Arquivo da tag: Evolução

Language and Tool-Making Skills Evolved at the Same Time (Science Daily)

Sep. 3, 2013 — Research by the University of Liverpool has found that the same brain activity is used for language production and making complex tools, supporting the theory that they evolved at the same time.

Three hand axes produced by participants in the experiment. Front, back and side views are shown. (Credit: Image courtesy of University of Liverpool)

Researchers from the University tested the brain activity of 10 expert stone tool makers (flint knappers) as they undertook a stone tool-making task and a standard language test.

Brain blood flow activity measured

They measured the brain blood flow activity of the participants as they performed both tasks using functional Transcranial Doppler Ultrasound (fTCD), commonly used in clinical settings to test patients’ language functions after brain damage or before surgery.

The researchers found that brain patterns for both tasks correlated, suggesting that they both use the same area of the brain. Language and stone tool-making are considered to be unique features of humankind that evolved over millions of years.

Darwin was the first to suggest that tool-use and language may have co-evolved, because they both depend on complex planning and the coordination of actions but until now there has been little evidence to support this.

Dr Georg Meyer, from the University Department of Experimental Psychology, said: “This is the first study of the brain to compare complex stone tool-making directly with language.

Tool use and language co-evolved

“Our study found correlated blood-flow patterns in the first 10 seconds of undertaking both tasks. This suggests that both tasks depend on common brain areas and is consistent with theories that tool-use and language co-evolved and share common processing networks in the brain.”

Dr Natalie Uomini from the University’s Department of Archaeology, Classics & Egyptology, said: “Nobody has been able to measure brain activity in real time while making a stone tool. This is a first for both archaeology and psychology.”

The research was supported by the Leverhulme Trust, the Economic and Social Research Council and the British Academy. It is published in PLOS ONE.

Journal Reference:

  1. Natalie Thaïs Uomini, Georg Friedrich Meyer. Shared Brain Lateralization Patterns in Language and Acheulean Stone Tool Production: A Functional Transcranial Doppler Ultrasound StudyPLoS ONE, 2013; 8 (8): e72693 DOI: 10.1371/journal.pone.0072693

Why Animals Compare the Present With the Past (Science Daily)

May 30, 2013 — Humans, like other animals, compare things. We care not only how well off we are, but whether we are better or worse off than others around us, or than we were last year. New research by scientists at the University of Bristol shows that such comparisons can give individuals an evolutionary advantage.

The ‘contrast effect’ has been reported in a number of living things, including bees. (Credit: © Daniel Prudek / Fotolia)

According to standard theory, the best response to current circumstances should be unaffected by what has happened in the past. But the Bristol study, published in the journalScience, shows that in a changing, unpredictable world it is important to be sensitive to past conditions.

The research team, led by Professor John McNamara in Bristol’s School of Mathematics, built a mathematical model to understand how animals should behave when they are uncertain about the pattern of environmental change. They found that when animals are used to rich conditions but then conditions suddenly worsen, they should work less hard than animals exposed to poor conditions all along.

The predictions from the model closely match findings from classic laboratory experiments in the 1940s, in which rats were trained to run along a passage to gain food rewards. The rats ran more slowly for small amounts of food if they were used to getting large amounts of food, compared to control rats that were always rewarded with the smaller amount.

This so-called ‘contrast effect’ has also been reported in bees, starlings and a variety of mammals including newborn children, but until now it lacked a convincing explanation.

Dr Tim Fawcett, a research fellow in Bristol’s School of Biological Sciences and a co-author on the study, said: “The effects in our model are driven by uncertainty. In changing environments, conditions experienced in the past can be a valuable indicator of how things will be in the future.”

This, in turn, affects how animals should respond to their current situation. “An animal that is used to rich conditions thinks that the world is generally a good place,” Dr Fawcett explained. “So when conditions suddenly turn bad, it interprets this as a temporary ‘blip’ and hunkers down, expecting that rich conditions will return soon. In contrast, an animal used to poor conditions expects those conditions to persist, and so cannot afford to rest.”

The model also predicts the reverse effect, in which animals work harder for food when conditions suddenly improve, compared to animals experiencing rich conditions all along. This too has been found in laboratory experiments on a range of animals.

The Bristol study highlights unpredictable environmental fluctuations as an important evolutionary force. “Rapid changes favour individuals that are responsive and able to adjust their behaviour in the light of past experience,” said Dr Fawcett. “The natural world is a dynamic and unpredictable place, but evolutionary models often neglect this. Our work suggests that models of more complex environments are important for understanding behaviour.”

Journal Reference:

  1. J. M. McNamara, T. W. Fawcett, A. I. Houston. An Adaptive Response to Uncertainty Generates Positive and Negative Contrast EffectsScience, 2013; 340 (6136): 1084 DOI: 10.1126/science.1230599

A mulher que encolheu o cérebro humano (O Globo)

Suzana Herculano é a primeira brasileira a falar na prestigiada conferência TED

Ela debaterá o cérebro de 86 bilhões de neurônios (e não 100 bilhões, como se acreditava) e como o homem se diferenciou dos primatas 

Publicado:24/05/13 – 7h00; Atualizado:24/05/13 – 11h41

Suzana Herculano-Houzel, professora do Instituto de Ciências Biomédicas da UFRJFoto: Guito Moreto

Suzana Herculano-Houzel, professora do Instituto de Ciências Biomédicas da UFRJ Guito Moreto

Neurocientista da UFRJ, Suzana Herculano-Houzel é a primeira brasileira a participar da TED (Tecnologia, Entretenimento e Design, em português) — prestigiada série de conferências que reúne grandes nomes das mais diversas áreas do conhecimento para debater novas ideias. Suzana falará no dia 12 de junho, sob o tema “Ouça a natureza”, e destacará suas descobertas únicas sobre o cérebro humano.

Sobre o que vai falar na TED?

Vou falar sobre o cérebro humano e mostrar como ele não é um cérebro especial, uma exceção à regra. Nossas pesquisas nos revelaram que se trata apenas de um cérebro de primata grande. O notável é que passamos a ter um cérebro enorme, do tamanho que nenhum outro primata tem, nem os maiores, porque inventamos o cozimento dos alimentos e, com isso, passamos a ter um número enorme de neurônios.

O cozimento foi fundamental para nos tornarmos humanos?

Sim, burlamos a limitação energética imposta pela dieta crua. E a implicação bacana e irônica é que, com isso, conseguimos liberar tempo no cérebro para nos dedicarmos a outras coisas (que não buscar alimentos), como criar a agricultura, as civilizações, a geladeira e a eletricidade. Até o ponto em que conseguir comida cozida e calorias em excesso ficou tão fácil que, agora, temos o problema inverso: estamos comendo demais. Por isso, voltamos à saladinha.

Se alimentarmos orangotangos e gorilas com comida cozida eles serão tão inteligentes quanto nós?

