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!

Thursday, 12 November 2009

Fair Play In Humans, Monkeys And Apes

A really nice article, in New Scientist, by Frans De Waal, of the Yerkes Primate Centre, looking at the likely evolutionary roots of a sense of fair play in primates. The article kicks off like this:

HOW often have you seen rich people take to the streets, shouting that they're earning too much? No, I thought not. Protesters are typically blue-collar workers yelling that the minimum wage has to go up, or that their jobs shouldn't go overseas. Lately, however, we have been hearing a new chorus, exclaiming that none of those fat cats on Wall Street or the City should be compensated for bad behaviour. No golden parachutes for those greedy bloodsuckers!

Concern about fairness is always asymmetrical (stronger in the poor than the rich), and the underlying emotions aren't half as lofty as the ideal itself. It is true to say that our sense of fairness seldom transcends self-interest, that it is seldom concerned with something larger than ourselves. Look at how it starts in life. Children react to the slightest discrepancy in the size of their slice of pizza compared to their sibling's. Their shouts of "That's not fair!" never transcend their own desires.

We're all for fair play so long as it helps us. There's even a biblical parable about this, in which the owner of a vineyard rounded up labourers at different times of the day. Early in the morning, he went out to find labourers, offering each 1 denarius. But he offered the same to those hired later in the day. The workers hired first thing in the morning expected to get more since they had worked through the heat of the day, yet the owner didn't feel he owed them any more than he had originally promised.

That this sense of unfairness may turn out to be quite ancient in evolutionary terms as well became clear when graduate student Sarah Brosnan and I discovered it in monkeys. While testing pairs of capuchin monkeys, we noticed how much they disliked seeing their partner get a better deal. At first, this was just an impression based on their refusal to participate in our tests. But then we realised that economists had given these reactions the fancy label of "inequity aversion," which they had turned into a topic of academic debate. This debate revolved entirely around human behaviour, but what if monkeys showed the same aversion?.............

Do Chimps Understand Beliefs?

The comparative cognitive psychology team at the Max Planck Institute in Leipzig continue to conjure up exciting and informative experiments to compare ape and human cognition. This reports on an experiment that has evolved from the competitive food-grabbing experiments designed by Brian Hare and reported on in the chapter POVINELLI'S GAUNTLET in the book. In that case a subordinate chimp and a dominant chimp faced doors into a common enclosure in which food was baited either in the open or behind obstacles in conditions where either or both animals could see the food baited. Would the subordinate chimp behave differently in its choice of which food to go for if the vision of the dominant chimp had been obscured by a shutter at the time the enclosure was baited? In other words, did the subordinate chimp have some idea of beliefs and knowledge in the head of the other chimp? Let cognitive daily pick up the story:

Juliane Kaminski, Josep Call, and Michael Tomasello set up a more complicated competitive situation for both chimps and human children. Two chimps sat in separate rooms with windows so they could see each other and a table between their rooms.

The table had a movable center with three inverted buckets, each capable of hiding a treat. Each chimp's view of the table could be blocked separately. For each task, the experimenter hid a piece of banana under one of the three buckets. In addition, each chimp had her own bucket which she knew contained a less appealing snack: a piece of apple. The children had a similar setup, except they played against an adult, and they weren't confined to chimp-proof rooms. The kids' appealing reward was a toy, and the less-appealing reward was a wooden block.

For the chimps, the game worked like this: While both chimps watched, the experimenter placed the banana under one of the buckets. Then the treat was either moved to a new bucket, or kept in the same place, while both chimps watched or while one had her view of the buckets blocked. Then the chimps got to pick which bucket they thought contained the treat. Only one of the two chimps was actually being tested, and the tested chimp always picked second--and she did not get to see her competitor making the choice. She always had the option of picking the guaranteed treat on the table next to her, or she could take a chance and go for the banana, a much more appealing treat.

There were four possible scenarios in each game: Both chimps saw the banana being moved or kept in the original bucket, or the chimp being studied saw the banana moved or kept in the original bucket while hidden from view of the competing chimp. How often did the chimps (and kids) try for the more appealing prize?

The 6-year-olds came closest to the optimal strategy. They generally didn't choose the better treat when the competitor saw the treat being moved (or not moved) from one bucket to another. Even though they didn't see the competitor choose a bucket, they guessed that the competitor would have already taken the treat, and therefore the best they could do would be to pick the guaranteed, lesser treat.

However, when the object had been moved from one bucket to another and the competitor didn't see the move, they picked the better treat more than 70 percent of the time, figuring that the competitor was unlikely to have guessed the correct location of the treat. When the treat was kept in the same location, even though the competitor didn't see what happened behind the occluder, they chose it less often, presumably because they figured that the competitor was most likely to believe that the treat was in the same spot it had been left in before.

Three-year-olds, by contrast, pretty much always chose the guaranteed lesser treat, presumably because they weren't sure what their competitor had done.

