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, 7 August 2009

Orang-utans Use Tools To Deceptively Communicate

Here a group of primatologists, including Carel Van Schaik, report that orang-utans use strips of leaves, placed over their mouths, to modulate the kiss squeaks they emit when in distress. The leaves drive down the frequency of the kiss squeak to give the impression that the sound is being made by a larger animal than is the case. If all this stands up to further scrutiny it will be first evidence of tool use linked to a form of communication in which deliberate deception is involved.

More Clever Corvid Stuff

Nice BBC piece which reports on work that builds on earlier amazing findings relating to corvid tool use. In the first piece of research, Nathan Emery and Christopher Bird have found that Aesop's fable about a crow enjoying a "Eureka" moment by displacing water by throwing pebbles into a jar until the water surface rose to the point that it could drink, may well be grounded in fact. Their rooks have shown that they can plop pebbles into a cylinder containing a floating worm - up to the point where they can reach the worm with their beaks. Two rooks did it spontaneously when first presented with the task, the other two on their second attempt. They used larger pebbles when given variety thereby raising the water level more efficiently and they avoided worms on sand in favour of worms floating on water.

In a separate paper, Alex Kacelnik's group in Oxford report repeating the famous experiment conducted with Betty, just before she died, where the New Caledonian crow used a short tool to retrieve a medium-length tool to retrieve a long tool to pull out food from deep inside a horizontal tube. Four out of seven birds were spontaneously able to use the tools in the correct order, repeating Betty's swansong. As I explain in the book, this is an exceptionally important finding because, had the crows been learning by simple trial and error they would have found it impossible because the reward only comes after successfully negotiating three stages of tool selection. As Kacelnik is reported saying, "We are aware that the animals probably do it by putting together, in creative ways, things that they have learned individually". This is meta-tool use - using a tool to make a tool to use a tool.....and so on, to gain a reward. This is very sophisticated, human-like, cognition.

Jumping Genes Add Diversity To Human Brain

Fred Gage's lab at the Salk Institute have just reported finding that human brain cells are hyper-variable because their DNA harbours variable numbers of small DNA elements called LINE-1 elements (formerly referred to as junk DNA) which copy and paste themselves in great numbers throughout the genome. In this way, brain cells resemble immune system cells which are also hyper-variable because they have to constantly counter the barrage of different antigens that bombard our bodies. They discovered that LINE-1 jumping occurred much more frequently in brain tissue than in tissue from heart and liver and that the LINE-1 promotor, the switch that turns LINE-1 elements on and off, is permanently switched to "on" in the human brain. In this sense, LINE-1 insertion follows a pattern of several other means of gene regulation where the brain differs markedly from other body organs, in keeping with its need to remain flexible in response to rapidly changing environmental conditions throughout life. What Gage's team have not yet looked at is whether LINE-1 insertion and self-copying is extremely different between chimps and humans. My guess, obviously, is that it will be.

Wednesday, 5 August 2009

Brain Difference In Psychopaths Identified.

In the chapter on neuroscience (Inside The Brain) in NOT A CHIMP I describe in detail what scientists have dubbed "the social brain" - a number of heavily interlinked brain regions that receive inputs of relevant emotional stimuli from the outside world (for instance the amygdalae receive images of fear and pain) and process them into appropriate pro-social behaviour like true empathy and the ability to plan and behave appropriately among other human beings. Besides the amygdala, other areas include the orbitofrontal cortex, the insula and the anterior cingulate cortex. People who have damage to their orbitofrontal cortices become withdrawn and anti-social and behave inappropriately. Now a team of neuroscientists from Kings College, London have discovered that in the brains of psychopaths the white matter tract that connects the amygdala with the orbitofrontal cortex - the uncinate fasciculus - has structural abnormalities when compared to the brains of normal individuals. The degree of abnormality in the UF was directly related to the degree of psychopathy. Real pathology of the social brain.

Tuesday, 4 August 2009

Did Malaria Jump To Humans From Chimpanzees?

This CNN piece is one of several posts today documenting the recent discovery of the genetic similarity between Plasmodium reichenowi - the form of Plasmodium (the malaria parasite) common to chimps - and Plasmodium falciparum, the form common to humans and the cause of over 1 million deaths a year. It appears to be a complete vindication of the scientific argument of Ajit Varki, reported in chapter 5 of NOT A CHIMP - called "Less Is More". Nathan Wolfe has isolated and sequenced DNA from both malaria parasites and suggests, as did Varki before him, that falciparum evolved from the common chimp parasite, reichenowi, and spread, via mosquito vector, from chimps to humans. In fact, Varki's take on this event, which could have happened at any time between 10s of 1000's of years ago to 2 or 3 million, is more interesting because it suggests that, back in Homo erectus days, reichenowi was THE common malaria parasite to humans and chimps and that humans underwent drastic evolution to their immune systems in order to counter it. For some reason, reichenowi appears to be relatively harmless to chimps today and it may have been forever thus - so chimps never did evolve resistance to it. Eventually, Plasmodium countered human resistance by evolving the falciparum form from reichenowi, though whether or not chimps were the seat of this parasite evolution - and why - remains to be seen.
If you want to read up on this in more detail the source paper is Open Access in PNAS. The URL is The authors specifically echo Varki's argument that humans inactivated the CMAH gene in a classic "less is more" mutation to prevent the sialic acid precursor Neu5Ac making Neu5Gc - which coats chimpanzee cells. A mutation converting P. reichenowi to P. falciparum then allowed it to target the now over-abundant Neu5Ac on human cells - accounting for its extreme pathogenicity in humans today.

Orangutans Our Nearest Kin?

All the world loves a heretic, it seems. This clear piece by David Templeton, in the Pittsburgh Post-Gazette, outlines local boy Jeffrey Schwartz's continuing insistence that orangutans are more closely related to us than chimps. His argument is not based at all on genome comparisons, and particularly those calculations, based on genome divergence, that construct family trees of related species by drawing in divergence points from common ancestors (the forks in the tree). He relies on a host of morphological comparisons of which 28 are shared between human and orangutan versus 2 with chimps and 11 with gorillas. These include enamel molars, similar hairlines and shoulder blades and aspects of skull structure. His theory continues to draw scorn from over 99% of the evolutionary anthropology community and Todd Disotell, of the New York University Center for the Study of Human Origins, is preparing a point-by-point rebuttal of Schwartz's argument. Watch this space!