Sim, porque não seriam limitados pelo número reduzido de calorias que conseguem com a comida crua. Claro que nós fizemos uma inovação cultural ao inventar a cozinha. Tem uma diferença entre dar comida cozida para o animal e ele ter o desenvolvimento cultural do cozimento. Mas, ainda assim, se em todas as refeições eles tiverem acesso à comida cozida, daqui a 200 mil ou 300 mil anos eles terão o cérebro maior. Com a alimentação que têm hoje, não é possível terem um cérebro maior dado o corpo grande que têm. É uma coisa ou outra.

Somos especiais?

A gente não é especial coisa alguma. Somos apenas um primata que burlou as regras energéticas e conseguiu botar mais neurônios no cérebro de um jeito que nenhum outro animal conseguiu. Por isso estudamos os outros animais e não o contrário.

Persistem ainda mitos sobre o cérebro? Como o dos 100 bilhões de neurônios, que seus estudos demonstraram que são, na verdade, 86 bilhões?

Sim, eles continuam existindo, mesmo na neurociência. O nosso trabalho já é muito citado como referência. As coisas estão mudando. E o mais legal é que é por conta da ciência tupiniquim, o que eu acho maravilhoso. Mas vemos que é um processo, que ainda tem muita gente que insiste no número antigo.

O novo manual de diagnóstico de doenças mentais dos EUA (que serve de referência para todo o mundo, inclusive para a OMS) foi lançado na semana passada em meio à controvérsia. Especialistas acham que são tantos transtornos que praticamente não resta mais nenhum espaço para a normalidade. Qual a sua opinião?

Acho que essa discussão é muito necessária, justamente para reconhecermos o que são as variações ao redor do normal e quais são os extremos problemáticos e doentios de fato. Então, a discussão é importante, ótima a qualquer momento. Mas acho também que há muita informação errada e sensacionalista circulando, sobretudo sobre o déficit de atenção. As estatísticas variam muito de país para país, às vezes porque varia o número de médicos que reconhece a criança como portadora do distúrbio. E acho que ainda há um problema enorme, um medo enorme do estereótipo da doença mental. Até hoje ainda existe uma resistência louca em ir a um psiquiatra. E acho que, pelo contrário, ganhamos muito reconhecendo que existem transtornos e que eles podem ser tratados.

Ainda há muito estigma?

O maior problema hoje em dia é que é feio ter um distúrbio no cérebro. Perceba que nem estou falando em transtorno mental. Precisar de remédio para o cérebro é terrível. E temos tanto a ganhar reconhecendo os problemas, fazendo os diagnósticos. O cérebro é tão complexo, tem tanta coisa para dar errado, que o espantoso é que não dê problema em todo mundo sempre. Então, acho normal que boa parte da população tenha algum problema, não me espanta nem um pouco. E, uma vez que se reconhece o problema, que se faz o diagnóstico, há a opção de poder tratar. Se dispomos de um tratamento, por que não usar?

O presidente dos EUA, Barack Obama, recentemente anunciou uma inédita iniciativa de reunir pesquisadores dos mais diversos centros para estudar exclusivamente o cérebro. O que podemos esperar de tamanho esforço científico?

Não só o cérebro, mas o cérebro em atividade. Obama quer ir além do que já tinham feito — estudar a função de diferentes áreas — e entender como se conectam, como falam umas com as outras, ter ideia desse funcionamento integrado, dessa interação. Essa é uma das grandes lacunas do conhecimento: entender como as várias partes do cérebro funcionam ao mesmo tempo. Não sabemos como o cérebro funciona como um todo; é uma das fronteiras finais do conhecimento.

Não sabemos como o cérebro funciona?

Como um todo, não. Sabemos o que as partes fazem, mas não sabemos como se dá a conversa entre elas. Não sabemos a origem da consciência, da sensação do “eu estou aqui agora”. Que áreas são fundamentais para isso? É esse tipo de conhecimento que se está buscando, do cérebro funcionando ao vivo e em cores, em tempo real.

O objetivo não é estudar doenças, então?

Não, o grande objetivo é estudar consciência, memória; entender como o cérebro reúne emoção e lógica, coisas que são fruto da ação coordenada de várias partes. Claro que desse conhecimento todo podem surgir implicações para o Alzheimer e outras doenças. Mas, na verdade, falar em doenças é uma roupagem usada pela divulgação do programa para o público assimilar melhor. Existe esse preconceito de que a ciência só vale quando resolve uma doença.

Leia mais sobre esse assunto em http://oglobo.globo.com/ciencia/a-mulher-que-encolheu-cerebro-humano-8482825#ixzz2UFWUvdYn © 1996 – 2013. Todos direitos reservados a Infoglobo Comunicação e Participações S.A. Este material não pode ser publicado, transmitido por broadcast, reescrito ou redistribuído sem autorização.

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

Convívio entre homens e cães criou semelhanças genéticas (O Globo)

Amigos há 32 mil anos, a milenar relação entre as duas espécies tem estudo apresentado por zoólogos chineses 

ROBERTA JANSEN

Publicado:17/05/13 – 6h00; Atualizado:17/05/13 – 6h00

<br />Amizade milenar . Um homem e seu cachorro: novo estudo revela que relação já dura 32 mil anos e funciona tão bem porque evoluiu de forma compartilhada<br />Foto: John Hart / APAmizade milenar . Um homem e seu cachorro: novo estudo revela que relação já dura 32 mil anos e funciona tão bem porque evoluiu de forma compartilhada John Hart / AP

RIO- Cachorros podem, de fato, ser os melhores amigos do homem porque compartilham uma história evolutiva em comum muito mais longa do que se imaginava. Estudo publicado esta semana na “Nature Communications” revelou que os cães teriam sido domesticados há 32 mil anos — quase o dobro do que se acreditava. Esta duradoura e intensa relação teria, inclusive, um impacto na genética dos animais e dos homens, que foi ficando parecida em alguns aspectos. Na verdade, conclui o estudo, os cães se auto-domesticaram para serem mais aceitos pelos humanos que, por sua vez, também se adaptaram aos animais.

Um grupo de pesquisadores do Instituto de Zoologia da China, coordenados por Ya-Ping Zhang, obteve o genoma completo de quatro lobos cinzentos de diferentes pontos da Ásia e da Europa, três cachorros nativos do sudoeste da China, e três representantes de raças atuais. Geneticistas confirmaram que os cães nativos da China representam o primeiro estágio da domesticação canina — o genoma deles traz informação sobre a transição de lobos para os cachorros ancestrais, tornando-os uma espécie de “elo perdido” da domesticação.

Os lobos se auto-domesticaram

A equipe descobriu também que os lobos apresentam a maior diversidade genética, enquanto que os cachorros modernos ficam com a menor. Analisando a quantidade de mutações, os especialistas conseguiram estabelecer que a separação entre lobos e cães nativos chineses ocorreu na Ásia, há 32 mil anos.

Diferentemente do que se imaginava, dizem os cientistas, os homens não adotaram filhotes de lobos. Teria sido bem o oposto disso.

