Arquivo da tag: Antropologia física

Sabrina Imbler

A growing number of forensic researchers are questioning how the field interprets the geographic ancestry of human remains.

Forensic anthropologists have relied on features of face and skull bones, known as morphoscopic traits, such as the post-bregmatic depression — a dip on the top of the skull — to estimate ancestry. — Credit: John M. Daugherty/Science Source

Oct. 19, 2021, 2:30 a.m. ET

Racial reckonings were happening everywhere in the summer of 2020, after George Floyd was killed in Minneapolis by the police. The time felt right, two forensic anthropologists reasoned, to reignite a conversation about the role of race in their own field, where specialists help solve crimes by analyzing skeletons to determine who those people were and how they died.

Dr. Elizabeth DiGangi of Binghamton University and Jonathan Bethard of the University of South Florida published a letter in The Journal of Forensic Science that questioned the longstanding practice of estimating ancestry, or a person’s geographic origin, as a proxy for estimating race. Ancestry, along with height, age at death and assigned sex, is one of the key details that many forensic anthropologists try to determine.

That fall, they published a longer paper with a more ambitious call to action: “We urge all forensic anthropologists to abolish the practice of ancestry estimation.”

In recent years, a growing number of forensic anthropologists have grown critical of ancestry estimation and want to replace it with something more nuanced.

Criminal cases in which the victim’s identity is entirely unknown are rare. But in these instances, some forensic anthropologists argue, a tool like ancestry estimation can be crucial.

The assessment of race has been a part of forensic anthropology since the field’s inception a century ago. The earliest scholars were white men who studied human skulls to support racist beliefs. Ales Hrdlicka, a physical anthropologist who joined the Smithsonian Institution in 1903, was a eugenicist who looted human remains for his collections and sought to classify humans into different races based on certain appearances and traits.

An expert on skeletons, Dr. Hrdlicka helped law enforcement identify human remains, laying the blueprint for the professional field. Forensic anthropologists thereafter were expected to produce a profile with the “Big Four” — age at death, sex, height and race.

In the 1990s, as more scientists debunked the myth of biological race — the notion that the humans species is divided into distinct races — anthropologists grew sharply divided over the issue. One survey found that 50 percent of physical anthropologists accepted the idea of a biological concept of race, while 42 rejected it. At the time, some researchers still used terms like “Caucasoid,” “Mongoloid” and “Negroid” to describe skeletons, and DNA as a forensic tool was still many years away. Today in the U.S., the field of forensic anthropology is 87 percent white.

The anthropologist Ales Hrdlicka, right, in 1925. — Credit: Sueddeutsche Zeitung Photo/Alamy

In 1992, Norman Sauer, an anthropologist at Michigan State University, suggested dropping the term “race,” which he considered loaded, and replacing it with “ancestry.” The term became universal. But some researchers contend that little changed about the practice.

When Shanna Williams, a forensic anthropologist at the University of South Carolina School of Medicine Greenville, was in graduate school around a decade ago, it was still customary to sort skeletons into one of the “Big Three” possible populations — African, Asian or European.

But Dr. Williams grew suspicious of the idea and the way ancestry was often assigned. She saw skulls designated as “Hispanic,” a term that refers to a language group and has no biological meaning. She considered how the field might try, and fail, to sort her own skull. “My mom is white, and my dad is Black,” she said. “Do I fit that mold? Am I perfectly one thing or the other?”

The body of a skeleton can provide a person’s age or height. But the question of ancestry is reserved for the skull — specifically, features of face and skull bones, known as morphoscopic traits, that vary across different groups of humans and can occur more frequently in certain populations.

One trait, called the post-bregmatic depression, is a small indentation located on top of some people’s heads. For a long time, forensic anthropologists assumed that if the skull was indented, the person may be Black.

But forensic anthropologists know little else about the post-bregmatic depression. “There’s not been any understanding as to why this trait exists, what causes it, and what it means,” Dr. Bethard said.

Moreover, the science linking the trait and African ancestry was flawed. In 2003, Joe Hefner, a forensic anthropologist at Michigan State University, used trait lists from a key textbook, “Skeletal Attribution of Race,” to examine more than 700 skulls for his masters thesis. He found that the post-bregmatic depression was present in only 40 percent of people with African ancestry, and is actually more common in many other populations.

Of the 17 morphoscopic traits typically used to estimate ancestry, only five have been studied for whether they are heritable, making it unclear why the unstudied traits would correspond with specific populations. “There’s been this use and reuse of these traits without a fundamental understanding of what they even are,” Dr. Bethard said.

Nonetheless, Dr. Hefner said, if nothing is known about a victim beyond the shape of their skull, ancestry might hold the key to their identity.

He cited a recent example in Michican in which the police had a skull that they believed belonged to a missing woman, one of two who were reported missing in the county at the time. When Dr. Hefner examined it and searched the list of missing people in the area, he concluded that the skull might have come from a missing Southeast Asian male. “They sent us his dental records over and five minutes later we had identified this person,” Dr. Hefner said.

Dr. DiGangi worries that these estimations could suggest to the police that biological race is real and increase racial bias. “When I say to the police, ‘OK, I took these measurements, I looked at these things on the skull and this person is African-American,’ of course they’re going to think it’s biological,” Dr. DiGangi said. “Why would they not?”

To what extent this concern plays out in the real world is hard to measure, however.

Dr. Shanna Williams, a forensic anthropologist and professor in South Carolina, grew suspicious of the idea of the way ancestry was assigned when in graduate school. — Credit: Juan Diego Reyes for The New York Times

For the past two years, Ann Ross, a forensic anthropologist at North Carolina State University, has pushed the American Academy of Forensic Sciences Standards Board to replace ancestry estimation with something new: population affinity.

Whereas ancestry aims to trace back to a continent of origin, population affinity aims to align someone with a population, such as Panamanian. This more nuanced framework looks at how the larger history of a place or community can lead to significant differences between populations that are otherwise geographically close.

A recent paper by Dr. Ross and Dr. Williams, who are close friends, examines Panama and Colombia as a test case. An ancestry estimation might suggest people from both countries would have similarly shaped skulls. But population affinity acknowledges that the trans-Atlantic slave trade and colonization by Spain resulted in new communities living in Panama that changed the makeup of the country’s population. “Because of those historical events, individuals from Panama are very, very different from those from Colombia,” said Dr. Ross, who is Panamanian.

Dr. Ross even designed her own software, 3D-ID, in place of Fordisc, the most commonly used forensic software that categorizes skulls into inconsistent terms: White. Black. Hispanic. Guatemalan. Japanese.

Other anthropologists say that, for all practical purposes, their own ancestry estimations have become affinity estimations. Kate Spradley, a forensic anthropologist at Texas State University, works with the unidentified remains of migrants found near the U.S.-Mexico border. “When we reference data that uses local population groups, that’s really affinity, not ancestry,” Dr. Spradley said.

In her work, Dr. Spradley uses missing persons’ databases from multiple countries that do not always share DNA data. The bones are often weathered, fragmenting the DNA. Estimating affinity can “help to provide a preponderance of evidence,” Dr. Spradley said.

Still, Dr. DiGangi said that switching to affinity may not address racial biases in law enforcement. Until she sees evidence that bias does not preclude people from becoming identified, she says, she does not want a “checkbox” that gets at ancestry or affinity.

As of mid-October, Dr. Ross is waiting for the American Academy of Forensic Sciences Standards Board to set a vote to determine whether ancestry estimation should be replaced with population affinity. But the larger debate — over how to bridge the gap between a person’s bones and identity in real life — is far from settled.

“In 10 or 20 years, we might find a better way to do it,” Dr. Williams said. “I hope that’s the case.”

