Arquivo da tag: Macacos

Cultura primata (Revista Fapesp)

Transmissão de práticas de uso de ferramentas por macacos-prego ajuda a repensar o papel das tradições na evolução

MARIA GUIMARÃES | ED. 259 | SETEMBRO 2017

Podcast: Eduardo Ottoni

Com uma pedra erguida acima da cabeça, o jovem Porthos bate vigorosamente no chão arenoso de modo a abrir um buraco. Seu objetivo: uma aranha, que logo consegue desentocar e rola entre as mãos para tontear a presa que em seguida come. Ele é um macaco-prego da espécie Sapajus libidinosus, habitante do Parque Nacional Serra da Capivara, no Piauí, e objeto de estudo de pesquisadores do Instituto de Psicologia da Universidade de São Paulo (IP-USP). O biólogo Tiago Falótico tem caracterizado o uso de ferramentas por esses animais (ver Pesquisa FAPESP nº 196) e mostrou, em artigo publicado em julho na revista Scientific Reports, que a ação do jovem macho envolve conhecimento, aprendizado e transmissão de práticas culturais – ou tradições, como alguns preferem chamar quando os sujeitos não são humanos – dentro de grupos sociais. A pesquisa está no bojo de um corpo teórico que busca entrelaçar biologia, ciências sociais e humanas e recém-desembocou na formação da Sociedade de Evolução Cultural. Sua reunião inaugural acaba de acontecer na Alemanha, entre 13 e 15 de setembro.

Até agora, o uso de pedras como ferramentas para cavar só foi documentado nessa população. Especialmente quando se trata de desentocar aranhas, é preciso experiência. O estudo, resultado de observações feitas durante o doutorado de Falótico, encerrado em 2011 sob orientação do biólogo Eduardo Ottoni, mostra que quase 60% dos adultos e jovens (como Porthos) têm sucesso na tarefa. Macacos juvenis (o correspondente a crianças), por outro lado, só conseguem em pouco mais de 30% dos casos. Isso acontece porque é preciso reconhecer o revestimento de seda que fecha a toca do aracnídeo, sinal de que o habitante está lá dentro. “Os juvenis às vezes cavam uma toca que acabou de ser aberta por outro macaco”, conta Falótico. Estruturas subterrâneas, parecidas com batatas, da planta conhecida como farinha-seca (Thiloa glaucocarpa), também são desenterradas com mais eficiência pelos adultos. Já as raízes de louro (Ocotea), outro alimento desses primatas, apesar de envolverem o uso de pedras maiores, não parecem apresentar um desafio especial para os aprendizes. Macacos dos dois sexos se mostraram igualmente capazes de cavar com pedras, com uma taxa de sucesso equivalente, embora eles pareçam ter mais interesse pela atividade: entre as 1.702 situações observadas, 77% envolviam machos e apenas 23%, fêmeas.

“Esperávamos encontrar uma correlação entre o uso de ferramentas e a escassez de alimentos, mas não foi o que vimos”, conta Falótico. Se os macacos da serra da Capivara encontram algo comestível que exija o uso de ferramentas, recorrem a elas. Seu modo de vida, em que passam metade do tempo no chão rodeados de pedras e gravetos, parece ser propício ao desenvolvimento das habilidades. Mas não é só isso. Embora não haja diferença entre os sexos nos hábitos alimentares, as fêmeas nunca usam gravetos – que seus companheiros masculinos utilizam para desentocar lagartos de frestas e retirar insetos de troncos, por exemplo. Há diferença apenas, aparentemente, no interesse. “Quando um macho vê outro usar uma vareta, ele observa atento; já uma fêmea, mesmo que esteja ao lado daquele usando a ferramenta, não se interessa e olha para o outro lado!”

Os macacos da mesma espécie que habitam a fazenda Boa Vista, em Gilbués, cerca de 300 quilômetros (km) para sudoeste, têm tradições distintas no uso de ferramentas. Ali, uma área com mais influência de Cerrado do que Caatinga, as pedras são menos abundantes, mas necessárias (e usadas) para quebrar cocos. Gravetos estão por toda parte, mas não têm uso. Essa diferença cultural entre grupos de macacos foi explorada em um experimento feito pelo psicólogo Raphael Moura Cardoso durante o doutorado, orientado por Eduardo Ottoni, e relatado em artigo de 2016 na Biology Letters. Eles puseram – tanto na fazenda Boa Vista como na serra da Capivara – caixas de acrílico recheadas de melado de cana. O único jeito de retirar a guloseima era por meio de uma fenda no alto com largura suficiente apenas para varetas. “Na serra da Capivara, um macho logo acertou uma pedrada na caixa”, lembra Ottoni, que, previdente, tinha planejado o aparato “à prova de macaco-prego”. “Quando nada aconteceu, ele largou a pedra, coçou a cabeça e pegou um graveto.” Ele brinca que nem precisou editar o vídeo para mostrar em um congresso – foi uma ação contínua e imediata. Ao longo de cinco dias de exposição à caixa, 10 dos 14 machos usaram o graveto logo na primeira sessão, e apenas os três mais jovens não foram bem-sucedidos. Os demais conseguiram um sucesso de 90% na empreitada. As fêmeas não tentaram, assim como os macacos da fazenda Boa Vista. Lá, os pesquisadores até tentaram ajudar: depois de seis horas expostos à tarefa, os macacos deparavam com um graveto já fincado na fenda. Mesmo tirando e lambendo o melado da ponta, nenhum deles voltou a inserir a ferramenta na caixa ao longo de 13 dias de experimento. Uma surpresa foi que os macacos da Boa Vista, exímios quebradores de coco, não tentaram partir a caixa. “Eu esperava isso deles, não dos outros”, diz Ottoni.

Aprendizado social

Os resultados, surpreendentes, podem reforçar a importância da transmissão de tradições entre os macacos. A capa da edição de 25 de julho deste ano da revista PNAS traz justamente a foto de um macaco-prego da fazenda Boa Vista comendo uma castanha que conseguiu quebrar com a ajuda de uma grande pedra redonda, observado de perto por um jovem. A imagem anuncia a coletânea especial sobre como a cultura se conecta à biologia, da qual faz parte um artigo do grupo liderado pelas primatólogas Patrícia Izar, do IP-USP, Dorothy Fragaszy, da Universidade da Georgia, nos Estados Unidos, e Elisabetta Visalberghi, do Instituto de Ciências e Tecnologias Cognitivas, na Itália, sobre os macacos da fazenda Boa Vista, que estudam sistematicamente desde 2006. Nas observações recolhidas ao longo desse tempo, chama a atenção a tolerância dos adultos em relação aos jovens aprendizes que olham de perto e até comem pedaços dos cocos partidos. “Os adultos competem pelos recursos e os imaturos podem ficar perto”, conta Patrícia. As análises publicadas no artigo recente mostram muito mais do que proximidade: os quebradores de coco influenciam a atividade dos outros, sobretudo os jovens, que também começam a manipular pedras e cocos. Isso dura alguns minutos. “A tradição canaliza a atividade para o mesmo tipo de ação importante para essa tradição”, define.

Patrícia ressalta que os macacos nascem nesse contexto. “Muitas vezes vemos filhotes nas costas das mães enquanto elas quebram”, conta. Com esse aprendizado contínuo, acabam se tornando especialistas na tarefa. Mas não basta observar, e daí a importância de os filhotes serem atraídos pela ação dos adultos – principalmente os mais eficazes. “O sucesso passa pela percepção da tarefa e das propriedades da ferramenta”, detalha, descrevendo um complexo corpo-ferramenta em que é constantemente necessário ajustar força, gestos e postura. Quando quebram tucum, um coquinho menos resistente, os macacos ajustam a força das pancadas depois de ouvirem o som da superfície rachando, o grupo mostrou em artigo do ano passado na Animal Behaviour. Para cocos mais difíceis, eles escolhem pedras que podem chegar a ser mais pesadas do que o próprio corpo. E a seleção da pedra é criteriosa, conforme mostrou um experimento em que Patrícia e seu grupo forneceram pedras artificiais com diferentes tamanhos, pesos e densidades. As pedras grandes logo atraíam a atenção dos macacos, mas se fossem pouco densas – mais leves do que aparentavam – eram abandonadas. “Eles têm a percepção de que o peso é importante na quebra”, diz Patrícia.

Tolerância: macho adulto da fazenda Boa Vista come castanha partida observado de perto por jovem

Essas sociedades primatas alteram o ambiente. Macacos escolhem pedras ou troncos achatados como base para quebrar coco, e para lá carregam as raras pedras grandes e duras que encontram no ambiente. Essa conformação é importante não só por criar oficinas de quebra, mas por canalizar a possibilidade de aprendizado, já que todos sabem onde a atividade acontece e pode ser observada. “Não faz sentido pensar em maturação motora independente do contexto social, alimentar”, afirma a bióloga Briseida Resende, também do IP-USP e coautora do artigo da PNAS. O desenvolvimento individual depende das experiências de cada um, de suas capacidades físicas e do acervo acumulado pelo grupo, no qual uma inovação criada pode se disseminar, perpetuar-se e fazer parte da cultura mantida por gerações. Resende defende que indivíduo e sociedade são indissociáveis, embora historicamente tenham sido vistos como entidades distintas.

Teoria revista

Reunir a evolução cultural e a biológica é justamente o foco da síntese estendida, agora sedimentada com a fundação, em 2016, da Sociedade de Evolução Cultural – o primeiro presidente é o zoólogo Peter Richerson, da Universidade da Califórnia em Davis, cujo grupo privilegia a estatística. Essa visão conjunta amplia o olhar evolutivo, já que a transmissão de ideias ou inovações não se dá apenas de pais para filhos e pode trazer vantagens seletivas favorecendo as capacidades cognitivas e sociais relevantes. Considera também que a cultura pode influenciar aspectos físicos, como a conformação e o tamanho do cérebro, ou o desenvolvimento de habilidades que por sua vez sedimentam o comportamento. Os genes e a cultura, duas vias de transmissão de informação, relacionam-se, portanto, por uma via de mão dupla.