O processo provavelmente começou com os lobos que rondavam em torno de populações humanas de caçadores-coletores em busca de restos de alimento e carcaças, num processo que os pesquisadores chamam de auto-domesticação.

— A hipótese mais interessante levantada por essa pesquisa é a auto-domesticação — afirmou Zhang em entrevista. — De acordo com essa hipótese, os primeiros lobos teriam sido atraídos para viver e caçar com os humanos. E com sucessivas mudanças adaptativas, esses animais se tornaram progressivamente mais propensos a viver com os homens.

Nesta situação, os lobos mais agressivos teriam se saído muito mal, porque a tendência seria que fossem mortos pelos homens. Os animais mais mansos, no entanto, teriam se adaptado melhor e se multiplicado. Ou seja, os lobos se auto-domesticaram.

A pesquisa conseguiu estabelecer que a domesticação impôs uma determinante força seletiva nos genes envolvidos na digestão e no metabolismo — provavelmente por conta da mudança de uma dieta estritamente carnívora para uma onívora.

Os genes que governam processos neurológicos complexos também sofreram tal pressão, sobretudo devido à necessidade de redução da agressão e do aumento de complexos processos de interação com os seres humanos.

Curiosamente, o grupo descobriu que a contraparte humana de diversos desses genes, particularmente aqueles envolvidos nos processos neurológicos, também sofreram uma forte pressão seletiva ao longo do tempo, refletindo os fatores ambientais similares vivenciados por homens e cachorros ao longo de milhares de anos de uma relação tão próxima.

Mais dóceis e mansos

Alguns dos genes estão associados a doenças similares no homem e no cão. Outros são ativos na região do córtex pré-frontal, onde os mamíferos tomam decisões sobre o comportamento. Alguns genes estão envolvidos no maior número de conexões entre os neurônios. Um gene em particular, o SLC6A4, é responsável pela codificação da proteína que transporta o neurotransmissor serotonina.

— Outros estudos já haviam revelado que o gene é relacionado ao comportamento agressivo e ao transtorno obsessivo-compulsivo não apenas em homens mas também em cachorros — afirmou Zhang.

Mudança semelhante foi também constatada nos homens — indicando que nós também tivemos que nos tornar menos agressivos para tolerar os outros e viver bem em grupos.

Para o cientista, o estudo da base genética de diversas doenças em cães pode ajudar na compreensão de doenças similares em humanos.

Leia mais sobre esse assunto em http://oglobo.globo.com/ciencia/convivio-entre-homens-caes-criou-semelhancas-geneticas-8415160#ixzz2TluyW7T9 © 1996 – 2013. Todos direitos reservados a Infoglobo Comunicação e Participações S.A. Este material não pode ser publicado, transmitido por broadcast, reescrito ou redistribuído sem autorização.

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

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

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

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

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

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

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

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

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

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

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

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

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

Journal Reference:

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

Playing for All Kinds of Possibilities (N.Y.Times)

Buckets of Blickets: Children and Logic: A game developed by researchers at the University of California, Berkeley hopes to show how imaginative play in children may influence development of abstract thought.

By DAVID DOBBS

Published: April 22, 2013

When it comes to play, humans don’t play around.

Alison Gopnik and the Gopnik Lab/University of California, Berkeley. Esther and Benny, both 4, play Blickets with Sophie Bridgers in a lab at the University of California, Berkeley. Children, lacking prior biases, excel in the game, based on associations, but adults flunk it.

Other species play, but none play for as much of their lives as humans do, or as imaginatively, or with as much protection from the family circle. Human children are unique in using play to explore hypothetical situations rather than to rehearse actual challenges they’ll face later. Kittens may pretend to be cats fighting, but they will not pretend to be children; children, by contrast, will readily pretend to be cats or kittens — and then to be Hannah Montana, followed by Spider-Man saving the day.

And in doing so, they develop some of humanity’s most consequential faculties. They learn the art, pleasure and power of hypothesis — of imagining new possibilities. And serious students of play believe that this helps make the species great.

The idea that play contributes to human success goes back at least a century. But in the last 25 years or so, researchers like Elizabeth S. SpelkeBrian Sutton-SmithJaak Panksepp and Alison Gopnik have developed this notion more richly and tied it more closely to both neuroscience and human evolution. They see play as essential not just to individual development, but to humanity’s unusual ability to inhabit, exploit and change the environment.

Dr. Gopnik, author of “The Scientist in the Crib” and “The Philosophical Baby,” and a professor of psychology at the University of California, Berkeley, has been studying the ways that children learn to assess their environment through play. Lately she has focused on the distinction between “exploring” new environments and “exploiting” them. When we’re quite young, we are more willing to explore, she finds; adults are more inclined to exploit.

To exploit, one leans heavily on lessons (and often unconscious rules) learned earlier — so-called prior biases. These biases are useful to adults because they save time and reduce error: By going to the restaurant you know is good, instead of the new place across town, you increase the chance that you’ll enjoy the evening.

Most adults are slow to set such biases aside; young children fling them away like bad fruit.

Dr. Gopnik shows this brilliantly with a game she invented with the psychologist David Sobel (her student, now a professor at Brown). In the game, which has the fetching name Blickets, players try to figure out what it is that makes an otherwise undistinguished clay figure a blicket. In some scenarios you can win even if you’re applying a prior bias. In others you can’t.

Last summer I joined Dr. Gopnik behind a wall of one-way glass to watch her lab manager, Sophie Bridgers, play the game with an extremely alert 4-year-old, Esther.

Seated at a child-size table, Esther leaned forward on her elbows to watch as Ms. Bridgers brought out a small bin of clay shapes and told her that some of them were blickets but most were not.

“You cannot tell which ones are blickets by looking at them. But the ones that are blickets have blicketness inside. And luckily,” Ms. Bridgers went on, holding up a box with a red plastic top, “I have my machine. Blicketness makes my machine turn on and play music.”

It’s a ruse, of course. The box responds not to the clay shapes but to a switch under the table controlled by Ms. Bridgers.

Now came the challenge. The game can be played by either of two rules, called “and” and “or.” The “or” version is easier: When a blicket is placed atop the machine, it will light the machine up whether placed there by itself or with other pieces. It is either a blicket or it isn’t; it doesn’t depend on the presence of any other object.

In the “and” trial, however, a blicket reveals its blicketness only if both it and another blicket are placed on the machine; and it will light up the box even if it and the other blicket are accompanied by a non-blicket. It can be harder than it sounds, and this is the game that Esther played.

First, Ms. Bridgers put each of three clay shapes on the box individually — rectangle, then triangle, then a bridge. None activated the machine. Then she put them on the box in three successive combinations.

1. Rectangle and triangle: No response.

2. Rectangle and bridge: Machine lighted up and played a tune!

3. Triangle and bridge: No response.

Ms. Bridgers then picked up each piece in turn and asked Esther whether it was a blicket. I had been indulging my adult (and journalistic) prior bias for recorded observation by filling several pages with notes and diagrams, and I started flipping frantically through my notebook.

