By Jeremy Taylor
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 neurochemical 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
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Not a Chimp: The Hunt to Find the Genes that Make Us Human is an exploration of why chimps and humans are far less similar than we have been led to believe. Genome mapping has revealed 
that the human and chimpanzee genetic codes differ by a mere 1.6%, but author Jeremy Taylor explains that the effects of seemingly small genetic difference are still vast. In the post below, he discusses how the discovery of “Ardi” deals a fatal blow to the chimpanzee ancestor myth.
Jeremy Taylor has been a popular science television producer since 1973, and has made a number of programs informed by evolutionary theory, including two with Richard Dawkins.
When discussing differences between chimpanzees and humans, I enjoy telling the hoary old joke about the traveler, lost in the midst of the Irish landscape, who approaches a farmer in a nearby field for directions. “Well,” says the farmer, on hearing his request, “If I were going to Kilkenny I wouldn’t start from here!”
I share this to highlight the point that we have chosen the chimpanzee as the bench-mark comparison with humans to help us answer the big questions as to how we evolved into humans, and when, for the simple reason that it is our nearest relative in terms of living DNA and behavior. But that does not mean that chimpanzees are cheek by jowl with us or that chimpanzees represent the perfect starting point. Those myriad genome scientists need no reminding from me that necessity has forced comparison with a species that is actually separated from us by twelve million years of evolutionary time since the split from the common ancestor–six million years for the branch that led to us, plus six million for the branch that led to them. Although we know even less about chimpanzee evolution than the precious little we have learned about the genetic changes that led to modern humans, it is clearly reasonable to assume that chimpanzees have not remained evolutionarily inert these past six million years and may well have evolved as far and as fast as we have–though not in the same direction.
Nevertheless, a number of primatologists who should know better, many great ape conservationists, large swathes of the science media, and therefore much of the lay audience, have become bewitched by incessant talk over the last few years about the extraordinary genetic proximity between apes and humans–what I call the 1.6% mantra–and the many cognitive and behavioral similarities that appear to have eroded the old idea of human uniqueness: tool manufacture and use, empathy, altruism, linguistic and mathematical skills, and an intuitive grasp of the way others’ minds work. All this has led to claims that chimps should be re-located, taxonomically, within the genus Homo, that they are more our brothers than our distant relatives, and that they should be therefore be accorded human rights. It has also led to the assumption that the common ancestor of chimps and humans must have looked and behaved very much like chimpanzees today and that our deep human ancestors must have clawed their way to us via a knuckle-walking chimpanzee-like stage before coming down from the trees, developing bipedality and bounding off into the savannas that were rapidly replacing dense forests due to climate change.
This “chimps are us” cozy day-dream has been dealt a welcome (to me) wake-up call by the publication of the discovery and analysis of the fossilized remains of Ardipithecus ramidus–”Ardi.” At 4.4 million years of age, she is perilously close to the time of the split from the common ancestor–and, as one of the main researchers, Tim White, is repeatedly quoted, “Ardi is not a chimp. It’s not a human. It’s what we used to be.” Ardi was clearly bipedal–she had a pelvis with a low center of gravity and had a foot structure which acted like a plate, allowing her to launch herself forward as she walked. Her hands were more flexible than a chimp’s, would have allowed careful palmigrade movement when in the forest canopy which would have supported her weight, and, crucially, would have presented more recent human ancestors with less evolutionary distance to travel to achieve the highly dexterous human hand essential for sophisticated tool use. Plant and animal remains found with her point to an environment of mixed forest and grassland in which she foraged omnivorously for nuts, insects and small mammals.
Was our common ancestor much more like Ardi than a chimp? Is the chimp we see today the result of six million years of specialized evolution away from this extraordinary biped with its mixture of primitive and derived features? Ardi seems fated to join two other odd-ball ancestors we have dug up in recent years: Sahelanthropus tchadensis (Toumai), who dates to approximately seven million years ago, around or before the split from the common ancestor–and Orrorin tugenensis, which dates between 5.8 and 6.1 million years. It is claimed that both were bipedal, though so little of the total skeleton in each case has been retrieved that these claims are open to dispute. Orrorin seems somewhat more similar to modern humans than the famous Lucy, Australopithecus afarensis, is three million years older, and appears to have inhabited a similar mixed forest/grassland environment as Ardi. These misfits may have been very similar, or identical to, the common ancestor, and represent a much better approximation of the deep roots of the human tree than do chimpanzees.
Chimp-hugging conservationists have been over-playing their cards on chimpanzee-human proximity for years. Recent genomic research has unearthed a number of important structural and regulatory mechanisms at work in genomes that widen the gap between humans and chimps, and recent fascinating cognitive research with dogs and members of the corvid family of birds has shown that species that diverged hundreds of millions of years ago from both chimps and humans can out-perform chimpanzees on cognitive tests involving following human cues and in the making and use of tools, respectively.
We are not “the third chimpanzee”–chimps with a tweak. The difference between human and chimp cognition, in the words of American psychologist Marc Hauser, is of the order of the difference in cognition between chimps and earthworms. Chimpanzees–and the other great apes–are the only species for which we erect the idea of near-identity as the motivating force for conservation. We don’t beseech the general public to save the white rhino because we share over 80% of our genes with it, or the tropical rain-forest because we share over 50% of our genes with the banana. Although I would be first into the firing line in the battle to save chimpanzees and their natural environments from extinction I believe this resort to chimp-human proximity is a distraction and the wrong way to go about it. As Ardi is showing us, it is high time we stopped ourselves falling prey to this narcissistic anthropomorphism that brands chimpanzees as the “nearly man.” Chimps are not us!
