Entre os estudiosos da vida, é comum a crença de que são necessários eventos em larga escala, tais como mudanças climáticas globais, para estimular o surgimento de espécies novas e diversificadas em grande quantidade. E sabe-se que um grande influxo de novas espécies animais, descrito como um “pulso” de novas espécies, pode ser visto nos registros de fósseis africanos entre 2,8 e 2,5 milhões de anos atrás - incluindo nosso próprio gênero Homo. Mas W. Andrew Barr, do Centro de Estudo Avançado da Paleobiologia Humana da Universidade George Washington, diz que suas pesquisas sugerem que esse evento pode ter ocorrido por acaso, independentemente de mudanças climáticas. O artigo relatando os resultados do estudo foi publicado no dia 31 de julho na revista científica Cambridge Core.
Considera-se que, de forma geral, a ocorrência de grandes mudanças ambientais levará ao surgimento de algumas espécies e à extinção de outras, o que pode gerar um conjunto de novas espécies, ou pulso, no registro fóssil. Entretanto, não há uma definição formal do que seja considerado um pulso. Por isso, os especialistas discordam sobre quais grupos constituem eventos significativos e quais podem ser explicados como flutuações aleatórias.
Barr utilizou simulações de computador para modelar como o registro fóssil se pareceria ao longo do tempo na ausência de qualquer mudança climática e encontrou conjuntos de novas espécies com magnitude semelhante à dos conjuntos observados no registro fóssil. Isso significa que padrões aleatórias provavelmente têm seu papel na flutuação do processo de especificação sub-avaliado, ele diz.
As descobertas de Barr apontam que os cientistas talvez precisem repensar ideias amplamente aceitas sobre por que os ancestrais humanos se tornaram mais inteligentes e sofisticados.
“A ideia de que nosso gênero se originou há mais de 2,5 milhões de anos como parte de um pulso de substituição em resposta direta a mudanças climáticas tem uma história profunda na paleoantropologia”, disse Barr. “Meu estudo mostra que a magnitude daquele pulso poderia ser causada por flutuações aleatórias em taxas de especiação. Uma implicação é que talvez precisemos ampliar nossa busca pelo motivo pelo qual nosso gênero surgiu naquele lugar e época.”
Ele comparou o padrão a lançar uma moeda. Se lançar uma moeda 100 vezes, você esperaria registrar “cara” 50 vezes e “coroa” outras 50. Contudo, se estiver olhando apenas para 10 arremessos de moeda, poderia ver um grande desequilíbrio, registrando, em vez disso, sete “cara” e apenas três “coroa”. Com o passar do tempo, as proporções iriam se aproximar, mas, no curto prazo, seria possível enxergar os conjuntos formados pelos resultados dos lançamentos independentes da moeda, segundo ele.
De forma similar, no modelo de Barr, as flutuações na substituição de espécies são expressivas, mas causadas puramente por processos aleatórios.
“Quando se olha com cuidado as evidências e se compara as possíveis explicações, a ideia de que a origem do Homo é parte de um pulso de substituição causado pelo clima realmente não se mantém”, disse Barr.
A pesquisa desafia os cientistas a serem cuidadosos com as histórias que contam sobre a história da adaptação humana, segundo Barr. Traços que fazem dos humanos diferentes de seus ancestrais - como cérebros maiores e grande sofisticação tecnológica - poderiam ter surgido por uma variedade de razões, ele diz.
“Podemos sentar no presente e contar histórias sobre o passado que fazem sentido com as adaptações dos nossos dias modernos”, ele disse. “Mas elas poderiam ter evoluído por razões que não conhecemos.”
O mito do dilúvio que mudou a China possuiria embasamento geológico, assim como lendas de enchentes da Escandinávia ao TibeT
Os antigos relatos sobre grandes inundações há muito têm mexido com as mentes modernas. Será que eles falam de eventos reais num passado distante ou são apenas mitos com raízes na imaginação? O mais familiar, para muitos de nós do Ocidente, é a história bíblica de Noé. Mas culturas do mundo todo passam para as gerações seguintes seus próprios contos de desastres naturais devastadores.
Uma nova pesquisa publicada na revista científica Science por um grupo de pesquisadores - cujo a maioria é chinesa - liderado por Qinglong Wu reportou a descoberta de evidência geológica para um evento que, segundo propõem, pode estar por trás de uma história chinesa sobre uma grande enchente. A pesquisa investiga o campo da geomitologia, que relaciona tradições orais e folclore com fenômenos naturais como terremotos, erupções vulcânicas e enchentes.
"O grande Yu controla as águas"
A história do Imperador Yu, o lendário fundador da primeira dinastia chinesa, gira em torno de sua habilidade de drenar a água de focos de enchente persistentes nas áreas de baixa altitude, trazendo ordem para a terra. Essa história de enchente antiga foca no triunfo da engenhosidade humana e do trabalho sobre as forças caóticas do mundo natural. É bastante diferente de outras tradições e histórias envolvendo enchentes, já que o herói não sobreviveu a uma inundação destruidora de mundos, mas realizou proezas relacionadas à engenharia fluvial que lhe permitiram estabelecer um caminho para a agricultura de várzea. Mas será que o Imperador Yu foi uma verdadeira figura histórica e, se sim, o que causou a grande enchente tão central em sua própria história?
