondeu às minhas ligações. Na apresentação do filme no festival de Sundance, ele não só não me convidou como chamou três antropólogos inimigos meus para debater. Um deles, Terence Turner, que teve participação ativa na elaboração do filme, me acusava de ser o Mengele das tribos ianomâmis. É doentio. Padilha deveria se limitar a filmar “Robocop”.

Depois de trabalhar muitos anos nas universidades do Michigan e de Missouri, o sr. agora é professor aposentado. Aposentou-se também da pesquisa científica?

Não. Continuo trabalhando com os dados que coletei nas tribos ao longo desses anos todos. Estou para publicar vários artigos em revistas importantes, como a “Science”, mostrando o impacto de conceitos caros à biologia, como o parentesco, na organização das tribos ianomâmis. Se os antropólogos brasileiros não gostam do meu trabalho, ainda não viram nada [risos]. No caso do público brasileiro, espero que os leitores encontrem no meu livro agora publicado uma melhor compreensão da natureza humana, seja no comportamento dos povos indígenas ou no de um vizinho.

RICARDO MIOTO, 25, é editor de “Ciência” e “Saúde” da Folha.

ANA PRATA, 34, é artista plástica.

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Livro contribui para distanciar ciências humanas e biológicas

André Strauss

22/02/2015  03h09

Por sua alegada coragem em sustentar hipóteses fundamentadas em princípios darwinianos, o antropólogo americano Napoleon Chagnon, que dedicou sua carreira a estudar a violência entre os índios ianomâmis, apresenta-se em “Nobres Selvagens” [trad. Isa Mara Lando, Três Estrelas, 608 págs., R$ 89,90] como vítima dos mais diversos ataques e preconceitos por parte de seus pares.

Os antropólogos culturais, os religiosos salesianos, os ativistas políticos e os próprios ianomâmis são retratados como grupos ferozes ou biofóbicos. Já Chagnon seria apenas um inocente antropólogo de Michigan. A tese não convence.

Embora o antropólogo pretenda ser um expoente da síntese entre biologia e antropologia, suas proposições são bastante limitadas e, muitas vezes, equivocadas. Exemplo disso é partir do princípio de que uma sociedade não contatada é o mesmo que uma sociedade não impactada, atribuindo aos ianomâmis condição análoga à de sociedades paleolíticas. Propor um contratualismo hobbesiano baseado na luta por mulheres também soa ingênuo.

Em seu livro, Napoleon Chagnon insiste na noção anacrônica de “ciência pura”, desmerecendo a militância pró-indígena dos antropólogos brasileiros como um capricho do politicamente correto.

Mesmo reconhecendo-se que em diversas ocasiões seus detratores exageraram, esse tipo de postura maniqueísta do autor não contribui para a necessária superação dos conflitos epistemológicos e políticos que seguem existindo, ainda que ligeiramente mitigados, entre as chamadas ciências humanas e biológicas.

Um famoso filósofo darwiniano certa vez reconheceu que as teorias antropológicas de cunho biológico têm, inegavelmente, o péssimo hábito de atrair os mais indesejáveis colaboradores. Daí a importância da cada vez maior politização dos bioantropólogos e o movimento explícito por parte deles para impedir que esses associados participem de seus círculos.

Ainda assim, provavelmente Chagnon não é culpado das acusações mais graves que lhe foram imputadas, tal como a de disseminar propositalmente uma epidemia de sarampo entre os indígenas ou a de incentivar, por escambo, que eles declarassem guerras uns contra os outros a fim de que ele pudesse incluir as cenas de violência em um documentário que estava produzindo.

Por outro lado –e isso não se pode negar a Chagnon–, é verdade que as humanidades muitas vezes parecem apresentar aquilo que se convencionou chamar de um “desejo irresistível para a incompreensão”, resultando em acusações injustas e de caráter persecutório.

Algumas décadas atrás, ainda era possível negar a relevância de campos como a genética comportamental, a ecologia humana, a neurociência cognitiva ou a etologia de grandes símios. Atualmente, entretanto, qualquer tentativa de mantê-los fora da esfera antropológica é um exercício vão.

Mais importante, a estratégia comumente utilizada no passado de atrelar os desdobramentos oriundos dessas áreas a implicações nefastas para a dignidade humana, torna-se, além de injusta, muito perigosa.

Juntos, antropólogos e biólogos precisam elaborar uma narrativa capaz de ressignificar esses novos elementos através de uma ótica benigna. Afinal, eles passarão, inevitavelmente, a fazer parte do arcabouço teórico de ambas as disciplinas.

ANDRÉ STRAUSS, 30, é antropólogo do Laboratório de Estudos Evolutivos Humanos da USP e do Instituto Max Planck de Antropologia Evolutiva, na Alemanha.

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Trajetória do pesquisador é marcada por querelas

Marcelo Leite

22/02/2015  03h13

Não é trivial resumir as objeções que a antropologia cultural levanta contra Napoleon Chagnon. A controvérsia tem quase meio século, e a tarefa fica mais complicada quando muitos dos antropólogos relevantes do Brasil se recusam a dar entrevistas sobre o caso.

O panorama se turvou de vez em 2000, com o livro “Trevas no Eldorado”. Nele o jornalista Patrick Tierney acusava Chagnon e o médico James Neel de, em 1968, terem causado uma epidemia de sarampo entre os ianomâmis da Venezuela e experimentado nos índios um tipo perigoso de vacina, além de negar-lhes socorro médico.

Chagnon e Neel foram depois inocentados dessas acusações graves. Bruce Albert, antropólogo e crítico de Chagnon que trabalha há 36 anos com os ianomâmis, já escreveu sobre a ausência de fundamento das alegações de Tierney.

Ana Prata

Nem por isso Albert deixa de assinalar sérios erros éticos da dupla. Para ele, os ianomâmis foram usados, sem saber, como grupo de controle para estudos sobre efeitos de radiação nuclear no sangue de sobreviventes de bombardeios em Hiroshima e Nagasaki.