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

08/07/2021UncategorizedAntropologia física, Evolução, Evolução humana, Evolucionismo, Paleoantropologiarenzotaddei

brasil.elpais.com

Nuño Domínguez, 04 jul 2021 – 12:48 BRT

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Escavações no sítio arqueológico de Nesher Ramla. Zaidner

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

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

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

17/06/2021UncategorizedAntropologia física, Cultura, Evolucionismo, Genética, Tecnologiarenzotaddei

sciencealert.com

Cameron Duke, Live Science – 15 JUNE 2021

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

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

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

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

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

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

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

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

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

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

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

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

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

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

As ideas spread, cultures develop new traits.

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

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

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

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

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

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

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

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

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

20/09/2020UncategorizedAdaptação, Antropologia física, Epigenética, Evolução, Evolucionismo, Genéticarenzotaddei

sciencealert.com

Eva Hamrud, Metafact – 20 Sept. 2020

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

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

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

Evolution is not the same as natural selection

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

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

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

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

Evolution can happen without natural selection

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

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

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

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

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

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

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

Natural selection is still happening in humans

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

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

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

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

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

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

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

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

Evolution can’t be stopped

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

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

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

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

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

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

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

14/02/2018UncategorizedAntropologia, Antropologia física, Cultura, Epigenética, Evolução, Genética, Interdisciplinaridade, Microbiotarenzotaddei

PUBLIC RELEASE: 13-FEB-2018

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.

Why did humans evolve such large brains? Because smarter people have more friends (The Conversation)

30/06/2017UncategorizedAntropologia física, Cérebro, neurociências, Psicologia, Sociologiarenzotaddei

June 19, 2017 10.01am EDT

Mark Maslin

Humans are the only ultrasocial creature on the planet. We have outcompeted, interbred or even killed off all other hominin species. We cohabit in cities of tens of millions of people and, despite what the media tell us, violence between individuals is extremely rare. This is because we have an extremely large, flexible and complex “social brain”.

To truly understand how the brain maintains our human intellect, we would need to know about the state of all 86 billion neurons and their 100 trillion interconnections, as well as the varying strengths with which they are connected, and the state of more than 1,000 proteins that exist at each connection point. Neurobiologist Steven Rose suggests that even this is not enough – we would still need know how these connections have evolved over a person’s lifetime and even the social context in which they had occurred. It may take centuries just to figure out basic neuronal connectivity.

Many people assume that our brain operates like a powerful computer. But Robert Epstein, a psychologist at the American Institute for Behavioural Research and Technology, says this is just shoddy thinking and is holding back our understanding of the human brain. Because, while humans start with senses, reflexes and learning mechanisms, we are not born with any of the information, rules, algorithms or other key design elements that allow computers to behave somewhat intelligently. For instance, computers store exact copies of data that persist for long periods of time, even when the power is switched off. Our brains, meanwhile, are capable of creating false data or false memories, and they only maintain our intellect as long as we remain alive.

We are organisms, not computers

Of course, we can see many advantages in having a large brain. In my recent book on human evolution I suggest it firstly allows humans to exist in a group size of about 150. This builds resilience to environmental changes by increasing and diversifying food production and sharing.

As our ancestors got smarter, they became capable of living in larger and larger groups. Mark Maslin, Author provided

A social brain also allows specialisation of skills so individuals can concentrate on supporting childbirth, tool-making, fire setting, hunting or resource allocation. Humans have no natural weapons, but working in large groups and having tools allowed us to become the apex predator, hunting animals as large as mammoths to extinction.

Our social groups are large and complex, but this creates high stress levels for individuals because the rewards in terms of food, safety and reproduction are so great. Hence, Oxford anthropologist Robin Dunbar argues our huge brain is primarily developed to keep track of rapidly changing relationships. It takes a huge amount of cognitive ability to exist in large social groups, and if you fall out of the group you lose access to food and mates and are unlikely to reproduce and pass on your genes.

Great. But what about your soap opera knowledge? ronstik / shutterstock

My undergraduates come to university thinking they are extremely smart as they can do differential equations and understand the use of split infinitives. But I point out to them that almost anyone walking down the street has the capacity to hold the moral and ethical dilemmas of at least five soap operas in their head at any one time. And that is what being smart really means. It is the detailed knowledge of society and the need to track and control the ever changing relationship between people around us that has created our huge complex brain.

It seems our brains could be even more flexible that we previously thought. Recent genetic evidence suggests the modern human brain is more malleable and is modelled more by the surrounding environment than that of chimpanzees. The anatomy of the chimpanzee brain is strongly controlled by their genes, whereas the modern human brain is extensively shaped by the environment, no matter what the genetics.

This means the human brain is pre-programmed to be extremely flexible; its cerebral organisation is adjusted by the environment and society in which it is raised. So each new generation’s brain structure can adapt to the new environmental and social challenges without the need to physically evolve.

Evolution at work. OtmarW / shutterstock

This may also explain why we all complain that we do not understand the next generation as their brains are wired differently, having grown up in a different physical and social environment. An example of this is the ease with which the latest generation interacts with technology almost if they had co-evolved with it.

So next time you turn on a computer just remember how big and complex your brain is – to keep a track of your friends and enemies.

Quando todos os europeus eram negros (El País)

05/05/2016UncategorizedAntropologia física, Europa, Raçarenzotaddei

Maior estudo genético de europeus da pré-história revela um passado complexo e violento no qual populações inteiras foram forçadas a emigrar ou desaparecer para sempre

NUÑO DOMÍNGUEZ

5 MAI 2016 – 03:05 CEST

Três crânios encontrados na República Checa associados com o período gravetiano.

Três crânios encontrados na República Checa associados com o período gravetiano. M. Frouz / J. Svoboda

O estudo genético de restos mortais de europeus que morreram há milhares de anos, abriu uma janela única para a pré-história do continente. O trabalho abrange grande parte do Paleolítico Superior, de 45.000 até 7.000 anos atrás, e revela vários episódios até agora desconhecidos.

“O que vemos é uma história das populações tão complexa quanto a dos últimos 7.000 anos, com muitos momentos em que populações substituem outras, imigração em uma escala dramática e em um momento no qual o clima estava mudando radicalmente”, resumiu David Reich, geneticista da Universidade de Harvard e principal autor do estudo, publicado na revista Nature.

O estudo analisou o DNA de 51 euroasiáticos, uma amostra 10 vezes maior que qualquer estudo anterior. Abarca desde os humanos modernos mais antigos registrados aos caçadores-coletores que viveram pouco antes da revolução neolítica que trouxe consigo a agricultura ao continente.

A primeira conclusão do estudo é que, embora os neandertais e os humanos modernos (os Homo sapiens) se cruzaram e tiveram filhos férteis, a percentagem de DNA dessa outra espécie que carregamos diminuiu rapidamente, passando de 6 % para os 2% de hoje. Isto implica certa incompatibilidade evolutiva que já tinha sido destacada por outros estudos recentes.

Há 19.000 anos, alguém enterrou na Cantábria uma das mulheres mais misteriosas da pré-história europeia. Trata-se da Dama Vermelha, que em seus 35 ou 40 anos recebeu uma sepultura muito estranha, o que poderia indicar um significado sagrado. Seu cadáver tinha decomposto ao ar livre e, em seguida, seus ossos foram cobertos com tinta vermelha. Tanto deviam respeitar aquela mulher que um de seus ossos foi cuidadosamente devolvido ao túmulo depois que um animal selvagem o profanou para se alimentar. Além de uns desenhos esquemáticos e a presença de pólen, pouco se sabe sobre a mulher e o significado que a cultura à qual pertencia queria dar à sua sepultura. A senhora é um dos 51 indivíduos que foram analisados neste estudo. A equipe de Manuel González Morales está preparando uma reconstrução do aspecto que teve essa mulher, cujo genes mostram que era negra, explica.