Jovens aprendizes tentam tirar proveito de escavação feita por fêmea

A oportunidade de ver comportamentos surgirem e se espalhar é rara, e por isso abordagens experimentais que provocam inovações são um acréscimo importante aos comportamentos diversos dos macacos-prego do Piauí. Ferramentas estatísticas recentes podem ajudar a aprofundar essa compreensão, como a Análise de Difusão Baseada em Redes (Network-Based Diffusion Analysis) que o grupo de Ottoni começa a usar. “O programa monta uma rede social aleatória e compara à real”, explica o pesquisador, que torna as análises mais robustas inserindo características medidas nos sujeitos em causa. Em agosto de 2016 ele apresentou, no congresso da Sociedade Primatológica Internacional, em Chicago, resultados do experimento feito pela bióloga Camila Coelho durante doutorado orientado por ele com um período passado na Universidade de Durham, no Reino Unido, para aprender o método. Os resultados indicam que, no caso dos macacos-prego, o aprendizado social prevê a difusão de informação na espécie.

Até meio século atrás, o uso de ferramentas era considerado privilégio humano. Ao observar chimpanzés na Tanzânia, a inglesa Jane Goodall derrubou essa exclusividade e, de certa maneira, causou a redefinição das fronteiras entre gente e bicho. Muito se descobriu de lá para cá, mas falar em cultura animal ainda esbarra em certo desconforto. Talvez não por muito mais tempo.

O uso de pedras para escavar só foi descrito na serra da Capivara

Sob o comando de hormônios

O cuidado com os filhotes está ligado ao hormônio oxitocina em mamíferos. O grupo liderado por Maria Cátira Bortolini, da Universidade Federal do Rio Grande do Sul, descreveu há poucos anos as variações na molécula de oxitocina em espécies de macacos nas quais há bons pais (ver Pesquisa FAPESP 228). Ensaios farmacológicos feitos no laboratório do bioquímico Claudio Costa-Neto, da Faculdade de Medicina de Ribeirão Preto da USP, agora desvendaram o caminho da oxitocina dentro das células e verificaram que os receptores das formas alteradas ficam mais expostos nas membranas das células, de maneira que o sistema não se dessensibiliza. “É como se o macaco recebesse constantemente a instrução ‘tenho que cuidar dos filhotes’”, explica Cátira. Faz diferença para a sobrevivência de saguis, que frequentemente têm filhotes gêmeos, por exemplo.

O resultado está em artigo publicado em agosto na PNAS, que também descreve o resultado da aplicação dessas oxitocinas em ratos por meio de borrifadas nasais, experimento realizado em colaboração com o fisiologista Aldo Lucion, da UFRGS. As fêmeas lactantes, já inundadas de oxitocina, alteraram pouco o comportamento. Mas os machos tratados com o hormônio alteraram radicalmente o hábito de ignorar os filhotes e correram para cheirá-los, uma reação que foi três vezes mais rápida com a oxitocina de sagui.

Os cebídeos, família que inclui os macacos-prego, também têm um tipo de oxitocina que aumenta a propensão à paternidade ativa. Os grupos de Cátira e de Ottoni recentemente iniciaram uma colaboração para investigar as características genéticas em machos mais e menos cuidadores. “Já conseguimos extrair material genético de amostras de fezes e estamos selecionando genes candidatos a serem rastreados”, conta ela, fascinada com a tolerância dos machos e as habilidades cognitivas dos primatas do Piauí. “A capacidade de inovar, por um lado, e a de sentar e observar, por outro, são necessárias para o desenvolvimento e a transmissão de traços culturais adaptativos e certamente há um cenário genético por trás disso.”

Projetos
1. Uso de ferramentas por macacos-prego (Sapajus libidinosus) selvagens: Ecologia, aprendizagem socialmente mediada e tradições comportamentais (nº 14/04818-0); Modalidade Projeto Temático; Pesquisador responsável Eduardo Benedicto Ottoni (USP); Investimento R$ 609.276,69.2. Variabilidade de comportamento social de macacos-prego (gênero Cebus): Análise comparativa entre populações para investigação de correlatos fisiológicos (nº 08/55684-3); Modalidade Auxílio à Pesquisa – Regular; Pesquisadora responsável Patrícia Izar (USP); Investimento R$ 186.187,33.
3. Desenvolvimento de novos ligantes/drogas com ação agonística seletiva (biased agonism) para receptores dos sistemas renina-angiotensina e calicreínas-cininas: Novas propriedades e novas aplicações biotecnológicas (nº 12/20148-0); ModalidadeProjeto Temático; Pesquisador responsável Claudio Miguel da Costa Neto (USP); Investimento R$ 3.169.674,21.

Artigos científicos
FALÓTICO, T. et alDigging up food: excavation stone tool use by wild capuchin monkeysScientific Reports. v. 7, n. 1, 6278. 24 jul. 2017.
CARDOSO, R. M. e OTTONI, E. B. The effects of tradition on problem solving by two wild populations of bearded capuchin monkeys in a probing task. Biology Letters. v. 12, n. 11, 20160604. nov. 2016.
FRAGASZY, D. M. et alSynchronized practice helps bearded capuchin monkeys learn to extend attention while learning a traditionPNAS. v. 114, n. 30, p. 7798-805. 25 jul. 2017.
MANGALAM, M., Izar, et alTask-specific temporal organization of percussive movements in wild bearded capuchin monkeysAnimal Behaviour. v. 114, p. 129–137. abr. 2016.
PARREIRAS-E-SILVA, L. T. et alFunctional new world monkey oxytocin forms elicit na altered signaling profile and promotes parental care in ratsPNAS. v. 114, n. 34, p. 9044-49. 22 ago. 2017.
VISALBERGHI, E. et al. Selection of effective stone tools by wild bearded capuchin monkeys (Cebus libidinosus)Current Biology, v. 19, n. 3, p. 213-17. 10 fev. 2009.

Anúncios

Ebola Is Wiping Out the World’s Gorillas (The Daily Beast)

Finbarr O’Reilly/Reuters

01.22.15

In just four decades, Ebola has wiped out one third of the world’s chimp and gorilla populations. If it continues, the results will be devastating.

While coverage of the current Ebola epidemic in West Africa remains centered on the human populations in Guinea, Sierra Leone, and Liberia, wildlife experts’ concern is mounting over the virus’ favorite victims: great apes.

Guinea, where the epidemic originated, has the largest population of chimpanzees in all of West Africa. Liberia is close behind. Central Africa is home to western lowland gorillas, the largest and most widespread of all four species. Due to forest density, the number of those infected is unknown. But with hundreds of thousands of ape casualties from Ebola, it’s doubtful they’ve escaped unscathed.

Animal activists are ramping up efforts to find an Ebola vaccine for great apes, but with inadequate international support for human research, their mission could be seen as competing with one to save humans. Experts from the Jane Goodall Institute of Canada insist such apprehension would be misplaced. Two streams of funding—one for humans, one for apes—can coexist in this epidemic, they assert, and must.

“The media was really focusing on human beings,” Sophie Muset, project manager for JGI, says. “But it has been traumatic to [the great ape] population for many years.”

Over the course of just four decades, Ebola has wiped out one third of the world’s population of chimpanzees and gorillas, which now stand at less than 300,000 and 95,000 respectively.

The first large-scale “die-offs” due to Ebola began in the late 1990s, and haven’t stopped. Over the course of just four decades, Ebola has wiped out one third of the world’s population of chimpanzees and gorillas, which now stand at less than 300,000 and 95,000 respectively. Both species are now classified as endangered by the International Union for Conservation of Nature; western gorillas are “critically” so.

One of earliest Ebola “die-offs” of great apes came in 1994, when an Ebola outbreak in Minkébé decimated the region’s entire population—once the second largest in the world. In 2002, an outbreak in the Democratic Republic of Congo wiped out 95 percent of the region’s gorilla population. And an equally brutal attack broke out in 2006, when Ebola Zaire in Gabon (the same strain as the current outbreak) left an estimated 5,000 gorillas dead.

The dwindling population of both species, combined with outside poaching threats, means Ebola poses a very real threat to their existence. To evaluate the damage thus far, the Wild Chimpanzee Foundation is conducting population assessments in West Africa, with the goal of getting a rough estimate of how many have died. Given the combined damage that Ebola has inflicted on this population, the results are likely to be troubling.

In a way, great apes are Ebola’s perfect victims. Acutely tactile mammals, their dynamic social environments revolve around intimacy with each other. Touching hands, scratching backs, hugging, kissing, and tickling, they are near constantly intertwined—giving Ebola a free ride.

In a May 2007 study from The American Naturalist, researchers studying the interactions between chimpanzees and gorillas found evidence the Ebola can even spread between the social groups. At three different sites in northern Republic of Congo, they found bacteria from gorillas and chimps on the same fruit trees. For a virus that spreads through bodily fluids, this is an ideal scenario.

“They live in groups [and] they are very close,” says Muset, who has worked with chimps on the ground in Uganda and the DRC. “Since Ebola transmission happens through body fluids, it spreads very fast.”

For gorillas in particular, this culture proves deadly, making their mortality rate for this virus closer to  95 percent. But like humans, the corpses of chimpanzees and gorillas remain contagious with Ebola for days. While the chimps and gorillas infected with Ebola will likely die in a matter of days, the virus can live on in their corpse for days—in turn, spreading to humans who eat or touch their meat.

It is one such interaction that could result in the spread from apes to humans. But in this particular outbreak, experts have zeroed in on the fruit bat (believed to be the original carrier) as the source. The index patient, a 2-year-old in Guinea, was reportedly playing on a tree with a fruit bat colony.

Whether or not a great ape was involved in the transmission of the virus to humans during this outbreak is unknown. Such an interaction is possible. Interestingly, however, it’s not the risk that great apes with Ebola pose to humans that wildlife experts find most concerning. It’s the risk that their absence poses to the wild.

Owing to a diet consisting mostly of fruit, honey, and leaves, gorillas and chimpanzees are crucial to forest life. Inadvertently distributing seeds and pollen throughout the forest, they stimulate biodiversity within it. Without them, the biodiversity of the vegetation may plummet, endangering all of the species that relied on it—and, in turn, the people that relied on them.

“They are not the only ones who act as seed dispersers,” says Muset. “But they are the big players in that field. So when [a die-off] happens, it can decimate an entire forest.”

Wildlife experts worldwide are working to raise both awareness and funds for a vaccination process. It’s a battle that she says was gaining speed last January, when a researcher announced that he had found a vaccine that could work in chimps But as the epidemic in West Africa grew, the focus shifted.

But Muset says its time to return to the project. “There is a vaccine, but it has never been tested on chimpanzees,” she says.  “Progress has been made, and preliminary testing done, but testing in the field need to happen to make it real.”

