NOT A CHIMP

NOT A CHIMP
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 15 November 2012

New brain gene gives us edge over apes, study suggests

http://phys.org/news/2012-11-brain-gene-edge-apes.html

Exciting new development, reported in Nature Communications, about the discovery of a new gene that arose very quickly, somewhere between 6 million and 1 million years ago, unique to humans. The team includes Martin Taylor from the University of Edinburgh and Philipp Khaitovitch from the Max Planck Institute in Leipzig. as this Physorg piece says: "Scientists say the gene – called miR-941 – appears to have played a crucial role in human brain development and may shed light on how we learned to use tools and language. Researchers say it is the first time that a new gene – carried only by humans and not by apes – has been shown to have a specific function within the human body."

It appears to have been assembled out of a non-coding region of the genome otherwise known as "junk DNA".

Martin Taylor is quoted saying: ""As a species, humans are wonderfully inventive – we are socially and technologically evolving all the time. But this research shows that we are innovating at a genetic level too. This new molecule sprang from nowhere at a time when our species was undergoing dramatic changes: living longer, walking upright, learning how to use tools and how to communicate. We're now hopeful that we will find more new genes that help show what makes us human."

Note that the sequence is actually a micro-RNA, that it seems very involved with cell pluripotency and the brain, and has been formed by evolution of one version of a copy number duplication in the genome. It remains to be seen precisely what effects this gene has in terms of growth in size of the brain, and neuronal organization relevant to the emergence of higher human cognition among our ancestor species several million years ago. What is exciting is that, although much evolution involves changes in the regulation of genes - how hard they work and when, rather than sequence changes in the genes themselves, there may be room in the mix for entirely de novo genes with profound and far-reaching effects. Watch this space!!

Here's the abstract for the Nature article which is open access:

microRnA-mediated gene regulation is important in many physiological processes. Here we explore the roles of a microRnA, miR-941, in human evolution. We find that miR-941 emerged de novo in the human lineage, between six and one million years ago, from an evolutionarily volatile tandem repeat sequence. Its copy-number remains polymorphic in humans and shows a trend for decreasing copy-number with migration out of Africa. Emergence of miR-941 was accompanied by accelerated loss of miR-941-binding sites, presumably to escape regulation. We further show that miR-941 is highly expressed in pluripotent cells, repressed upon differentiation and preferentially targets genes in hedgehog- and insulin-signalling pathways, thus suggesting roles in cellular differentiation. Human-specific effects of miR-941 regulation are detectable in the brain and affect genes involved in neurotransmitter signalling. Taken together, these results implicate miR-941 in human evolution, and provide an example of rapid regulatory evolution in the human linage.

And here is the url for the open access PDF: http://www.nature.com/ncomms/journal/v3/n10/pdf/ncomms2146.pdf





Monday 12 November 2012

Humans, chimpanzees and monkeys share DNA but not gene regulatory mechanisms

http://phys.org/news/2012-11-humans-chimpanzees-monkeys-dna-gene.html

In NOT A CHIMP I try to untangle the conundrum as to how such close relatives as humans and chimpanzees - in terms of genetic sequence - could turn out into such different animals. I suggested that crucial differences in the timing and amount of gene activity are more important than the actual DNA sequence of genes (though there are a good many interesting differences at that level also). I cited the work of Yoav Gilad, at University of Chicago, on gene regulation and he has now done a several species comparison of gene regulation comparing human, chimp and rhesus monkeys. He has discovered that, while 67% of the promotor sequences of genes are equivalent among all three species, over 40% of genes differed with respect to the activity of the gene - the amount it gets transcribed into mRNA and thence protein.

Wednesday 31 October 2012

Crows do not plan their clever tricks

http://phys.org/news/2012-10-crows-clever.html

Alex Taylor and his colleagues in New Zealand continue to probe the limits to corvid intelligence. Here they report using an old test of bird intelligence - whether the bird can plan its actions to successfully retrieve food, or whether it simply reacts quickly to a random guess. The birds are presented with a number of strings. Food is attached to some such that pulling on the string will retrieve the food. In others there is a break in the string between bird and food. Do they "case" the problem and select for continuous string? The answer is no.

