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!

Tuesday, 24 August 2010

The Great Debate - Are We Masters Of Our Own Destiny?

On Friday, 20th August, I joined the panel for a Great Debate entitled “Are We Masters Of Our Own Destiny?” at the University of Newcastle, organized as part of the Green Phoenix Festival, 2010. My fellow panelists were science writer Rita Carter, most famous for her books on neuroscience: “The Brain Book” and “Mapping The Mind”, and local philosopher David Large. The debate was chaired by Caspar Hewett. As we suspected, this pitted two biology-oriented commentators against a more conventional philosopher who answered the question in the affirmative because he believed we can control our own destiny in the sense that Joyce could write his masterpiece “Ulysses” and Wittgenstein formulate his idiosyncratic theories. The nature of Joyce-ness, Ulysses-ness, Wittgenstein-ness, and the product of the mind and skill of great artists - Rembrandt-ness if you like - transcended “mere” functional explanations of what the mind is. He took umbrage with psychology which, he claimed, pretends its functional explanation of how the mind works is the explanation. It isn’t.

Rita Carter saw things very much from the bottom up rather than the top down. The mind is made up (literally!) by myriads of tiny, unconscious neuro-chemical events in our brains. She therefore believed free will is an illusion deeply wired into the brain as a set of mechanisms which automatically create the sense of self and agency to make it feel as though we decide what our acts will be - that we are responsible for them - rather than merely responding to stimuli.

I agreed strongly with Rita by suggesting that - like the illusion of free will - a large school of modern neuroscientists believe that our moral behaviour is produced not by moral reasoning but by input of extremely simple neuro-chemical data from our sense organs and receptors which is turned into moral intuitions in our brains by processes of which we are oblivious - the intuition simply pops into our heads. We then apply moral reasoning to our intuitions in a post-hoc sense in order to justify these instinctive beliefs. I agreed with one prominent such neuroscientist who claims that the conscious mind is like the mahout on an elephant. The elephant is the other 99% of what is going on in our minds - things that are unconscious and automatic.

If free will and morality are the unconscious products of the way our brains work, thought a number of members of the audience, what, then, is the advantage to us of the illusion that we are in control? Carter argued that without the illusion that we are responsible for our own actions, and that we are therefore accountable for them, no society could possibly function; while I argued that the illusion of moral responsibility is a social phenomenon which evolved as a sort of social glue holding human groups together by commonly agreed norms and principles “outsiders” do not share. In that sense it is similar to the evolution of theory of mind - by which we explain other peoples’ actions by inferring to ourselves the hidden states of mind - their wants, beliefs and knowledge - that must be guiding them. If a teacher could have no inkling that he owned a state of knowledge his pupil lacked, and could not learn unless that knowledge was efficiently transferred from one brain to another, no culture could thrive and be built upon.

How can unconscious process explain the more spiritual side of our nature, thought others. What is the nature of love - affairs of the heart? Near-death experiences? Phantom limbs? The experience of strong emotions like love, I argued, are similar to the experience we have of the presence of a hand after amputation. Both are registered and processed unconsciously in the brain. We do not physically feel love in our hearts though our hearts may send raw autonomic data to our brains, along with data from our eyes, ears, nose and gut, to form the basis of our feelings. Large was not convinced. “I cannot approach the love of my life”, he exclaimed, “And tell her ‘I love you with all my.....brain!’, it just wouldn’t work!”

What were the limits to science in a full explanation of human agency, wondered others. Reductionism can never provide the answer. Large agreed. The creation of a great work of art on canvas is invulnerable to dissection by the scientific method. Science, in attempting a reductionist explanation, was forever throwing babies out with bath-water. There must be explanations at other levels. For Carter, however, science was the only game in town. What else could any other form of enquiry be based on, if not science and the scientific method, she asked. Neither is science pathologically reductionist, I argued. We no longer have to explain how the machine works by examining one single cog. Psychologists are Skinnerians no longer. Modern technologies like brain-scanning allow them to view phenomena like the mind-brain in multi-dimensional, dynamic terms.

Perhaps, said Large, tongue firmly in cheek, it is scientists who are the masters of our destiny, after all? I responded that we might have an invidious choice in trying to master our destiny: Reduce our civilization to the level which corresponds to the complexity faced by our stone-age intuitive moral minds scores of thousands of years ago - as some primitive philosophers have argued - or behave more like scientists (and philosophers!) by training our pre-frontal cortices - the most recent evolved additions to our brains - to squeeze out as much moral reasoning as possible - over-riding our intuitive inclinations. Only then can we stand a chance of a rational, unbiased approach to facing the extremely complex problems standing between us and any secure future. Hunter-gatherers or geeks?

Carter shuddered at either possibility. Ultimately, she said, there is great humility to be gained from the understanding that much of what we take for granted in terms of will and reasoning is actually the invisible and un-knowable activity of trillions of molecules in our brains responding to the laws of nature in much the same way as rain-drops falling through the atmosphere.

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