NOT A CHIMP

NOT A CHIMP
Click on the cover to link to OUP's e-catalogue then turn to the biology section.

Interview Podcast with George Miller

Interview Podcast with George Miller
Click on the pic to link to the NOT A CHIMP podcast on Blackwell's Website

Preface to "Not A Chimp: The Hunt For The Genes That Make Us Human"

In many ways, this book is born out of frustration for a professional career in popular science television where ideas about comparative primate cognition, and the similarities and differences between us and our primate relatives, have continually circled me but constantly evaded my grasp in terms of the opportunity to transform them into science documentary. On the plus side, keeping a watching brief for over a quarter of a century on subjects like comparative animal cognition and evolution allows you to watch a great deal of water flow under the bridge. Fashions come and fashions go - specifically, perspectives on the similarity - or otherwise - of human and ape minds.

I remember the first Horizon science documentary about the chimpanzee Washoe, the great ape communicator, using American Sign Language to bridge the species barrier. And, later, Kanzi the bonobo jabbing his lexicon. These were the apes, as Sue Savage-Rumbaugh has put it, that were "on the brink of the human mind".

I remember when the pre-print of Machiavellian Intelligence, by Andrew Whiten and Dick Byrne, plopped onto the doormat of the BBC Antenna science series office in 1988. Suddenly primatology had become a great deal more exciting. Could primates, and especially higher primates like chimpanzees, really be as full of guile, as dastardly, as cunning, and as manipulative as the eponymous Florentine politician? Could they really reach deep into the minds of other individuals to see what they believed and what they wanted, and turn that information into deception?

I remember discussing primate cognition with a young Danny Povinelli, as we sat finger-feeding ourselves shrimp gumbo and new potatoes out of plastic Tupperware containers in a Lafayette restaurant surrounded by an alligator-infested moat, before returning to his kingdom - the New Iberia Research Centre - where the University of Louisiana had lured him back to his native deep South by turning a chimpanzee breeding centre for medical laboratory fodder into a primate cognition laboratory with one of the largest groups of captive chimpanzees in the country. He looked like a kid who had just been thrown the keys to the tuck shop.

In those days Povinelli shared the zeitgeist - spread by Whiten's and Byrne's work, and started by Nick Humphrey and Alison Jolly before them - that, since the most exacting and potentially treacherous environment faced by chimpanzees and other primates was not physical, but the social environment of their peers, they had evolved a form of social cognition very much like our own, in order to deal with it. This was further elaborated into a full-blown "social brain" hypothesis by Robin Dunbar, who related brain neocortex size to social group size throughout the primates and up to man. Povinelli's early work reflects this optimism for the mental life of apes, but both ape-language and ape-cognition research was subjected to a cold douche of searching criticism during the 1990s, and misgivings set in regarding the effectiveness of the experiments that had been constructed to guage ape cognition. Now the worm has turned again, with a number of research groups emerging with bolder and bolder claims for the Machiavellian machinations of primate minds, only to be powerfully countered by the curmudgeonly skepticism, chiefly by Povinelli, that these researchers are merely projecting their mental life onto that of their subjects; that, rather in the frustrating manner of Zeno's arrow that could never quite reach its target because it continually halved its distance to it, no experiment constructed thus far can actually get inside the mind of a chimp and show us exactly what it does and doesn't know, or how much, about the minds of others or the way the physical world works. One influential part of the world of comparative animal cognition talks of a continuum between ape and human minds and shrinks the cognitive distance between us and chimps to almost negligible proportions, while another returns us to the unfashionable idea that human cognition is unique, among the primates, after all.

When I began writing this book the working title was "The 1.6% that makes us human". My aim had always been to scrutinize the impression put about in the popular science media that humans and chimps differ by a mere 1.6% in our genetic code - or even less - and that it therefore makes complete sense that this minuscule genetic difference translates into equally small differences in cognition and behaviour between apes and man. However, contemporary genome science and technology, over the last few years, have dramatically advanced the power and resolution with which scientists can investigate genomes, eclipsing the earlier days of genomic investigation that gave rise to the "1.6% mantra".