The full paper is at  http://dx.doi.org/10.1098/rspb.2012.1998?utm_source=royalsociety-org&utm_medium=referral&utm_campaign=journal-news&utm_content=2012-10-24

LAS VEGAS MAN JOINS RANKS OF CHIMPS-AT-HOME IDIOTS

http://www.lasvegasnvblog.com/2012/10/las-vegas-residents-protest-against-one-mans-attempt-to-house-chimps-at-his-home/

In the opening to NOT A CHIMP I preached dire warnings of the possible downside to keeping a chimp at home as a pet - as an alarming number of American households do. Here the residents of an area of Las Vegas are up in arms about a man's attempt to share his domestic bliss with 4 chimps!

Wednesday 10 October 2012

Why clever crow is no bird brain

http://phys.org/news/2012-10-clever-crow-bird-brain.html

In the chapter CLEVER CORVIDS in NAC there is a lot of information about the extraordinary cognitive abilities of new Caledonian crows - particularly with regard to their intelligence and dexterity in using tools to retrieve food. In this lovely piece of scientific work, researchers, using field of vision cameras, have determined that these crows have much better binocular vision than most birds, and indeed, than other members of the crow family and other corvids. "the binocular overlap is 61.5 degrees, which is at least 23.9 degrees greater than in non-tool-using species of crow that the researchers also examined." This allows them to judge distance much better than other animals with eyes mounted on the sides of their heads and explains why these crows are much better tool users than birds with similar powers of cognition.

Tuesday 2 October 2012

New Caledonian crows reason about hidden causal agents

http://www.pnas.org/content/109/40/16389.abstract.html?etoc
A few days ago I posted about the New Zealand research group who have claimed that New Caledonian crows can infer the causal role of hidden agents. This is now an open access paper in PNAS and the link to it is above.

Scientists find homolog of mammalian neocortex in bird brain

http://phys.org/news/2012-10-scientists-homolog-mammalian-neocortex-bird.html

In the chapter CLEVER CORVIDS in NOT A CHIMP I relay Nathan Emery's complaint that the brains of birds have been given short shrift in comparative biology. He points out that both birds and mammals have an embryonic brain region - the telencephalon - that can give rise to comparable structures. Furthermore, the cognitive feats of corvids allow them to shrug off the discouraging moniker "bird brains" for ever. Now scientists at Chicago have found an area of nuclei in the dorso-ventricular ridge in bird brains that behave very much like the neocortex in mammals.

Monday 1 October 2012

A Comparison of Brain Gene Expression Levels in Domesticated and Wild Animals

http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1002962

When I wrote NOT A CHIMP, Frank Albert, at the Max Planck Institute for Evolutionary Anthropology, was just beginning to cross rats to produce a violently feral strain and a docile, more domesticated behavioural variant. He hoped to be able to find genes that underlie these traits and, eventually, to compare genes that seem important in, say, rat domestication, with genes important in domesticated traits in other species. Is there a universal genetic foundation for domestication throughout the animal kingdom? Here, in this open access PLoS Genetics paper, he presents his results for rats, compared with wild and domesticated representatives from a range of species. "We used mRNA sequencing to analyze genome-wide gene expression patterns in brain frontal cortex in three pairs of domesticated and wild species (dogs and wolves, pigs and wild boars, and domesticated and wild rabbits). We compared the expression differences with those between domesticated guinea pigs and a distant wild relative (Cavia aperea) as well as between two lines of rats selected for tameness or aggression towards humans."

Unfortunately there was no evidence at all for such universal genetics: "There were few gene expression differences between domesticated and wild dogs, pigs, and rabbits (30–75 genes (less than 1%) of expressed genes were differentially expressed), while guinea pigs and C. aperea differed more strongly. Almost no overlap was found between the genes with differential expression in the different domestication events. In addition, joint analyses of all domesticated and wild samples provided only suggestive evidence for the existence of a small group of genes that changed their expression in a similar fashion in different domesticated species."

He concludes: "In summary, the majority of brain gene expression changes in domesticated animals are specific to the given domestication event, suggesting that the causative variants of behavioral domestication traits may likewise be different."

Tuesday 18 September 2012

New Caledonian crows reason about hidden causal agents

http://www.pnas.org/content/early/2012/09/10/1208724109.abstract?etoc

For anyone out there who remains interested in the "evolving" story of corvid (crow) cognition here is the latest from the New Zealand camp who study New Caledonian crows. Because it is an open access paper you can download the whole thing for free if you so wish.