Em sua nova análise, Wu e seus colegas se basearam em estudos prévios sobre deslizamentos de terra em Jishi Gorge que represaram o Rio Amarelo na região onde ele flui desde o alto do Planalto Tibetano. Eles organizaram evidências geo e arqueológicas para argumentar que quando a barragem formada pelos deslizamentos cedeu, uma enchente avançou pelo Rio Amarelo, em torno de 1920 a.C. Eles dataram os sedimentos lacustres que ficaram armazenados rio acima da barragem de detritos e sedimentos da enchente depositados rio abaixo, em elevações de até 50 metros acima do nível do rio. Os pesquisadores estimaram que a falha na barragem de sedimentos enviou aproximadamente meio milhão de metros cúbicos de água por segundo para o Rio Amarelo e por toda a China antiga. Também notou-se que o período dessa inundação coincide com uma enorme transição arqueológica, do Neolítico para a Idade do Bronze, nas planícies à jusante do Rio Amarelo.
O estudo publicado na Science não apenas reportou evidências do acontecimento de uma grande enchente no mesmo local e época em que, acredita-se, a de Yu teria ocorrido, mas também nota que ela coincide com uma mudança previamente identificada no curso do Rio Amarelo, em direção a uma nova saída através da planície norte da China. Os pesquisadores sugerem que a enchente identificada por eles pode ter destruído diques no rio localizados naquela região de planície, e provocado essa mudança.
E isso, por sua vez, ajudaria a explicar o aspecto singular da história da enchente de Yu. Um rio grande, redirecionado para um novo curso, poderia desencadear enchentes persistentes em áreas baixas. Uma rota mais longa para o mar imporia um declive gentil que promoveria deposição sedimentar, entupindo o canal, e dividindo a corrente em múltiplos canais — isso tudo causaria uma inundação exacerbada das áreas baixas. Esse parece um bom cenário para a história do longo trabalho de Yu para drenar as águas da inundação e canalizá-las para o mar.
Histórias de enchente de diferentes culturas ao redor do globo
Quando eu pesquisei as possíveis origens geológicas das histórias de enchente do mundo para o meu livro “The Rocks Don’t Lie: A Geologist Investigates Noah’s Flood," fiquei impressionado ao reparar como a geografia de detalhes aparentemente curiosos de muitos mitos locais era consistente com processos geológicos que causam enchentes desastrosas em regiões diferentes. Mesmo ao longo do Nilo, onde as enchentes anuais são bem previsíveis, a falta de histórias de inundações é consistente com o fato das secas serem o real perigo no antigo Egito. Lá, a falta de enchentes teria sido catastrófica.
Perto do Pacífico, área propensa a tsunamis, histórias de enchentes contam de ondas gigantes que surgiram no mar. Antigos missionários cristãos ficaram perplexos ao saber que as tradições relacionadas à inundações no Sul do Pacífico não mencionavam o dilúvio bíblico de 40 dias e 40 noites; ao invés disso, falavam sobre ondas gigantes que vinham sem aviso. Uma história tradicional da costa do Chile descreve como duas grandes cobras competiam para ver qual podia fazer o mar se levantar mais, desencadeando um terremoto e enviando uma enorme onda para a praia.
Contos nativo-americanos de comunidades litorâneas do Noroeste Pacífico falam de batalhas entre pássaros mitológicos e baleias que faziam o chão balançar e provocavam ondas enormes. Todas essas histórias parecem descrições pré-científicas de um tsunami: uma onda provocada por um terremoto que pode inundar a costa de repente e deixar consequências catastróficas.
Outras histórias sobre inundações evocam falhas em barragens de gelo e detritos nas margens de geleiras que liberaram de repente os rios que elas seguravam. Uma história escandinava, por exemplo, fala sobre como Odin e seus irmãos mataram o gigante de gelo Ymir, causando uma enorme enchente e afogando pessoas e animais. Não é preciso muita imaginação para ver como isso descreve a falha em uma barreira glacial.
Enquanto fazia trabalho de campo no Tibet, aprendi uma história local sobre um guru que drenava um lago no vale do Rio Tsangpo, no limite da Planície Tibetana — depois que nosso time descobriu terraços feitos de sedimentos empoleirados bem acima do chão do vale. Os fragmentos de madeira de mais de 1.200 anos que coletamos dos sedimentos do lago correspondem à época em que o guru chegou no vale e converteu a população local ao Budismo ao derrotar, segundo conta a história, o demônio do rio e revelar o fértil fundo do rio no qual os moradores da vila ainda praticam agricultura.
Não espere provas definitivas
Claro, tentativas de usar a ciência para relacionar contos antigos com eventos reais são repletas de especulação. Mas fica claro que histórias sobre grandes enchentes são algumas das mais antigas da humanidade. E o padrão global de tsunamis, enchentes causadas por quebra de geleiras, e inundações catastróficas de áreas baixas se encaixam muito bem com detalhes incomuns dessas histórias.
E mesmo que evidências geológicas tenha acabado com a ideia de uma enchente global há quase dois séculos, existem opções de explicação racional para o dilúvio bíblico. Uma é a inundação catastrófica que os oceanógrafos Bill Ryan e Walter Pitman sugerem que aconteceu quando o aumento pós-glacial do nível do oceano rompeu o Bósforo e decantou o Mediterrâneo em um vale de planície de água doce, formando o Mar Negro. Ou talvez esteja relacionado com a inundação cataclísmica na planície da zona estuarina da Mesopotâmia, como a que inundou o delta de Irrawaddy em 2008, matando mais de 130.000 pessoas.
O novo trabalho de Wu e seus colegas prova que a enchente que eles reconstruíram foi, de fato, a do Imperador Yu? Não, mas monta um caso intrigante sobre essa possibilidade. Ainda assim, pesquisadores que estudaram barragens de detritos em Jishi George anteriormente concluíram que os lagos antigos do local foram drenados lentamente, e foram datados como sendo 1000 anos mais velhos do que as datas reportadas nesse novo artigo. Houve mais de uma geração de barragens de detritos e enchentes? Sem dúvida os geólogos continuarão debatendo sobre as evidências. Isto é, afinal, o que fazemos.