Chagnon, capataz de Neel na expedição, obtinha amostras de sangue em troca de machados, facões e panelas. Embora essa prática perdurasse nos anos 1960-70, Albert ressalva que regras exigindo consentimento informado já vigiam desde 1947 (Código de Nuremberg) e 1964 (Declaração de Helsinque).

Os reparos ao trabalho de Chagnon abarcam também a própria ciência. Ele se diz superior aos antropólogos tradicionais, que acusa de relativistas pós-modernos, xingamento comum nos setores cientificistas da academia americana.

A polêmica teve início com o livro “Yanomamö: The Fierce People”, em que Chagnon apresentou sua tese de que ianomâmis são uma relíquia ancestral da espécie humana: selvagens com compulsão pela guerra como forma de obter mulheres, escassas devido à prática do infanticídio feminino.

Os críticos da etnografia de Chagnon afirmam que ele nunca comprovou o infanticídio seletivo. Com efeito, a explicação foi abandonada em outros estudos, como um famigerado artigo de 1988 no periódico científico “Science”.

O trabalho recorre a dados demográficos coletados por Chagnon para corroborar sua noção, bem ao gosto da sociobiologia, de que os homens mais violentos eram os que tinham mais mulheres e filhos. Esses seriam os que os ianomâmis chamam “unokai” –segundo o autor, os mais temidos no grupo (e, por isso, mais prolíficos).

Albert, Jacques Lizot e outros antropólogos consideram que ele misturou alhos com bugalhos. “Unokai” não seria um atributo individual, mas o estado de impureza (simbólica) daquele que mata alguém com armas ou feitiçaria, ou mesmo só entra em contato com o sangue de cadáveres de inimigos.

Além disso, em incursões contra outras aldeias, os guerreiros muitas vezes dão golpes e flechadas em adversários já mortos. Isso os tornaria “unokai”, não homicidas.

Os mais admirados não seriam esses, mas os “waitheri”, algo como “valorosos”, que se distinguem não só pela valentia, mas também pela capacidade de liderar, de falar bem, até pelo humor.

Não bastasse isso, os críticos apontam manipulação de números. Para inflar seus dados e chegar a 44% de homens que teriam participado de mortes e tinham até o triplo de filhos na comparação com os não “unokai”, Chagnon teria excluído da amostra jovens de 20 a 25 anos e homens mortos –violentos ou não, com ou sem filhos.

Em fevereiro de 2013, o antropólogo Marshall Sahlins renunciou à Academia Nacional de Ciências dos EUA após o ingresso de Chagnon. Num artigo em que explicava o ato, defendeu que um antropólogo alcança entendimento superior de outros povos quando toma seus integrantes como semelhantes –e não objetos naturais, “selvagens”, ao modo de Chagnon.

“É claro que esse não é o único meio de conhecer os outros. Podemos também utilizar nossa capacidade simbólica para tratá-los como objetos físicos”, escreveu. “Mas não obteremos o mesmo conhecimento dos modos simbolicamente ordenados da vida humana, do que é a cultura, ou até a mesma certeza empírica.”

MARCELO LEITE, 57, é repórter especial e colunista da Folha.

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Morte sistemática de Ianomâmis é um tabu

Leão Serva

23/02/2015  02h00

Folha publicou com grande destaque na edição de domingo (22) a notícia do lançamento do livro “Nobres Selvagens” (pela Três Estrelas, selo do Grupo Folha), de autoria do antropólogo norte-americano Napoleon Chagnon. Títulos na capa e no caderno da Ilustríssima chamaram a obra de “livro tabu”.

Trata-se de um exagero baseado no discurso persecutório do autor, que sempre responde às críticas a seu trabalho com alegações de perseguição pessoal ou boicote. Uma pesquisa no Google News apresenta 872 respostas com notícias sobre o antropólogo e 64 referências ao livro, incluindo veículos de grande prestígio internacional como “The New York Times” e “Washington Post”.

No Brasil, certamente a obra não foi tema de reportagens simplesmente porque não havia sido lançada.

Na edição, textos de Marcelo Leite e André Strauss compilam as principais fragilidades apontadas pelos críticos da obra de Chagnon.

Uma bem importante, no entanto, não foi mencionada: o antropólogo dá pouca importância ao caráter simbólico das expressões da cultura que aparecem nos depoimentos de índios (e de brancos também, é bom que se diga), o que o leva a tomar o que ouve literalmente. Assim, em sua entrevista, é quase infantil a descrição dos perigos de uma aldeia Ianomâmi. Os medos que Chagnon menciona que concentrariam a atenção dos índios para longe dos cuidados médicos (risco de onças e cobras) são próprios de um alienígena. Já os índios criam cobras em casa para comer ratos; sabem que onças têm medo dos homens e, em situações raras, quando se aproximam furtivamente da periferia da aldeia para tocaiar uma criança, logo são capturadas pelos índios, como eu mesmo testemunhei. Não quer dizer que não haja medo, mas o antropólogo o amplifica para reforçar o estereótipo de atraso.

A história de que um casal ianomâmi teria atribuído o desaparecimento de seu filhinho a uma anaconda esfomeada é bizarra: o bebê na aldeia não fica um minuto longe dos outros e uma sucuri no lento processo de engolir uma criança seria vista por dúzias de pessoas e morta. Chagnon certamente não entendeu o que lhe foi dito ou tomou por verdade uma mentira (vale lembrar que um “civilizado” banqueiro suíço também mente).