Embora os primeiros sapiens tenham chegado à Europa há cerca de 45.000 anos, sua marca genética desapareceu completamente nas populações atuais. As primeiras populações que possuem algum parentesco com os europeus de hoje remontam a uns 37.000 anos atrás. Os autores do trabalho identificam essa população com o período aurignaciano.

Embora os primeiros sapiens tenham chegado à Europa há cerca de 45.000 anos, sua marca genética desapareceu completamente nas populações atuais

“Estão associados a esta cultura os primeiros exemplos de arte e música, assim como as pinturas da caverna de Chauvet na França ou as flautas de ossos”, diz Manuel González Morales, pesquisador da Universidade da Cantábria e coautor do trabalho.

Naquela época, a Europa vivia a última idade do gelo, com geleiras avançando do norte da Europa e empurrando povos inteiros à migração ou ao extermínio. Segundo dados do trabalho, há 33.000 anos outro grupo substitui quase totalmente o anterior e é associado com o período gravetiano, caracterizado por pinturas com as mãos em negativo e as redondas estatuetas das Vênus paleolíticas esculpidas em osso, explica González.

Inesperadamente, há cerca de 19.000 anos, reaparecem os descendentes do período aurignaciano. Os restos humanos encontrados na Cantábria mostram agora que os habitantes desta região estavam diretamente relacionados com eles.

Uma das possíveis explicações é que aquele povo migrou para refúgios quentes do sul da Europa, em particular a Península Ibérica. Depois do momento mais frio da última idade do gelo esta população volta a se expandir para o norte da Europa, recuperando o território perdido e substituindo seus habitantes.

Última onda

Mais uma vez, cerca de 14.000 anos atrás, outra população vinda das terras do Oriente Médio desembarca no continente e passa a ser dominante, substituindo boa parte das anteriores. Esta última onda, que não era conhecida até agora, foi identificada pelos restos de um caçador e coletor encontrado em Villabruna, Itália e que deu nome a esta população.

A marca genética deste grupo se perpetuou durante milênios, já que, por exemplo, o caçador coletor de La Braña (Leão), que viveu há 7.000 anos estava relacionado com este grupo.

Os genes do homem de La Braña mostram que tinha pele escura e olhos azuis. De acordo com González, até a chegada de seus ancestrais à Europa cerca de 14.000 anos atrás, todos os europeus tinham a pele escura e os olhos castanhos. “O trabalho mostra que os primeiros indivíduos com genes de pele clara viveram há uns 13.000 anos”, explica o pesquisador da Universidade da Cantábria. Depois, com a chegada dos primeiros agricultores do Oriente Médio começa o Neolítico e a pele branca se torna muito mais comum. Em outras palavras, os europeus foram negros durante a maior parte de sua história.

How the introduction of farming changed the human genome (Science Daily)

25/04/2016UncategorizedAgricultura, Antropologia física, Genéticarenzotaddei

Study tracks gene changes during the introduction of farming in Europe

Date:: November 23, 2015
Source:: Harvard Medical School
Summary:: Genomic analysis of ancient human remains identifies specific genes that changed during and after the transition in Europe from hunting and gathering to farming about 8,500 years ago. Many of the genes are associated with height, immunity, lactose digestion, light skin pigmentation, blue eye color and celiac disease risk.

Ancient DNA can provide insight into when humans acquired the adaptations seen in our genomes today. Credit: Image courtesy of Harvard Medical School

The introduction of agriculture into Europe about 8,500 years ago changed the way people lived right down to their DNA.

Until recently, scientists could try to understand the way humans adapted genetically to changes that occurred thousands of years ago only by looking at DNA variation in today’s populations. But our modern genomes contain mere echoes of the past that can’t be connected to specific events.

Now, an international team reports in Nature that researchers can see how natural selection happened by analyzing ancient human DNA.

“It allows us to put a time and date on selection and to directly associate selection with specific environmental changes, in this case the development of agriculture and the expansion of the first farmers into Europe,” said Iain Mathieson, a research fellow in genetics at Harvard Medical School and first author of the study.

By taking advantage of better DNA extraction techniques and amassing what is to date the largest collection of genome-wide datasets from ancient human remains, the team was able to identify specific genes that changed during and after the transition from hunting and gathering to farming.

Many of the variants occurred on or near genes that have been associated with height, the ability to digest lactose in adulthood, fatty acid metabolism, vitamin D levels, light skin pigmentation and blue eye color. Two variants appear on genes that have been linked to higher risk of celiac disease but that may have been important in adapting to an early agricultural diet.

Other variants were located on immune-associated genes, which made sense because “the Neolithic period involved an increase in population density, with people living close to one another and to domesticated animals,” said Wolfgang Haak, one of three senior authors of the study, a research fellow at the University of Adelaide and group leader in molecular anthropology at the Max Planck Institute for the Science of Human History.

“Although that finding did not come fully as a surprise,” he added, “it was great to see the selection happening in ‘real time.'”

The work also supports the idea that Europe’s first farmers came from ancient Anatolia, in what is now Turkey, and fills in more details about how ancient groups mixed and migrated.

“It’s a great mystery how present-day populations got to be the way we are today, both in terms of how our ancestors moved around and intermingled and how populations developed the adaptations that help us survive a bit better in the different environments in which we live,” said co-senior author David Reich, professor of genetics at HMS. “Now that ancient DNA is available at the genome-wide scale and in large sample sizes, we have an extraordinary new instrument for studying these questions.”

“From an archaeological perspective, it’s quite amazing,” said co-senior author Ron Pinhasi, associate professor of archaeology at University College Dublin. “The Neolithic revolution is perhaps the most important transition in human prehistory. We now have proof that people did actually go from Anatolia into Europe and brought farming with them. For more than 40 years, people thought it was impossible to answer that question.”

“Second,” he continued, “we now have evidence that genetic selection occurred along with the changes in lifestyle and demography, and that selection continued to happen following the transition.”

Prying more from the past

Members of the current team and others have used ancient DNA in the past few years to learn about Neanderthals and the genes they passed to humans, identify ancestors of present-day Europeans, trace migrations into the Americas and probe the roots of Indo-European languages. Studying natural selection, however, remained out of reach because it required more ancient genomes than were available.

“In the past year, we’ve had a super-exponential rise in the number of ancient samples we can study on a genome scale,” said Reich, who is also an associate member of the Broad Institute of Harvard and MIT and a Howard Hughes Medical Investigator. “In September 2014, we had 10 individuals. In this study, we have 230.”

The DNA came from the remains of people who lived between 3,000 and 8,500 years ago at different sites across what is now Europe, Siberia and Turkey. That time span provided snapshots of genetic variation before, during and after the agricultural revolution in Europe.

Among the 230 ancient individuals were 83 who hadn’t been sequenced before, including the first 26 to be gathered from the eastern Mediterranean, where warm conditions usually cause DNA to degrade.

Members of the team used several technological advances to obtain and analyze the new genetic material. For example, they exploited a method pioneered by Pinhasi’s laboratory to extract DNA from a remarkably rich source: a portion of the dense, pyramid-shaped petrous bone that houses the internal auditory organs. In some cases, the bone yielded 700 times more human DNA than could be obtained from other bones, including teeth.

“That changed everything,” said Pinhasi. “Higher-quality DNA meant we could analyze many more positions on the genome, perform more complex tests and simulations, and start systematically studying allele frequency across populations.”

What made the cut

Although the authors caution that sample size remains the biggest limitation of the study, comparing the ancient genomes to one another and to those of present-day people of European ancestry revealed 12 positions on the genome where natural selection related to the introduction of farming in northern latitudes appears to have happened.