As to the question of whether it’s ethical to be searching for a vaccine for wild animals when humans are still suffering as well, Muset is honest. “For sure there is a direct competition here. But wildlife and humans have a lot of diseases in common that they can transmit from one to the other,” she says. “And I think you can think of it as two streams of funding, one to wildlife and the other to human beings.”

While it’s great apes that wildlife experts are seeking to save, human nature as a whole, Muset argues, is at stake. “If you want a healthy ecosystem, the more you have to invest in health for wildlife and humans,” she says. “Then, the better place it will be.  Because really, it all works together.”

A Magisterial Synthesis Of Apes And Human Evolution (Forbes)

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.

Humans, baboons share cumulative culture ability (Science Daily)

Date: November 5, 2014

Source: Le Centre national de la recherche scientifique (CNRS)

Summary: The ability to build up knowledge over generations, called cumulative culture, has given humankind language and technology. While it was thought to be limited to humans until now, researchers have recently found that baboons are also capable of cumulative culture.

Baboon using a touch screen. Credit: © 2014 Nicolas Claidière

The ability to build up knowledge over generations, called cumulative culture, has given mankind language and technology. While it was thought to be limited to humans until now, researchers from the Laboratoire de psychologie cognitive (CNRS/AMU), working in collaboration with colleagues at the University of Edinburgh (UK), have recently found that baboons are also capable of cumulative culture. Their findings are published in Proceedings of the Royal Society B on 5 November 2014.

Humankind is capable of great accomplishments, such as sending probes into space and eradicating diseases; these achievements have been made possible because humans learn from their elders and enrich this knowledge over generations. It was previously thought that this cumulative aspect of culture — whereby small changes build up, are transmitted, used and enriched by others — was limited to humans, but it has now been observed in another primate, the baboon.

While it is clear that monkeys like chimpanzees learn many things from their peers, each individual seems to start learning from scratch. In contrast, humans use techniques that evolve and improve from one generation to the next, and also differ from one population to another. The origin of cumulative culture in humans has therefore remained a mystery to scientists, who are trying to identify the necessary conditions for this cultural accumulation.

Nicolas Claidière and Joël Fagot, of the Laboratoire de psychologie cognitive, conducted the present study at the CNRS Primatology Center in Rousset, southeastern France. Baboons live in groups there and have free access to an area with touch screens where they can play a “memory game” specifically designed for the study. The screen briefly displays a grid of 16 squares, four of which are red and the others white. This image is then replaced by a similar grid, but composed of only white squares, and the baboons must touch the four squares that were previously red. Phase one of the experiment started with a task-learning period in which the position of the four red squares was randomized. Phase two comprised a kind of visual form of “Chinese whispers” wherein information was transmitted from one individual to another. In this second phase, a baboon’s response (the squares touched on the screen) was used to generate the next grid pattern that the following baboon had to memorize and reproduce, and so on for 12 “generations.”

The researchers, in collaboration with Simon Kirby and Kenny Smith from the University of Edinburgh, noted that baboons performed better in the phase involving a transmission chain (compared with random testing, which continued throughout the period of the experiment): success rate (1) increased from 80% to over 95%. Due to errors by the baboons, the patterns evolved between the beginning and the end of each chain. Yet to the surprise of researchers, the random computer-generated patterns were gradually replaced by “tetrominos” (Tetris®-like shapes composed of four adjacent squares), even though these forms represent only 6.2% of possible configurations! An even more surprising result was that the baboons’ performance on these rare shapes was poor during random testing, but increased throughout the transmission chain, during which the tetrominos accumulated. Moreover, when the experiment was replicated several times, the starting patterns did not lead to the same set of tetrominos. This study shows that, like humans, baboons have the ability to transmit and accumulate changes over “cultural generations” and that these incremental changes, which may differ depending on the chain, become structured and more efficient.

Researchers have ensured that all the necessary conditions were present to observe a type of cumulative cultural evolution in non-human primates, with its three characteristic properties (progressive increase in performance, emergence of systematic structures, and lineage specificity). These results show that cumulative culture does not require specifically human capacities, such as language. So why have no examples of this type of cultural evolution been clearly identified in the wild? Perhaps because the utilitarian dimension of non-human primate culture (e.g., the development of tools) hinders such evolution.

(1) The task was considered successful if at least 3 out of 4 squares were correctly memorized.


Journal Reference:

  1. N. Claidière, K. Smith, S. Kirby, J. Fagot. Cultural evolution of systematically structured behaviour in a non-human primate. Proceedings of the Royal Society B, November 2014 DOI: 10.1098/rspb.2014.1541

Nature of war: Chimps inherently violent; Study disproves theory that ‘chimpanzee wars’ are sparked by human influence (Science Daily)

Date: September 17, 2014

Source: Lincoln Park Zoo

Summary: Of all of the world’s species, humans and chimpanzees are some of the only species to coordinate attacks on their own members. Since Jane Goodall introduced lethal inter-community killings, primatologists have debated the concept of warfare in this genus. New research from an international coalition of ape researchers has shed new light on the subject, suggesting that human encroachment and interference is not, as previous researchers have claimed, an influential predictor of chimp-on-chimp aggression.


The Ngogo males have just killed a male from a neighboring group. After the male is dead, one of the Ngogo males leaps on the body of the dead animal. Credit: Image courtesy of John Mitani 

Of all of the world’s species, humans and chimpanzees are some of the only to engage in coordinated attacks on other members of their same species. Jane Goodall was among the first to introduce the occurrence of lethal inter-community killings and since then primatologists and anthropologists have long debated the concept of warfare in this genus. Research theories have pointed to increased gains and benefits of killing off competitors and opening up increased access to key resources such as food or mates. In contrast, others have argued that warfare is a result of human impact on chimpanzees, such as habitat destruction or food provisioning, rather than adaptive strategies.

New research from an international coalition of ape researchers, published September 18 in the journalNature, has shed new light on the subject, suggesting that human encroachment and interference is not, as previous researchers have claimed, an influential predictor of chimp-on-chimp aggression.

The study began as a response to a growing number of commentators claiming that chimpanzee violence was caused by human impacts. “This is an important question to get right. If we are using chimpanzees as a model for understanding human violence, we need to know what really causes chimpanzees to be violent,” said University of Minnesota researcher Michael L. Wilson, lead author on the study.

“Humans have long impacted African tropical forests and chimpanzees, and one of the long-standing questions is if human disturbance is an underlying factor causing the lethal aggression observed,” explained co-author David Morgan, PhD, research fellow with the Lester E Fisher Center for the Study and Conservation of Apes at Lincoln Park Zoo in Chicago. Morgan has studied chimpanzees deep in the forests of Republic of Congo for 14 years. “A key take-away from this research is that human influence does not spur increased aggression within or between chimpanzee communities.”

A team of 30 ape researchers assembled extensive data sets spanning five decades of research gathered from 18 chimpanzee communities experiencing varying degrees of human influence. In all, data included pattern analysis of 152 killings by chimpanzees. The key findings indicate that a majority of violent attackers and victims of attack are male chimpanzees, and the information is consistent with the theory that these acts of violence are driven by adaptive fitness benefits rather than human impacts.

“Wild chimpanzee communities are often divided into two broad categories depending on whether they exist in pristine or human disturbed environments,” explained Morgan. “In reality, however, human disturbance can occur along a continuum and study sites included in this investigation spanned the spectrum. We found human impact did not predict the rate of killing among communities.

“The more we learn about chimpanzee aggression and factors that trigger lethal attacks among chimpanzees, the more prepared park managers and government officials will be in addressing and mitigating risks to populations particularly with changing land use by humans in chimpanzee habitat,” explained Morgan.

Journal Reference:

  1. Michael L. Wilson, Christophe Boesch, Barbara Fruth, Takeshi Furuichi, Ian C. Gilby, Chie Hashimoto, Catherine L. Hobaiter, Gottfried Hohmann, Noriko Itoh, Kathelijne Koops, Julia N. Lloyd, Tetsuro Matsuzawa, John C. Mitani, Deus C. Mjungu, David Morgan, Martin N. Muller, Roger Mundry, Michio Nakamura, Jill Pruetz, Anne E. Pusey, Julia Riedel, Crickette Sanz, Anne M. Schel, Nicole Simmons, Michel Waller, David P. Watts, Frances White, Roman M. Wittig, Klaus Zuberbühler, Richard W. Wrangham. Lethal aggression in Pan is better explained by adaptive strategies than human impacts. Nature, 2014; 513 (7518): 414 DOI: 10.1038/nature13727

Brain circuit differences reflect divisions in social status (Science Daily)

Date: September 2, 2014

Source: University of Oxford

Summary: Life at opposite ends of primate social hierarchies is linked to specific brain networks, research has shown. The more dominant you are, the bigger some brain regions are. If your social position is more subordinate, other brain regions are bigger.

 

Group of young barbary macaques (stock image). The research determined the position of 25 macaque monkeys in their social hierarchy and then analyzed non-invasive scans of their brains that had been collected as part of other ongoing University research programs. The findings show that brain regions in one neural circuit are larger in more dominant animals. The regions composing this circuit are the amygdala, raphe nucleus and hypothalamus. Credit: © scphoto48 / Fotolia

Life at opposite ends of primate social hierarchies is linked to specific brain networks, a new Oxford University study has shown.

The importance of social rank is something we all learn at an early age. In non-human primates, social dominance influences access to food and mates. In humans, social hierarchies influence our performance everywhere from school to the workplace and have a direct influence on our well-being and mental health. Life on the lowest rung can be stressful, but life at the top also requires careful acts of balancing and coalition forming. However, we know very little about the relationship between these social ranks and brain function.

The new research, conducted at the University of Oxford, reveals differences between individual primate’s brains which depend on the their social status. The more dominant you are, the bigger some brain regions are. If your social position is more subordinate, other brain regions are bigger. Additionally, the way the brain regions interact with each other is also associated with social status. The pattern of results suggests that successful behaviour at each end of the social scale makes specialised demands of the brain.

The research, led by Dr MaryAnn Noonan of the Decision and Action Laboratory at the University of Oxford, determined the position of 25 macaque monkeys in their social hierarchy and then analysed non-invasive scans of their brains that had been collected as part of other ongoing University research programs. The findings, publishing September 2 in the open access journal PLOS Biology, show that brain regions in one neural circuit are larger in more dominant animals. The regions composing this circuit are the amygdala, raphe nucleus and hypothalamus. Previous research has shown that the amygdala is involved in learning, and processing social and emotional information. The raphe nucleus and hypothalamus are involved in controlling neurotransmitters and neurohormones, such as serotonin and oxytocin. The MRI scans also revealed that another circuit of brain regions, which collectively can be called the striatum, were found to be larger in more subordinate animals. The striatum is known to play a complex but important role in learning the value of our choices and actions.

