Huffington Post Review For "Not A Chimp"

NOT A CHIMP was released in the US and Canada this week and the influential Huffington Post is the first to review it. Although neuroscientist Dan Agin disagrees with the book's premise he concludes:

Into this debate about similarities and differences between chimpanzees and humans now arrives a new book by Jeremy Taylor, a UK BBC science journalist and film producer. It's an interesting and readable book, particularly since Taylor takes a strong position in the debate. His focus is on differences, but his argument is biological rather than religious or philosophical. He makes three main points:

1) We have been evolving much faster than the chimpanzees. The rate of evolution in the human genome has apparently increased since we and the chimps split from a common ancestor. At least 7 percent of human genes have evidently changed within the past 50,000 years.

2) We humans have apparently domesticated ourselves in exactly the same way that we have cultivated farm animals, dogs, and crop plants from their wild progenitors.

3) Taylor believes that misguided scientists have suggested a closer genetic relationship between humans and chimpanzees in order to build sympathy for an endangered species.

These are strong views. Many people (including myself) may be opposed to Taylor's conclusions, but this is a provocative book that should be read by anyone interested in the debate about similarities and differences between humans and chimpanzees.

How Humans Became Such Other-Regarding Apes

Really nice essay on the essential differences between humans and the rest of the higher primates from an old friend of mine, the anthropologist Sarah Blaffer Hrdy - based on her most recent book MOTHERS AND OTHERS. Hrdy argues that the crucial wide differences between the species come in the social realm and involve huge increases in the human propensities for mutual tolerance, social communication and intention-reading.

Explaining Wolf-Dog Differences In The Ability To Follow Human Cues

In the chapter on domestication in NOT A CHIMP I present evidence showing that dogs are much better than chimps and wolves (from whom dogs are supposed to have evolved) at following human pointing gestures as to the location of food. I also show that tamed Arctic foxes are as good as dogs on these sorts of tasks. So, have dogs (tamed wolves) and tamed foxes evolved some aspects of social intelligence that is peculiar to the domestication process, and, if so, what? Adam Miklosi and colleagues from Eotvos University in Hungary have added a little complexity to the story. They show that socialised young wolves are capable of following simple human pointing cues after all - though there is delayed emergence of these social skills compared with dogs. The young wolves had been human-reared and bottle fed since pups. The experimenter drops food into bowls in a hidden way by turning away from the subject. On turning back and placing bowls to her left and right she signals with a finger point which bowl has the food - it is not possible, because of the equipment, for the animal to use its own sense of smell. The wolves equaled the performance of dogs on the simpler task where the pointing finger is less than 50 cm. from the bowl, but slightly worse which the pointing gesture was more distal - in excess of 50 cm. Also, the wolves took longer to attend to the experimenter - they took longer to establish eye contact, stop wrestling with their handlers and stop attempting to bite the experimenter! The researchers conclude that, while the difference between human reared wolves and dogs on these tasks is not as marked as previously thought, the delay in the wolves suggests they do not react to the same extent to extensive socialisation as the dogs which "are able to control agonistic behaviours". In other words the dogs are still slightly ahead because their natural tendency for fight or flight has been bred out of them over thousands of years of co-existence with humans. They therefore find it easier to fix attention on humans with less fear and aggression.

Chimps Develop "Specialised Tool Kits" To Catch Army Ants

A research team from the Goualougo Triangle Ape Project, headed by Crickette Sanz, have provided evidence that chimp tool-making and use to dip for several species of ant is more sophisticated than previously thought. Chimps generally use a long twig to actually dip for the ants - the ants climb up the twig and are thus transported to the chimp's mouth. But, where they have to break into the nest, they use a different twig tool to penetrate the nest and make an opening. Specifically, the number of tools used per site was an average of 3.37 and just over one third of recovered tool sets contained a mixture of nest perforating and ant dipping tools. There was evidence that the nest perforation tools were selectively used by the chimps to open the nests of the more aggressive epigaeic ants - where wholesale smashing of the nests would release swarms of highly aggressive biting ants driven with retaliatory intent. Using a perforation tool is clearly a more delicate technique to control ant emergence and collateral damage to self. However this report is tarnished, in my eyes, by a couple of highly anthropomorphic observations attributed to the researchers. The first is that by delicately perforating the nests, rather than smashing them, the chimps are practicing "sustainable harvesting". This begs the assumption that chimps have a deep forward planning knowledge which allows them to manage resources long into the future - which is not sustained by the mainstream of primatological research. The authors also assert that the chimps practice recycling by re-using tools that have been left by other individuals. I hope that, in the original paper, they word it to say that the effect is to recycle - rather than the intent is to recycle!