“Some of those specific traits have been studied before,” said Reich. “This work with ancient DNA enriches our understanding of those traits and when they appeared.”

Besides the adaptations that appear to be related to diet, pigmentation, immunity and height, the possible selective pressure on other variants was less clear.

“We can guess by looking at the function of the gene, but our power is limited,” said Mathieson. “It’s quite frustrating.”

It’s too early to tell whether some of the variants were themselves selected for or whether they hitched a ride with a nearby beneficial gene. The question pertains especially to variants that seem to be disadvantageous, like increased disease risk.

Being able to look at numerous positions across the genome also allowed the team to examine complex traits for the first time in ancient DNA.

“We can see the evolution of height across time,” said Mathieson.

Researchers had noticed that people from southern Europe tend to be shorter than those from northern Europe. The new study suggests that the height differential arises both from people in the north having more ancestry from Eurasian steppe populations, who seem to have been taller, and people in the south having more ancestry from Neolithic and Chalcolithic groups from the Iberian peninsula, who seem to have been shorter.

The team wasn’t able to draw conclusions about the other complex traits it investigated: body mass index, waist-hip ratio, type 2 diabetes, inflammatory bowel disease and lipid levels.

Reich, for one, hopes researchers will one day have thousands of ancient genomes to analyze. He would also like to see this type of study applied to non-European populations and even to other species.

“It will be interesting to study selection in domesticated animals and to see if there is coevolution between them and the people who were domesticating them,” said Mathieson.

Journal Reference:

Iain Mathieson, Iosif Lazaridis, Nadin Rohland, Swapan Mallick, Nick Patterson, Songül Alpaslan Roodenberg, Eadaoin Harney, Kristin Stewardson, Daniel Fernandes, Mario Novak, Kendra Sirak, Cristina Gamba, Eppie R. Jones, Bastien Llamas, Stanislav Dryomov, Joseph Pickrell, Juan Luís Arsuaga, José María Bermúdez de Castro, Eudald Carbonell, Fokke Gerritsen, Aleksandr Khokhlov, Pavel Kuznetsov, Marina Lozano, Harald Meller, Oleg Mochalov, Vyacheslav Moiseyev, Manuel A. Rojo Guerra, Jacob Roodenberg, Josep Maria Vergès, Johannes Krause, Alan Cooper, Kurt W. Alt, Dorcas Brown, David Anthony, Carles Lalueza-Fox, Wolfgang Haak, Ron Pinhasi, David Reich. Genome-wide patterns of selection in 230 ancient Eurasians. Nature, 2015; DOI: 10.1038/nature16152

Doenças sexualmente transmissíveis explicam a monogamia (El País)

13/04/2016UncategorizedAntropologia física, DST, Modelagem, Reducionismo, Sexorenzotaddei

Com a ampliação das sociedades, as infecções sexuais se tornaram endêmicas e afetaram os que mantinham muitas relações

DANIEL MEDIAVILLA

13 ABR 2016 – 02:29 CEST

A origem da monogamia imposta ainda é um mistério. Em algum momento na história da humanidade, quando o advento da agricultura e da pecuária começou a transformar as sociedades, começou a mudar a ideia do que era aceitável nas relações entre homens e mulheres. Ao longo da história, a maioria das sociedades tem permitido a poligamia. O estudo sobre caçadores-coletores sugere que, entre as sociedades pré-históricas, era frequente que um grupo relativamente pequeno de homens monopolizasse as mulheres da tribo para aumentar sua prole.

No entanto, aconteceu algo para que muitos dos grupos que conseguiram se sobrepor adotassem um sistema de organização do sexo tão distante das inclinações humanas, como a monogamia. Como se pode ler em várias passagens da Bíblia, a recomendação para resolver conflitos geralmente consistia na morte dos adúlteros por apedrejamento.

Um grupo de pesquisadores da Universidade de Waterloo (Canadá) e do Instituto Max Planck de Antropologia Evolutiva (Alemanha), que publicou nesta terça-feira um artigo sobre o tema na revista Nature Communications, acredita que as doenças sexualmente transmissíveis desempenharam um papel fundamental. Segundo a hipótese, que foi testada com modelos tecnológicos, os pesquisadores sugerem que, quando a agricultura permitiu o surgimento de populações nas quais mais de 300 pessoas viviam juntas, nossa relação com bactérias como a gonorreia ou sífilis mudou.

A sífilis e a gonorreia afetavam a fertilidade em uma sociedade sem antibióticos ou preservativos

Nos pequenos grupos do Plistoceno, os surtos causados por esses micróbios duravam pouco e tinham um impacto reduzido sobre a população. No entanto, quando o número de indivíduos na sociedade é maior, os surtos se tornam endêmicos e o impacto sobre aqueles que praticam a poligamia é maior. Em uma sociedade sem preservativos de látex ou antibióticos, as infecções bacterianas têm um grande impacto sobre a fertilidade.

Essa condição biológica teria dado vantagem às pessoas que se acasalavam de forma monogâmica e, além disso, também teria tornado mais aceitáveis castigos, como os descritos na Bíblia, para indivíduos que desrespeitassem a norma. Eventualmente, nas crescentes sociedades agrárias do início da história da humanidade, a interação entre a monogamia e a imposição de normas para sustentá-la acabaria dando vantagem sob a forma de maior fertilidade para as sociedades que as praticassem.

Os autores do estudo acreditam que estas abordagens, que testam premissas onde se tenta compreender a interação entre as dinâmicas sociais e naturais, podem ajudar a entender não só o surgimento da monogamia imposta socialmente, mas também outras normas sociais relacionadas com o contato físico entre os seres humanos.

“Nossas normas sociais não se desenvolveram isoladas do que estava acontecendo em nosso ambiente natural”, afirmou em um comunicado Chris Bauch, professor de matemática aplicada da Universidade de Waterloo e um dos autores do estudo. “Pelo contrário, não podemos compreender as normas sociais sem entender sua origem em nosso ambiente natural”, acrescentou. “As normas foram moldadas por nosso ambiente natural”, conclui.

As vantagens evolutivas de termos feito sexo com os neandertais (El País)

28/03/2016UncategorizedAntropologia física, Neandertaisrenzotaddei

Novos indícios de que antigos cruzamentos entre as três espécies tiveram consequências evolutivas

JAVIER SAMPEDRO

26 MAR 2016 – 17:22 CET

Localização geográfica das 159 populações estudadas.

Localização geográfica das 159 populações estudadas. SCIENCE

Estamos tão acostumados a ser os únicos humanos sobre a Terra que quase não podemos imaginar um passado em que, saindo da África para um mundo desconhecido, o mais fácil era encontrar pelo caminho gentes de outras espécies do gênero Homo que compartilhavam conosco um passado esquecido, e com as quais, conforme sabemos agora, não descartávamos compartilhar o sonho de uma noite de verão. Sem que nossa lógica mais profunda, a genética, considerasse isso algo inconveniente.

Segundo a última pesquisa de 1.523 genomas de pessoas de todo o mundo, incluindo pela primeira vez os de 35 melanésios, os neandertais se relacionaram não uma, mas três vezes (em três épocas diferentes), com diversas populações de humanos modernos. Só ficaram de fora os africanos, pela simples razão de que os neandertais não estavam ali. Os melanésios atuais carregam o DNA de outra espécie arcaica, os misteriosos denisovanos que viviam na Sibéria há 50.000 anos, mas nem por isso se livraram da promiscuidade neandertal: seus genomas atuais têm as marcas inconfundíveis tanto de neandertais como de denisovanos.