I was still looking when Esther, having given maybe three seconds’ thought to the matter, correctly identified all three. The rectangle? “A blicket,” she said. Triangle? A shake of the head: No. Bridge? “A blicket.” A 4-year-old had instantly discerned a rule that I recognized only after Dr. Gopnik explained it to me.

Esther, along with most other 4- and 5-year-olds tested, bested not just me but most of 88 California undergraduates who took the “and” test. We educated grown-ups failed because our prior biases dictated that we play the game by the more common and efficient “or” rule.

“Or” rules apply far more often in actual life, when a thing’s essence seldom depends on another object’s presence. An arrow’s utility may depend on a bow, but its identity as an arrow does not. Since the “or” rule is more likely correct and simpler to use, I grabbed it and clung.

Esther, however, quickly ditched the “or” rule and hit upon the far less likely “and” rule. Such low-probability hypotheses often fail. But children, like adventurous scientists in a lab, will try these wild ideas anyway, because even if they fail, they often produce interesting results.

Esther and her twin brother, Benny (who played another version of the game), generated low-probability hypotheses as fast as I could breathe. “Maybe if you turn it over and put it on the other end!” “Let’s put all three on!” They were hypothesis machines. Their mother, Wendy Wolfson (who is a science writer), told me they’re like this all the time. “It’s like living with a pair of especially inquisitive otters.”

Alas, Dr. Gopnik said, this trait peaks around 4 or 5. After that, we gradually take less interest in seeing what happens and more in getting it right.

Yet this playlike spirit of speculation and exploration does stay with us, both as individuals and as a species. Studies suggest that free, self-directed play in safe environments enhances resilience, creativity, flexibility, social understanding, emotional and cognitive control, and resistance to stress, depression and anxiety. And we continue to explore as adults, even if not so freely. That’s how we got to the Internet, the moon, and Dr. Gopnik’s lab.

Finally, in the long game of evolution, Dr. Gopnik and some of her fellow scientists hypothesize that humans’ extended period of imaginative play, along with the traits it develops, has helped select for the big brain and rich neural networks that characterize Homo sapiens. This may strike you either as a low-probability or a high-probability hypothesis. But it certainly seems worth playing with.

A ontogênese e o aprender (O Estado de São Paulo)

[A despeiro das boas intenções do autor, esse artigo é um retrocesso. Se acumulam evidências e contribuições da antropologia – ver Clifford Geertz, Tim Ingold, Bruno Latour, pra citar apenas alguns – em sentido oposto: desenvolvimento biológico e cultural estão relacionados diretamente; na genética, todo o campo da epigenética se desenvolve também na direção oposta. O discurso do artigo se funda mais em argumentos burocráticos, de organização do conhecimento e da atividade estatal de educação, do que numa discussão verdadeiramente ontológica. RT] 

JC e-mail 4703, de 11 de Abril de 2013.

Artigo de Fernando Reinach publicado no jornal O Estado de São Paulo

O uso da palavra aprender não acompanhou o progresso científico. O resultado é que ainda usamos a mesma palavra para descrever dois fenômenos distintos. Considere a seguinte frase: “Meu filho aprendeu a andar com 1 ano e aprendeu a escrever com 6”. Esses dois processos, descritos como “aprender”, são fenômenos muito diferentes. Não reconhecer essa diferença atrapalha nossa concepção de educação.

Todas as pessoas, de qualquer origem, nascidas em qualquer sociedade nos últimos milhares de séculos, começaram a andar na infância. Por outro lado, somente uma pequena fração das pessoas sabe escrever – e essa capacidade apareceu entre os humanos faz alguns milhares de anos. A razão é simples e conhecida dos biólogos há muito tempo. Andar faz parte de nossa ontogênese; escrever faz parte de nossa herança cultural.

Ontogênese é o nome dado ao processo de formação de um ser vivo. Descreve a transformação de uma semente em árvore ou o surgimento de uma pessoa a partir de um óvulo fecundado. Inicialmente, o conceito de ontogênese era usado para descrever as mudanças de forma durante o desenvolvimento de um ser vivo. Descrevia a formação da espinha vertebral, do coração, o aparecimento dos dedos, o crescimento do cabelo, e todas as mudanças que ocorrem antes do nascimento. Mas o processo de ontogênese continua após o nascimento. O corpo cresce, atingimos a maturidade sexual, paramos de crescer e finalmente começamos a envelhecer. São as etapas inevitáveis de nossa ontogênese.

A ontogênese se caracteriza por uma sequência de eventos que ocorrem de maneira precisa e semelhante em todos os seres vivos de uma espécie. Ela é determinada por nossos genes e modulada pelo meio ambiente. Todas as crianças crescem, mas, se bem alimentadas, crescem mais rápido.

Não é usual utilizarmos a palavra aprender para descrever processos que fazem parte da ontogênese. É por isso que afirmar que “minha filha aprendeu a menstruar aos 13 anos” soa estranho. Ao longo de todo o século XX houve uma melhor compreensão dos processos que fazem parte de nossa ontogênese e se descobriu que um número crescente de etapas pelas quais passamos durante a vida é parte de nossa ontogênese.

É o caso do andar e do falar, cujos aparecimentos estão codificados em nossos genes da mesma maneira que a capacidade de crescer pelos pubianos. É muito difícil, e é necessário um ambiente muito hostil, para evitar que uma criança desenvolva o andar e a capacidade de falar. No caso da fala, sabemos que a língua que a pessoa vai utilizar depende unicamente do ambiente ao qual ela está exposta, mas o surgimento, nos primeiros anos, da capacidade de falar alguma língua faz parte de nossa ontogênese.

Aos poucos, os cientistas descobriram que um número crescente de características que desenvolvemos em alguma fase de nossa vida faz parte de nossa ontogenia. Hoje sabemos que nascemos com a capacidade de fazer adições e subtrações de pequenos números (até três ou quatro). Sabemos que parte de nossa capacidade de julgamento moral, de convivência social, de comunicação por meio de expressões faciais e inúmeras outras características comportamentais também fazem parte de nosso processo ontogenético.

Nossa ontogênese surgiu à medida que nossa espécie e a de nossos ancestrais foi moldada pelo processo de seleção natural. Cada etapa e cada característica de nossa ontogênese foram incorporadas ao longo de milhões de anos e agora fazem parte das características de nossa espécie. O surgimento de um dedo durante nossa vida no útero e de nossa capacidade de somar números pequenos ao nascer é o resultado de um único e longo processo de seleção natural. É por isso que essas capacidades surgem aparentemente de forma espontânea durante as diferentes fases de nossa vida. Como são programadas para ocorrer, seu aparecimento é difícil de ser evitado e, caso seu aparecimento seja inibidos violentamente, as consequências podem ser nefastas para o indivíduo.