Early Tools Were Born Of Fire

How long ago did early humans begin using fire to make tools? Previous reports suggest it was a relatively new invention - dating back a mere 30,000 years or so. However, a team from the University of Capetown have re-calibrated the event. They discovered that it was impossible for them to re-create the stone tools found at the Pinnacle Point caves in South Africa unless they used 20 to 40 kilograms of hardwood and heated the silcrete from which they were fashioned to more than 300 degrees C over 30 hours. Tests reveal that original heat-treated tools are at least 70,000 years old and may even be as old as 164,000 years. So, humans had a much more sophisticated fire-assisted technology, earlier than previously thought. My interest lies in Richard Wrangham's theory for cooking being the explosive force behind earlier human brain expansion. His theory is be-deviled, so far, by lack of evidence for hearths going back 2 million + years. Evidence suggesting a far more sophisticated use of fire than that for cooking, dating back to the earliest origins of Homo sapiens in Africa, pushes the boundary of fire technology deeper into the past and may help make Wrangham's theory more tenable.

Chimps Can Be More Rational Than Humans

Whatever the rampant growth of human neo-cortex does it does not always make us more rational than other animals. Keith Jenson, Josep Call and Mike Tomasello, from the Max Planck Institute in Leipzig, compared humans and chimps on species-suitable versions of the ultimatum game in which one individual is expected to maximize assets he is given by being miserly toward the second partner. The assumption is that humans will be rationally self-interested - indeed the idea underpins most of economics. However, humans play irrationally because they factor in notions of fairness and cooperation such that they give more than they "should". This clearly reflects the intense evolutionary development of our "social brain". Chimps, however, are ruthlessly rational - giving the tiniest amounts away. The other partner in the game seems always happy with whatever crumbs he receives.

Human Chimp Interbreeding Challenged

As this fascinating Nature piece explains, in 2006 David Reich and colleagues from the Broad Institute in Cambridge, MA compared the genomes of humans, chimps and three other primates and concluded that the divergence of human and chimp ancestors could not have been a clean break but was a messy business involving more than 4 million years and two splits - an initial divide followed by a long period of interbreeding, and then a final separation in which only the young X chromosome was retained. It was the apparent youth of the X chromosome, compared with all the non-sex chromosomes, that demanded this explanation.

Now, however, Soojin Yi and colleagues, from the Georgia Institute of Technology, have challenged an interpretation which has always proved difficult to swallow for the genomics community at large. No need to involve complex speciation, they argue, because the data can be explained by a well-known difference in female promiscuity ranging from high in chimps, through intermediate in humans, to low in gorilla. High female promiscuity leads to relatively large testes and sperm counts. This means, says Yi, more rounds of cell division making all that sperm - in chimps - which increases the mutation load on chimp sperm - more mutations in males than females. This male-biased mutation rate will favour non-sex chromosomes, the mutation rate in the X will be lower, and, since the molecular clock of evolution is calculated in mutation over time, the X will therefore appear to be younger - when, in fact, it is not. Reich challenges back but, at least, as Nick Barton suggests, we now have an exciting alternative explanation for the chimp-human divergence which can be tested. Watch this space!

Novel Genes Made Us Human

Here is an extremely novel approach to explaining the origin of genes unique to the human line. David Knowles and Aoife McLysaght, from the Smurfit Institute of Genetics in Dublin, have identified 3 genes that are present in the human genome but not present in the chimp. They appear to have been made active in humans from inactive sequences of DNA in chimps and a range of other primates. The researchers have determined that these genes are active in humans because they do produce protein but they have no information yet on what, exactly, these genes do. They do point out, however, that they have only filtered about 20% of the human genome for human-chimp comparison and that their research may yet realize some 18+ genes that have arisen from non-coding DNA in human evolution.

Latest News On Dog Evolution

In the chapter on domestication in NOT A CHIMP I favour a version of dog evolution which posits that humans did not actively go out to tame wild wolves but that, if anything, wolves are too large to have been likely dog progenitors and that at least the early stages in the evolution of dogs involved a loose form of commensalism in which a smaller wolf-like species or other wild canid tamed itself by selecting for the ability to tolerate human proximity while foraging in rubbish dumps on the periphery of early human settlements. This still leaves open the question of likely dates during which this process might have occurred. Now Peter Savolainen and a number of Chinese colleagues have examined mitochondrial DNA from wolves and extant dogs and decided that the cradle for domestication of dogs was in China, probably just south of the Yangtse river, about 16,000 years ago. Humans and dogs subsequently ranged widely over Asia and dogs thereby wound up in Natufian settlements in present-day Israel by about 11,000 years ago. 16,000 years ago was the earliest time for a change from hunter-gatherer to sedentary agriculturalists in present-day China, and the beginning of rice cultivation. These researchers believe the progenitor was the smallish Chinese wolf, and, while nodding in the direction of the commensalism theory, they clearly favour a more active role for humans in selection among wolf females for tamable offspring. This runs counter to a large body of information on wolves that suggests they are, effectively, un-tamable. Interestingly they present a completely new angle on the motivation for this supposed domestication of wolves by suggesting they were used as a food resource! The Chinese are reputedly fond of dog-meat to this day but I think this is a shaggy dog domestication story!