E um prêmio de consolação: os genes da evolução do córtex, a sede da mente humana, são inteiramente nossos, dos Homo sapiens. Os demais parecem ser adaptações ao clima local. São os resultados que 17 cientistas da Universidade de Washington em Seattle, a Universidade de Ferrara, o Instituto Max Planck de Antropologia Evolutiva em Leipzig e o Instituto de Pesquisa Médica da Goroka, na Papua Nova Guiné, entre outros, apresentaram na revista Science.

Os genomas costumam ser medidos em megabases, ou milhões de bases (as letras do DNA, gatacca…). O genoma humano tem 3.235 megabases. Dessas, 51 megabases são arcaicas nos europeus, 55 nos asiáticos meridionais e 65 nos asiáticos orientais. Quase todas essas sequências arcaicas são de origem neandertal nessas populações. Em contraste, os melanésios apresentam uma média de 104 megabases arcaicas, das quais 49 são neandertais e 43 são denisovanas (as 12 restantes são ambíguas por enquanto). São só números, mas dão uma ideia do grau de precisão alcançado pela genômica humana.

Segundo a última pesquisa, os neandertais se cruzaram não uma, mas três vezes (em três épocas diferentes), com diversas populações de humanos modernos

Mas o diabo mora nos detalhes. As sequências arcaicas não estão distribuídas de maneira homogênea pelo genoma, muito pelo contrário. Há zonas onde estão muito pouco representadas, ou seja, onde há trechos de 8 megabases ou mais sem uma única letra neandertal ou denisovana. Estes trechos de puro DNA moderno, ou sapiens, são ricos em genes implicados no desenvolvimento do córtex cerebral – a sede da mente humana – e o corpo estriado (ou núcleo estriado), uma região interna do cérebro responsável pelos mecanismos de recompensa e, portanto, envolvida a fundo no planejamento de ações e na tomada de decisões.

Segundo as análise estatísticas dos autores, não é por mera casualidade que os genes envolvidos nessas altas funções mentais estão livres de sequências neandertais ou denisovanas. O fato implica, provavelmente, que a presença de DNA arcaico ali se revelou desvantajosa durante os últimos 50 milênios e, portanto, foi varrida pela seleção natural.

Entre os genes modernos se encontra o famoso gene da linguagem, FOXP2, o que volta a levantar dúvidas sobre a capacidade de linguagem dos neandertais. A sequência idêntica deste gene em neandertais e sapiens foi considerada uma prova de que os neandertais falavam, mas os genes são mais que sua sequência de código (a que se traduz em proteínas): existem ainda zonas reguladoras essenciais, as que dizem ao gene onde, quando e quanto se ativar. Outros genes puramente modernos são, quando em mutação, os responsáveis pelo autismo.

Entre os genes modernos se encontra o famoso gene da linguagem, FOXP2, o que volta a levantar dúvidas sobre a capacidade de linguagem dos neandertais

Também são interessantes as regiões genômicas contrárias, isto é, as particularmente ricas em genes neandertais ou denisovanos. Os genomas melanésios revelaram 21 regiões desse tipo que mostram evidências de terem sido favorecidas pela seleção natural. Muitas delas contêm genes implicados no metabolismo (a cozinha da célula), como o do hormônio GCG, que incrementa os níveis de glicose no sangue, ou o da proteína PLPP1, encarregada de processar as gorduras; também há cinco genes implicados na resposta imune inata, a primeira linha de defesa contra as infecções.

Tudo isso reforça os indícios anteriores de que os cruzamentos de nossos ancestrais sapiens com as espécies arcaicas que encontraram durante suas migrações fora do continente africano foram importantes para adaptar-se às condições locais: clima, dieta e infecções frequentes na região. Faz sentido, certamente.

Foram sonhos de uma noite do verão, mas voltam agora para nosso encontro, como em uma boa peça de teatro clássico.

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

21/03/2016UncategorizedAntropologia física, Evolução, Hominídeosrenzotaddei

Carl Zimmer

MARCH 17, 2016

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)

17/02/2016UncategorizedAntropologia física, Evolução, Fósseis humanos, Primatasrenzotaddei

16-FEB-2016

Nature paper places human evolution in Africa, not Eurasia

DOE/Los Alamos National Laboratory

IMAGE: 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)

15/02/2016UncategorizedAntropologia física, Biologia, Evolução, Microbiologia, Microbiotarenzotaddei

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.

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

14/05/2015UncategorizedAnimais, Antropologia física, Chimpanzés, Evolução, Evolucionismo, Inteligência animal, Interação humanos-animais, Primatas, Socialidade animal, Tecnologiarenzotaddei

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

JAVIER SALAS 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.

Did a Volcanic Cataclysm 40,000 Years Ago Trigger the Final Demise of the Neanderthals? (Geological Society of America)

20/03/2015UncategorizedAntropoceno, Antropologia, Antropologia física, Desastre, Extinção, Geologia, Neandertaisrenzotaddei

19 March 2015

Boulder, Colo., USA – The Campanian Ignimbrite (CI) eruption in Italy 40,000 years ago was one of the largest volcanic cataclysms in Europe and injected a significant amount of sulfur-dioxide (SO2) into the stratosphere. Scientists have long debated whether this eruption contributed to the final extinction of the Neanderthals. This new study by Benjamin A. Black and colleagues tests this hypothesis with a sophisticated climate model.

Black and colleagues write that the CI eruption approximately coincided with the final decline of Neanderthals as well as with dramatic territorial and cultural advances among anatomically modern humans. Because of this, the roles of climate, hominin competition, and volcanic sulfur cooling and acid deposition have been vigorously debated as causes of Neanderthal extinction.

They point out, however, that the decline of Neanderthals in Europe began well before the CI eruption: “Radiocarbon dating has shown that at the time of the CI eruption, anatomically modern humans had already arrived in Europe, and the range of Neanderthals had steadily diminished. Work at five sites in the Mediterranean indicates that anatomically modern humans were established in these locations by then as well.”

“While the precise implications of the CI eruption for cultures and livelihoods are best understood in the context of archaeological data sets,” write Black and colleagues, the results of their study quantitatively describe the magnitude and distribution of the volcanic cooling and acid deposition that ancient hominin communities experienced coincident with the final decline of the Neanderthals.

In their climate simulations, Black and colleagues found that the largest temperature decreases after the eruption occurred in Eastern Europe and Asia and sidestepped the areas where the final Neanderthal populations were living (Western Europe). Therefore, the authors conclude that the eruption was probably insufficient to trigger Neanderthal extinction.

However, the abrupt cold spell that followed the eruption would still have significantly impacted day-to-day life for Neanderthals and early humans in Europe. Black and colleagues point out that temperatures in Western Europe would have decreased by an average of 2 to 4 degrees Celsius during the year following the eruption. These unusual conditions, they write, may have directly influenced survival and day-to-day life for Neanderthals and anatomically modern humans alike, and emphasize the resilience of anatomically modern humans in the face of abrupt and adverse changes in the environment.

FEATURED ARTICLE
Campanian Ignimbrite volcanism, climate, and the final decline of the Neanderthals
Benjamin A. Black et al., University of California, Berkeley, California, USA. Published online ahead of print on 19 March 2015; http://dx.doi.org/10.1130/G36514.1.

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

17/01/2015UncategorizedAntropologia, Antropologia física, Evolução, Homo sapiens, Neandertaisrenzotaddei

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 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)

28/11/2014UncategorizedAntropologia física, Evolução, LGBT, Sexualidaderenzotaddei

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

By: Bryan Nelson

Fri, Apr 08, 2011 at 05:47 AM

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.

A Magisterial Synthesis Of Apes And Human Evolution (Forbes)

24/11/2014UncategorizedAnimais, Antropologia física, Evolucionismo, Interação humanos-animais, Macacos, Primatas, Socialidade animalrenzotaddei

11/23/2014 @ 10:31AM By John Farrell

There are books to read from cover to cover in a week or two, and then there are the ones you dip into over and over again, because they aren’t books so much as encyclopedias.