A distinção entre esses dois fenômenos seria mais fácil se a palavra aprender fosse restrita à aquisição de novas características e habilidades que não fazem parte de nosso processo ontogenético. Fazer operações matemáticas com números grandes, escrever, andar de bicicleta, calcular a órbita de um satélite e programar um computador são capacidades que podemos adquirir porque nosso corpo e cérebro têm a flexibilidade para incorporar novos comportamentos e conhecimentos, mas não foram moldadas pela seleção natural nem incorporadas à nossa ontogênese.

Essas habilidades foram descobertas muito recentemente pelo homem e derivam da evolução cultural. Esses aprendizados podem ser incluídos no repertório de cada um de nós de maneira opcional, num processo que chamamos de educação. E, como todos sabemos, sua incorporação depende de um grande esforço e dedicação de quem ensina e de quem aprende, leva um longo tempo e consome muita energia dos indivíduos e da sociedade.

Reconhecer as mudanças que fazem parte de nossa ontogênese e separar e cultivar de maneira distinta as mudanças ontogenéticas das induzidas pelo processo educacional podem gerar seres humanos mais felizes. Mas para isso não podemos confundir os dois fenômenos que hoje chamamos de “aprender”.

Fernando Reinach é biólogo.

Environmental Change Triggers Rapid Evolution (Science Daily)

Apr. 8, 2013 — Environmental change can drive hard-wired evolutionary changes in animal species in a matter of generations. A University of Leeds-led study, published in the journal Ecology Letters, overturns the common assumption that evolution only occurs gradually over hundreds or thousands of years.

Female soil mite. (Credit: Umeå universitet.)

Instead, researchers found significant genetically transmitted changes in laboratory populations of soil mites in just 15 generations, leading to a doubling of the age at which the mites reached adulthood and large changes in population size. The results have important implications in areas such as disease and pest control, conservation and fisheries management because they demonstrate that evolution can be a game-changer even in the short-term.

Professor Tim Benton, of the University of Leeds’ Faculty of Biological Sciences, said: “This demonstrates that short-term ecological change and evolution are completely intertwined and cannot reasonably be considered separate. We found that populations evolve rapidly in response to environmental change and population management. This can have major consequences such as reducing harvesting yields or saving a population heading for extinction.”

Although previous research has implied a link between short-term changes in animal species’ physical characteristics and evolution, the Leeds-led study is the first to prove a causal relationship between rapid genetic evolution and animal population dynamics in a controlled experimental setting.

The researchers worked with soil mites that were collected from the wild and then raised in 18 glass tubes. Forty percent of adult mites were removed every week from six of the glass tubes. A similar proportion of juveniles were removed each week in a further six tubes, while no “harvesting” was conducted in the remaining third of the tubes.

Lead author Dr Tom Cameron, a postdoctoral Fellow in the Faculty of Biological Sciences at Leeds at the time of the research and now based in Umeå University, Sweden, said: “We saw significant evolutionary changes relatively quickly. The age of maturity of the mites in the tubes doubled over about 15 generations, because they were competing in a different way than they would in the wild. Removing the adults caused them to remain as juveniles even longer because the genetics were responding to the high chance that they were going to die as soon as they matured. When they did eventually mature, they were so enormous they could lay all of their eggs very quickly.”

The initial change in the mites’ environment — from the wild into the laboratory — had a disastrous effect on the population, putting the mites on an extinction trajectory. However, in every population, including those subjected to the removal of adults or juveniles, the trajectory switched after only five generations of evolution and the population sizes began to increase.

The researchers found that the laboratory environment was selecting for those mites that grew more slowly. Under the competitive conditions in the tubes, the slow growing mites were more fertile when they matured, meaning they could have more babies.

Dr Cameron said: “The genetic evolution that resulted in an investment in egg production at the expense of individual growth rates led to population growth, rescuing the populations from extinction. This is evolutionary rescue in action and suggests that rapid evolution can help populations respond to rapid environmental change.”

Short-term ecological responses to the environment — for instance, a reduction in the size of adults because of a lack of food — and hard-wired evolutionary changes were separated by placing mites from different treatments into a similar environment for several generations and seeing whether differences persisted.

Professor Benton said: “The traditional idea would be that if you put animals in a new environment they stay basically the same but the way they grow changes because of variables like the amount of food. However, our study proves that the evolutionary effect — the change in the underlying biology in response to the environment — can happen at the same time as the ecological response. Ecology and evolution are intertwined,” he said.

Unpicking evolutionary change from ecological responses is particularly important in areas such as the management of fisheries, where human decisions can result in major changes to an entire population’s environment and life histories. The size at which cod in the North Sea mature is about half that of 50 years ago and this change has been linked to a collapse in the cod population because adult fish today are less fertile than their ancestors.

“The big debate has been over whether this is an evolutionary response to the way they are fished or whether this is, for instance, just the amount of food in the sea having a short-term ecological effect. Our study underlined that evolution can happen on a short timescale and even small 1 to 2 per cent evolutionary changes in the underlying biology caused by your harvesting strategy can have major consequences on population growth and yields. You can’t just try to bring the environment back to what it was before and expect everything to return to normal,” Professor Benton said.

The research was funded by the Natural Environment Research Council (NERC) and involved researchers from the University of Leeds and Professor Stuart Piertney of the University of Aberdeen’s School of Biological Sciences.

Journal Reference:

  1. Tom C. Cameron, Daniel O’Sullivan, Alan Reynolds, Stuart B. Piertney, Tim G. Benton. Eco-evolutionary dynamics in response to selection on life-historyEcology Letters, 2013; DOI: 10.1111/ele.12107

The Ethics of Resurrecting Extinct Species (Science Daily)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Journal Reference:

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

Controversial Worm Keeps Its Position as Progenitor of Humankind (Science Daily)

Xenoturbella bocki worm. (Credit: Hiroaki Nakano)

Mar. 27, 2013 — Researchers are arguing about whether or not the Xenoturbella bocki worm is the progenitor of humankind. But new studies indicate that this is actually the case.

Swedish researchers from the University of Gothenburg and the Gothenburg Natural History Museum are involved in the international study. The results have been published in Nature Communications.

The Xenoturbella bocki worm is a one-centimetre long worm with a simple body plan that is only found regularly by the west coast of Sweden. The worm lacks a brain, sexual organs and other vital organs.

Zoologists have long disagreed about whether or not the Xenoturbella bocki worm holds a key position in the animal tree of life. If it does have a key position, it is very important for the understanding of the evolutionary development of organs and cell functions, such as stem cells, for example. The question is therefore not only important in the field of biology, but also for potential biomedical applications.

“It’s absolutely fantastic that one of the key evolutionary organisms in the animal kingdom lives right on the doorstep of the University of Gothenburg’s Centre for Marine Research. And this is actually the only place in the whole world where you can do research on the creature,” says Matthias Obst from the Department of Biological and Environmental Sciences at the University of Gothenburg.

Genetic studies indicate that theXenoturbella bocki worm belongs to the group of deuterostomes, the exclusive group to which human’s belongs.