Em texto mais antigo, Chagnon apontava o gesto de bater no peito, comum em festas de ianomâmis como expressão da violência da cultura desses grupos. Ora, o mesmo movimento pode ser encontrado diariamente em culturas mais “evoluídas”, segundo seu critério, das grandes cidades da Europa e dos EUA (nas missas católicas quando se diz “Minha culpa, minha culpa, minha máxima culpa”) à Mesopotâmia, berço das civilizações (onde soldados contemporâneos reproduzem o gesto antes de ataques de infantaria). Chagnon não leva em conta o alicerce básico do estudo da antropologia, que as culturas humanas são simultâneas, embora diferentes na expressão material.

Por fim, para desfazer as críticas feitas pelo líder Davi Kopenawa, criou a história de que ele é manipulado por antropólogos. A Folha parte dessa premissa para questionar Chagnon: “As entrevistas com ele costumam ser mediadas por antropólogos”, ao que o autor diz: “Pois é”, e segue sua catilinária.

Trata-se de uma inverdade que qualquer repórter que fale bem português ou ianomâmi pode comprovar. Eu entrevistei Kopenawa três vezes em épocas e lugares diferentes, duas delas sem aviso prévio. Me aproximei, pedi para falar e conversamos sem mediação. Uma vez, em seu escritório em Boa Vista, ele pediu que outras pessoas (que eu não conhecia, índios e brancos) saíssem da sala para ser entrevistado. Fala fluentemente um português simples (de brasileiro não universitário) com forte sotaque. É preciso ter calma e prestar atenção, por vezes pedir que repita para entender a pronúncia de algumas palavras.

A última vez que o encontrei foi numa entrevista para a revista Serafina, com hora marcada. Também ficou só, enquanto eu estava acompanhado da jovem fotógrafa Helena Wolfenson, da Folha. É possível que estrangeiros que falem mal ou não falem português precisem de tradutor. E são certamente raras as pessoas que falam português, ianomâmi e línguas estrangeiras. Talvez daí a história de que ele se faça acompanhar de “antropólogos” ou gente de ONG.

*

O que de fato é um “tabu” (aquilo de que não se fala) na imprensa brasileira é o lento processo de abandono dos Ianomâmi à morte, em curso por incompetência ou (depois de tanto tempo) decisão do governo federal.

Como noticiei nesta coluna em maio do ano passado, as mortes de Ianomâmi por problemas de saúde cresceram nos dois governos do PT (Lula e Dilma). Muitas das doenças são simples de evitar, como provam as estatísticas da segunda metade dos anos 1990.

O aumento se deve em grande medida à interrupção dos trabalhos de medicina preventiva nas aldeias e ao crescimento dos gastos com transporte dos doentes das aldeias para a capital de Roraima, Boa Vista.

A maior parte dos custos do Ministério da Saúde com a saúde indígena em Roraima tem sido despejada em frete de aviões para levar índios a Boa Vista. São poucas as empresas de táxi aéreo, as mesmas que levam políticos locais em seus deslocamentos.

Em janeiro do ano passado, quando a entrevistei, a coordenadora do Ministério da Saúde para as áreas indígenas de Roraima, Maria de Jesus do Nascimento, explicou o aumento das mortes dizendo: “Não, dinheiro não falta… Foi problema de gestão, mesmo”.

Na área Ianomâmi, uma médica cubana do programa Mais Médicos se desesperava: “Não tenho antibióticos, não tenho oxigênio, não tenho equipamentos”. Eu perguntei o que fazia: “Não quero mas sou forçada a mandar os índios de avião para Boa Vista”. O meio se tornou o fim. A saúde dos índios se tornou desculpa para enriquecer as empresas de táxi aéreo.

Quem procura no mesmo Google News notícias sobre as mortes de Ianomâmi pela improbidade dos órgãos de saúde local só encontra quatro notícias, uma delas do espanhol El País, as demais noticiando os protestos dos índios e um debate no Congresso.

Esse genocídio lento e discreto é o verdadeiro tabu.

Stone Age humans weren’t necessarily more advanced than Neanderthals (Science Daily)

Date: January 14, 2015

Source: Universite de Montreal

Summary: A multi-purpose bone tool dating from the Neanderthal era has been discovered by researchers, throwing into question our current understanding of the evolution of human behavior. It was found at an archaeological site in France.

The tool in question was uncovered in June 2014 during the annual digs at the Grotte du Bison at Arcy-sur-Cure in Burgundy, France. Extremely well preserved, the tool comes from the left femur of an adult reindeer and its age is estimated between 55,000 and 60,000 years ago. Marks observed on it allow us to trace its history. Obtaining bones for the manufacture of tools was not the primary motivation for Neanderthals hunting — above all, they hunted to obtain the rich energy provided by meat and marrow. Evidence of meat butchering and bone fracturing to extract marrow are evident on the tool. Percussion marks suggest the use of the bone fragment for carved sharpening the cutting edges of stone tools. Finally, chipping and a significant polish show the use of the bone as a scraper. Credit: University of Montreal – Luc Doyon

A multi-purpose bone tool dating from the Neanderthal era has been discovered by University of Montreal researchers, throwing into question our current understanding of the evolution of human behaviour. It was found at an archaeological site in France. “This is the first time a multi-purpose bone tool from this period has been discovered. It proves that Neanderthals were able to understand the mechanical properties of bone and knew how to use it to make tools, abilities usually attributed to our species, Homo sapiens,” said Luc Doyon of the university’s Department of Anthropology, who participated in the digs. Neanderthals lived in Europe and western Asia in the Middle Paleolithic between around 250,000 to 28,000 years ago. Homo sapiens is the scientific term for modern man.

The production of bone tools by Neanderthals is open to debate. For much of the twentieth century, prehistoric experts were reluctant to recognize the ability of this species to incorporate materials like bone into their technological know-how and likewise their ability to master the techniques needed to work bone. However, over the past two decades, many clues indicate the use of hard materials from animals by Neanderthals. “Our discovery is an additional indicator of bone work by Neanderthals and helps put into question the linear view of the evolution of human behaviour,” Doyon said.