Not a Chimp: The hunt to find the genes that make us human is an exploration of why chimps and humans are far less similar than we have been led to believe. Genome mapping has revealed that the human and chimpanzee genetic codes differ by a mere 1.6%, but author Jeremy Taylor explains that the effects of seemingly small genetic difference are still vast. In the post below, he looks at cases of domesticated chimps turning on their owners and argues that humans must learn to keep chimpanzees at arms’ length, literally and intellectually.
Jeremy Taylor has been a popular science television producer since 1973, and has made a number of programmes informed by evolutionary theory, including two with Richard Dawkins. You can visit his blog here.
In the first chapter of Not A Chimp I tell the blood-thirsty and cautionary tale of how two male chimpanzees attacked a middle-aged American couple and savaged the husband to within an inch of his life. I wanted to highlight the strangely ambivalent world of chimpanzee-human relations which can turn on a sixpence from anthropomorphic domestic bliss to berserk savagery. Sadly, but not surprisingly, attacks on humans by chimpanzee pets are not rare. Earlier this year, a young chimp called Travis, who had lived happily and docilely at home with a Connecticut woman, suddenly showed his dark side and mauled her friend, terrified the neighbourhood, attacked a posse of policemen who had rushed to the scene, and was dispatched, Dirty Harry style, by an officer’s fire-arm. One minute you can be sitting peacefully with your simian chum, both sipping Budweisers while watching a baseball game on TV, the next minute he’s biting a neighbour’s fingers off and causing havoc.
There are over 200 chimpanzees kept as domestic pets - companions - in the United States, where their owners feel compelled to disregard the fact that chimps are immensely strong, emotionally labile, and potentially highly dangerous wild animals, in favour of the comfy tea-and-slippers notion that they are so like us humans in terms of genetics, behaviour and cognition, that they are, quite literally, one of the family. Not so long ago we were thought to have diverged from the line that led to chimps a massive 25 million years ago, and had since evolved unique cognitive powers that set us apart from them. Now we know that chimp and human ancestors diverged a mere 6 million years ago, and that, over many stretches of the DNA in our respective genomes, we appear to be almost 99% identical. Although hotly contested, a good number of cognitive psychologists contend that the mental lives of chimps and humans are also closer than we once thought, and that chimps can empathize, deceive and manipulate each other because, like us, they understand that other individuals have mental lives in which their actions are governed by beliefs, desires and knowledge - rather than acting like unconscious lumbering robots.
Our lay persons’ ability to anthropomorphize our pets - in this case chimps - plays into the hands of what I call the “chimps are us” industry where scientists who should know better accentuate the similarities and trivialize the differences between chimps and humans such that humans, as Jared Diamond so memorably dubbed us, have become perceived as the “third chimpanzee”. But these scientists are simply behind the times, reading from a genetic script festooned with cobwebs. Over the last 10 years or so, thanks to increasingly powerful means to investigate the genetic structure and DNA sequence, we now know that chimpanzee and human genomes are nowhere near as similar as we have been told; that there are crucial differences between the timing and rate at which near-identical genes work in humans and chimps, particularly in the brain; and that there are a host of exotic structural differences between chimp and human genomes, caused by copy number variation of genes, multiple duplications of enormous sections of DNA, insertions, inversions and deletion of genetic code, and many more mechanisms, all of which serve to reduce the similarity of chimp and human DNA.
I am not quite sure what the best explanation is for this persistent over-stressing of the similarity between us and chimpanzees, apart from a need to anchor us more firmly to the animal kingdom by abolishing the speciesism that has, in the past, held us apart, above, “better than” all the other great apes. Something unique. Perhaps this idea of cognitive uniqueness, an unbridgeable cognitive gap between us and chimps, sniffs too suspiciously, and dangerously, of religion - the perpetual assault on conventional evolutionary biology by creationists. We use science to close the ranks between us and the other great apes for fear that God will get a foot in between us and replace Darwinian origins with divine ones. Certainly, what similarity there is between us and chimps has been used to bolster our sense of affinity with them, the better to urge us to conserve them in a world in which their habitats are becoming rapidly decimated. Indeed, we are perilously close, in my opinion, to the philosophical insanity of widely using the concept of human rights to protect and conserve chimpanzees. Here the concepts of cognitive and genetic proximity are used to argue that chimps are “virtually human”, or even worse, that they are as human as little children or the feeble-minded. Though why we need to be persuaded to save chimps because they are nearly genetically identical to us, when we need no bidding through shared genetics to try to save the rainforest, the green-flowered Helleborine orchid or the Javan rhino, is beyond me.
Even if, over parts of our respective genomes, chimps and humans are 99% identical this does not mean that chimps are 99% human or alternatively that we are 99% chimp. We must learn to keep chimpanzees at arms’ length - literally and intellectually - while still being capable of thrilling to their complex social intelligence and using them as an essential scientific tool to find out how we evolved from something that very probably looked and behaved quite like them. Chimps are NOT us!
