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!

Friday, 29 January 2010

Oliver James' Rant

My attention was drawn to a recent rant against the role genes play in human behaviour, by the psychologist Oliver James, by a rebuke, yesterday, from two prominent scientists working in the area of genomics and neurobiology, Chris Ponting and Keith Talbot.

James had blithely asserted that there has been a shambolic and wholesale retreat from the role genes play in determining our behaviour, ever since the human genome was fully published some nine years ago. He misunderstands comments made by Craig Venter regarding the way in which genes can or cannot have an impact on the human brain in the light of the discovery that there are "only" 25,000 working genes in the human genome; suggests that research into the genetic component of ADHD has run into the sand; and sounds the death knell for theories that genes can contribute to human behavioural traits by applauding a meta-analysis by Risch, in JAMA last year, that could not uphold the results of earlier longitudinal studies on the role short variants of the serotonin transporter gene have on depression. I've linked to James' original article and here is the riposte:

Genetic contribution to human behaviour

The Guardian, Thursday 28 January 2010

In his latest rant against genetics, Oliver James either does not understand, or ­wilfully misunderstands, the genetic basis of neurobiology, and purposefully overlooks huge swathes of scientific literature (Nature v nurture – what are the latest genetic ­findings, 23 January).

Despite the enormous complexity of the human genome, geneticists are continuing to reveal many DNA changes that explain disorders such as learning disability and autism. These changes are often private to each ­individual. This tells us that ­different parts of the human genome can be ­disrupted independently in people with a single ­disease: there are likely to be many dozens, possibly ­hundreds, of "autism genes", for example.

It is, indeed, "extremely unlikely that there are single genes for major mental illnesses such as schizophrenia" but this does not indicate that genetics play no part. Like the brain itself, the genetic contribution to behaviour is complex.

This is not a "fallback position", but a straightforward and ­dispassionate appraisal of the facts. Far from ­having "to admit defeat", geneticists have begun to disperse the fog that has ­enveloped genetic disease. Their new insights should ensure that unwarranted pronouncements of fault are not levelled at ­parents who ­produce anyone other than a "normal" child.

Chris Ponting

Medical research council and professor of genomics, University of Oxford

Kevin Talbot

Reader in the department of neurology, University of Oxford

Dear reader make what you will of James' target article. He has for years fought against the idea that genes play a prominent role in the development of human behavioural traits and is fond of exclusively stressing "the environment" and, therefore, the unique plasticity of human mental traits. I consider him to be a stupid and wilfuly ignorant commentator, as do Ponting and Talbot, and anyone who has ploughed through the genetics chapters in NOT A CHIMP will, I hope, be convinced that - to the contrary of James' assertions - the last nine years have uncovered a host of genetic mechanisms, and structural features of the human genome, that have sculpted our brains and cognition over the last six million years. However, the Risch findings do deserve further comment. You can access a careful and balanced report on them, by Bruce Bower, at:

As Bower points out, Caspi and Moffitt, the authors of the longitudinal Dunedin study, mentioned by James and covered in the penultimate chapter of NOT A CHIMP, mount a solid defence against the negative findings of Risch's meta-analysis, which took into consideration a number of larger studies done with much less satisfactory measures of depression etc. than the Dunedin study. Moreover, as I reported, James ignores, or does not know about, the numerous pieces of scientific work on normal volunteers which links variants in MAO and serotonin transporter genes to hyper-vigilance and depression, and poor coupling between amygdala (the brain's fear centre), the anterior cingulate cortex, and the frontal lobes of the brain.

James concludes thus: "In Darwinian terms, it has always made much more sense that we should be born plastic. Obviously, genes confer fundamentals, such as the capacity for humour or anger, but how much we express these is in response to our particular FAMILY situation, for which we need flexibility, not predetermination. if genes play little part in how our children turn out, that is incredibly good news. Unlike our DNA, we can do something about them."

The obvious point is that the action of genes in the brain does not imply predetermination of behaviour, and the fine and intricate nature - through numerous mechanisms - of control of gene expression actually creates the flexible engine James searches for. Genes DO play a fundamental part in who and what we are as advanced cognitive animals. Generations of parents who have brought up several children apiece know full well, from individual differences and their attempted effects on outcomes, the role that genes play in the development of mental traits in all of us. Their experiences reveal James' smugness for what it is - a deliberate "one eye shut" approach to the evolution and expression of human functional neurobiology. Exclude the subtle nature of gene-environment interaction, and the co-evolution of genes and environment at your peril - you will dance witlessly around the enigma of human behaviour for ever.

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