The tool in question was uncovered in June 2014 during the annual digs at the Grotte du Bison at Arcy-sur-Cure in Burgundy, France. Extremely well preserved, the tool comes from the left femur of an adult reindeer and its age is estimated between 55,000 and 60,000 years ago. Marks observed on it allow us to trace its history. Obtaining bones for the manufacture of tools was not the primary motivation for Neanderthals hunting — above all, they hunted to obtain the rich energy provided by meat and marrow. Evidence of meat butchering and bone fracturing to extract marrow are evident on the tool. Percussion marks suggest the use of the bone fragment for carved sharpening the cutting edges of stone tools. Finally, chipping and a significant polish show the use of the bone as a scraper.

“The presence of this tool at a context where stone tools are abundant suggests an opportunistic choice of the bone fragment and its intentional modification into a tool by Neanderthals,” Doyon said. “It was long thought that before Homo sapiens, other species did not have the cognitive ability to produce this type of artefact. This discovery reduces the presumed gap between the two species and prevents us from saying that one was technically superior to the other.”

Luc Doyon, Geneviève Pothier Bouchard, and Maurice Hardy published the article “Un outil en os à usages multiples dans un contexte moustérien,” on December 15, 2014 in the Bulletin de la Société préhistorique française. Luc Doyon and Geneviève Potheir Bouchard are affiliated with the Department of Anthropology of the Université de Montréal. Maurice Hardy, who led the archaeological digs at the Grotte du Bison, is affiliated with Université Paris X — Nanterre.

Archaeologists unearth 5,000-year-old ‘third-gender’ caveman (Mother Nature Network)

Caveman was buried like a woman, leading scientists to question his sexual orientation.

Photo: ZUMA Press

Archaeologists investigating a 5,000-year-old Copper Age grave in the Czech Republic believe they may have unearthed the first known remains of a gay or transvestite caveman, reports the Telegraph.
The man was apparently buried as if he were a woman, an aberrant practice for an ancient culture known for its strict burial procedures.
Since the grave dates to between 2900 and 2500 BC, the man would have been a member of the Corded Ware culture, a late Stone Age and Copper Age people named after the unique kind of pottery they produced. Men in this culture were traditionally buried lying on their right side with their heads pointing west, but this man was instead buried on his left side with his head pointing east, which is how women were typically buried.
“From history and ethnology, we know that people from this period took funeral rites very seriously so it is highly unlikely that this positioning was a mistake,” said lead archaeologist Kamila Remisova Vesinova. “Far more likely is that he was a man with a different sexual orientation, homosexual or transsexual.”
Another clue is that Corded Ware men would typically be buried alongside weapons, hammers and flint knives, as well as food and drink to prepare them for their journey to the other side. But this man’s grave instead contained only a traditional egg-shaped pot, which was what women were typically buried with.
With all the evidence taken together, archaeologists are confident that the best explanation for the strange burial is that the man was effeminate, perhaps a homosexual, and possibly a transvestite.
“We believe this is one of the earliest cases of what could be described as a ‘transsexual’ or ‘third gender grave’ in the Czech Republic,” reiterated cooperating archaeologist Katerina Semradova.
Semradova also noted that archaeologists from a previous dig had uncovered a grave from the Mesolithic period where a female warrior was buried as a man, so mixed gender burials, though rare, were not unprecedented.

Read more: http://www.mnn.com/lifestyle/arts-culture/stories/archaeologists-unearth-5000-year-old-third-gender-caveman?utm_content=buffer6fa50&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer#ixzz3KOhZ8gxq

Epigenetics

Transgenerational effects of prenatal exposure to the 1944–45 Dutch famine – BJOG: An International Journal of Obstetrics & Gynaecology

Volume 120, Issue 5, pages 548–554, April 2013

MVE Veenendaal et al.

DOI: 10.1111/1471-0528.12136

http://onlinelibrary.wiley.com/doi/10.1111/1471-0528.12136/full

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Mothers’ stress during 1998 ice storm shows up in children’s DNA, study says (Fox News)

Mothers' stress during 1998 ice storm shows up in children's DNA: study

File photo of the aftermath of an ice storm. (AP Photo/Matt Rourke)

Just how bad was an epic 1998 ice storm in Canada? You can read all about it in the DNA of kids who were born around that time.

An intriguing study in PLoS One finds that women who were especially stressed during the storm gave birth to kids whose immune cells have telltale signs of their mothers’ trouble, reports Raw Story.

The storm was brutal, leaving people without power for more than a month. Researchers at the time surveyed expectant moms to gauge their “objective” distress, measuring things such as how many days they went without electricity.

Then they tracked down their kids more than a decade later and found that moms who were in the most distress bore children whose DNA had specific markers as a result.

The genes affected are related to immune function and sugar metabolism. Toronto’s Globe and Mail has a nice explanation of what’s going on, with help from Suzanne King of McGill University.

It involves “epigenetics,” as opposed to genetics:

  • “An individual’s genetics are like a musical score, and what’s written comes from the mother and father. … Although nothing can change what’s written on the page, environmental factors act as an orchestral conductor might, amplifying some aspects and tempering others, leaving markings, or methylation of the DNA.”

This isn’t necessarily a bad thing.

A pregnant woman in a famine, for instance, might “amplify” traits that would give her child a better chance of surviving—traits that could then backfire in terms of health if the famine goes away.

It’s not clear what, if any, health effects the Canadian kids will see as a result, explains a post at McGill University. But given the genes affected, they might have a greater risk of developing asthma, diabetes, or obesity.

(You can blame your coffee craving on DNA, too.)

This article originally appeared on Newser: Moms’ Stress in Ice Storm Shows Up in Kids’ DNA

Neandertal trait in early human skull suggests that modern humans emerged from complex labyrinth of biology and peoples (Science Daily)

Date: July 7, 2014

Source: Washington University in St. Louis

Summary: Re-examination of a circa 100,000-year-old archaic early human skull found 35 years ago in Northern China has revealed the surprising presence of an inner-ear formation long thought to occur only in Neandertals.