Chimps did somewhat better: they chose to go after the prefered treat significantly more often when they saw that their competitor hadn't seen it moved (or kept in the same place). However, their decision was the same whether or not the treat was actually moved. This suggests their understanding of their competitor's knowledge is not as sophisticated as a six-year-old's: they didn't behave differently when there was reason to believe that their competitor had a mistaken impression of where the treat was located.

Chimps, it seems, do have some idea what other chimps are thinking. They have less of an understanding of their competitors' mistaken beliefs.

FOXP2 Gene And Ramifying Roots Of Language

Here is news of a very important paper indeed. I've given the url for the Wired article as it is a clear and simple in-road, but there is also good info on the John Hawks weblog (see this blog's side-bar) and the source articles and commentary by Pasko Rakic are in this week's NATURE (vol. 462 pp. 213-217, and pp. 169-170). Lead authors are Genevieve Konopka and Dan Geschwind, of UCLA.

The work concerns the gene FOXP2 - star of chapter 2 in my book, THE LANGUAGE GENE THAT WASN'T. Most will recall that FOXP2 is at the root of an extraordinary speech AND language disorder in an extended London family, that it has accumulated two mutations inside the last 200,000 years (compared to the chimp), that it appears to have come under considerable selection pressure, and that it codes for a protein called a transcription factor which, when released, targets a range of genes under its control and regulates their activity. In this way, FOXP2, while not being the "language gene" itself, is some sort of master controller of a whole orchestra of genes, all or many of which may be part responsible for our unique human language faculty. The question, ever since the discovery of FOXP2, is "what are the members of this orchestra and what do they do?"

Now Geschwind and co. are beginning to supply the answer - thanks to some ultra-modern genomics technology as wielded by Todd Preuss at Emory University. Basically, they gene-engineered human brain cells in which they could either turn FOXP2 on or off, or substitute human for chimp FOXP2 and turn it on or off. The cell lines could be interrogated to see exactly which genes were targeted by the different versions of FOXP2. Human and chimp FOXP2 behaved very differently in the way they regulated their down-stream orchestras. They discovered 116 genes whose regulation seemed connected only to the activity of the human form of FOXP2. Many of them were active in the brain, others in non-nervous system tissue and also cranial structures associated with language function. As they say: "FOXP2 has been the window, but the network is going to be the story". Now that they have drawn the network - the subservient genetic orchestra - they can look at each gene to determine its function and, hopefully, shed more and more light on what underpins language. They have, so far, discovered 5 genes in the network - AMT, C6orf48, MAGEA10, PHACTR2, and SH3PXD2B - which appear to have been positively selected and no doubt these will be among their first investigations as to function.

This is an incredibly important and exciting step and opens the way to a methodical and purposeful slog through the genome to put the complex picture of the genetic foundations of language together. This will be a space well worth watching!

Wednesday, 11 November 2009

Cafe Scientifique - Medway - TONIGHT!!

I am talking tonight at the Medway Cafe Scientifique - held at 7.30 p.m. at the Innovation Centre, Medway, Phase 2, Maidstone Road, Chatham, Kent ME5 9FD.

Language Affixation In Non-Human Primates

This research group, which included Harvard psychologist Marc Hauser (author of the "humaniqueness" concept), wondered, while stating firmly that genuine language competence was unique to humans, whether or not components - building-blocks - of language competence could be found in monkeys. Using cotton top tamarins they show that the monkeys can discriminate bisyllabic words that either start (prefix) or end (suffix) with the same syllable. This is similar to the affixation rule we use to inflect words, for instance with the past tense, as in walk/walked. They conclude - in their abstract: "These results suggest that some of the computational mechanisms subserving affixation in a diversity of languages are shared with other animals, relying on basic perceptual or memory primitives that evolved for non-linguistic functions."

Tuesday, 10 November 2009

Words And Gestures Translated By Same Brain Regions

It has long been suspected that language evolved from the ability to transfer meaning through gesture. This American study shows that the same areas in the brain - the anterior and posterior temporal lobe regions we call Broca's and Wernicke's areas - are used, not only for translating gestures that constitute sign language - which has a grammar and structure - but also for translating gestures that convey meaning without resort to words and phrases: pantomimes mimicking actions or objects, and emblematic gestures like a hand sweeping across a forehead to indicate "Phew! It's hot in here!" As one of the lead researchers is quoted saying: "Our results fit a longstanding theory which says that the common ancestor of humans and apes communicated through meaningful gestures, and, over time, the brain regions that processed gestures became adapted or using words.....If the theory is correct, our language areas may actually be the remnant of this ancient communication system, one that continues to process gesture as well as language in the human brain."

It may be that Wernicke's area serves as a storehouse for words out of which Broca's area selects the most appropriate match. These researchers also suggest that these regions are not limited to deciphering words but applying meaning to any incoming symbols: words, gestures, images, sounds or objects.

Interestingly, the article notes, a baby's ability to communicate using gestures precedes language and you can predict a child's language skills based on their gestural repertoire in the first few months of life.