Sempre fez parte da natureza humana se fascinar por e prestar atenção no mundo natural. Grandes inundações e outros desastres naturais por muito tempo foram vistos como obra de divindades ou entidades sobrenaturais bravas. Mas agora que estamos aprendendo que algumas histórias antes vistas como folclóricas e mitos podem ter suas raízes plantadas em eventos reais, os cientistas estão prestando um pouco mais de atenção aos contadores de histórias.
On the outskirts of Beijing, a small limestone mountain named Dragon Bone Hill rises above the surrounding sprawl. Along the northern side, a path leads up to some fenced-off caves that draw 150,000 visitors each year, from schoolchildren to grey-haired pensioners. It was here, in 1929, that researchers discovered a nearly complete ancient skull that they determined was roughly half a million years old. Dubbed Peking Man, it was among the earliest human remains ever uncovered, and it helped to convince many researchers that humanity first evolved in Asia.
Since then, the central importance of Peking Man has faded. Although modern dating methods put the fossil even earlier — at up to 780,000 years old — the specimen has been eclipsed by discoveries in Africa that have yielded much older remains of ancient human relatives. Such finds have cemented Africa's status as the cradle of humanity — the place from which modern humans and their predecessors spread around the globe — and relegated Asia to a kind of evolutionary cul-de-sac.
But the tale of Peking Man has haunted generations of Chinese researchers, who have struggled to understand its relationship to modern humans. “It's a story without an ending,” says Wu Xinzhi, a palaeontologist at the Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing. They wonder whether the descendants of Peking Man and fellow members of the species Homo erectus died out or evolved into a more modern species, and whether they contributed to the gene pool of China today.
Keen to get to the bottom of its people's ancestry, China has in the past decade stepped up its efforts to uncover evidence of early humans across the country. It is reanalysing old fossil finds and pouring tens of millions of dollars a year into excavations. And the government is setting up a $1.1-million laboratory at the IVPP to extract and sequence ancient DNA.
The investment comes at a time when palaeoanthropologists across the globe are starting to pay more attention to Asian fossils and how they relate to other early hominins — creatures that are more closely related to humans than to chimps. Finds in China and other parts of Asia have made it clear that a dazzling variety of Homo species once roamed the continent. And they are challenging conventional ideas about the evolutionary history of humanity.
“Many Western scientists tend to see Asian fossils and artefacts through the prism of what was happening in Africa and Europe,” says Wu. Those other continents have historically drawn more attention in studies of human evolution because of the antiquity of fossil finds there, and because they are closer to major palaeoanthropology research institutions, he says. “But it's increasingly clear that many Asian materials cannot fit into the traditional narrative of human evolution.”
Chris Stringer, a palaeoanthropologist at the Natural History Museum in London, agrees. “Asia has been a forgotten continent,” he says. “Its role in human evolution may have been largely under-appreciated.”
EVOLVING STORY
In its typical form, the story of Homo sapiens starts in Africa. The exact details vary from one telling to another, but the key characters and events generally remain the same. And the title is always 'Out of Africa'.
In this standard view of human evolution, H. erectus first evolved there more than 2 million years ago (see 'Two routes for human evolution'). Then, some time before 600,000 years ago, it gave rise to a new species: Homo heidelbergensis, the oldest remains of which have been found in Ethiopia. About 400,000 years ago, some members of H. heidelbergensis left Africa and split into two branches: one ventured into the Middle East and Europe, where it evolved into Neanderthals; the other went east, where members became Denisovans — a group first discovered in Siberia in 2010. The remaining population of H. heidelbergensis in Africa eventually evolved into our own species, H. sapiens, about 200,000 years ago. Then these early humans expanded their range to Eurasia 60,000 years ago, where they replaced local hominins with a minuscule amount of interbreeding.
A hallmark of H. heidelbergensis — the potential common ancestor of Neanderthals, Denisovans and modern humans — is that individuals have a mixture of primitive and modern features. Like more archaic lineages, H. heidelbergensis has a massive brow ridge and no chin. But it also resembles H. sapiens, with its smaller teeth and bigger braincase. Most researchers have viewedH. heidelbergensis — or something similar — as a transitional form between H. erectus and H. sapiens.
Unfortunately, fossil evidence from this period, the dawn of the human race, is scarce and often ambiguous. It is the least understood episode in human evolution, says Russell Ciochon, a palaeoanthropologist at the University of Iowa in Iowa City. “But it's central to our understanding of humanity's ultimate origin.”
The tale is further muddled by Chinese fossils analysed over the past four decades, which cast doubt over the linear progression from African H. erectus to modern humans. They show that, between roughly 900,000 and 125,000 years ago, east Asia was teeming with hominins endowed with features that would place them somewhere between H. erectus and H. sapiens, says Wu (see‘Ancient human sites’).
“Those fossils are a big mystery,” says Ciochon. “They clearly represent more advanced species than H. erectus, but nobody knows what they are because they don't seem to fit into any categories we know.”
The fossils' transitional characteristics have prompted researchers such as Stringer to lump them with H. heidelbergensis. Because the oldest of these forms, two skulls uncovered in Yunxian in Hubei province, date back 900,000 years, Stringer even suggests that H. heidelbergensis might have originated in Asia and then spread to other continents.
But many researchers, including most Chinese palaeontologists, contend that the materials from China are different from European and African H. heidelbergensis fossils, despite some apparent similarities. One nearly complete skull unearthed at Dali in Shaanxi province and dated to 250,000 years ago, has a bigger braincase, a shorter face and a lower cheekbone than most H. heidelbergensis specimens, suggesting that the species was more advanced.