As with comparative cognitive studies, conclusions on chimp-human similarity and difference in genome research depend crucially on perspective. To look at the complete set of human chromosomes, side by side with chimpanzee chromosomes, at the level of resolution of a powerful light microscope, for instance, is to be overwhelmed by the similarity between them. Overwhelmed with a sense of how close our kinship is with the other great apes. True, our chromosome 2 is a combination of two chimp chromosomes - giving humans a complement of 23 chromosome pairs to 24 in chimps, gorillas and orang-utans - but even here you can see exactly where the two chimp chromosomes have fused to produce one. The banding patterns you visualize by staining the chromosomes match up with astonishing similarity - and that banding similarity extends to many of the other chromosomes in the two genomes. However, look at a recent map of the chromosomes of chimps and humans, aligned side by side, produced by researchers who have mapped all inversions - end-on-end flips of large chunks of DNA - and the chromosomes are all but blotted out by a blizzard of red lines denoting inverted sequence. Now you become overwhelmed by how much structural change has occurred between the two genomes in just 6 million years. True, not all inversions result in changes in the working of genes - but many do - and inversions might even have been responsible for the initial divergence of chimp ancestor from human ancestor.

The extent to which you estimate the difference between chimp and human genomes depends entirely on where you look and how deeply. Modern genomics technology has led us deep into the mine that is the genome and has uncovered an extraordinary range of genetic mechanisms, many of which have one thing in common. They operate to promote variability - they amplify differences between individuals in one species. We now know, for instance, that each human is less genetically identical to anyone else than we thought only three years ago. When we compare human genomes to chimpanzee genomes these mechanisms magnify genetic distance still further. I have tried, in this book, to follow in the footsteps of these genome scientists as they dig deeper and deeper into the "Aladdin's Cave" of the genome. At times the going gets difficult. Scientists, like any explorers, are prone to taking wrong turnings, getting trapped in thickets, and covering hard ground, before breaking through into new insights. I hope that those of you who recoil from genetics with all the visceral horror with which many regard the sport of pot-holing will steel yourselves and follow me as far as I have dared to go into Aladdin's Cave. For only then will you see the riches within and begin to appreciate, as I have, just how limited popular accounts of human-chimpanzee genetic difference really are. Let me try and persuade you that this is a journey, if a little arduous at times, that is well worth taking.

There are a number of scientists around the world who have the breadth and the vision to have begun the task of rolling genetics, comparative animal cognition, and neuroscience into a comprehensive new approach to the study of human nature and this is part, at least, of their story. They strive to describe the nature of humans in terms of the extent to which we are genuinely different to chimpanzees and the other great apes. Somehow, over 6 million years, we humans evolved from something that probably resembled a chimpanzee (though we cannot yet be entirely sure) and the answer to our evolution has to lie in a growing number of structural changes in our genome, versus that of the chimpanzee, that have led to the evolution of a large number of genes that have, effectively, re-designed our brains and led to our advanced and peculiar human cognition.

If you don't believe me, hand this book to your nearest friendly chimpanzee and see what he makes of it!

Saturday 31 July 2010

Carol Jahme Goes Ape

Agony aunt and comedienne Carl Jahme has taken a monkey suit to the Edinburgh Festival, where, describing herself as a humanzee, or chimp human hybrid, she intends to regale festival-goers with a comic look at human evolution and origins. In this article she trots out the depressingly familiar list of half-truths about the chimpanzee human relationship - no longer are we unique in making tools, fire, having language etc. etc. She allies herself with Richard Dawkins' bizarre wish for a humanzee hybrid to exist because "it would change everything" and will exhort her audiences to get in touch with their "inner ape". Humour it may provide - accurate portrayal of human origins it certainly will not. More of the "chimps 'r us" brigade!

Thursday 29 July 2010

Cur cognition: Do stray dogs have qualitatively different kinds of canine minds?

Another Sciam post from the ever amusing Jesse Bering. Here he takes a long look at dog social cognition - particularly the extraordinary ability of pet dogs to interpret cues like pointing from humans. Stray dogs, he muses, who have been stray, clearly, for generations, display different social cognition to beloved pets. So what is the default condition for dog social cognition? He refers to a series of experiments using human pointing cues with stray dogs on the one hand, and pet dogs on the other and comments that the former category could only reliably correctly interpret less ambiguous cues like a finger pointing to a source of food barely centimetres from its tip. Is the acute social cognition of pet dogs a developmental attribute after all, rather than some evolutionary quirk of the dog brain arrived at through thousands of years of domestication? Although Jesse mentions Brian Hare's research he neglects what might be an important finding of Hares' - that dogs in New Guinea, which had been domesticated but then had returned to a feral condition, appeared to have lost a great deal of the sharpness of social cognition displayed by human commensal dogs. In other words, evolution had rapidly acted to reverse the functional analogue of human social cognition that tamer ancestors had shown.

Nevertheless, Bering is never boring and I strongly suggest everyone interested in a breezy look at contemporary evolutionary science to subscribe to his RSS feed.