“So maybe we’re more closely related to the Xenoturbella bocki worm, which doesn’t have a brain, than we are to lobsters and flies, for example,” says Matthias Obst.

Even though the worm does not particularly resemble man, development biologists have referred to the fact that the early embryonic development of the worm may display similarities with the group to which man belongs. But the problem has been that no one has previously been able to see the development of the creature.

But now a group of researchers at the Sven Lovén Centre for Marine Sciences and the Gothenburg Natural History Museum have succeeded in doing what no one else has done before: to isolate newly born little Xenoturbella bocki worms.

“And these new-born worms revealed absolutely no remnants at all of advanced features! Instead, they exhibit similarities with quite simple, ancient animals such as corals and sponges,” says Matthias Obst.

The studies also reveal the value of the University of Gothenburg’s marine stations for important basic research.

“The Lovén Centre at the University of Gothenburg is the only place in the whole world where you can study this paradoxical animal (in Swedish called ‘Paradox worm’). That’s one reason why researchers come from all over the world to Gullmarsfjorden to solve one of the great mysteries in the evolution of animal life,” says Matthias Obst.

Journal Reference:

  1. Hiroaki Nakano, Kennet Lundin, Sarah J. Bourlat, Maximilian J. Telford, Peter Funch, Jens R. Nyengaard, Matthias Obst, Michael C. Thorndyke. Xenoturbella bocki exhibits direct development with similarities to AcoelomorphaNature Communications, 2013; 4: 1537 DOI: 10.1038/ncomms2556

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

THE STONEFebruary 24, 2013, 7:30 pm

By EDWARD O. WILSON

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

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

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

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

Leif Parsons

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

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

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

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

Leif Parsons

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

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

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

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


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

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

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

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

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

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

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

*   *   *

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

February 26, 2013 – 01:23 PM

By Philip Bethge and Johann Grolle

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

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

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

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

‘Blessed with Brilliant Enemies’

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

SPIEGEL: Would our ancestors not have caught their eye?

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

SPIEGEL: What do you mean?

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

SPIEGEL: … similar to birds.

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

SPIEGEL: And our ancestors followed the same path?

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

SPIEGEL: What difference would that make?

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

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

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

SPIEGEL: Meaning that this is the origin of warfare?

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

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

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

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

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

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

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

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

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

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

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

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

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

SPIEGEL: So how do we negotiate this conflict?

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

SPIEGEL: Which element of this human condition is stronger?

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

SPIEGEL: … the ultimate form of communism?

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

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

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

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

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

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

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

SPIEGEL: … or American football.

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

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

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

SPIEGEL: How?

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

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

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

SPIEGEL: That might well be a futile endeavour …

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

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

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

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

Interview conducted by Philip Bethge and Johann Grolle

Fluctuating Environment May Have Driven Human Evolution (Science Daily)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The National Science Foundation funded this research.

*   *   *

How climate shifts in Africa sparked human evolution (MSNBC)

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

Image: Nutcracker Man

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

By Charles Choi – LiveScience Contributor

updated 12/26/2012 2:16:27 PM ET

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

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

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

The Great Drying? 

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

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

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

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

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

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

Losing water 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Human intelligence ‘peaked thousands of years ago and we’ve been on an intellectual and emotional decline ever since’ (The Independent)

STEVE CONNOR, MONDAY 12 NOVEMBER 2012

Richard Gardner/Rex Features

Is the human species doomed to intellectual decline? Will our intelligence ebb away in centuries to come leaving our descendants incapable of using the technology their ancestors invented? In short: will Homo be left without his sapiens?

This is the controversial hypothesis of a leading geneticist who believes that the immense capacity of the human brain to learn new tricks is under attack from an array of genetic mutations that have accumulated since people started living in cities a few thousand years ago.

Professor Gerald Crabtree, who heads a genetics laboratory at Stanford University in California, has put forward the iconoclastic idea that rather than getting cleverer, human intelligence peaked several thousand years ago and from then on there has been a slow decline in our intellectual and emotional abilities.

Although we are now surrounded by the technological and medical benefits of a scientific revolution, these have masked an underlying decline in brain power which is set to continue into the future leading to the ultimate dumbing-down of the human species, Professor Crabtree said.

His argument is based on the fact that for more than 99 per cent of human evolutionary history, we have lived as hunter-gatherer communities surviving on our wits, leading to big-brained humans. Since the invention of agriculture and cities, however, natural selection on our intellect has effective stopped and mutations have accumulated in the critical “intelligence” genes.

“I would wager that if an average citizen from Athens of 1000BC were to appear suddenly among us, he or she would be among the brightest and most intellectually alive of our colleagues and companions, with a good memory, a broad range of ideas and a clear-sighted view of important issues,” Professor Crabtree says in a provocative paper published in the journal Trends in Genetics.

“Furthermore, I would guess that he or she would be among the most emotionally stable of our friends and colleagues. I would also make this wager for the ancient inhabitants of Africa, Asia, India or the Americas, of perhaps 2,000 to 6,000 years ago,” Professor Crabtree says.

“The basis for my wager comes from new developments in genetics, anthropology, and neurobiology that make a clear prediction that our intellectual and emotional abilities are genetically surprisingly fragile,” he says.

A comparison of the genomes of parents and children has revealed that on average there are between 25 and 65 new mutations occurring in the DNA of each generation. Professor Crabtree says that this analysis predicts about 5,000 new mutations in the past 120 generations, which covers a span of about 3,000 years.

Some of these mutations, he suggests, will occur within the 2,000 to 5,000 genes that are involved in human intellectual ability, for instance by building and mapping the billions of nerve cells of the brain or producing the dozens of chemical neurotransmitters that control the junctions between these brain cells.

Life as a hunter-gatherer was probably more intellectually demanding than widely supposed, he says. “A hunter-gatherer who did not correctly conceive a solution to providing food or shelter probably died, along with his or her progeny, whereas a modern Wall Street executive that made a similar conceptual mistake would receive a substantial bonus and be a more attractive mate,” Professor Crabtree says.

However, other scientists remain sceptical. “At first sight this is a classic case of Arts Faculty science. Never mind the hypothesis, give me the data, and there aren’t any,” said Professor Steve Jones, a geneticist at University College London.

“I could just as well argue that mutations have reduced our aggression, our depression and our penis length but no journal would publish that. Why do they publish this?” Professor Jones said.

“I am an advocate of Gradgrind science – facts, facts and more facts; but we need ideas too, and this is an ideas paper although I have no idea how the idea could be tested,” he said.

THE DESCENT OF MAN

Hunter-gatherer man

The human brain and its immense capacity for knowledge evolved during this long period of prehistory when we battled against the elements

Athenian man

The invention of agriculture less than 10,000 years ago and the subsequent rise of cities such as Athens relaxed the intensive natural selection of our “intelligence genes”.