Such transitional forms persisted for hundreds of thousands of years in China, until species appeared with such modern traits that some researchers have classified them as H. sapiens. One of the most recent of these is represented by two teeth and a lower jawbone, dating to about 100,000 years ago, unearthed in 2007 by IVPP palaeoanthropologist Liu Wu and his colleagues. Discovered in Zhirendong, a cave in Guangxi province, the jaw has a classic modern-human appearance, but retains some archaic features of Peking Man, such as a more robust build and a less-protruding chin.
Most Chinese palaeontologists — and a few ardent supporters from the West — think that the transitional fossils are evidence that Peking Man was an ancestor of modern Asian people. In this model, known as multiregionalism or continuity with hybridization, hominins descended from H. erectus in Asia interbred with incoming groups from Africa and other parts of Eurasia, and their progeny gave rise to the ancestors of modern east Asians, says Wu.
Support for this idea also comes from artefacts in China. In Europe and Africa, stone tools changed markedly over time, but hominins in China used the same type of simple stone instruments from about 1.7 million years ago to 10,000 years ago. According to Gao Xing, an archaeologist at the IVPP, this suggests that local hominins evolved continuously, with little influence from outside populations.
POLITICS AT PLAY?
Some Western researchers suggest that there is a hint of nationalism in Chinese palaeontologists' support for continuity. “The Chinese — they do not accept the idea that H. sapiens evolved in Africa,” says one researcher. “They want everything to come from China.”
Chinese researchers reject such allegations. “This has nothing to do with nationalism,” says Wu. It's all about the evidence — the transitional fossils and archaeological artefacts, he says. “Everything points to continuous evolution in China from H. erectus to modern human.”
But the continuity-with-hybridization model is countered by overwhelming genetic data that point to Africa as the wellspring of modern humans. Studies of Chinese populations show that 97.4% of their genetic make-up is from ancestral modern humans from Africa, with the rest coming from extinct forms such as Neanderthals and Denisovans. “If there had been significant contributions from Chinese H. erectus, they would show up in the genetic data,” says Li Hui, a population geneticist at Fudan University in Shanghai. Wu counters that the genetic contribution from archaic hominins in China could have been missed because no DNA has yet been recovered from them.
Many researchers say that there are ways to explain the existing Asian fossils without resorting to continuity with hybridization. The Zhirendong hominins, for instance, could represent an exodus of early modern humans from Africa between 120,000 and 80,000 years ago. Instead of remaining in the Levant in the Middle East, as was thought previously, these people could have expanded into east Asia, says Michael Petraglia, an archaeologist at the University of Oxford, UK.
Other evidence backs up this hypothesis: excavations at a cave in Daoxian in China's Hunan province have yielded 47 fossil teeth so modern-looking that they could have come from the mouths of people today. But the fossils are at least 80,000 years old, and perhaps 120,000 years old, Liu and his colleagues reported last year. “Those early migrants may have interbred with archaic populations along the way or in Asia, which could explain Zhirendong people's primitive traits,” says Petraglia.
Another possibility is that some of the Chinese fossils, including the Dali skull, represent the mysterious Denisovans, a species identified from Siberian fossils that are more than 40,000 years old. Palaeontologists don't know what the Denisovans looked like, but studies of DNA recovered from their teeth and bones indicate that this ancient population contributed to the genomes of modern humans, especially Australian Aborigines, Papua New Guineans and Polynesians — suggesting that Denisovans might have roamed Asia.
María Martinón-Torres, a palaeoanthropologist at University College London, is among those who proposed that some of the Chinese hominins were Denisovans. She worked with IVPP researchers on an analysis, published last year, of a fossil assemblage uncovered at Xujiayao in Hebei province — including partial jaws and nine teeth dated to 125,000–100,000 years ago. The molar teeth are massive, with very robust roots and complex grooves, reminiscent of those from Denisovans, she says.
A third idea is even more radical. It emerged when Martinón-Torres and her colleagues compared more than 5,000 fossil teeth from around the world: the team found that Eurasian specimens are more similar to each other than to African ones. That work and more recent interpretations of fossil skulls suggest that Eurasian hominins evolved separately from African ones for a long stretch of time. The researchers propose that the first hominins that left Africa 1.8 million years ago were the eventual source of modern humans. Their descendants mostly settled in the Middle East, where the climate was favourable, and then produced waves of transitional hominins that spread elsewhere. One Eurasian group went to Indonesia, another gave rise to Neanderthals and Denisovans, and a third ventured back into Africa and evolved into H. sapiens, which later spread throughout the world. In this model, modern humans evolved in Africa, but their immediate ancestor originated in the Middle East.
Not everybody is convinced. “Fossil interpretations are notoriously problematic,” says Svante Pääbo, a palaeogeneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. But DNA from Eurasian fossils dating to the start of the human race could help to reveal which story — or combination — is correct. China is now making a push in that direction. Qiaomei Fu, a palaeogeneticist who did her PhD with Pääbo, returned home last year to establish a lab to extract and sequence ancient DNA at the IVPP. One of her immediate goals is to see whether some of the Chinese fossils belong to the mysterious Denisovan group. The prominent molar teeth from Xujiayao will be an early target. “I think we have a prime suspect here,” she says.
FUZZY PICTURE
Despite the different interpretations of the Chinese fossil record, everybody agrees that the evolutionary tale in Asia is much more interesting than people appreciated before. But the details remain fuzzy, because so few researchers have excavated in Asia.
When they have, the results have been startling. In 2003, a dig on Flores island in Indonesia turned up a diminutive hominin, which researchers named Homo floresiensis and dubbed the hobbit. With its odd assortment of features, the creature still provokes debate about whether it is a dwarfed form of H. erectus or some more primitive lineage that made it all the way from Africa to southeast Asia and lived until as recently as 60,000 years ago. Last month, more surprises emerged from Flores, where researchers found the remains of a hobbit-like hominin in rocks about 700,000 years old.