Russell H. Tuttle’s Apes and Human Evolution is one of these. Like the late Stephen Jay Gould’s magisterial Structure of Evolutionary Theory, Tuttle’s tome is a grand synthesis of all the latest research and data about apes and their relation to us.

Tuttle is Professor of Anthropology, Evolutionary Biology, History of Science and Medicine and the College at the University of Chicago.

Tuttle believes that bipedalism preceded the development of the brain in early humans –and was likely something inherited from smaller apes already used to using their feet to move laterally along branches in trees. Although chimpanzees and bonobos are our closest relatives on the evolutionary tree, they do not represent in their own locomotion good proto-models of what led to human upright posture and walking.

While the book does not need to be read in any particular order, the first two chapters set the stage and the terminology for the rest of Apes and Human Evolution, which consists of five parts, totaling 13 dense chapters. A glossary of terms would have helped, but it’s not too much of a distraction to look up the specialist terms Tuttle introduces in these opening sections.

But lest you think it is intended chiefly for colleagues in the fields of anthropology and evolutionary biology, Tuttle’s style throughout is crisp and often witty. (The chapter on the development of human bipedalism, for example, is called ‘How to Achieve an Erection’.)

Professor Russell H. Tuttle, University of Chicago. Image courtesy of Phys.org.

The opening chapter, ‘Mongrel Models and Seductive Scenarios of Human Evolution’ discusses several hypotheses of human origins, some of which Tuttle argues are biased and which in recent years more detailed study of apes has refuted.

He has a low opinion, for example, of the idea that humans are in essence a species of ‘killer apes’, a notion that gained popularity during the last century. “The views of Charles Darwin,” he writes, “are restrained in comparison with the speculations by the advocates of killer ape scenarios, which flourished for several decades after the horrors of World War I and World War II.”

Darwin portrayed early man (his term) as having “sprung from some comparatively weak creature,” who was not speedy and who lacked natural bodily defenses, namely, formidable canine teeth. Consequently, this bipedal creature was stimulated to use his intellectual powers to make weapons for defense and hunting and to cooperate with “his fellow-men”.

What distinguishes humans among the approximately 400 extant species of primates? In Tuttle’s view, a constellation of morphological and behavioral characteristics, some of which only can be traced precisely through the fossil and archeological records.

Obligate terrestrial bipedalism, precision-gripping hands, reduced teeth and jaws, and ballooned brains can be identified if fossils are complete enough in the skeletal regions under study. Archeological artifacts and features can indicate the presence of tool use and manufacture, control of fire, fabricated shelters, bodily ornamentation, mortuary practice, plastic and graphic arts, and other indications of cognitive skills and culture.

There are also the features that can’t be easily found in fossils or the archeological records, primarily social: cooperation, the ability to enlist new members from outside the immediate community of hominids.

Space does not allow a detailed review of each chapter, summaries of which you can find here. But in the final part, ‘What Makes Us Human?’, Tuttle reveals more of his own philosophical reflections on the matter.

One passage that struck me, for example, occurs in the sub-section, ‘What is More Real: God or Race?’

I believe that God is an ever-increasing collective emergent of the love of all beings past, present and future, but this cannot be proven by available scientific methods of experimentation or controlled comparison. In contrast, the belief in race, in the sense of biological subspecies of Homo Sapiens, lacks a tangible basis; indeed, it has been proven unsupportable genomically, behaviorally, and phenotypically.

Individuals and political groups have manipulated both God and race for nefarious purposes, but actions rooted in the human capacity to affiliate with non-kin, to cooperate, and especially to unite in love and respect for the agency of others has given rise to a variety of constructive social codes that facilitate intragroup and extensive intergroup harmony and mitigate disruptive personal and social behavior.

Whereas scientists possess the means to eliminate belief in human races, they lack the means to eradicate belief in God, and frankly they are probably wasting time and treasure on the exercise.

There’s an optimism here I found somewhat reminiscent of the Jesuit paleontologist Teilhard de Chardin, who had a very goal-oriented view of humanity and its role in cosmic evolution.

I could’t resist asking Tuttle whether Teilhard’s writings had any influence on his own thought as he embarked on his career in the 1960s. This was around the time that Teilhard’s writings were becoming most influential.

“Quite the contrary,” Tuttle replied in an email. “I thought Phenomenon of Man was rubbish. Father Teilhard wanted to be an evolutionary biologist while not giving up God. He did a shoddy job of reconciling deep religious belief with evolutionary biology…for one, he was an orthogenecist [i.e., he believed in progressive, directional evolution, toward a universal goal].”

“I cannot see a reconciliation of the two realms,” Tuttle added. “I believe in the power of love which some or many see as an aspect of God. But I do not think there is a celestial, etherial being that is interested in us or that makes good or bad things happen.”

Tuttle elaborated on this in a recent review he wrote for the American Journal of Psychology: “As a Christian participant observer into my late teens, followed by two decades attempting to be an atheist, and then participation in the music ministry at a wide variety of churches over the past 30 years, I aver that the bonding of congregations based on love of God and one another are substantive enough to withstand the sarcastic remarks and mockery of professed atheists who command notable space in print media and on the airways.”

Apes and Human Evolution is also available in Kindle Edition. But given the slight difference in price, I recommend getting the print edition.

Beyond the bones: The archaeology of human networks (New Scientist)

17/07/2014UncategorizedAntropologia física, Evolucionismo, Redesrenzotaddei

21 July 2014 by Alun Anderson

Magazine issue 2978

Book information

Thinking Big: How the evolution of social life shaped the human mindby Clive Gamble, John Gowlett and Robin Dunbar
Published by: Thames & Hudson
Price: £18.95
Human Evolution: A Pelican introduction by Robin Dunbar
Published by: Pelican Books
Price: £5.99

Did a focus on local life leave Neanderthals perilously isolated? (Image: Elisabeth Daynes/SPL)

The idea of human as networker is fast replacing the idea of human as toolmaker in the story of the human brain, claim two new books on our evolution

“HELL is other people,” goes Jean-Paul Sartre’s famous line. It is a hell that may have created us and our culture, judging by two new books. They show that the idea that we are defined by our struggles to deal with our fellow humans is shaking up archaeology and how we think about the key force driving human evolution.

The first book is Thinking Big by archaeologists Clive Gamble and John Gowlett and evolutionary psychologist Robin Dunbar. It is the story of a seven-year project – From Lucy to Language – that confronted archaeologists with the social brain hypothesis of human evolution.

The result is a dramatic demolition of the “stones and bones” approach to archaeology, which keeps researchers firmly fixed only on the physical evidence they dig up, and a move towards a grand look at the evolving human mind. There is “more to humanity than the bits of chipped bone”, write the authors as they seek a framework for all human psychological traits, from kinship and laughter to language and ceremony. Old dogma is derided as never moving beyond “WYSWTW” (What You See is What There Was).

The second book is a solo effort by Dunbar, the key thinker behind the social brain hypothesis. In Human Evolution, he lays out the big ideas that the archaeologists later took up. At its heart is the observation that as brains grew bigger, so did the groups we live in: bigger brains were built for and by social life. Modern humans have a cognitive limit of about 150 friends and family (the well-known “Dunbar’s number”). Within that circle are an average of five “intimates”, 15 best friends and 50 good friends. Chimps have an average community size of 55.