Couch-potato man

As genetic mutations increase over future generations, are we doomed to watching  soap-opera repeats without knowing how to use the TV remote control?

iPad man

The fruits of science and technology enabled humans to rise above the constraints of nature and cushioned our fragile intellect from genetic mutations.

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.

When did humans get smart? Maybe a lot earlier than some thought (The Christian Science Monitor)

A find in South Africa suggests that humans had mastered the skill of producing small stone blades – and could pass on the know-how – as early as 71,000 years ago.

By Pete Spotts, Staff writer / November 7, 2012

Small stone blades found in a cave along a rugged stretch of South Africa‘s coast have pushed back by thousands of years evidence for persistent, advanced stone-toolmaking skills in early modern humans, according to a new study.

The results suggest that by 71,000 years ago, these people had long since developed the mental horsepower to tackle production problems and pass their manufacturing techniques to subsequent generations – a lot earlier than some researchers had thought.

Indeed, to some scientists the find supports the idea that mental abilities associated with modern humans emerged when anatomically modern humans did, about 200,000 years ago, rather than resulting from a genetic mutation cropping up between 40,000 and 50,000 years ago, as others have posited.

The evidence comes in the form of a large number of stone blades that average about one inch long. The blades were excavated from successive layers in soil deposits some 46 feet thick in a cave at Pinnacle Point, on the coast some 210 miles east of Cape Town. The deposits span some 18,000 years.

The oldest bladlets were found in a layer dated to 71,000 years ago and continued to appear in layers representing the ensuing 11,000 years. The same technique was used to prepare the parent stones throughout the period, but the designs evolved over time according to the international team reporting the results in Thursday’s edition of the journal Nature.

Pinnacle Point boasts “a very impressive record” of advanced cognitive abilities in early modern humans at the time period the site covers, says Rick Potts, director of the human origins program at the Smithsonian Institution‘s Museum of Natural History in Washington.

Fleeting snapshots of such creativity appear in east Africa dating back far earlier, he explains. That creativity appears in the manufacture and use of pigments for symbolic and decorative purposes, groups separated by long distances exchanging raw materials, as well as shifts from hand axes to stone-tipped projectiles for hunting.

“You get things that fly through the air. The world has never been the same,” he quips.

From disparate sites spanning different, far earlier periods than Pinnacle Point, the evidence suggests that “cognitive capacities and the social capacities had already evolved earlier on,” he says. But invention can fizzle if populations are dispersed, making it hard for the innovation to spread, or the inventor gets eaten by some animal along the way as he heads home with his new invention.

The finds at Pinnacle Point, he suggests, highlight the role a persistent regional population with readily available shelter can play in perpetuating and improving a technology.

Pinnacle Point’s blades required following some critical steps, according to the international team led by the University of Cape Town‘s Kyle Brown and Curtis Marean with Arizona State University‘s Institute of Human Origins.

People would have had to hunt for the right kind of rock, called silcrete. They would have to gather fuel for heat-treating the rock, a process that by then had been used for 91,000 years at the site. Then comes the preparation of cores from the rock, which would be shaped into blades, chipping to make the blades themselves, then reshaping them yet again. Then comes making the wood or bone handles or shafts that would become tools or weapons. Finally, the small blades would have to be affixed to the handles or shafts.

Maintaining know-how like this over an 11,000-year span, along with the skills needed to execute the various steps, would require accurate instructions to be handed down from generation to generation and over a fairly wide region, the team says.

These days, the ability to organize and perpetuate these skills over long periods and across a region would be dubbed “executive function,” notes Sally McBrearty, a paleoanthropologist at the University of Connecticut in Storrs.

Executive function “is an essential component of the modern mind,” she writes in an assessment for Nature that accompanied the new results from Pinnacle Point.

The tiny stone blades like those at Pinnacle Point could have affected the success modern humans had as they migrated out of Africa beginning a bit earlier than the oldest dates for the Pinnacle Point blades, she writes. The research team notes that the stone mini-blades could have been used as tips for arrows or spear-thrower darts – either of which have far greater range than a hand-thrown spear. That would allow hunters, or warriors, to operate at a safer distance from their targets.

If the migrants “were armed with the bow and arrow, they would have been more than a match for anything or anyone they met,” Dr. McBrearty notes.

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.”

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

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

by Morgan Kelly, Office of Communications

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

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

Andolfatto bug

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

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

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

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

Andolfatto lab

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

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

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

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

Andolfatto bug

Milkweed tussock moth (Photo courtesy of Peter Andolfatto)

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

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

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

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

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

Andolfatto bug

Large milkweed bugs (Photo courtesy of Peter Andolfatto)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Alternative model challenges a basic assumption of evolution

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

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

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

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

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

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

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

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

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

Evolution could explain the placebo effect (New Scientist)

06 September 2012 by Colin Barras

Magazine issue 2881

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

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

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

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

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

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

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

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

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

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

New DNA Analysis Shows Ancient Humans Interbred with Denisovans (Scientific American)

A new high-coverage DNA sequencing method reconstructs the full genome of Denisovans–relatives to both Neandertals and humans–from genetic fragments in a single finger bone

By Katherine Harmon  | Thursday, August 30, 2012

denisovan genome finger boneFRAGMENT OF A FINGER: This replica of the Denisovan finger bone shows just how small of a sample the researchers had to extract DNA from.Image: Image courtesy of Max Planck Institute for Evolutionary Anthropology

Tens of thousands of years ago modern humans crossed paths with the group of hominins known as the Neandertals. Researchers now think they also met another, less-known group called the Denisovans. The only trace that we have found, however, is a single finger bone and two teeth, but those fragments have been enough to cradle wisps of Denisovan DNA across thousands of years inside a Siberian cave. Now a team of scientists has been able to reconstruct their entire genome from these meager fragments. The analysis adds new twists to prevailing notions about archaic human history.

“Denisova is a big surprise,” says John Hawks, a biological anthropologist at the University of Wisconsin–Madison who was not involved in the new research. On its own, a simple finger bone in a cave would have been assumed to belong to a human, Neandertal or other hominin. But when researchers first sequenced a small section of DNA in 2010—a section that covered about 1.9 percent of the genome—they were able to tell that the specimen was neither. “It was the first time a new group of distinct humans was discovered” via genetic analysis rather than by anatomical description, said Svante Pääbo, a researcher at the Max Planck Institute (M.P.I.) for Evolutionary Anthropology in Germany, in a conference call with reporters.

Now Pääbo and his colleagues have devised a new method of genetic analysis that allowed them to reconstruct the entire Denisovan genome with nearly all of the genome sequenced approximately 30 times over akin to what we can do for modern humans. Within this genome, researchers have found clues into not only this group of mysterious hominins, but also our own evolutionary past. Denisovans appear to have been more closely related to Neandertals than to humans, but the evidence also suggests that Denisovans and humans interbred. The new analysis also suggests new ways that early humans may have spread across the globe. The findings were published online August 30 in Science.