The study also reports that the brain’s activity, not just its structure, varies with position in the social hierarchy. The researchers found that the strength with which activity in some of these areas was coupled together was also related to social status. Collectively, these results mean that social status is not only reflected in the brain’s hardware, it is also related to differences in the brain’s software, or communication patterns.

Finally, the size of another set of brain regions correlated not only with social status but also with the size of the animal’s social group. The macaque groups ranged in size between one and seven. The research showed that grey matter in regions involved in social cognition, such as the mid-superior temporal sulcus and rostral prefrontal cortex, correlated with both group size and social status. Previous research has shown that these regions are important for a variety of social behaviours, such as interpreting facial expressions or physical gestures, understanding the intentions of others and predicting their behaviour.

“This finding may reflect the fact that social status in macaques depends not only on the outcome of competitive social interactions but on social bonds formed that promote coalitions,” says Matthew Rushworth, the head of the Decision and Action Laboratory in Oxford. “The correlation with social group size and social status suggests this set of brain regions may coordinate behaviour that bridges these two social variables.”

The results suggest that just as animals assign value to environmental stimuli they may also assign values to themselves — ‘self-values’. Social rank is likely to be an important determinant of such self-values. We already know that some of the brain regions identified in the current study track the value of objects in our environment and so may also play a key role in monitoring longer-term values associated with an individual’s status.

The reasons behind the identified brain differences remain unclear, particularly whether they are present at birth or result from social differences. Dr Noonan said: “One possibility is that the demands of a life in a particular social position use certain brain regions more frequently and as a result those areas expand to step up to the task. Alternatively, it is possible that people born with brains organised in a particular way tend towards certain social positions. In all likelihood, both of these mechanisms will work together to produce behaviour appropriate for the social context.”

Social status also changes over time and in different contexts. Dr Noonan added: “While we might be top-dog in one circle of friends, at work we might be more of a social climber. The fluidity of our social position and how our brains adapt our behavior to succeed in each context is the next exciting direction for this area of research.”

 

Journal Reference:

  1. MaryAnn P. Noonan, Jerome Sallet, Rogier B. Mars, Franz X. Neubert, Jill X. O’Reilly, Jesper L. Andersson, Anna S. Mitchell, Andrew H. Bell, Karla L. Miller, Matthew F. S. Rushworth. A Neural Circuit Covarying with Social Hierarchy in Macaques. PLoS Biology, 2014; 12 (9): e1001940 DOI:10.1371/journal.pbio.1001940

Monkeys Use Researchers as Human Shields (IFLScience)

July 26, 2014 | by Janet Fang

photo credit: hyper7pro via Flickr

A team of researchers working in South Africa have a sneaking suspicion that they’re being used as human shields. Monkeys who normally spend their time in trees avoiding predators like leopards and raptors seem to relax their vigilance a little around humans, venturing down to eat.

Humans, as well as human infrastructure, can alter the relationship between predators and prey by shielding one from the other. A stone wall filled with crevices could provide a refuge for a small critter, while a person’s presence might indirectly guard an animal against its would-be killer. Those who are used to us may actually begin to take more risks when we’re around.

To quantify this alteration in risk-taking behavior, Katarzyna Nowak of Durham University and colleagues tested the magnitude of the “human shield effect” on two groups of samango monkeys (Cercopithecus mitis erythrarcus) at a site with high natural predator density and no human hunting pressure.

Samango monkeys spend most of their time in trees avoiding predators on the ground, like large cats, and those in the canopies above, like birds of prey. They don’t stray very far, and they don’t climb too high. When observed by humans, however, the monkeys preferred to climb down to eat food from the forest floor. The work was published in Behavioral Ecology earlier this month.

The researchers set up feeding stations at various levels in the forest and looked at a fear measure known as “giving-up densities.” That’s the density of food remaining in a patch when a forager leaves. (It’s a little like, say, you were in a hurry and didn’t eat your whole burger.) With lots of predators at this site, the giving-up densities were greatest at ground level (0.1 meter) relative to the three tree canopy levels (2.5, 5, and 7.5 meters up). This highlights a strong vertical axis of fear, as they researchers say.

“The amount of food monkeys depleted from buckets over the course of the experiment varied with height, with the most food left uneaten at ground level, where there is a risk of predation by leopards and caracals,” Nowak tells The Independent.

When human followers were present, giving-up densities were reduced at all four heights. In one of the groups, the vertical axis totally disappeared in the presence of human observers. By passively keeping terrestrial predators away from the area, we seem to lower the monkeys’ perceived risks.

“When a human observer was following monkeys, they ate more food at every height, with the most notable differences at the bottom two levels,” Nowak explains. “Animals are expected to deplete more food where and when they feel safe [but] we had not expected human followers to have such strong effect!”

Read more at http://www.iflscience.com/plants-and-animals/monkeys-use-researchers-human-shields#WutB7Z7V2WuAe7ou.99

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

Date: July 1, 2014

Source: Washington University in St. Louis

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

What does this all mean for hominids?

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

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

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

Journal Reference:

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

‘Free choice’ in primates altered through brain stimulation (Science Daily)

Date: May 29, 2014

Source: KU Leuven

Summary: When electrical pulses are applied to the ventral tegmental area of their brain, macaques presented with two images change their preference from one image to the other. The study is the first to confirm a causal link between activity in the ventral tegmental area and choice behavior in primates.

The study is the first to show a causal link between activity in ventral tegmental area and choice behaviour.. Credit: Image courtesy of KU Leuven

When electrical pulses are applied to the ventral tegmental area of their brain, macaques presented with two images change their preference from one image to the other. The study by researchers Wim Vanduffel and John Arsenault (KU Leuven and Massachusetts General Hospital) is the first to confirm a causal link between activity in the ventral tegmental area and choice behaviour in primates.

The ventral tegmental area is located in the midbrain and helps regulate learning and reinforcement in the brain’s reward system. It produces dopamine, a neurotransmitter that plays an important role in positive feelings, such as receiving a reward. “In this way, this small area of the brain provides learning signals,” explains Professor Vanduffel. “If a reward is larger or smaller than expected, behavior is reinforced or discouraged accordingly.”

Causal link

This effect can be artificially induced: “In one experiment, we allowed macaques to choose multiple times between two images — a star or a ball, for example. This told us which of the two visual stimuli they tended to naturally prefer. In a second experiment, we stimulated the ventral tegmental area with mild electrical currents whenever they chose the initially nonpreferred image. This quickly changed their preference. We were also able to manipulate their altered preference back to the original favorite.”

The study, which will be published online in the journal Current Biology on 16 June, is the first to confirm a causal link between activity in the ventral tegmental area and choice behaviour in primates. “In scans we found that electrically stimulating this tiny brain area activated the brain’s entire reward system, just as it does spontaneously when a reward is received. This has important implications for research into disorders relating to the brain’s reward network, such as addiction or learning disabilities.”

Could this method be used in the future to manipulate our choices? “Theoretically, yes. But the ventral tegmental area is very deep in the brain. At this point, stimulating it can only be done invasively, by surgically placing electrodes — just as is currently done for deep brain stimulation to treat Parkinson’s or depression. Once non-invasive methods — light or ultrasound, for example — can be applied with a sufficiently high level of precision, they could potentially be used for correcting defects in the reward system, such as addiction and learning disabilities.”

 Journal Reference:
  1. John T. Arsenault, Samy Rima, Heiko Stemmann, Wim Vanduffel. Role of the Primate Ventral Tegmental Area in Reinforcement and MotivationCurrent Biology, 2014; DOI: 10.1016/j.cub.2014.04.044

Brain regions thought to be uniquely human share many similarities with monkeys (Science Daily)

January 28, 2014

Source: Cell Press

Summary: New research suggests a surprising degree of similarity in the organization of regions of the brain that control language and complex thought processes in humans and monkeys. The study also revealed some key differences. The findings may provide valuable insights into the evolutionary processes that established our ties to other primates but also made us distinctly human.

 (A) The right vlFC ROI. Dorsally it included the inferior frontal sulcus and, more posteriorly, it included PMv; anteriorly it was bound by the paracingulate sulcus and ventrally by the lateral orbital sulcus and the border between the dorsal insula and the opercular cortex. (B) A schematic depiction of the result of the 12 cluster parcellation solution using an iterative parcellation approach. We subdivided PMv into ventral and dorsal regions (6v and 6r, purple and black). We delineated the IFJ area (blue) and areas 44d (gray) and 44v (red) in lateral pars opercularis. More anteriorly, we delineated areas 45 (orange) in the pars triangularis and adjacent operculum and IFS (green) in the inferior frontal sulcus and dorsal pars triangularis. We found area 12/47 in the pars orbitalis (light blue) and area Op (bright yellow) in the deep frontal operculum. We also identified area 46 (yellow), and lateral and medial frontal pole regions (FPl and FPm, ruby colored and pink). Credit: Neuron, Neubert et al.

New research suggests a surprising degree of similarity in the organization of regions of the brain that control language and complex thought processes in humans and monkeys. The study, publishing online January 28 in the Cell Press journal Neuron, also revealed some key differences. The findings may provide valuable insights into the evolutionary processes that established our ties to other primates but also made us distinctly human.

The research concerns the ventrolateral frontal cortex, a region of the brain known for more than 150 years to be important for cognitive processes including language, cognitive flexibility, and decision-making. “It has been argued that to develop these abilities, humans had to evolve a completely new neural apparatus; however others have suggested precursors to these specialized brain systems might have existed in other primates,” explains lead author Dr. Franz-Xaver Neubert of the University of Oxford, in the UK.

By using non-invasive MRI techniques in 25 people and 25 macaques, Dr. Neubert and his team compared ventrolateral frontal cortex connectivity and architecture in humans and monkeys. The investigators were surprised to find many similarities in the connectivity of these regions. This suggests that some uniquely human cognitive traits may rely on an evolutionarily conserved neural apparatus that initially supported different functions. Additional research may reveal how slight changes in connectivity accompanied or facilitated the development of distinctly human abilities.

The researchers also noted some key differences between monkeys and humans. For example, ventrolateral frontal cortex circuits in the two species differ in the way that they interact with brain areas involved with hearing.