Abstract

The ability to make inferences about hidden causal mechanisms underpins scientific and religious thought. It also facilitates the understanding of social interactions and the production of sophisticated tool-using behaviors. However, although animals can reason about the outcomes of accidental interventions, only humans have been shown to make inferences about hidden causal mechanisms. Here, we show that tool-making New Caledonian crows react differently to an observable event when it is caused by a hidden causal agent. Eight crows watched two series of events in which a stick moved. In the first set of events, the crows observed a human enter a hide, a stick move, and the human then leave the hide. In the second, the stick moved without a human entering or exiting the hide. The crows inspected the hide and abandoned probing with a tool for food more often after the second, unexplained series of events. This difference shows that the crows can reason about a hidden causal agent. Comparative studies with the methodology outlined here could aid in elucidating the selective pressures that led to the evolution of this cognitive ability.

Tuesday 11 September 2012

Crows react to threats in human-like way

http://phys.org/news/2012-09-crows-react-threats-human-like-neural.html

In my chapter CLEVER CORVIDS I describe some of John Marzluff's work on corvid cognition. He has now shown that crows recognize and respond to faces much in the same way we humans do. They are capable of perceiving a threatening mask - and remembering it - even though the individual wearing the mask does them no actual harm. Deep in the bird's brain is a structure analogous to our amygdala which is strongly involved in face recognition - and the valency of emotion in the face, and other fear reactions.

Wednesday 29 August 2012

More sophisticated wiring, not just bigger brain, helped humans evolve beyond chimps

http://medicalxpress.com/news/2012-08-sophisticated-wiring-bigger-brain-humans.html

Yet more evidence that the human brain is not only bigger than that of the chimp but better. Dan Geschwind and colleagues in LA have been looking at gene expression particularly in the pre-frontal cortex and find much more complex patterns of gene expression there.

""When we looked at gene expression in the frontal lobe, we saw a striking increase in molecular complexity in the human brain," said Geschwind, who is also a professor of psychiatry at the Semel Institute for Neuroscience and Behavior at UCLA.

Tuesday 28 August 2012

No third-party punishment in chimpanzees

http://www.pnas.org/content/early/2012/08/22/1203179109.abstract?etoc

The research machine headed by Mike Tomasello at EVA Leipzig has been comparing chimpanzees to humans with respect to social justice. Humans will punish a third party even if they themselves are not the prime subject of injury. Chimpanzees will by-stand while one chimpanzee robs another and there is no third-party policing of behaviour.

Saturday 18 August 2012

Man’s Underground Best Friend: Domestic Ferrets

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043267

In NOT A CHIMP I go into great detail about social cognition and look closely about what we know about the domestication of dogs and how the process of domestication in dogs and arctic foxes has led to changes in structure and brain chemistry that have accompanied a heightened ability to empathize with humans, track human movements closely, and react accurately to human cues as to the location of something. Here researchers extend the canon to ferrets- showing that domesticated ferrets test very much the same as dogs over a range of social cognition tasks involving interaction with their owners. fascinating stuff - and because it is in PLoS1 it is open access so you can download the whole paper.

When it comes to food, chimps only think of themselves

http://phys.org/news/2012-08-food-chimps.html

There have been many ingenious test set ups designed to evaluate a sense of fairness and sharing in chimps and bonobos. Some experiments have suggested that a chimp will actively manipulate an apparatus so that a human can reach an object or a fellow chimp get access to food otherwise denied him. Other experiments have suggested chimps have little concept of fairness and sharing. The debate shuttles back and forth. The experiment described here, run by researchers under Keith Jensen at Queen Mary College, London, suggests very strongly that chimps do not have any real sense of fairness whereas you can see an impulse to share in very young children.

Wednesday 8 August 2012

The Wisdom of Not Being Too Rational

http://news.sciencemag.org/sciencenow/2012/07/the-wisdom-of-not-being-too-rati.html?ref=em

Very nice article by Michael Balter which refers to the prodigious learning of which crows, and other corvids, are capable (citing Nickie Clayton's work) and some very important ways in which children's learning behaviour goes beyond, allowing them to solve problems that crows find beyond them.