Recovering more fossils from all parts of Asia will clearly help to fill in the gaps. Many palaeoanthropologists also call for better access to existing materials. Most Chinese fossils — including some of the finest specimens, such as the Yunxian and Dali skulls — are accessible only to a handful of Chinese palaeontologists and their collaborators. “To make them available for general studies, with replicas or CT scans, would be fantastic,” says Stringer. Moreover, fossil sites should be dated much more rigorously, preferably by multiple methods, researchers say.
But all agree that Asia — the largest continent on Earth — has a lot more to offer in terms of unravelling the human story. “The center of gravity,” says Petraglia, “is shifting eastward.”
This article is reproduced with permission and was first published on July 12, 2016.
On a cold evening last March, as researchers descended upon St. Louis, Missouri, for the annual meeting of the American Association of Physical Anthropologists (AAPA), a dramatic scene unfolded at the rooftop bar of the St. Louis Hilton at the Ballpark, the conference hotel. From here, attendees had spectacular views of the city, including Busch Stadium and the Gateway Arch, but many were riveted by an animated discussion at one table.
Loudly, and apparently without caring who heard her, a research assistant at the American Museum of Natural History (AMNH) in New York City charged that her boss—noted paleoanthropologist Brian Richmond, the museum’s curator of human origins—had “sexually assaulted” her in his hotel room after a meeting the previous September in Florence, Italy. (She requested that her name not appear in this story to protect her privacy.) Over the next several days, as the 1700 conference attendees presented and discussed the latest research, word of the allegations raced through the meeting.
Richmond, who was also at the meeting, has vigorously denied the accusations in a statement to Science and in email responses. (He declined to be interviewed in person or by telephone.) The encounter in the hotel room, he wrote, was “consensual and reciprocal,” adding that “I never sexually assaulted anyone.”
Although the most recent high-profile cases of sexual harassment in science have arisen in astronomy and biology, many researchers say paleoanthropology also has been rife with sexual misconduct for decades. Fieldwork, often in remote places, can throw senior male faculty and young female students together in situations where the rules about appropriate behavior can be stretched to the breaking point. Senior women report years of unwanted sexual attention in the field, at meetings, and on campus. A widely cited anonymous survey of anthropologists and other field scientists, called the SAFE study and published in July 2014 in PLOS ONE, reported that 64% of the 666 respondents had experienced some sort of sexual harassment, from comments to physical contact, while doing fieldwork.
Even a few years ago, the research assistant might not even have aired her complaint, as few women—or men—felt emboldened to speak out about harassment. Of the 139 respondents in the SAFE study who said they experienced unwanted physical contact, only 37 had reported it (see graphic, below). Those who remained silent may have feared retaliation. Senior paleoanthropologists control access to field sites and fossils, write letters of recommendation, and might end up as reviewers on papers or grant proposals. “The potential for [senior scientists] to make a phone call and kill a careermaking paper feels very real,” says Leslea Hlusko, a paleontologist at the University of California (UC), Berkeley.
This is a tragedy of many dimensions, and contemplating it makes me infinitely sad.
Now, however, the SAFE study, along with a few high-profile cases has spurred a major shift in how some academic communities deal with harassment, says anthropologist Katie Hinde of Arizona State University, Tempe, who co-authored the study. What was once tolerated, overlooked, or kept quiet now may be publicly censured, and institutions are increasingly sensitive to how faculty can—sometimes unwittingly—abuse their power over students and employees. Last month, the California Institute of Technology in Pasadena suspended astronomer Christian Ott for a year for allegedly harassing graduate students. Astronomer Geoff Marcy at UC Berkeley was found to have sexually harassed women students for a decade, and when Berkeley did not fire him, the outrage among astronomers forced him to resign late last year. “How the astronomy community responded to [the Marcy case] is a model for every other field,” Hinde says.
Now, paleoanthropology is responding to its own complex case. Outsiders may never know for sure what happened in that Florence hotel room. But the incident ultimately triggered a cascade of other allegations against Richmond and a resolve by some senior paleoanthropologists to do battle against sexual misconduct, hoping to change the climate of their field. The charges and the community’s response also roiled two leading institutions, which struggled with shifting cultural expectations, inadequate reporting and disciplinary tools, and the challenge of treating all parties fairly.
V. ALTOUNIAN/SCIENCE
The research assistant, who still feels that she did not get justice, continues to tell her story. Richmond, who says the museum has asked him to resign and who is the subject of a new investigation, continues to protest his innocence. She no longer reports to him, but until recently they passed each other almost daily in the halls of AMNH. Other paleoanthropologists are working to limit Richmond’s contact with students, and find the current situation distressing for all parties. “This is a tragedy of many dimensions, and contemplating it makes me infinitely sad,” says Ian Tattersall, the former curator of human origins at the museum.
From Florence to St. Louis
In 2010,Tattersall, who had led human origins research at AMNH for more than 30 years, retired, and the search was on for his replacement. It would not be easy, because the personable Tattersall had become a leading voice of paleoanthropology, writing numerous books and making endless public appearances. “He was the spokesperson for our profession,” Hlusko says.
In 2014, after a long search, Richmond, then at George Washington University (GWU) in Washington, D.C., was chosen. He began work at the museum in August of that year.
"I never sexually assaulted anyone." — Brian Richmond
Described as charming and sociable, Richmond, 47, is best known for the co-discovery of 1.5-million-year-old hominin footprints at the site of Ileret, in Kenya. He has co-authored at least 170 publications and served as principal adviser for several grad students and postdocs. Researchers who know Richmond well say that he was a good mentor and worked hard to give his students both field and laboratory experience.
Richmond also supervised the research assistant, who has a key job in AMNH’s anthropology division. She received a master’s degree in anthropology from New York University (NYU) in New York City, began working at AMNH about a decade ago, and is widely described as hard-working and well-liked.