Wednesday 28 July 2010

Monkey Generosity: No Strings Attached

In my final chapter I point out that altruism need not simply be a product of evolutionary proximity to humans, but that its emergence may depend on the social structure of any species. Primate species that practice allo-parenting, for instance, like marmosets - where the adults cooperate in the raising and care of the kids irrespective of genetic relationship - demonstrate a greater willingness to facilitate access to food for each other than non allo-parenting species which are more likely to be selfish hoarders. This article, based on he research of Charles Snowden's group at the University of Wisconsin-Madison, shows the propensity for forgiveness, or rather perhaps, the erosion of mistrust between cotton-top tamarin pairs, over time, when one of them has been perceived by the other of selfish behaviour. In experiments where one member of the pair can elect to withhold or dole out food to the other member who has wronged them in the recent past, altruistic sharing soon reasserts itself.

New Hypothesis For Human Evolution And Human Nature

Well, of course, nothing under the sun is truly new, but Pat Shipman has come up with a thesis about the evolution of human behaviour which hangs on our growing understanding of animals that came about through our domestication of them.

"Domestication, she explained, is a process that takes generations and puts selective pressure on abilities to observe, empathize, and communicate across species barriers. Once accomplished, the domestication of animals offers numerous advantages to those with these attributes. "The animal connection is an ancient and fundamentally human characteristic that has brought our lineage huge benefits over time," Shipman said. "Our connection with animals has been intimately involved with the evolution of two key human attributes -- tool making and language -- and with constructing the powerful ecological niche now held by modern humans."

It looks as if Shipman buys into the disputed view that humans domesticated wild wolves by importing pups into their camps - an implausible thesis in itself. As the article quotes her:

Shipman concludes that detailed information about animals became so advantageous that our ancestors began to nurture wild animals -- a practice that led to the domestication of the dog about 32,000 years ago. She argues that, if insuring a steady supply of meat was the point of domesticating animals, as traditionally has been assumed, then dogs would be a very poor choice as an early domesticated species. "Why would you take a ferocious animal like a wolf, bring it into your family and home, and think this was advantageous?" Shipman asks. "Wolves eat so much meat themselves that raising them for food would be a losing proposition."

Well you wouldn't. But wild wolves and dog-like canids might become commensal with humans by inhibiting their fight-flight reactions the better to scavenge around the perimeter of human encampments. More ethologically-minded early humans might then have begun to perceive the potential value of these self-taming animals as guards and hunting allies etc. etc.

Nevertheless her "animal connection" deserves a close look at. As the article says-

"Establishing an intimate connection to other animals is unique and universal to our species," said Shipman, a professor of biological anthropology. Her paper describing the new hypothesis for human evolution based on the tendency to nurture members of other species will be published in the August 2010 issue of the journal Current Anthropology.

Oxytocin Gene Variants, Prosocial Behaviour And Associated Brain Structure

In my chapter THE APE THAT DOMESTICATED ITSELF I detail a geat deal of research, some of it featuring Andreas Meyer-Lindenburg, which linked variants in serotonin transporter gene and MAO-A to hyper-vigilant or anti-social behaviour in which there were correlated differences between carriers of long variants and short variants of these genes and the strength of coupling, and therefore feedback, between the amygdala and frontal cortex structures in the brain. Here, Meyer-Lindenburg and colleagues continue the tie-up between gene variants, pro-social behaviour and brain structure by looking at oxytocin. Interesting stuff. Here's the abstract:


Abstract

The evolutionarily highly conserved neuropeptide oxytocin is a key mediator of social and emotional behavior in mammals, including humans. A common variant (rs53576) in the oxytocin receptor gene (OXTR) has been implicated in social-behavioral phenotypes, such as maternal sensitivity and empathy, and with neuropsychiatric disorders associated with social impairment, but the intermediate neural mechanisms are unknown. Here, we used multimodal neuroimaging in a large sample of healthy human subjects to identify structural and functional alterations in OXTR risk allele carriers and their link to temperament. Activation and interregional coupling of the amygdala during the processing of emotionally salient social cues was significantly affected by genotype. In addition, evidence for structural alterations in key oxytocinergic regions emerged, particularly in the hypothalamus. These neural characteristics predicted lower levels of reward dependence, specifically in male risk allele carriers. Our findings identify sex-dependent mechanisms impacting the structure and function of hypothalamic-limbic circuits that are of potential clinical and translational significance.

The Evolution Of Gene Regulation

Really interesting article by Miranda Robertson about the need to look outside gene number and small changes to DNA sequence for the explanation for organismal diversity and complexity. The article pays due homage to the path-breaking work in the 1970s of Allan Wilson and Mary-Claire King and others - well before the day of modern genomics technology - in pointing the finger at gene regulation, rather than sequence evolution in genes. Robertson then up-dates this picture by looking at RNA regulation.