Who were the Denisovans?
Unfortunately, the Denisovan genome doesn’t provide many more clues about what this hominin looked like than a pinky bone does. The researchers will only conclude that Denisovans likely had dark skin. They also note that there are alleles “consistent” with those known to call for brown hair and brown eyes. Other than that, they cannot say.

Yet the new genetic analysis does support the hypothesis that Neandertals and Denisovans were more closely related to one another than either was to modern humans. The analysis suggests that the modern human line diverged from what would become the Denisovan line as long as 700,000 years ago—but possibly as recently as 170,000 years ago.

Denisovans also interbred with ancient modern humans, according to Pääbo and his team. Even though the sole fossil specimen was found in the mountains of Siberia, contemporary humans from Melanesia (a region in the South Pacific) seem to be the most likely to harbor Denisovan DNA. The researchers estimate that some 6 percent of contemporary Papuans’ genomes come from Denisovans. Australian aborigines and those from Southeast Asian islands also have traces of Denisovan DNA. This suggests that the two groups might have crossed paths in central Asia and then the modern humans continued on to colonize the islands of Oceania.

Yet contemporary residents of mainland Asia do not seem to posses Denisovian traces in their DNA, a “very curious” fact, Hawks says. “We’re looking at a very interesting population scenario”—one that does not jibe entirely with what we thought we knew about how waves modern human populations migrated into and through Asia and out to Oceania’s islands. This new genetic evidence might indicate that perhaps an early wave of humans moved through Asia, mixed with Denisovans and then relocated to the islands—to be replaced in Asia by later waves of human migrants from Africa. “It’s not totally obvious that that works really well with what we know about the diversity of Asians and Australians,” Hawks says. But further genetic analysis and study should help to clarify these early migrations.

Just as with modern Homo sapiens, the genome of a single individual cannot tell us exactly what genes and traits are specific to all Denisovans. Yet, just one genome can reveal the genetic diversity of an entire population. Each of our genomes contains information about generations far beyond those of our parents and grandparents, said David Reich, a researcher at the Massachusetts Institute of Technology–Harvard University Broad Institute and a co-author on the paper. Scientists can compare and contrast the set of genes on each chromosome—passed down from each parent—and extrapolate this process back through the generations. “You contain a multitude of ancestors within you,” Reich said, borrowing from Walt Whitman.

The new research reveals that the Denisovans had low genetic diversity—just 26 to 33 percent of the genetic diversity of contemporary European or Asian populations. And for the Denisovans, the population on the whole seems to have been very small for hundreds of thousands of years, with relatively little genetic diversity throughout their history.

Curiously, the researchers noted in their paper, the Denisovan population shows “a drastic decline in size at the time when the modern human population began to expand.”

Why were modern humans so successful whereas Denisovans (and Neandertals) went extinct? Pääbo and his co-authors could not resist looking into the genetic factors that might be at work. Some of the key differences, they note, center around brain development and synaptic connectivity. “It makes sense that what pops up is connectivity in the brain,” Pääbo noted. Neandertals had a similar brain size–to-body ratio as we do, so rather than cranial capacity, it might have been underlying neurological differences that could explain why we flourished while they died out, he said.

Hawks counters that it might be a little early to begin drawing conclusions about human brain evolution from genetic comparisons with archaic relatives. Decoding the genetic map of the brain and cognition from a genome is still a long way off, he notes—unraveling skin color is still difficult enough given our current technologies and knowledge.

New sequencing for old DNA
The Denisovan results rely on a new method of genetic analysis developed by paper co-author Matthias Meyer, also of M.P.I. The procedure allows the researchers to sequence the full genome by using single strands of genetic material rather than the typical double strands required. The technique, which they are calling a single-stranded library preparation, involves stripping the genetic material down to individual strands to copy and avoids a purification step, which can lose precious genetic material.

The finger bone—just one disklike phalanx—is so small that it does not contain enough usable carbon for dating, the researchers note. But by counting the number of genetic mutations in a genome and comparing them with other living relatives, such as modern humans and chimpanzees, given assumed rates of mutations since breaking with a last common ancestor, “for the first time you can try to estimate this number into a date and provide molecular dating of the fossil,” Meyer said. With the new resolution, the researchers estimate the age of the bone to 74,000 to 82,000 years ago. But that is a wide window, and previous archaeological estimates for the bone are a bit younger, ranging from 30,000 to 50,000 years old. These genetic estimations are also still in limbo because of ongoing debate about the average rate of genetic mutations over time, which could skew the age. “Nevertheless,” the researchers noted in their paper, “the results suggest that in the future it will be possible to determine dates of fossils based on genome sequences.”

This new sequencing approach can be used for any DNA that is too fragmented to be read well through more traditional methods. Meyer noted that it could come in handy for analysis of both ancient DNA and contemporary forensic evidence, which also often contains only fragments of genetic material.

Hawks is excited about the new sequencing technology. It is also helpful to have a technology developed specifically for the evolutionary field, he notes. “We’re always using the new techniques from other fields, and this is a case where the new technique is developed just for this.”

Hawks himself has heard from the researchers that have worked with the Denisovan samples that “the Denisovan pinky is just extraordinary” in terms of the amount of DNA preserved in it. Most bone fragments would be expected to contain less than 5 percent of the individual’s endogenous DNA, but this fortuitous finger had a surprising 70 percent, the researchers noted in the study. And many Neandertal fragments have been preserved in vastly different states—many are far worse off than this Denisovan finger bone.

The new sequencing approach could also improve our understanding of known specimens and the evolutionary landscape as a whole. “It’s going to increase the yield from other fossils,” Hawks notes. Many of the Neandertal specimens, for example, have only a small fraction of their genome sequenced. “If we can go from 2 percent to the whole genome, that opens up a lot more,” Hawks says. “Going back further in time will be exciting,” he notes, and this new technique should allow us to do that. “There’s a huge race on—it’s exciting.”

The Denisovans might be the first non-Neandertal archaic human to be sequenced, but they are likely not going to be the last. The researchers behind this new study are already at work using the new single-strand sequencing technique to reexamine older specimens. (Meyer said they were working on reassessing old samples but would not specify which specimens they were studying—the mysterious “hobbit” H. floresiensis would be a worthy candidate.) Pääbo suggests Asia as a particularly promising location to look for other Denisovan-like groups. “I would be surprised if there were not other groups to be found there in the future,” he said.

Taking this technique to specimens from Africa is also likely to yield some exciting results, Hawks says. Africa, with its rich human evolutionary history, holds the greatest genetic diversity. The genomes of contemporary pygmy and hunter–gatherer tribes in Africa, for example, have roughly as many differences as do those of European modern humans and Neandertals. So “any ancient specimen that we find in Africa might be as different from us as Neandertals,” Hawks says. “Anything we find from the right place might be another Denisovan.”

To Bring Back the Extinct (Edge)

A Conversation with Ryan Phelan [8.28.12]

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

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


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


TO BRING BACK THE EXTINCT

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

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


Video 


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


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

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

THE REALITY CLUB:

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

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