The Xujiayao 15 late archaic human temporal bone from northern China with the extracted temporal labyrinth superimposed on a view of the Xujiayao site. Credit: Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Science

Re-examination of a circa 100,000-year-old archaic early human skull found 35 years ago in Northern China has revealed the surprising presence of an inner-ear formation long thought to occur only in Neandertals.

“The discovery places into question a whole suite of scenarios of later Pleistocene human population dispersals and interconnections based on tracing isolated anatomical or genetic features in fragmentary fossils,” said study co-author Erik Trinkaus, PhD, a physical anthropology professor at Washington University in St. Louis.

“It suggests, instead, that the later phases of human evolution were more of a labyrinth of biology and peoples than simple lines on maps would suggest.”

The study, forthcoming in the Proceedings of the National Academy of Sciences, is based on recent micro-CT scans revealing the interior configuration of a temporal bone in a fossilized human skull found during 1970s excavations at the Xujiayao site in China’s Nihewan Basin.

Trinkaus, the Mary Tileston Hemenway Professor in Arts & Sciences, is a leading authority on early human evolution and among the first to offer compelling evidence for interbreeding and gene transfer between Neandertals and modern human ancestors.

His co-authors on this study are Xiu-Jie Wu, Wu Liu and Song Xing of the Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, and Isabelle Crevecoeur of PACEA, Université de Bordeaux.

“We were completely surprised,” Trinkaus said. “We fully expected the scan to reveal a temporal labyrinth that looked much like a modern human one, but what we saw was clearly typical of a Neandertal. This discovery places into question whether this arrangement of the semicircular canals is truly unique to the Neandertals.”

Often well-preserved in mammal skull fossils, the semicircular canals are remnants of a fluid-filled sensing system that helps humans maintain balance when they change their spatial orientations, such as when running, bending over or turning the head from side-to-side.

Since the mid-1990s, when early CT-scan research confirmed its existence, the presence of a particular arrangement of the semicircular canals in the temporal labyrinth has been considered enough to securely identify fossilized skull fragments as being from a Neandertal. This pattern is present in almost all of the known Neandertal labyrinths. It has been widely used as a marker to set them apart from both earlier and modern humans.

The skull at the center of this study, known as Xujiayao 15, was found along with an assortment of other human teeth and bone fragments, all of which seemed to have characteristics typical of an early non-Neandertal form of late archaic humans.

Trinkaus, who has studied Neandertal and early human fossils from around the globe, said this discovery only adds to the rich confusion of theories that attempt to explain human origins, migrations patterns and possible interbreedings.

While it’s tempting to use the finding of a Neandertal-shaped labyrinth in an otherwise distinctly “non-Neandertal” sample as evidence of population contact (gene flow) between central and western Eurasian Neandertals and eastern archaic humans in China, Trinkaus and colleagues argue that broader implications of the Xujiayao discovery remain unclear.

“The study of human evolution has always been messy, and these findings just make it all the messier,” Trinkaus said. “It shows that human populations in the real world don’t act in nice simple patterns.

“Eastern Asia and Western Europe are a long way apart, and these migration patterns took thousands of years to play out,” he said. “This study shows that you can’t rely on one anatomical feature or one piece of DNA as the basis for sweeping assumptions about the migrations of hominid species from one place to another.”

Journal Reference:

  1. Xiu-Jie Wu, Isabelle Crevecoeur, Wu Liu, Song Xing, and Erik Trinkaus. Temporal labyrinths of eastern Eurasian Pleistocene humansPNAS, July 7, 2014 DOI:10.1073/pnas.1410735111

Insect diet helped early humans build bigger brains: Quest for elusive bugs spurred primate tool use, problem-solving skills (Science Daily)

Date: July 1, 2014

Source: Washington University in St. Louis

Summary: Figuring out how to survive on a lean-season diet of hard-to-reach ants, slugs and other bugs may have spurred the development of bigger brains and higher-level cognitive functions in the ancestors of humans and other primates, suggests new research.

An adult female tufted capuchin monkey of the Sapajus lineage using a stone tool and a sandstone anvil to crack a palm nut as her infant hangs on. Credit: E. Visalberghi

Figuring out how to survive on a lean-season diet of hard-to-reach ants, slugs and other bugs may have spurred the development of bigger brains and higher-level cognitive functions in the ancestors of humans and other primates, suggests research from Washington University in St. Louis.

“Challenges associated with finding food have long been recognized as important in shaping evolution of the brain and cognition in primates, including humans,” said Amanda D. Melin, PhD, assistant professor of anthropology in Arts & Sciences and lead author of the study.

“Our work suggests that digging for insects when food was scarce may have contributed to hominid cognitive evolution and set the stage for advanced tool use.”

Based on a five-year study of capuchin monkeys in Costa Rica, the research provides support for an evolutionary theory that links the development of sensorimotor (SMI) skills, such as increased manual dexterity, tool use, and innovative problem solving, to the creative challenges of foraging for insects and other foods that are buried, embedded or otherwise hard to procure.

Published in the June 2014 Journal of Human Evolution, the study is the first to provide detailed evidence from the field on how seasonal changes in food supplies influence the foraging patterns of wild capuchin monkeys.

The study is co-authored by biologist Hilary C. Young and anthropologists Krisztina N. Mosdossy and Linda M. Fedigan, all from the University of Calgary, Canada.

It notes that many human populations also eat embedded insects on a seasonal basis and suggests that this practice played a key role in human evolution.

“We find that capuchin monkeys eat embedded insects year-round but intensify their feeding seasonally, during the time that their preferred food — ripe fruit — is less abundant,” Melin said. “These results suggest embedded insects are an important fallback food.”

Previous research has shown that fallback foods help shape the evolution of primate body forms, including the development of strong jaws, thick teeth and specialized digestive systems in primates whose fallback diets rely mainly on vegetation.