In late September 2014, less than 2 months after Richmond had begun at AMNH, he and the research assistant attended a meeting of the European Society for the study of Human Evolution (ESHE) in Florence. The research assistant says that on the last night of the meeting, she, Richmond, and several young European researchers were out on the town, visiting bars and drinking red wine and shots of limoncello, an Italian liqueur. She recalls “walking around Florence and realizing that I was way too drunk.” The next thing she remembers, she says, is waking up on the bed in Richmond’s hotel room in the wee hours of the morning with him on top of her, kissing her and groping under her skirt.
The research assistant says that she immediately told Richmond to stop, and left the room. Because she was not a guest at the hotel, the reception desk in the lobby, perhaps concerned that she was not supposed to be there, would not let her leave without authorization. She had to call up to Richmond and get him to vouch for her. Still in shock, she says, she allowed Richmond to accompany her to her Airbnb nearby. With just a couple of hours before her flight back to New York, she quickly packed and made her way to the airport.
Shortly after her return to New York, the research assistant told her story to at least three friends, all of whom report hearing essentially the same version of events that she later told toScience. But she says she delayed officially reporting the incident until sometime in November 2014, fearing that she would not be believed or would be fired. She says she considered making a police report, but doubted that the Italian authorities, who have jurisdiction, would prosecute now that she and Richmond were back in the United States. Finally, after telling her husband, she went to AMNH’s human resources (HR) department.
Richmond tells a different story of that night. Although he confirmed in an email to Sciencethat he made his room “available” to the research assistant when she could not find her Airbnb, in his written statement Richmond says that the encounter was consensual. It “did not progress beyond kissing and embracing,” he wrote, and “ceased the instant my colleague said, ‘This isn’t a good idea.’” Richmond also says that “while we were both drinking, neither of us was incapacitated.”
Back in New York in the late fall, the museum’s human resources staff spoke to both Richmond and the research assistant. An email to her from AMNH’s vice president for HR, Daniel Scheiner, dated 22 July 2015, describes the results of that late 2014 investigation—the first of three initiated by the museum. Scheiner wrote: “We had determined that Brian violated the Museum’s policy prohibiting inappropriate relationships between supervisors” and their subordinates. Scheiner added that “Brian would be held accountable for the violation of the policy” and that the research assistant would report to a different supervisor.
Anne Canty, AMNH’s senior vice president for communications and marketing, clarified that decision in a statement to Science, writing that “a zero tolerance warning was issued to Dr. Richmond.” According to Canty, from then on the only contact allowed between the two was by email.
In his statement, Richmond confirms that AMNH “disciplined me for violating Museum policy against personal activity between supervisors and those who report to them,” and says that he “sincerely apologized to my colleague and the Museum for the breach of that policy.” Richmond adds that during the HR investigation, “I was advised that … my colleague recalled virtually nothing” of the incident. He says that he has “since been informed that my colleague’s stance has changed over time from simply not remembering what took place after a night in which we had both been drinking with other people, to accusing me of taking advantage of her when she was incapable of consent.”
The research assistant vigorously rejects the assertion that she changed her story. She has “no memory of going to Brian’s hotel,” she says, but does recall waking up in his room. “My clearest memory of that night is waking up to being touched below the waist and how shocking and distressing that was.”
George Washington University responds
Still upset and angry in March 2015, the research assistant headed for the St. Louis meeting. She felt that the museum should have fired Richmond, and she decided to tell her story to everyone who would listen, especially female colleagues.
At the meeting, one person who heard the allegations was Bernard Wood, 70, a senior paleoanthropologist originally from the United Kingdom. Wood is now at GWU, where Richmond was on the faculty for 12 years before moving to AMNH. Widely regarded as one of Richmond’s key mentors, Wood was stunned by the allegations. He says he had no way to know whether they were true. But he was mindful that his recommendations had bolstered Richmond’s career for years, and he wanted to be sure that Richmond’s behavior while on the GWU faculty had been professional. Also, Richmond continued to teach at the Koobi Fora Field School in Kenya, a summer institute that is now co-run by GWU and the National Museums of Kenya and is mainly attended by undergraduates.
In St. Louis, Wood canvassed younger researchers about their experiences with Richmond. He asked everyone the same question: “Does this alleged behavior come as any surprise to you?” But he didn’t get the “yes” he was expecting. Nearly all said that they were not surprised, and two individuals told Wood that they had been the direct subjects of unwanted sexual advances by Richmond. “It was clear that there was a pattern of behavior,” Wood says. He continued his efforts once he returned to GWU, speaking to present and former members of the multidisciplinary program he leads, the Center for Advanced Study of Human Paleobiology (CASHP). “As I talked to more and more current and former students at GWU, I became more concerned and alarmed about what I heard,” he says.
"As I talked to more and more current and former students at GWU, I became more concerned and alarmed about what I heard." — Bernard Wood
Sergio Almécija
In important ways, the ground had been prepared at GWU to deal with such allegations. Hinde had spoken to CASHP members about the SAFE study in March 2014, and GWU archaeologist David Braun, co-director of the Koobi Fora Field School, had asked her to help create a policy document about sexual harassment for field school staff to sign. “I have been doing fieldwork in Kenya, Ethiopia, and South Africa for the past 20 years and I have definitely observed these kinds of problems,” Braun wrote Hinde, adding that he wanted there to be “no question about our policy.”
Now, CASHP responded quickly to the allegations concerning Richmond. Just a few days after the St. Louis meeting ended, program members contacted GWU’s coordinator for enforcement of Title IX, a 1972 education law that prohibits discrimination based on sex in educational institutions that receive federal funds. (Most early claims of Title IX violations focused on discrimination in athletics, but today sexual harassment and misconduct are the No. 2 cause of claims.) On 3 April 2015, the coordinator wrote to all members of GWU’s anthropology department, soliciting “any knowledge about specific incidents” of sexual harassment.