“This could explain why monkeys perform very poorly in some auditory tasks and might suggest that we humans use auditory information in a different way when making decisions and selecting actions,” says Dr. Neubert.

A region in the human ventrolateral frontal cortex — called the lateral frontal pole — does not seem to have an equivalent area in the monkey. This area is involved with strategic planning, decision-making, and multi-tasking abilities.

“This might relate to humans being particularly proficient in tasks that require strategic planning and decision making as well as ‘multi-tasking’,” says Dr. Neubert.

Interestingly, some of the ventrolateral frontal cortex regions that were similar in humans and monkeys are thought to play roles in psychiatric disorders such as attention deficit hyperactivity disorder, obsessive compulsive disorder, and substance abuse. A better understanding of the networks that are altered in these disorders might lead to therapeutic insights.

Journal Reference:

  1. Franz-Xaver Neubert et al. Comparison of human ventral frontal cortex areas for cognitive control and language with areas in monkey frontal cortex.Neuron, Jan 28, 2014

Homem evolui mais devagar que macaco, diz estudo (Folha de S.Paulo)

24 de outubro de 2013

Reportagem da Folha de SP mostra que pesquisa descobriu que diferenças entre espécies está em genes ativos

A comparação da atividade genética de humanos com a de chimpanzés sugere que o Homo sapiens está evoluindo de forma mais lenta que os macacos. A descoberta foi feita por cientistas que investigam por que o homem e seu primo mais próximo são tão diferentes, apesar de terem 98% do DNA idêntico.

O segredo das diferenças físicas e comportamentais está em quais genes são de fato ativos em cada espécie. Analisando células embrionárias, a brasileira Carolina Marchetto, do Instituto Salk, de San Diego (EUA), descobriu mecanismos que freiam a taxa de transformação genética da espécie humana.

A descoberta favorece a hipótese de que o advento da cultura desacelerou a evolução biológica: uma vez que humanos se adaptam a distintos ambientes usando o conhecimento, nossa espécie não depende mais tanto de variação genética para evoluir e sobreviver a mudanças.

Já os macacos, mamíferos de cognição mais limitada, precisam que seu DNA evolua de forma rápida para sobreviver a mudanças: eles não têm como compensar a falta de características inatas necessárias usando apenas conhecimento e tecnologia.

Mas o DNA humano também não carece de evoluir? “Não sabemos o que estamos pagando por isso em termos de adaptação, mas por enquanto funciona de forma eficiente”, diz Marchetto.

O trabalho da cientista, descrito hoje na revista “Nature”, ajuda a explicar o mistério da maior diversidade do DNA símio. Um leigo pode achar que todos os chimpanzés são iguais, mas uma só colônia selvagem desses macacos na África tem mais variabilidade genética do que toda a humanidade.

O PULO DO GENE

Segundo o estudo de Marcheto, a maior variabilidade genética dos macacos tem a ver com os chamados transpósons, genes que saltam de um lugar para outro dos cromossomos. Nesse processo, os transpósons reorganizam o genoma, ativando alguns genes e desativando outros.

Esses “genes saltadores” são bastante ativos em chimpanzés e bonobos (macacos igualmente próximos da linhagem humana). Em humanos, o transpóson é suprimido por dois outros genes que são ativados em abundância e inibem o “pulo” genético.

Chimpanzés, de certa forma, precisam de transpósons. Com ferramentas rudimentares e sem linguagem para transmitir conhecimento, eles têm de oferecer maior variabilidade genética à seleção natural para que ela os torne mais bem adaptados, caso o ambiente se altere.

A pesquisa de Marchetto só foi possível porque seu o laboratório no Salk, liderado pelo biólogo Fred Gage, domina a técnica de reverter células ao estágio embrionário.

O material usado na pesquisa foi extraído da pele de macacos e pessoas, pois há uma série de limitações para o uso de embriões em experimentos científicos.

Revertido ao estágio de “células pluripotentes induzidas”, o tecido cutâneo se comporta como embrião, e é possível investigar a biologia molecular dos estágios iniciais do desenvolvimento, quando o surgimento de diversidade genética tem consequências futuras.

“Uma das coisas especiais do nosso estudo é que a reprogramação de células de chimpanzés e bonobos nos dá um modelo para começar a estudar questões evolutivas que antes não tínhamos como abordar”, diz Marchetto.

RUMO AO CÉREBRO

As diferenças de ativação de genes entre humanos e chimpanzés, explica, não se restringem a células embrionárias. A ideia de Marcheto e de seus colegas agora é transformar essas células em neurônios, por exemplo, para entender como a biologia molecular de ambos se altera durante a formação do cérebro.

(Rafael Garcia/ Folha de São Paulo)

http://www1.folha.uol.com.br/ciencia/2013/10/1361208-homem-evolui-mais-devagar-que-macaco-diz-estudo.shtml

Oldest Evidence of Split Between Old World Monkeys and Apes: Primate Fossils Are 25 Million Years Old (Science Daily)

May 15, 2013 — Two fossil discoveries from the East African Rift reveal new information about the evolution of primates, according to a study published online in Nature this week led by Ohio University scientists. 

Artist’s reconstruction of Rukwapithecus (front, center) and Nsungwepithecus (right). (Credit: Mauricio Anton)

The team’s findings document the oldest fossils of two major groups of primates: the group that today includes apes and humans (hominoids), and the group that includes Old World monkeys such as baboons and macaques (cercopithecoids).

Geological analyses of the study site indicate that the finds are 25 million years old, significantly older than fossils previously documented for either of the two groups.

Both primates are new to science, and were collected from a single fossil site in the Rukwa Rift Basin of Tanzania.Rukwapithecus fleaglei is an early hominoid represented by a mandible preserving several teeth. Nsungwepithecus gunnelli is an early cercopithecoid represented by a tooth and jaw fragment.

The primates lived during the Oligocene epoch, which lasted from 34 to 23 million years ago. For the first time, the study documents that the two lineages were already evolving separately during this geological period.

“The late Oligocene is among the least sampled intervals in primate evolutionary history, and the Rukwa field area provides a first glimpse of the animals that were alive at that time from Africa south of the equator,” said Nancy Stevens, an associate professor of paleontology in Ohio University’s Heritage College of Osteopathic Medicine who leads the paleontological team.

Documenting the early evolutionary history of these groups has been elusive, as there are few fossil-bearing deposits of the appropriate age, Stevens explained. Using an approach that dated multiple minerals contained within the rocks, team geologists could determine a precise age for the specimens.

“The rift setting provides an advantage in that it preserves datable materials together with these important primate fossils,” said lead geologist Eric Roberts of James Cook University in Australia.

Prior to these finds, the oldest fossil representatives of the hominoid and cercopithecoid lineages were recorded from the early Miocene, at sites dating millions of years younger.

The new discoveries are particularly important for helping to reconcile a long-standing disagreement between divergence time estimates derived from analyses of DNA sequences from living primates and those suggested by the primate fossil record, Stevens said. Studies of clock-like mutations in primate DNA have indicated that the split between apes and Old

World monkeys occurred between 30 million and 25 million years ago.

“Fossils from the Rukwa Rift Basin in southwestern Tanzania provide the first real test of the hypothesis that these groups diverged so early, by revealing a novel glimpse into this late Oligocene terrestrial ecosystem,” Stevens said.

The new fossils are the first primate discoveries from this precise location within the Rukwa deposits, and two of only a handful of known primate species from the entire late Oligocene, globally.

The scientists scanned the specimens in the Ohio University’s MicroCT scanner, allowing them to create detailed 3-dimensional reconstructions of the ancient specimens that were used for comparisons with other fossils.

“This is another great example that underscores how modern imaging and computational approaches allow us to address more refined questions about vertebrate evolutionary history,” said Patrick O’Connor, co-author and professor of anatomy in Ohio University’s Heritage College of Osteopathic Medicine.

In addition to the new primates, Rukwa field sites have produced several other fossil vertebrate and invertebrate species new to science. The late Oligocene interval is interesting because it provides a final snapshot of the unique species inhabiting Africa prior to large-scale faunal exchange with Eurasia that occurred later in the Cenozoic Era, Stevens said.

A key aspect of the Rukwa Rift Basin project is the interdisciplinary nature of the research team, with paleontologists and geologists working together to reconstruct vertebrate evolutionary history in the context of the developing East African Rift System.

“Since its inception this project has employed a multifaceted approach for addressing a series of large-scale biological and geological questions centered on the East African Rift System in Tanzania,” O’Connor said.

The team’s research, funded by the U.S. National Science Foundation, the Leakey Foundation and the National Geographic Society, underscores the integration of paleontological and geological approaches that are essential for addressing complex issues in vertebrate evolutionary history, the scientists noted.

Co-authors on the study are Patrick O’Connor, Cornelia Krause and Eric Gorscak of Ohio University, Erik Seiffert of SUNY Stony Brook University, Eric Roberts of James Cook University in Australia, Mark Schmitz of Boise State University, Sifa Ngasala of Michigan State University, Tobin Hieronymus of Northeast Ohio Medical University and Joseph Temu of the Tanzania Antiquities Unit.

Journal Reference:

  1. Nancy J. Stevens, Erik R. Seiffert, Patrick M. O’Connor, Eric M. Roberts, Mark D. Schmitz, Cornelia Krause, Eric Gorscak, Sifa Ngasala, Tobin L. Hieronymus, Joseph Temu.Palaeontological evidence for an Oligocene divergence between Old World monkeys and apes.Nature, 2013; DOI: 10.1038/nature12161

Mascote em extinção? (Ciência Hoje)

Pesquisadores criam plano de ação para preservar o macaco muriqui. Confira a entrevista concedida por um dos responsáveis pelo projeto à CH On-line.

Por: Mariana Rocha, Ciência Hoje On-line

Publicado em 19/03/2013 | Atualizado em 20/03/2013

Mascote em extinção?Maior primata não humano das Américas, o muriqui sofre em função do desmatamento desenfreado e da caça para consumo humano. (foto: Sinara Conessa/ Flickr – CC BY 2.0)

Menos de três mil exemplares. É tudo o que resta do macaco muriqui na Mata Atlântica. Forte candidato a mascote das Olimpíadas de 2016, o primata corre o risco de sumir das florestas por conta do desmatamento desenfreado e da caça para consumo humano. No intuito de reverter esse quadro, pesquisadores traçam estratégias para garantir a sobrevivência do muriqui.