This study suggests that fallback foods can also play an important role in shaping brain evolution among primates that fall back on insect-based diets, and that this influence is most pronounced among primates that evolve in habitats with wide seasonal variations, such as the wet-dry cycles found in some South American forests.

“Capuchin monkeys are excellent models for examining evolution of brain size and intelligence for their small body size, they have impressively large brains,” Melin said. “Accessing hidden and well-protected insects living in tree branches and under bark is a cognitively demanding task, but provides a high-quality reward: fat and protein, which is needed to fuel big brains.”

But when it comes to using tools, not all capuchin monkey strains and lineages are created equal, and Melin’s theories may explain why.

Perhaps the most notable difference between the robust (tufted, genus Sapajus) and gracile (untufted, genus Cebus) capuchin lineages is their variation in tool use. While Cebus monkeys are known for clever food-foraging tricks, such as banging snails or fruits against branches, they can’t hold a stick to their Sapajus cousins when it comes to theinnovative use and modification of sophisticated tools.

One explanation, Melin said, is that Cebus capuchins have historically and consistently occupied tropical rainforests, whereas the Sapajus lineage spread from their origins in the Atlantic rainforest into drier, more temperate and seasonal habitat types.

“Primates who extract foods in the most seasonal environments are expected to experience the strongest selection in the ‘sensorimotor intelligence’ domain, which includes cognition related to object handling,” Melin said. “This may explain the occurrence of tool use in some capuchin lineages, but not in others.”

Genetic analysis of mitochondial chromosomes suggests that the Sapajus-Cebus diversification occurred millions of years ago in the late Miocene epoch.

“We predict that the last common ancestor of Cebus and Sapajus had a level of SMI more closely resembling extant Cebus monkeys, and that further expansion of SMI evolved in the robust lineage to facilitate increased access to varied embedded fallback foods,necessitated by more intense periods of fruit shortage,” she said.

One of the more compelling modern examples of this behavior, said Melin, is the seasonal consumption of termites by chimpanzees, whose use of tools to extract this protein-rich food source is an important survival technique in harsh environments.

What does this all mean for hominids?

While it’s hard to decipher the extent of seasonal dietary variations from the fossil record, stable isotope analyses indicate seasonal variation in diet for at least one South African hominin, Paranthropus robustus. Other isotopic research suggests that early human diets may have included a range of extractable foods, such as termites, plant roots and tubers.

Modern humans frequently consume insects, which are seasonally important when other animal foods are limited.

This study suggests that the ingenuity required to survive on a diet of elusive insects has been a key factor in the development of uniquely human skills: It may well have been bugs that helped build our brains.

Journal Reference:

  1. Amanda D. Melin, Hilary C. Young, Krisztina N. Mosdossy, Linda M. Fedigan.Seasonality, extractive foraging and the evolution of primate sensorimotor intelligenceJournal of Human Evolution, 2014; 71: 77 DOI:10.1016/j.jhevol.2014.02.009

Domestication of Dogs May Explain Mammoth Kill Sites and the Success of Early Modern Humans (The Pennsylvania State University)

Pat Shipman and Barbara K. Kennedy

May 30, 2014

a dog's skullA fragment of a large bone, probably from a mammoth, Pat Shipman reports, was placed in this dog’s mouth shortly after death. This finding suggests the animal was according special mortuary treatment, perhaps acknowledging its role in mammoth hunting. The fossil comes from the site of Predmosti, in the Czech republic, and is about 27,000 years B.P. old. This object is one of three canid skulls from Predmosti that were identified as dogs based on analysis of their morphology. Photo credit: Anthropos Museum, Brno, the Czech Republic, courtesy of Mietje Germonpre.

29 May 2014 — A new analysis of European archaeological sites containing large numbers of dead mammoths and dwellings built with mammoth bones has led Penn State Professor Emerita Pat Shipman to formulate a new interpretation of how these sites were formed. She suggests that their abrupt appearance may have been due to early modern humans working with the earliest domestic dogs to kill the now-extinct mammoth — a now-extinct animal distantly related to the modern-day elephant. Shipman’s analysis also provides a way to test the predictions of her new hypothesis. Advance publication of her article “How do you kill 86 mammoths?” is available online throughQuaternary International.

Spectacular archaeological sites yielding stone tools and extraordinary numbers of dead mammoths — some containing the remains of hundreds of individuals — suddenly became common in central and eastern Eurasia between about 45,000 and 15,000 years ago, although mammoths previously had been hunted by humans and their extinct relatives and ancestors for at least a million years. Some of these mysterious sites have huts built of mammoth bones in complex, geometric patterns as well as piles of butchered mammoth bones.

“One of the greatest puzzles about these sites is how such large numbers of mammoths could have been killed with the weapons available during that time,” Shipman said. Many earlier studies of the age distribution of the mammoths at these sites found similarities with modern elephants killed by hunting or natural disasters, but Shipman’s new analysis of the earlier studies found that they lacked the statistical evaluations necessary for concluding with any certainty how these animals were killed.

Surprisingly, Shipman said, she found that “few of the mortality patterns from these mammoth deaths matched either those from natural deaths among modern elephants killed by droughts or by culling operations with modern weapons that kill entire family herds of modern elephants at once.” This discovery suggested to Shipman that a successful new technique for killing such large animals had been developed and its repeated use over time could explain the mysterious, massive collections of mammoth bones in Europe.

hand-drawn mapThese maps show the locations of collections of mammoth bones at the archaeological sites that Pat Shipman analyzed in her paper that will be published in the journal Quaternary International. Credit: Jeffrey Mathison. 

The key to Shipman’s new hypothesis is recent work by a team led by Mietje Germonpré of the Royal Belgian Institute of Natural Sciences, which has uncovered evidence that some of the large carnivores at these sites were early domesticated dogs, not wolves as generally had been assumed. Then, with this evidence as a clue, Shipman used information about how humans hunt with dogs to formulate a series of testable predictions about these mammoth sites.