Despite his association with Koobi Fora, Richmond was no longer a GWU employee, so the university could not launch a formal investigation, Wood says. So, according to Wood and three others in the meetings, the CASHP faculty decided in early April 2015 to use their discretion to remove Richmond from teaching at the field school.
Braun then communicated this decision to Richmond, according to sources at the meetings. On 6 April 2015, Richmond responded to Braun in an email saying that he was “writing to indicate my willingness to resign my role in the Koobi Fora Field School.” On 13 April 2015, CASHP faculty removed Richmond’s name and photo from the faculty list on the field school’s website. The CASHP faculty also asked the university administration to send Richmond a letter formally confirming that his ties to the field school had been severed. “I urged the university to make it clear that Brian Richmond was no longer welcome at the Koobi Fora Field School and was no longer part of it,” Wood says. The university reportedly did so about a month later.
Wood also signaled his growing vigilance about harassment in other ways. He called for zero tolerance for sexual misconduct in two blog posts on the CASHP website, on 21 April 2015 and 9 September 2015, and in a Science editorial in October 2015. He timed his 9 September blog, posted the day before the 2015 ESHE meeting opened in London, to head off Richmond’s candidacy for a seat on the organization’s governing council. (Richmond did not receive enough votes to be elected.) At the meeting, Wood also resigned as chair of a session just before Richmond spoke in it.
Richmond notes in his statement to Science that before the incident in Italy, “there had never been a complaint or report against me throughout my career,” including from students at the field school. He stresses that he “voluntarily resigned my affiliation” with the field school, and explained in an email that he hoped his resignation “would help address the anger Wood reported to me” from those accusing him of inappropriate behavior.
Richmond also says that his relationships with female researchers were consensual. Nevertheless, he says in his statement, “I take full responsibility for exercising poor judgment in the past by mixing my professional and personal lives, including having consensual affairs, and I have changed my thinking and my behavior. I am deeply distressed to learn that I have upset the women involved and colleagues in my field. I regret that I was not sensitive to how my academic position could impact the dynamics of consensual relationships.”
The American Museum of Natural History responds
Word quickly reached AMHN officials about the events in St. Louis. Although HR chief Scheiner, who is also the museum’s Title IX coordinator, had completed his investigation, the museum soon assigned in-house attorney Rhea Gordon to conduct a second investigation. The research assistant gave Gordon several people to talk to about Richmond’s alleged past actions, including Rebecca Ackermann, 46, a U.S. physical anthropologist at the University of Cape Town in South Africa.
On 14 April 2015, Gordon emailed Ackermann to ask for her help with investigating “instances of misconduct in the field in connection with Brian Richmond.” Gordon told Ackermann that she was “particularly interested in hearing from any individuals who can speak first-hand about their experiences.”
Ackermann agreed to help. She says she had been the object of sexual harassment from high school through graduate school but always felt she had limited power to do anything about it. For her, the Richmond allegations set off alarm bells, because some of her own students had reported that he had made sexual advances to them at Koobi Fora.
Back home in Cape Town, she spoke with two former undergraduates at the field school who had previously told her that Richmond had engaged in inappropriate behavior with them, as well as a third person whose experiences she had heard about. All three agreed to provide written testimony that Ackermann could transmit to Gordon. They asked not to be named but said they were willing to provide their names in case of formal proceedings at the museum.
On 30 April 2015, Ackermann began to send the written accounts and vouched for the former students’ identities. Science interviewed the three women, two by phone and one by email.
"This is the classic thing that happens when women report [sexual misconduct] ... They go through the trauma of doing it and then nothing happens." — Rebecca Ackermann
K. Warren
One account, written together by two former students who identify themselves as P1 and P2, describes events that allegedly took place late in the evening of 4 July 2007 at the field school, which at that time was run jointly by Rutgers University, New Brunswick, in New Jersey, and the National Museums of Kenya. During a celebration of U.S. Independence Day, the pair related that people were dancing and socializing. P1 was dancing when she “felt someone come up behind her, startling her,” according to the account. She turned around and saw that it was Richmond. “Dr. Richmond smiled and grabbed P1[’s] breast,” the account relates. “P1 removed herself from the situation as soon as she could.” P1 told P2 what had happened.
Later that night, the testimonial relates, while P1 and P2 were sitting together around the fire, Richmond sat down next to P2, “and subtly moved his hand to P2[’s] leg” while continuing to converse with someone else. The testimonial concludes that “Neither P1 nor P2 reported these incidents to senior members of the staff of the Koobi Fora Field School as it was generally accepted that this was part of the field school experience.” P1, interviewed by email, elaborated: “There was an atmosphere of tolerance or at least a ‘what happens in the field stays in the field’ mentality.”
In the third account provided to Gordon, a former Koobi Fora undergraduate related that one evening in July 2012 she and Richmond were part of a group standing around a bonfire. “Brian put his arm around me, and plunged his hand down the back of my skirt all the way to my thighs, and forcefully grabbed my posterior,” she wrote. This witness, who admits that she was “properly drunk,” wrote that she put her hand around Richmond’s waist while he “continued to fondle my bottom.” Shortly afterwards, she related, Richmond “pulled me away from the circle” and “kissed me quite passionately,” asking her to go to a more remote spot and have sex with him. But she was not interested and declined, slipping away to her friends.
Richmond in an email declined to make a “point-by-point response” to these incidents, “except to say that I strongly disagree with the central salacious details.” He added that it is “unfair” for Science to “publish and confront me with anonymous complaints.” Richmond noted that the incidents “would have occurred before the Koobi Fora Field School became affiliated with GWU” and did not involve GWU students or students whom he graded or supervised.