Batizado de Plano de Ação Nacional para a Conservação dos Muriquis (PAN Muriquis) e desenvolvido no âmbito do Instituto Chico Mendes de Conservação da Biodiversidade(ICMBio), o projeto conta com dez metas e 54 ações. As atividades são diversas e englobam medidas como a contagem das populações de muriquis, a fiscalização das florestas para protegê-los de caçadores e iniciativas de educação ambiental que conscientizem a população sobre a importância do macaco.

Na lista vermelha da União Internacional para a Conservação da Natureza, o muriqui-do-norte, que ocupa Minas Gerais e Espírito Santo, é classificado como animal criticamente em perigo e, dentro de três gerações, pode sofrer uma redução populacional de 80%. Já o muriqui-do-sul, encontrado no Rio de Janeiro, São Paulo e norte do Paraná, é classificado como espécie em perigo e pode ter sua população diminuída em pelo menos 20% dentro de duas gerações.

Até 2020, o PAN Muriquis pretende retroceder em pelo menos um nível o risco de extinção do primata. A meta é fazer com que o muriqui-do-norte seja classificado como espécie em perigo e o do sul como vulnerável.

Candidato a mascote

De origem indígena, a palavra muriqui significa povo manso da floresta e descreve um animal de comportamento pacífico e solidário. O hábito de abraçar seus companheiros fez do macaco um forte candidato a representar os anfitriões brasileiros nas Olimpíadas de 2016.

Veja vídeo da campanha em favor do muriqui como mascote das Olimpíadas de 2016

A campanha para eleger o primata-mascote do evento conta com o apoio de instituições envolvidas no PAN Muriquis e discute a necessidade de preservá-lo.

Para saber mais sobre ações que buscam garantir a sobrevivência do macaco muriqui, a CH On-line conversou com Maurício Talebi, bioantropólogo da Universidade Federal de São Paulo-Diadema e coautor do PAN Muriquis.

Maurício TalebiComo e quando começou a elaboração do PAN Muriquis?
O projeto surgiu a partir do Plano de Sobrevivência das Espécies, uma ferramenta conceitual da Comissão de Sobrevivência das Espécies (CSE), uma divisão da União Internacional para Conservação da Natureza. A CSE desenvolve atividades para a conservação de diversas espécies ameaçadas no planeta. O documento que descreve as ações do PAN Muriqui começou a ser desenvolvido em 2003 pelo ICMBio e foi finalizado em 2010. Esse planejamento contou com a participação de diversos setores da sociedade, como governo, universidades e organizações não governamentais.

Quais são as principais atividades do homem que prejudicam os muriquis?
Diversas ameaças acometem populações selvagens de muriquis. As principais são a redução de hábitat, caça ilegal, baixos investimentos em vigilância e fiscalização, índices reduzidos de reprodução em cativeiro e a fragmentação do hábitat em ilhas de florestas.

O senhor coordena o monitoramento das populações de muriquis em vários locais – alguns deles já são estudados há 20 anos. Como essa medida auxilia no planejamento de ações para preservar os muriquis?
Pesquisas de longa duração são fundamentais por vários motivos. É importante obter informações sobre os animais em várias épocas do ano, conhecer seu comportamento frente a variações ambientais, entender como eles organizam sua vida cotidiana e como executam tarefas vitais para a sobrevivência. Obtemos, também, informações sobre quais variáveis ambientais devem ser levadas em conta durante ações de reflorestamento do hábitat desses primatas. Complementarmente, esses estudos propiciam o treinamento das futuras gerações de pesquisadores. Nosso grupo de pesquisa na Associação Pró-muriqui treinou mais de 200 estudantes de graduação e pós-graduação nos últimos dez anos.

Quais são as principais dificuldades na execução do PAN Muriquis?
O principal fator restritivo é a baixa disponibilidade de recursos financeiros. Atualmente, contamos com recursos humanos qualificados para a execução desses trabalhos, mas faltam recursos para financiar a mão de obra. Uma das metas é criar um fundo financeiro que viabilize a execução de todas as ações do plano. Lamentamos que, no Brasil, os fundos financeiros para a conservação de hábitat e de espécies ainda sejam praticamente inexistentes.

O senhor acredita que a candidatura do muriqui a mascote das Olimpíadas de 2016 pode auxiliar na preservação do primata?

Caso seja confirmado como mascote olímpico, o muriqui será conhecido globalmente e diversos setores da economia se interessarão por investir em um emblema tão poderoso quanto ele

Certamente sim. A maioria dos brasileiros desconhece que o maior primata (não humano) das Américas ocorre exclusivamente em nosso país. Caso seja confirmado como mascote olímpico, o muriqui será conhecido globalmente e diversos setores da economia se interessarão por investir em um emblema tão poderoso quanto ele. Assim, será possível conseguir recursos para os esforços que poucos brasileiros e estudantes estão fazendo para a pesquisa e conservação da espécie. A conscientização nos níveis nacional e internacional poderá gerar recursos para continuarmos trabalhando e assim contribuirmos para que o muriqui possa ser visto ao vivo e a cores em seu hábitat natural pelas futuras gerações.

Este texto foi atualizado para incluir a seguinte alteração:
Além de Rio de Janeiro e São Paulo, o muriqui-do-sul é encontrado no norte do Paraná. (20/03/2013)

UCSB anthropologist studies reciprocity among chimpanzees and bonobos (UC Santa Barbara)

20-Nov-2012
By Andrea Estrada

Primate behavior may reveal clues to evolution of favor exchange in humans

Adrian Jaeggi, a postdoctoral researcher in anthropology at UC Santa Barbara, and a junior research fellow at the campus’s SAGE Center for the Study of the Mind, is studying this question of reciprocity, using chimpanzees and bonobos as his test subjects. His findings appear in the current online issue of the journal Evolution & Human Behavior.(Santa Barbara, Calif.) –– When your neighbor asks to borrow a cup of sugar and you readily comply, is your positive response a function of the give and take that characterize your longstanding relationship? Or does it represent payment –– or prepayment –– for the cup of sugar you borrowed last week, or may need to borrow a month from now?

“The article focuses on the question of whether individuals do favors because they expect them to be reciprocated at some other time, and, more specifically, whether such exchanges have to happen immediately, or can take place over longer time spans,” Jaeggi explained. “We studied the question in chimpanzees and bonobos –– our two closest living relatives –– and looked at the exchanges of grooming and food sharing, which are two common types of favors among these apes.”

Two female chimpanzees take food from a male (center).

According to Jaeggi, while results of his research provide some evidence for immediate exchanges, they more strongly support the notion that favors are exchanged over long periods of time. Calculated exchanges, in which individuals keep a detailed score of past interactions, are much less common than the more loosely balanced exchanges that take place in stable relationships.

“In the chimp group we studied, we knew there was a lot of this long-term exchange,” said Jaeggi. “We didn’t find any evidence for a short-term effect.” Chimpanzees live in stable social groups, he continued, and have a relatively long life span. They recognize others in the group, form long-term relationships, and associate with individuals who have helped them in the past.

“In the wild, for example, chimps hunt for smaller monkeys, and they commonly share the meat. It’s similar to what hunters and gatherers do,” Jaeggi said. “Our experiment is meant to mimic the situation in which you have a large monopolized food item.” Using grooming as the favor, the researchers studied whether or not a chimp that had just been groomed was more likely to share food with the pal who had groomed him. “That would provide evidence for keeping track of who has done a favor,” Jaeggi said. However, grooming releases endorphins, he added, and that general sense of wellbeing on the part of the food owner might lead to more indiscriminate food sharing.

One female bonobo rests her hand on another’s shoulder.

Bonobos, on the other hand, presented a different result. While chimpanzees have a formalized dominance hierarchy, food is available to most individuals, no matter what their group status. That is not the case with bonobos. Bonobos don’t establish formal hierarchies, so they don’t know on an individual basis where they fit within the group. Also, they don’t form coalitions as much as chimpanzees do. “The food sharing situation sort of freaked them out,” said Jaeggi. “All of a sudden there’s all this food that’s owned by one individual, and they don’t really know what to do about it. They want to get it, but they don’t dare, because they don’t know what the consequence will be.””We found that sharing was predicted by who the chimps’ long-term friends and partners were,” he said. “Grooming just before didn’t play a role. Food owners didn’t share specifically with their groomers. Nor did the groomers act in return. They didn’t pay for the food, and they didn’t reward the food owner’s generosity afterward.”

Jaeggi added that bonobos did a lot more grooming, most likely because they sought the calming effects of the endorphins. “And there we did see an effect of grooming on sharing,” he said. “Chimps would go and take food pretty confidently, but Bonobos were more reticent. They’d reach out and then groom. It seemed to be that they’d groom to release tension, and then there would be these short-term reciprocal exchanges.”

But even those exchanges seem to be more a byproduct of the need to reduce tension, he noted, rather than short-term contingencies used to establish reciprocity.

So, what do these findings tell us about ourselves? Jaeggi suggests we should take seriously this evidence of long-term reciprocity in animals. “It’s really not qualitatively different from what people do,” he said. “They establish these lasting relationships, and within them, services are exchanged without the participants keeping close track of who’s doing what for whom.”

However, humans also have the capacity for more contingent reciprocity, which raises questions about its purpose, and how it developed. “Maybe that’s something that’s more culturally learned,” said Jaeggi.

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

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

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

By Stephanie Pappas

updated 11/13/2012 3:30:35 PM ET

 

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

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

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

Three intestinal ecosystems

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

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

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

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

Shared bacteria

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

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

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

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

Our shared history

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

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

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

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

Reciprocity an Important Component of Prosocial Behavior: Scorekeeping of Past Favors Isn’t, However, a Factor (Science Daily)

ScienceDaily (Sep. 3, 2012) — While exchanging favors with others, humans tend to think in terms of tit-for-tat, an assumption easily extended to other animals. As a result, reciprocity is often viewed as a cognitive feat requiring memory, perhaps even calculation. But what if the process is simpler, not only in other animals but in humans as well?

Researchers at the Yerkes National Primate Research Center, Emory University, have determined monkeys may gain the advantages of reciprocal exchange of favors without necessarily keeping precise track of past favors. Malini Suchak, a graduate student at Emory University, and Frans de Waal, PhD, director of the Living Links Center at Yerkes and C.H. Candler Professor of Psychology at Emory, led the study. Their findings will appear in an Early Online Edition of theProceedings of the National Academy of Sciences this week.