“Dogs help hunters find prey faster and more often, and dogs also can surround a large animal and hold it in place by growling and charging while hunters move in. Both of these effects would increase hunting success,” Shipman said. “Furthermore, large dogs like those identified by Germonpré either can help carry the prey home or, by guarding the carcass from other carnivores, can make it possible for the hunters to camp at the kill sites.” Shipman said that these predictions already have been confirmed by other analyses. In addition, she said, “if hunters working with dogs catch more prey, have a higher intake of protein and fat, and have a lower expenditure of energy, their reproductive rate is likely to rise.”

Another unusual feature of these large mammoth kill sites is the presence of extraordinary numbers of other predators, particularly wolves and foxes. “Both dogs and wolves are very alert to the presence of other related carnivores — the canids — and they defend their territories and food fiercely,” Shipman explained. “If humans were working and living with domesticated dogs or even semi-domesticated wolves at these archaeological sites, we would expect to find the new focus on killing the wild wolves that we see there.”

bonesThe photo shows part of the very-high-density concentration of mammoth bones at the Krakow-Spadzista Street archaeological site. Credit line Piotr Wojtal.

Two other types of studies have yielded data that support Shipman’s hypothesis. Hervé Bocherens and Dorothée Drucker of the University of Tubingen in Germany, carried out an isotopic analysis of the ones of wolves and purported dogs from the Czech site of Predmostí. They found that the individuals identified as dogs had different diets from those identified as wolves, possibly indicating feeding by humans. Also, analysis of mitochondrial DNA by Olaf Thalmann of the University of Turku in Finland, and others, showed that the individuals identified as dogs have a distinctive genetic signature that is not known from any other canid. “Since mitochondrial DNA is carried only by females, this finding may indicate that these odd canids did not give rise to modern domesticated dogs and were simply a peculiar, extinct group of wolves,” Shipman said. “Alternatively, it may indicate that early humans did domesticate wolves into dogs or a doglike group, but the female canids interbred with wild wolf males and so the distinctive female mitochondrial DNA lineage was lost.”

As more information is gathered on fossil canids dated to between 45,000 and 15,000 years ago, Shipman’s hunting-dog hypothesis will be supported “if more of these distinctive doglike canids are found at large, long-term sites with unusually high numbers of dead mammoths and wolves; if the canids are consistently large, strong individuals; and if their diets differ from those of wolves,” Shipman said. “Dogs may indeed be man’s best friend.”

Modern humans were not any smarter than Neanderthals, say scientists (The Christian Science Monitor)

Neanderthals that lived in Eurasia for more than 300,000 years were skillful hunters making use of the landscape to kill animals, say researchers.

By Staff writer / April 30, 2014

This Jan. 8, 2003 file photo shows a reconstructed Neanderthal skeleton, right, and a modern human version of a skeleton, left, on display at the Museum of Natural History in New York. AP Photo/Frank Franklin II

Some scientists have speculated that they were out-competed by brainier H. sapiens, but researchers now say that Neanderthals, who lived in Eurasia for more than 300,000 years, were not that dumb after all.

In a paper titled “Neandertal Demise: An Archaeological Analysis of the Modern Human Superiority Complex” published in PLOS One, researchers challenge the notion that modern humans were superior to Neanderthals “in a wide range of domains, including weaponry and subsistence strategies, which would have led to the demise of Neandertals.”

After examining the remains from various archaeological sites associated with Neanderthals, CU-Boulder researcher Paola Villa and co-author of the paper said, “The evidence for cognitive inferiority is simply not there. What we are saying is that the conventional view of Neanderthals is not true.”

Artifacts and remains of animal bones reveal that Neanderthals used the landscape to hunt animals. An archaeological site excavated in France shows that they used sinkhole as a trap to hunt bison. And other evidence shows the use of deep ravines to hunt animals.

“Neandertals were by all means accomplished large game hunters, who survived in a wide range of environments subsisting by hunting a wide range of animals in a variety of topographical settings,” note the researchers in their paper.

Microfossils found in their teeth show that Neanderthals had a diverse diet that included aquatic foods, small and fast game such as birds and rabbits, date palms, and grass seeds.

Recent information available on “Neandertal use of ochre and manganese as well as on Neandertal production of pitch, the presence of transported and ochre-smeared shells, of ornaments such as eagle claws and perhaps bird feathers,” goes to show that they had cultural rituals.

So far, Neanderthals have been subjected to unfair comparison because “[r]esearchers were comparing Neanderthals not to their contemporaries on other continents but to their successors,” Dr. Villa said. “It would be like comparing the performance of Model T Fords, widely used in America and Europe in the early part of the last century, to the performance of a modern-day Ferrari and conclude that Henry Ford was cognitively inferior to Enzo Ferrari.”

When it comes to what caused the demise of Neanderthals, researchers say that there is no evidence that Neanderthal extinction was due to behavioral or technological inferiority. Current genetic studies suggest that the Neanderthal demise was a complex process including many factors, such as interbreeding, possible male hybrid sterility, and assimilation by the increasing numbers of modern immigrants, Villa wrote in an email.

Talking Neanderthals challenge the origins of speech (Science Daily)

Date:

March 2, 2014

Source: University of New England

Summary: We humans like to think of ourselves as unique for many reasons, not least of which being our ability to communicate with words. But ground-breaking research shows that our ‘misunderstood cousins,’ the Neanderthals, may well have spoken in languages not dissimilar to the ones we use today.

A model of an adult Neanderthal male head and shoulders on display in the Hall of Human Origins in the Smithsonian Museum of Natural History in Washington, D.C. Reconstruction based on the Shanidar 1 fossil (c. 80-60 kya). Credit: By reconstruction: John Gurche; photograph: Tim Evanson [CC-BY-SA-2.0], via Wikimedia Commons

We humans like to think of ourselves as unique for many reasons, not least of which being our ability to communicate with words. But ground-breaking research by an expert from the University of New England shows that our ‘misunderstood cousins,’ the Neanderthals, may well have spoken in languages not dissimilar to the ones we use today.