Studies of living, non-human primates show why you might need bigger brains to live in bigger groups. The more others are around, the more likely you are to be bullied out of a juicy food patch or a safe sleeping site. Such stress can be hell, especially for low-ranking females, who can be driven into infertility. To cope, primates create cliques of allies which they sustain through the pleasurable endorphin rush induced by regular mutual grooming. This solution fails if groups grow bigger, for there is not enough time for one-on-one attention. Bigger brains are key to developing smarter ways of dealing with others, the theory goes.

For Dunbar, these included laughter and singing, both great endorphin-releasers within groups. There was also fire, which gave light so evenings could be used for cooking and more “social grooming”. Then came language, together with a growing ability to read others’ intentions, which ultimately made it possible to tell stories, maintain far-flung relationships and usereligion to bind communities.

The Thinking Big archaeologists take from Dunbar the grand hypothesis that social life drives human change, switching from a view of “man the toolmaker” to “man the networker”. Alongside that, the proven relationship between brain size, group size and mental skills makes it possible to estimate the size of groups our ancestors lived in and their capacity to interact with others.

A fresh look at the Neanderthals is telling. They dominated Europe for 250,000 years, much longer than modern humans. They were skilled hunters, toolmakers and had mastered fire. Their brain size suggests they lived in groups of about 110 and had the cognitive skills to understand the feelings of others. That fits well with archaeological evidence that older and disabled Neanderthals were cared for: they perhaps knew compassion.

So why did they vanish so fast during a time of changing climate, when modern humans prospered? It may be that their mental skills were not quite adequate to maintain relationships beyond immediate group members, something we can do easily. That may have been crucial to our success: in hard times, bigger networks can mean gaining help from distant friends who are still doing well, and who you’ll help in turn. Without that “social storage” of resources, local extinction may loom. Archaeological evidence again tallies with the social brain theory: one study shows that 70 per cent of the raw materials of Neanderthal tools travelled less than 25 kilometres, while 60 per cent of those of contemporaneous humans had travelled more than 25 kilometres.

The two books fit well together but are very different. Thinking Big inspires, but much wonderful research is passed over too briefly amid general argument. An exception is a story from Beeches Pit, a 400,000-year-old site in the east of England. Archaeologists there painstakingly reassembled the flint flakes struck from a rock in the process of making a hand axe. Two flakes were found burnt bright red; they had fallen into a fire just in front of the axe-maker. We can almost see our ancestors working around what must have been a communal fire, for no one person could have gathered enough wood to keep it burning.

Dunbar’s solo work, Human Evolution, however, is a must-read. It has the great strength of showing you the inner workings of an imaginative mind, while allowing you the freedom to think, and even to disagree about whether that hellish social pressure really has given us our distinct cognitive design, along with science and the arts.

This article appeared in print under the headline “Beyond bones and stones”

Alun Anderson is a consultant for New Scientist

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

10/07/2014UncategorizedAntropologia física, Ecologia, Evolução, Neandertaisrenzotaddei

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:

Xiu-Jie Wu, Isabelle Crevecoeur, Wu Liu, Song Xing, and Erik Trinkaus. Temporal labyrinths of eastern Eurasian Pleistocene humans. PNAS, 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)

02/07/2014UncategorizedAntropologia física, Cogni, Corpo, Evolução, Evolucionismo, Hominídeos, Insetos, Macacosrenzotaddei

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:

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

Ancient Man Used “Super-Acoustics” to Alter Consciousness (… and speak with the dead?) (Phys.Org)

20/06/2014UncategorizedAntropologia física, Arqueologia, Corpo, Espiritualidade, Malta, Religião, Tecnologias do corpo, Visceralidaderenzotaddei

June 16th, 2014 Linda Eneix

Ancient Man Used “Super-Acoustics” to Alter Consciousness (... and speak with the dead?)

Research team members enter the “Oracle Room” of the Hal Saflieni Hypogeum, Malta (ca. 3600 BCE)

A prehistoric necropolis yields clues to the ancient use of sound and its effect on human brain activity.Researchers detected the presence of a strong double resonance frequency at 70Hz and 114Hz inside a 5,000-years-old mortuary temple on the Mediterranean island of Malta. The Ħal Saflieni Hypogeum is an underground complex created in the Neolithic (New Stone Age) period as a depository for bones and a shrine for ritual use. A chamber known as “The Oracle Room” has a fabled reputation for exceptional sound behavior.

During testing, a deep male voice tuned to these frequencies stimulated a resonance phenomenon throughout the hypogeum, creating bone-chilling effects. It was reported that sounds echoed for up to 8 seconds. Archaeologist Fernando Coimbra said that he felt the sound crossing his body at high speed, leaving a sensation of relaxation. When it was repeated, the sensation returned and he also had the illusion that the sound was reflected from his body to the ancient red ochre paintings on the walls. One can only imagine the experience in antiquity: standing in what must have been somewhat odorous dark and listening to ritual chant while low light flickered over the bones of one’s departed loved ones.

Sound in a Basso/Baritone range of 70 – 130 hz vibrates in a certain way as a natural phenomenon of the environment in the Hypogeum, as it does in Newgrange passage tomb, megalithic cairns and any stone cavity of the right dimensions. At these resonance frequencies, even small periodic driving forces can produce large amplitude oscillations, because the system stores vibrational energy. Echoes bounce off the hard surfaces and compound before they fade. Laboratory testing indicates that exposure to these particular resonant frequencies can have a physical effect on human brain activity.

In the publication from the conference on Archaeoacoustics which sparked the study, Dr. Paolo Debertolis reports on tests conducted at the Clinical Neurophysiology Unit at the University of Trieste in Italy: “…each volunteer has their own individual frequency of activation, …always between 90 and 120 hz. Those volunteers with a frontal lobe prevalence during the testing received ideas and thoughts similar to what happens during meditation, whilst those with occipital lobe prevalence visualized images.” He goes on to state that under the right circumstances, “Ancient populations were able to obtain different states of consciousness without the use of drugs or other chemical substances.”

Hal Saflieni (ca. 3600 BCE)

Credit: Mediterranean Institute of Ancient CivilizationsWriting jointly, Anthropologist, Dr. Ezra Zubrow, Archaeologist and Psychologist, Dr. Torill Lindstrom state: “We regard it as almost inevitable that people in the Neolithic past in Malta discovered the acoustic effects of the Hypogeum, and experienced them as extraordinary, strange, perhaps even as weird and “otherworldly”.

What is astounding is that five thousand years ago the builders exploited the phenomenon, intentionally using architectural techniques to boost these “super-acoustics”. Glenn Kreisberg, a radio frequency spectrum engineer who was with the research group, observed that in the Hypogeum, “The Oracle Chamber ceiling, especially near its entrance from the outer area, and the elongated inner chamber itself, appears to be intentionally carved into the form of a wave guide.”

Project organizer Linda Eneix points to other features: “The carving of the two niches which concentrate the effect of sound, the curved shape of the Oracle Chamber with its shallow “shelf” cut high across the back, the corbelled ceilings and concave walls in the finer rooms are all precursors of todays’ acoustically engineered performance environments.” She says, “If we can accept that these developments were not by accident, then it’s clear that Ħal Saflieni’s builders knew how to manipulate a desired human psychological and physiological experience, whether they could explain it or not.”

Why?

It was demonstrated at the conference that special sound is associated with the sacred: from prehistoric caves in France and Spain to musical stone temples in India; from protected Aztec codexes in Mexico to Eleusinian Mysteries and sanctuaries in Greece to sacred Elamite valleys in Iran. It was human nature to isolate these hyper-acoustic places from mundane daily life and to place high importance to them because abnormal sound behavior implied a divine presence.