Ackermann argues that all three accounts represent examples of an abuse of power. “With undergraduates especially, there can be no consensual acts on the part of the women, who have no power.” For a young student approached by a senior figure, as that third undergraduate explained to Science, “it is so hard to understand what is appropriate or not appropriate.”
A growing number of university campuses in the United States now acknowledge that the power imbalance between professors and students makes sexual relationships problematic. In February 2015, for example, Harvard University’s Faculty of Arts and Sciences (FAS) formally banned sexual relationships between professors and undergraduates, and Yale University and the University of Connecticut have adopted similar policies in recent years. “We were trying to avoid situations where one party might think a relationship was consensual and another party might not feel safe expressing that it wasn’t,” explains Alison Johnson, a historian at Harvard who chaired the panel that wrote the new policy.
Harvard allows relationships between faculty and graduate students only if the student is not under the professor’s supervision or otherwise linked to them. GWU’s current guidelines do not go as far, but consider it “inappropriate” for a faculty member to have such a relationship with a student in their class or whose work they are currently evaluating. They also proscribe “unwelcome sexual advances” and “unwelcome physical contact of a sexual nature.”
All three of the Koobi Fora incidents were part of Gordon’s broader investigation, which she finished by June 2015. Gordon wrote to sources to thank them for their help, but according to both Canty and Richmond, the museum took no further action against him at the time. Richmond says that sometime after this second investigation he received a raise and a positive job evaluation. (Canty declined to comment on this.)
Ackermann, for one, says she “was shocked and deeply disappointed” that the museum apparently did nothing further. “This is the classic thing that happens when women report” sexual misconduct, she says. “They go through the trauma of doing it and then nothing happens.”
According to sources at the museum, the ultimate decision about disciplining Richmond was made by paleontologist Michael Novacek, AMNH’s provost of science, who also convened the lengthy search for Richmond’s position. (Canty, citing “the confidentiality of the information involved,” declined Science’s request for an interview with Novacek.) But Canty’s statement helps explain the museum’s response: “Those reporting misconduct requested anonymity and none had filed complaints at the institutions where this occurred, thus inhibiting further action.”
Richmond argues that the museum’s protracted investigation process has been unfair to him. He wrote in an email that “on or about the first days of December 2015, I was informed by the Museum that if I did not voluntarily resign, [it] would launch a new investigation.” (Canty declined to confirm or deny this, again citing confidentiality.) Richmond says that the new investigation constitutes double jeopardy and that its timing, after he was asked to resign and shortly after Science began investigating the case, “would seem to speak for itself.”
As they pay more attention to allegations of sexual misconduct, institutions around the United States are struggling to balance the rights of victims and accused. Unlike in a criminal trial, which requires certainty beyond a reasonable doubt to convict, current Title IX guidelines require only a “preponderance of the evidence” for faculty or students to be found guilty of misconduct. “Universities have to be the prosecutor and the defense attorney and the judge and the jury,” says Billie Dziech, a professor of English at the University of Cincinnati in Ohio known for her work on sexual harassment in academia. “It’s a very difficult position to be in.” Some, for example, have criticized Harvard’s new FAS guidelines for insufficient due process to the accused, and Harvard Law School has adopted different procedures.
What can be done?
AMNH has launched its third investigation, which deals with “all allegations” concerning Richmond, Canty says, and is conducted by an outside firm, T&M Protection Resources in New York. Richmond is still employed by AMNH although working offsite during this investigation, Canty says. There are signs that the museum is taking the episode as a broader wakeup call. On 22 December 2015, Scheiner sent a memo to all staff announcing that the museum had asked T&M to review its sexual harassment policies and to institute training.
For many researchers and activists, the growing institutional sensitivity to alleged sexual misconduct has been a long time coming, and reflects changing societal views. Evolving interpretations of Title IX have also played a part, in particular a 2011 letter released by the Office for Civil Rights reminding educational institutions of their obligations to both prevent and respond to sexual misconduct, including sexual violence. “Title IX makes it very clear that a beautiful 19-year-old female wearing a halter top and a miniskirt can go check on her fruit flies at night without being touched or made uncomfortable by her professor,” Harvard’s Johnson says.
Last November AAPA released a new nine-page statement on sexual harassment and assault. AAPA President Susan Antón of NYU says that for years the organization has had a code of ethics that prohibits sexual harassment, but that after the SAFE study, she and other AAPA leaders realized that it needed a separate, more detailed statement focusing specifically on this issue. The new guidelines do not have a provision for investigating complaints, unlike guidelines adopted by the American Astronomical Society. But Antón agrees with other advocates that going beyond rules on paper and changing the culture of the field is the only real way to stop sexual misconduct. “Changing each individual institutional environment is the only answer to that,” she says.
One way to go about it, Ackermann suggests, is to create a network of mentors, senior scientists “who have the power to do something about it. … If you have a famous field school, you could have people outside the field school who could be reported to, a formal structure with real people attached to it rather than just a document.”
Others insist that science needs policies to encourage witnesses to speak out. “By turning a blind eye, senior colleagues are accessories to what is happening,” Hinde says. “We need to hold colleagues accountable who violate professionally accepted norms of sexual conduct.” She praises the examples set by Wood and Ackermann, who used their power and experience to act and speak on behalf of younger and vulnerable researchers. “Leaders in my field are saying we won’t accept this anymore,” Hinde says. “I am incredibly hopeful. We are seeing the culture change in real ways in real time. We are seeing it now.”
*Update: 11 February, 6:20 p.m.: In the paragraph that mentions Christian Ott, “sexual misconduct” was changed to “harassment” to more precisely describe the allegations against him.
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