Pinpointing the origin and evolution of speech and human language is one of the longest running and most hotly debated topics in the scientific world. It has long been believed that other beings, including the Neanderthals with whom our ancestors shared Earth for thousands of years, simply lacked the necessary cognitive capacity and vocal hardware for speech.

Associate Professor Stephen Wroe, a zoologist and palaeontologist from UNE, along with an international team of scientists and the use of 3D x-ray imaging technology, made the revolutionary discovery challenging this notion based on a 60,000 year-old Neanderthal hyoid bone discovered in Israel in 1989.

“To many, the Neanderthal hyoid discovered was surprising because its shape was very different to that of our closest living relatives, the chimpanzee and the bonobo. However, it was virtually indistinguishable from that of our own species. This led to some people arguing that this Neanderthal could speak,” A/Professor Wroe said.

“The obvious counterargument to this assertion was that the fact that hyoids of Neanderthals were the same shape as modern humans doesn’t necessarily mean that they were used in the same way. With the technology of the time, it was hard to verify the argument one way or the other.”

However advances in 3D imaging and computer modelling allowed A/Professor Wroe’s team to revisit the question.

“By analysing the mechanical behaviour of the fossilised bone with micro x-ray imaging, we were able to build models of the hyoid that included the intricate internal structure of the bone. We then compared them to models of modern humans. Our comparisons showed that in terms of mechanical behaviour, the Neanderthal hyoid was basically indistinguishable from our own, strongly suggesting that this key part of the vocal tract was used in the same way.

“From this research, we can conclude that it’s likely that the origins of speech and language are far, far older than once thought.”

Journal Reference:

  1. Ruggero D’Anastasio, Stephen Wroe, Claudio Tuniz, Lucia Mancini, Deneb T. Cesana, Diego Dreossi, Mayoorendra Ravichandiran, Marie Attard, William C. H. Parr, Anne Agur, Luigi Capasso. Micro-Biomechanics of the Kebara 2 Hyoid and Its Implications for Speech in NeanderthalsPLoS ONE, 2013; 8 (12): e82261 DOI: 10.1371/journal.pone.0082261

Theory on origin of animals challenged: Some animals need extremely little oxygen (Science Daily)

Date: February 17, 2014

Source: University of Southern Denmark

Summary: One of science’s strongest dogmas is that complex life on Earth could only evolve when oxygen levels in the atmosphere rose to close to modern levels. But now studies of a small sea sponge fished out of a Danish fjord shows that complex life does not need high levels of oxygen in order to live and grow.

Sea sponge Halichondria panicea was used in the experiment at the University of Southern Denmark. Credit: Daniel Mills/SDU

One of science’s strongest dogmas is that complex life on Earth could only evolve when oxygen levels in the atmosphere rose to close to modern levels. But now studies of a small sea sponge fished out of a Danish fjord shows that complex life does not need high levels of oxygen in order to live and grow.

The origin of complex life is one of science’s greatest mysteries. How could the first small primitive cells evolve into the diversity of advanced life forms that exists on Earth today? The explanation in all textbooks is: Oxygen. Complex life evolved because the atmospheric levels of oxygen began to rise app. 630 — 635 million years ago.

However new studies of a common sea sponge from Kerteminde Fjord in Denmark shows that this explanation needs to be reconsidered. The sponge studies show that animals can live and grow even with very limited oxygen supplies.

In fact animals can live and grow when the atmosphere contains only 0.5 per cent of the oxygen levels in today’s atmosphere.

“Our studies suggest that the origin of animals was not prevented by low oxygen levels,” says Daniel Mills, PhD at the Nordic Center for Earth Evolution at the University of Southern Denmark.

Together with Lewis M. Ward from the California Institute of Technology he is the lead author of a research paper about the work in the journal PNAS.

A little over half a billion years ago, the first forms of complex life — animals — evolved on Earth. Billions of years before that life had only consisted of simple single-celled life forms. The emergence of animals coincided with a significant rise in atmospheric oxygen, and therefore it seemed obvious to link the two events and conclude that the increased oxygen levels had led to the evolution of animals.

“But nobody has ever tested how much oxygen animals need — at least not to my knowledge. Therefore we decided to find out,” says Daniel Mills.

The living animals that most closely resemble the first animals on Earth are sea sponges. The species Halichondria panicea lives only a few meters from the University of Southern Denmark’s Marine Biological Research Centre in Kerteminde, and it was here that Daniel Mills fished out individuals for his research.

“When we placed the sponges in our lab, they continued to breathe and grow even when the oxygen levels reached 0.5 per cent of present day atmospheric levels,” says Daniel Mills.

This is lower than the oxygen levels we thought were necessary for animal life.

The big question now is: If low oxygen levels did not prevent animals from evolving — then what did? Why did life consist of only primitive single-celled bacteria and amoebae for billions of years before everything suddenly exploded and complex life arose?

“There must have been other ecological and evolutionary mechanisms at play. Maybe life remained microbial for so long because it took a while to develop the biological machinery required to construct an animal. Perhaps the ancient Earth lacked animals because complex, many-celled bodies are simply hard to evolve,” says Daniel Mills.

His colleagues from the Nordic Center for Earth Evolution have previously shown that oxygen levels have actually risen dramatically at least one time before complex life evolved. Although plenty of oxygen thus became available it did not lead to the development of complex life.

Journal Reference:

  1. Daniel B. Mills, Lewis M. Ward, CarriAyne Jones, Brittany Sweeten, Michael Forth, Alexander H. Treusch and Donald E. Canfield. The oxygen requirements of the earliest animalsPNAS, February 17, 2014