In the same conference publication Emeritus Professor Iegor Reznikoff suggests that Ħal Saflieni is a link between Palaeolithic painted caves and Romanesque chapels … “That people sang laments or prayers for the dead in the Hypogeum is certain, for a) it is a universal practice in all oral traditions we know, b) at the same period, around 3,000 BC, we have the Sumerian or Egyptian inscriptions mentioning singing to the Invisible, particularly in relationship with death and Second Life, and finally c) the resonance is so strong in the Hypogeum already when simply speaking, that one is forced to use it and singing becomes natural.”

Drs. Lindstrom and Zubrow hint at a more hierarchal purpose for the manipulation of sound. “The Neolithic itself was characterized by cultures focused on new invention…enormous collective collaborations over extended periods of time. For these large-scale projects of agriculture and building, social cohesion and compliance was absolutely necessary.”

The same people who created Ħal Saflieni also engineered a complete solar calendar with solstice and equinox sunrise alignments that still function today in one of their above-ground megalithic structures. There is no question that a sophisticated school of architectural, astronomic and audiologic knowledge was already in place a thousand years before the Egyptians started building pyramids. Eneix believes that Malta’s Ħal Saflieni Hypogeum is a remnant of a rich cultural tradition carried by the Neolithic migrations that spanned thousands of years and thousands of miles.

Stronger Brains, Weaker Bodies (New York Times)

28/05/2014UncategorizedAntropologia física, Evolucionismo, Fisiologia, Neurofisiologiarenzotaddei

MAY 27, 2014

Why does the metabolism of a sloth differ from that of a human? Brains are a big reason, say researchers who recently carried out a detailed comparison of metabolism in humans and other mammals. CreditFelipe Dana/Associated Press

Carl Zimmer

All animals do the same thing to the food they eat — they break it down to extract fuel and building blocks for growing new tissue. But the metabolism of one species may be profoundly different from another’s. A sloth will generate just enough energy to hang from a tree, for example, while some birds can convert their food into a flight from Alaska to New Zealand.

For decades, scientists have wondered how our metabolism compares to that of other species. It’s been a hard question to tackle, because metabolism is complicated — something that anyone who’s stared at a textbook diagram knows all too well. As we break down our food, we produce thousands of small molecules, some of which we flush out of our bodies and some of which we depend on for our survival.

An international team of researchers has now carried out a detailed comparison of metabolism in humans and other mammals. As they report in the journal PLOS Biology, both our brains and our muscles turn out to be unusual, metabolically speaking. And it’s possible that their odd metabolism was part of what made us uniquely human.

When scientists first began to study metabolism, they could measure it only in simple ways. They might estimate how many calories an animal burned in a day, for example. If they were feeling particularly ambitious, they might try to estimate how many calories each organ in the animal’s body burned.

Those tactics were enough to reveal some striking things about metabolism. Compared with other animals, we humans have ravenous brains. Twenty percent of the calories we take in each day are consumed by our neurons as they send signals to one another.

Ten years ago, Philipp Khaitovich of the Max Planck Institute of Evolutionary Anthropology and his colleagues began to study human metabolism in a more detailed way. They started making a catalog of the many molecules produced as we break down food.

“We wanted to get as much data as possible, just to see what happened,” said Dr. Khaitovich.

To do so, the scientists obtained brain, muscle and kidney tissues from organ donors. They then extracted metabolic compounds like glucose from the samples and measured their concentrations. All told, they measured the levels of over 10,000 different molecules.

The scientists found that each tissue had a different metabolic fingerprint, with high levels of some molecules and low levels of others.

These distinctive fingerprints came as little surprise, since each tissue has a different job to carry out. Muscles need to burn energy to generate mechanical forces, for example, while kidney cells need to pull waste out of the bloodstream.

The scientists then carried out the same experiment on chimpanzees, monkeys and mice. They found that the metabolic fingerprint for a given tissue was usually very similar in closely related species. The same tissues in more distantly related species had fingerprints with less in common.

But the scientists found two exceptions to this pattern.

The first exception turned up in the front of the brain. This region, called the prefrontal cortex, is important for figuring out how to reach long-term goals. Dr. Khaitovich’s team found that the way the human prefrontal cortex uses energy is quite distinct from other species; other tissues had comparable metabolic fingerprints across species, and even in other regions of the brain, the scientists didn’t find such a drastic difference.

This result fit in nicely with findings by other scientists that the human prefrontal cortex expanded greatly over the past six million years of our evolution. Its expansion accounts for much of the extra demand our brains make for calories.

The evolution of our enormous prefrontal cortex also had a profound effect on our species. We use it for many of the tasks that only humans can perform, such as reflecting on ourselves, thinking about what others are thinking and planning for the future.

But the prefrontal cortex was not the only part of the human body that has experienced a great deal of metabolic evolution. Dr. Khaitovich and his colleagues found that the metabolic fingerprint of muscle is even more distinct in humans.

“Muscle was really off the charts,” Dr. Khaitovich said. “We didn’t expect to see that at all.”

It was possible that the peculiar metabolism in human muscle was just the result of our modern lifestyle — not an evolutionary shift in our species. Our high-calorie diet might change the way muscle cells generated energy. It was also possible that a sedentary lifestyle made muscles weaker, creating a smaller metabolic demand.

To test that possibility, Dr. Khaitovich compared the strength of humans to that of our closest relatives. They found that chimpanzees and monkeys are far stronger, for their weight, than even university basketball players or professional climbers.

The scientists also tested their findings by putting monkeys on a couch-potato regime for a month to see if their muscles acquired a human metabolic fingerprint.

They barely changed.

Dr. Khaitovich suspects that the metabolic fingerprint of our muscles represents a genuine evolutionary change in our species.

Karen Isler and Carel van Schaik of the University of Zurich have argued that the gradual changes in human brains and muscles were intimately linked. To fuel a big brain, our ancestors had to sacrifice other tissues, including muscles.

Dr. Isler said that the new research fit their hypothesis nicely. “It looks quite convincing,” she said.

Daniel E. Lieberman, a professor of human evolutionary biology at Harvard, said he found Dr. Khaitovich’s study “very cool,” but didn’t think the results meant that brain growth came at the cost of strength. Instead, he suggested, our ancestors evolved muscles adapted for a new activity: long-distance walking and running.

“We have traded strength for endurance,” he said. And that endurance allowed our ancestors to gather more food, which could then fuel bigger brains.

“It may be that the human brain is bigger not in spite of brawn but rather because of brawn, albeit a very different kind,” he said.

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

02/05/2014UncategorizedAntropologia física, Evolução, Neandertaisrenzotaddei

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 Sudeshna Chowdhury, 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.

Uma (in)certa antropologia

An (un)certain anthropology

Arquivo da tag: Antropologia física

Can Skeletons Have a Racial Identity? (New York Times)

A growing number of forensic researchers are questioning how the field interprets the geographic ancestry of human remains.

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

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

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

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

Evolution is not the same as natural selection

Evolution can happen without natural selection

Natural selection is still happening in humans

Evolution can’t be stopped

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

Why did humans evolve such large brains? Because smarter people have more friends (The Conversation)

We are organisms, not computers

Quando todos os europeus eram negros (El País)

Última onda

How the introduction of farming changed the human genome (Science Daily)

Doenças sexualmente transmissíveis explicam a monogamia (El País)

As vantagens evolutivas de termos feito sexo com os neandertais (El País)

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

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

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

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

Did a Volcanic Cataclysm 40,000 Years Ago Trigger the Final Demise of the Neanderthals? (Geological Society of America)

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

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

A Magisterial Synthesis Of Apes And Human Evolution (Forbes)

11/23/2014 @ 10:31AM By John Farrell

Beyond the bones: The archaeology of human networks (New Scientist)

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

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

Ancient Man Used “Super-Acoustics” to Alter Consciousness (… and speak with the dead?) (Phys.Org)

Stronger Brains, Weaker Bodies (New York Times)

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