“Prosocial is defined as a motivation to assist others regardless of benefits for self, explained Suchak. “We used a prosocial choice test to study whether direct reciprocity could promote generosity among brown capuchin monkeys. We found one monkey willing to do another favors if the first monkey was the only one to choose, and we found the monkeys became even more prosocial if they could alternate and help each other. We did not find any evidence that the monkeys paid close attention to each other’s past choices, so they were prosocial regardless of what their partner had just done,” she continued.

Suchak and de Waal suggest the synchronization of the same actions in alternation creates a more positive attitude the same way humans who row a boat together or work toward a shared goal develop a more positive attitude about each other.

Another interesting finding according to the researchers is the capuchin monkeys were prosocial whether they were paired with a familiar partner from their own group {in-group} or a partner from a different social group {out-group}.

According to de Waal, “This research has several implications for better understanding human behavior. First, we observed an increase in prosocial behavior as a result of reciprocity, but the monkeys did not develop a contingency between their own and their partners’ behaviors. Like humans, the capuchins may have understood the benefits of reciprocity and used this understanding to maximize their own benefits. Second, that the capuchins responded similarly to in-group and out-group partners has implications for the commonly held view that humans are unique in their ability to cooperate with strangers,” de Waal explained.

According to the researchers, capuchin monkeys (Cebus apella) are ideal subjects for this type of study given the numerous observations of cooperative and prosocial behavior in the field, their sensitivity to other monkeys’ efforts in coordination experiments, and their robust, spontaneous prosocial behavior in the prosocial choice test compared with, for example, chimpanzees, which seem more sensitive to methodological variables.

In this study, the researchers tested 12 brown capuchin monkeys in pairs on a prosocial choice task. The monkeys had the choice between a selfish token that benefited only them and a prosocial token that benefited themselves and a partner. By comparing each monkey’s behavior with a familiar partner from the monkey’s own group and a partner from a different social group, the researchers examined the influence of each monkey’s relationship outside the experimental context on prosocial behavior. There was no difference between in-group and out-group pairs in any of the test conditions. To test the role of reciprocity, the researchers allowed the monkeys to take turns making choices and found this greatly increased prosocial behavior, but the researchers did not observe any tit-for-tat behavior. The researchers also tested whether the monkeys could overcome their aversion for inequity by creating a situation in which both individuals could provide each other with superior rewards, making reciprocity an even more attractive strategy. The monkeys did, but again without keeping track of each other’s choices. Finally, through a series of control conditions, the researchers established the monkeys were responding to their partners’ behaviors, rather than the rewards delivered by their partners, and that the monkeys understood the values of the tokens and were flexibly responding to changing conditions throughout the test sessions.

This research opens several avenues for future research, including further examining the emergence of reciprocity among humans without the cognition required for tit-for-tat and the tendency to cooperate with out-group partners.

Journal Reference:

  1. Malini Suchak and Frans B. M. de Waal. Monkeys benefit from reciprocity without the cognitive burden.Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1213173109

Chimpanzees Create ‘Social Traditions’: Unique Handclasp Grooming Behavior Reveals Local Difference (Science Daily)

ScienceDaily (Aug. 28, 2012) — Researchers have revealed that chimpanzees are not only capable of learning from one another, but also use this social information to form and maintain local traditions.

Wrist-to-wrist grooming handclasp. (Credit: Mark Bodamer)

A research collaboration between the Gonzaga University and the Max Planck Institute shows that the way in which chimpanzees groom each other depends on the community to which they belong. Specifically, it is the unique handclasp grooming behaviour that reveals this local difference.

The specific behaviour that the researchers focused on was the ‘grooming handclasp’, a behaviour where two chimpanzees clasp onto each other’s arms, raise those arms up in the air, and groom each other with their free arm. This behaviour has only been observed in some chimpanzee populations. The question remained whether chimpanzees are instinctively inclined to engage in grooming handclasp behaviour, or whether they learn this behaviour from each other and pass it on to subsequent generations.

Edwin van Leeuwen and Katherine Cronin of the Comparative Cognitive Anthropology research group of the Max Planck Institute for Psycholinguistics led by Daniel Haun conducted their observations between 2007 and 2012 at the Chimfunshi Wildlife Orphanage Trust in Zambia. At Chimfunshi, a mix of wild- and captive-born chimpanzees live in woodlands in some of the largest enclosures in the world. The Max Planck team collaborated with students from Gonzaga University led by Mark Bodamer, a team of local chimpanzee caretakers, and Roger Mundry of the Max Planck Institute for Evolutionary Anthropology in order to collect and comprehend the detailed chimpanzee data.

Previous research suggested that the grooming handclasp might be a cultural phenomenon, just like humans across cultures engage in different ways of greeting each other. However, these suggestions were primarily based on observations that some chimpanzee communities handclasp and others don’t — not whether there are differences between communities that engage in handclasping. Moreover, the early observations could have been explained by differences in genetic and/or ecological factors between the chimpanzee communities, which precluded the interpretation that the chimpanzees were exhibiting ‘cultural’ differences.

The present research shows that even between chimpanzee communities that engage in the grooming handclasp, subtle yet stable differences exist in the styles that they prefer: one chimpanzee group highly preferred the style where they would grasp each other’s hands during the grooming, while another group engaged much more in a style where they would fold their wrists around each other’s wrists.

“We don’t know what mechanisms account for these differences,” van Leeuwen says. “But our study at least reveals that these chimpanzee communities formed and maintained their own local grooming traditions over the last 5 years. Our observations may also indicate that chimpanzees can overcome their innate predispositions, potentially allowing them to manipulate their environment based on social constructs rather than on mere instincts.”

Apart from the different style preferences of the chimpanzee communities, the research team also observed that the grooming handclasp behaviour was a long-lasting part of the chimpanzees’ behavioural repertoire: the behaviour was even transmitted to the next generation of potential handclaspers.

“By following the chimpanzees over time, we were able to show that 20 young chimpanzees gradually developed the handclasp behaviour over the course of the five-year study. The first handclasps by young individuals were mostly in partnership with their mothers. These observations support the conclusion that these chimpanzees socially learn their local tradition, and that this might be evidence of social culture,” Bodamer explains.

“Continued monitoring of these groups of chimpanzees will shed light on the question of how these group-traditions are maintained over time and potentially even why the chimpanzees like to raise their arms up in the air during social grooming in the first place,” van Leeuwen adds.

Journal Reference:

  1. Edwin J. C. van Leeuwen, Katherine A. Cronin, Daniel B. M. Haun, Roger Mundry and Mark D. Bodamer. Neighbouring chimpanzee communities show different preferences in social grooming behaviourProceedings of the Royal Society B, August 29, 2012

Ape ‘genius’ smarter than the average chimp (Discovery News)

Geniuses exist among non-humans, but no one attribute constitutes intelligence.

By Jennifer Viegas – Mon Aug 27, 2012 06:01 AM ET

Chimp

Natasha, who appears in this photo, outperformed other chimps on tests given by researchers to measure intelligence. Max Planck Institute for Evolutionary Anthropology/Esther Herrmann

Certain apes appear to be much smarter than others, with at least one chimpanzee now called “exceptional” when compared to other chimps.

The standout chimp, an adult female in her 20s named Natasha, scored off the charts in a battery of tests. The findings, published in the latest Philosophical Transactions of the Royal Society B, suggest that geniuses exist among non-humans, but that no one attribute constitutes intelligence.

Instead, a perfect storm of abilities seems to come together to create the Einsteins of the animal kingdom. Natasha’s keepers at the Ngamba Island chimpanzee sanctuary in Uganda knew she was special even before the latest study.

“The caretakers named Natasha as the smartest chimpanzee, precisely the same chimpanzee that our tests had revealed to be exceptional,” study authors Esther Herrmann and Josep Call of the Max Planck Institute for Evolutionary Anthropology wrote.

“All three of the most experienced caretakers included Natasha in their lists (of the most intelligent chimps),” they added.

Natasha has made headlines over the months for her attention-grabbing antics. For instance, she repeatedly escaped her former enclosure, surrounded by an electric fence. She did this by tossing branches at the fence until she didn’t see a spark, letting her know that the power was off.

She also learned how to tease humans, beckoning them to throw food her way, only to spray the unsuspecting person with water.

Herrmann and Call decided to study this chimp, along with numerous others, to see if there really are chimp prodigies among non-human great apes. To do this, the researchers created a multi-part mental challenge consisting of eight tasks.

chimp"WATCH VIDEO: See how chimp family groups cope with the death of a close relative. (Caution: Images may be disturbing to some viewers.)

For the first task, the chimps had to find hidden food, testing their spatial knowledge. For the second, the chimps wielded a tool — avoiding a trap — to again obtain a food reward. The remaining tasks demonstrated understanding of things like color, size and shape.

“We identified some individuals who consistently scored well across (the) multiple tasks,” wrote the authors, who again made note of Natasha, who aced nearly every task.

The researchers could not identify “a general intelligence factor.” They instead indicate that ape intelligence might be a bundling of skills related to learning, tool usage, understanding of quantities, and an ability to reach conclusions based on evidence and reasoning.

As the saying goes, necessity may be the mother of invention and, at least in some cases, one reason behind chimp cleverness.

Call, for example, told Discovery News about chimps that make tools for extracting termites out of mounds. The process requires several steps.

“They uproot the stem or use their teeth to clip the stem at the base and then remove the large leaf from the distal end by clipping it with their teeth before transporting the stem to the termite nest, where they complete tool manufacture by modifying the end into a ‘paint brush’ tip by pulling the stem through their teeth, splitting the probe lengthwise by pulling off strands of fiber, or separating the fibers by biting them,” he said.

As for why only some chimps go through such an elaborate process, “a lot depends on the ecological constraints and needs,” he said.

In terms of other animals, Herrmann and Call mention the dogs Rico and Chaser, who knew the meaning of hundreds of words.

“Interestingly,” the scientists point out, “all of these dogs (considered to be very smart) are border collies. And many of their owners reported that they did not train the dogs to play the fetching game; it was the dogs who trained them!”

The jury is still out on what exactly constitutes such cleverness. The researchers propose that more studies be conducted, with “tasks that capture cognitive, motivational and temperament dimensions.”

That’s because, in part, a willingness to learn and a positive attitude seem to make as big of a difference in dogs, chimps and other animals as they do in humans.

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

13:09 21 August 2012 by Hannah Krakauer

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

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

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

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

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

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

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

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

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

How Computation Can Predict Group Conflict: Fighting Among Captive Pigtailed Macaques Provides Clues (Science Daily)

ScienceDaily (Aug. 13, 2012) — When conflict breaks out in social groups, individuals make strategic decisions about how to behave based on their understanding of alliances and feuds in the group.

Researchers studied fighting among captive pigtailed macaques for clues about behavior and group conflict. (Credit: iStockphoto/Natthaphong Phanthumchinda)

But it’s been challenging to quantify the underlying trends that dictate how individuals make predictions, given they may only have seen a small number of fights or have limited memory.

In a new study, scientists at the Wisconsin Institute for Discovery (WID) at UW-Madison develop a computational approach to determine whether individuals behave predictably. With data from previous fights, the team looked at how much memory individuals in the group would need to make predictions themselves. The analysis proposes a novel estimate of “cognitive burden,” or the minimal amount of information an organism needs to remember to make a prediction.

The research draws from a concept called “sparse coding,” or the brain’s tendency to use fewer visual details and a small number of neurons to stow an image or scene. Previous studies support the idea that neurons in the brain react to a few large details such as the lines, edges and orientations within images rather than many smaller details.

“So what you get is a model where you have to remember fewer things but you still get very high predictive power — that’s what we’re interested in,” says Bryan Daniels, a WID researcher who led the study. “What is the trade-off? What’s the minimum amount of ‘stuff’ an individual has to remember to make good inferences about future events?”

To find out, Daniels — along with WID co-authors Jessica Flack and David Krakauer — drew comparisons from how brains and computers encode information. The results contribute to ongoing discussions about conflict in biological systems and how cognitive organisms understand their environments.

The study, published in the Aug. 13 edition of the Proceedings of the National Academy of Sciences, examined observed bouts of natural fighting in a group of 84 captive pigtailed macaques at the Yerkes National Primate Research Center. By recording individuals’ involvement — or lack thereof — in fights, the group created models that mapped the likelihood any number of individuals would engage in conflict in hypothetical situations.

To confirm the predictive power of the models, the group plugged in other data from the monkey group that was not used to create the models. Then, researchers compared these simulations with what actually happened in the group. One model looked at conflict as combinations of pairs, while another represented fights as sparse combinations of clusters, which proved to be a better tool for predicting fights. From there, by removing information until predictions became worse, Daniels and colleagues calculated the amount of information each individual needed to remember to make the most informed decision whether to fight or flee.

“We know the monkeys are making predictions, but we don’t know how good they are,” says Daniels. “But given this data, we found that the most memory it would take to figure out the regularities is about 1,000 bits of information.”

Sparse coding appears to be a strong candidate for explaining the mechanism at play in the monkey group, but the team points out that it is only one possible way to encode conflict.

Because the statistical modeling and computation frameworks can be applied to different natural datasets, the research has the potential to influence other fields of study, including behavioral science, cognition, computation, game theory and machine learning. Such models might also be useful in studying collective behaviors in other complex systems, ranging from neurons to bird flocks.

Future research will seek to find out how individuals’ knowledge of alliances and feuds fine tunes their own decisions and changes the groups’ collective pattern of conflict.

The research was supported by the National Science Foundation, the John Templeton Foundation through the Santa Fe Institute, and UW-Madison.

See Dan read: Baboons can learn to spot real words (Guardian)

AP foreign, Saturday April 14 2012 (The Guardian)

SETH BORENSTEIN

AP Science Writer= WASHINGTON (AP) — Dan the baboon sits in front of a computer screen. The letters BRRU pop up. With a quick and almost dismissive tap, the monkey signals it’s not a word. Correct. Next comes, ITCS. Again, not a word. Finally KITE comes up.

He pauses and hits a green oval to show it’s a word. In the space of just a few seconds, Dan has demonstrated a mastery of what some experts say is a form of pre-reading and walks away rewarded with a treat of dried wheat.

Dan is part of new research that shows baboons are able to pick up the first step in reading — identifying recurring patterns and determining which four-letter combinations are words and which are just gobbledygook.

The study shows that reading’s early steps are far more instinctive than scientists first thought and it also indicates that non-human primates may be smarter than we give them credit for.

“They’ve got the hang of this thing,” said Jonathan Grainger, a French scientist and lead author of the research.

Baboons and other monkeys are good pattern finders and what they are doing may be what we first do in recognizing words.

It’s still a far cry from real reading. They don’t understand what these words mean, and are just breaking them down into parts, said Grainger, a cognitive psychologist at the Aix-Marseille University in France.

In 300,000 tests, the six baboons distinguished between real and fake words about three-out-of-four times, according to the study published in Thursday’s journal Science.

The 4-year-old Dan, the star of the bunch and about the equivalent age of a human teenager, got 80 percent of the words right and learned 308 four-letter words.

The baboons are rewarded with food when they press the right spot on the screen: A blue plus sign for bogus combos or a green oval for real words.

Even though the experiments were done in France, the researchers used English words because it is the language of science, Grainger said.

The key is that these animals not only learned by trial and error which letter combinations were correct, but they also noticed which letters tend to go together to form real words, such as SH but not FX, said Grainger. So even when new words were sprung on them, they did a better job at figuring out which were real.

Grainger said a pre-existing capacity in the brain may allow them to recognize patterns and objects, and perhaps that’s how we humans also first learn to read.

The study’s results were called “extraordinarily exciting” by another language researcher, psychology professor Stanislas Dehaene at the College of France, who wasn’t part of this study. He said Grainger’s finding makes sense. Dehaene’s earlier work says a distinct part of the brain visually recognizes the forms of words. The new work indicates this is also likely in a non-human primate.

This new study also tells us a lot about our distant primate relatives.

“They have shown repeatedly amazing cognitive abilities,” said study co-author Joel Fagot, a researcher at the French National Center for Scientific Research.

Bill Hopkins, a professor of psychology at the Yerkes Primate Center in Atlanta, isn’t surprised.

“We tend to underestimate what their capacities are,” said Hopkins, who wasn’t part of the French research team. “Non-human primates are really specialized in the visual domain and this is an example of that.”

This raises interesting questions about how the complex primate mind works without language or what we think of as language, Hopkins said. While we use language to solve problems in our heads, such as deciphering words, it seems that baboons use a “remarkably sophisticated” method to attack problems without language, he said.

Key to the success of the experiment was a change in the testing technique, the researchers said. The baboons weren’t put in the computer stations and forced to take the test. Instead, they could choose when they wanted to work, going to one of the 10 computer booths at any time, even in the middle of the night.

The most ambitious baboons test 3,000 times a day; the laziest only 400.

The advantage of this type of experiment setup, which can be considered more humane, is that researchers get far more trials in a shorter time period, he said.

“They come because they want to,” Fagot said. “What do they want? They want some food. They want to solve some task.”

Chimpanzees Have Police Officers, Too (Science Daily)

Mostly high-ranking males or females intervene in a conflict. (Credit: Claudia Rudolf von Rohr)

ScienceDaily (Mar. 7, 2012) — Chimpanzees are interested in social cohesion and have various strategies to guarantee the stability of their group. Anthropologists now reveal that chimpanzees mediate conflicts between other group members, not for their own direct benefit, but rather to preserve the peace within the group. Their impartial intervention in a conflict — so-called “policing” — can be regarded as an early evolutionary form of moral behavior.

Conflicts are inevitable wherever there is cohabitation. This is no different with our closest relatives, the chimpanzees. Sound conflict management is crucial for group cohesion. Individuals in chimpanzee communities also ensure that there is peace and order in their group. This form of conflict management is called “policing” — the impartial intervention of a third party in a conflict. Until now, this morally motivated behavior in chimpanzees was only ever documented anecdotally.

However, primatologists from the University of Zurich can now confirm that chimpanzees intervene impartially in a conflict to guarantee the stability of their group. They therefore exhibit prosocial behavior based on an interest in community concern.

The more parties to a conflict there are, the more policing there is

The willingness of the arbitrators to intervene impartially is greatest if several quarrelers are involved in a dispute as such conflicts particularly jeopardize group peace. The researchers observed and compared the behavior of four different captive chimpanzee groups. At Walter Zoo in Gossau, they encountered special circumstances: “We were lucky enough to be able to observe a group of chimpanzees into which new females had recently been introduced and in which the ranking of the males was also being redefined. The stability of the group began to waver. This also occurs in the wild,” explains Claudia Rudolf von Rohr, the lead author of the study.

High-ranking arbitrators

Not every chimpanzee makes a suitable arbitrator. It is primarily high-ranking males or females or animals that are highly respected in the group that intervene in a conflict. Otherwise, the arbitrators are unable to end the conflict successfully. As with humans, there are also authorities among chimpanzees. “The interest in community concern that is highly developed in us humans and forms the basis for our moral behavior is deeply rooted. It can also be observed in our closest relatives,” concludes Rudolf von Rohr.

Great apes make sophisticated decisions (Max-Planck-Gesellschaft)

By Daniel Haun
Max-Planck-Gesellschaft

Chimpanzees, orangutans, gorillas and bonobos make more sophisticated decisions than was previously thought. Great apes weigh their chances of success, based on what they know and the likelihood to succeed when guessing, according to a study of MPI researcher Daniel Haun, published on December 21 in the online journal PLoS ONE. The findings may provide insight into human decision-making as well.

The authors of the study, led by Daniel Haun of the Max Planck Institutes for Psycholinguistics (Nijmegen) and Evolutionary Anthropology (Leipzig), investigated the behaviour of all four non-human great ape species. The apes were presented with two banana pieces: a smaller one, which was always reliably in the same place, and a larger one, which was hidden under one of multiple cups, and therefore the riskier choice.

The researchers found that the apes’ choices were regulated by their uncertainty and the probability of success for the risky choice, suggesting sophisticated decision-making. Apes chose the small piece more often when they where uncertain where the large piece was hidden. The lower their chances to guess correctly, the more often they chose the small piece.

Risky choices

The researchers also found that the apes went for the larger piece – and risked getting nothing at all – no less than 50% of the time. This risky decision-making increased to nearly 100% when the size difference between the two banana pieces was largest. While all four species demonstrated sophisticated decision making strategies, chimpanzees and orangutans were overall more likely to make risky choices relative to gorillas and bonobos. The precise reason for this discrepancy remains unknown.

Haun concludes: “Our study adds to the growing evidence that the mental life of the other great apes is much more sophisticated than is often assumed.”