Wednesday 4 July 2012

Texas graduate student attacked by chimps at Goodall sanctuary in South Africa

http://worldnews.msnbc.msn.com/_news/2012/07/01/12509158-texas-student-attacked-by-chimps-in-south-africa-undergoes-6-hours-of-surgery?lite

Readers of Not A Chimp will be well aware of my ambivalent attitude toward mans "nearest neighbour", or, more precisely, the dangers inherent in mixing too closely with them. Texan student Andrew Oberle is the latest victim of "quick-as-a-flash" chimp violence, in this case because he apparently crossed a crucial territorial line. He is, thankfully, presently recovering after massive surgery to repair his many soft tissue injuries. Ironically, the attack seems to have occurred at a Jane Goodall-funded chimp refuge. How many times.... chimps don't play nice.

Thursday 21 June 2012

Human brain evolution: From gene discovery to phenotype discovery

http://www.pnas.org/content/early/2012/06/19/1201894109.abstract?etoc

One of the main tubs I kept on thumping in NAC was that the human genome and the chimpanzee genome are not as closely related as most commentators would like us to believe - that the so-called 1.6% difference is a myth. In this PNAS paper, Todd Preuss, whose research is mentioned extensively in my text, expands on precisely that point as well as examining the difficulty extrapolating from genotype to phenotype. As he puts it: "Our knowledge of the genes that underwent expression changes or were targets of positive selection in human evolution is rapidly increasing, as is our knowledge of gene duplications, translocations, and deletions. It is now clear that the genetic differences between humans and chimpanzees are far more extensive than previously thought; their genomes are not 98% or 99% identical."

Wednesday 13 June 2012

Dog domestication may have helped humans thrive while Neandertals declined

http://www.americanscientist.org/issues/id.15294,y.0,no.,content.true,page.1,css.print/issue.aspx

In my chapter in NAC called "The Ape That Domesticated Itself" I deal with the various hypotheses to explain when and how dogs became domesticated. In this fascinating, if very arguable, piece, Pat Shipman details more recent research on dog origins including dating work on finds from several European sites that shows that dogs were buried with full ceremonial honours in human encampments between 35,000 and 23,000 years ago. The relationships with dogs might have begun even earlier, she says, and might have been unique to Homo sapiens because no dog remains have ever been found at Neanderthal sites. Shipman details a lot of recent research which shows that dogs large and small can increase hunting efficiency many-fold, bringing huge extra nutritional benefits to humans - especially gestating mothers - even after accounting for the amount fed to the dogs. We all know about the extraordinary level of communication that exists between humans and dogs, and dogs' uncanny ability to fasten onto and follow human cues - even direction of gaze. What might have facilitated gaze communication between dogs and humans? Shipman points to the evolution of the whites of the eyes - the sclerae - which are absent in chimps (except for one or two rare mutations). If a fortuitous mutation in sapiens' history led to the formation of sclerae this would have accelerated and tightened the bond between dog and man, improved their ability to work as a combined hunting unit, contributed to human nutrition and perhaps proved the edge that Homo sapiens enjoyed over the Neanderthals! Shipman admits there is no evidence to back up this last part of her tale - but it is a rattling, and thought-provoking just-so story - and may be a lot more!

Friday 8 June 2012

Domestic dogs display empathic response to distress in humans

http://medicalxpress.com/news/2012-06-domestic-dogs-empathic-response-distress.html

Yet more evidence - if needed - of the empathic power of dogs in the context of approaching and empathizing with sounds of crying from humans, even if the individual concerned is not known to the dog.

Friday 11 May 2012

Sneaky Rambo Chimp

A fun story about further research into the malicious forward planning of the infamous stone-throwing chimp, Santino, in the Furuvik Zoo, north of Stockholm. Over the course of a year, researchers from Lund University, tracked his ability to camouflage his intentions to throw stones at unsuspecting zoo visitors by curbing his aggressive displays so as to reduce clues to immediate intent, and to build clumps of hay on the perimeter of his enclosure to hide caches of stones, ready for the next onslaught. It clearly seems that he has some degree of foresight and planning or the future, rather similar to the behaviour of the crows that I mentioned in CLEVER CORVIDS where they provisioned for a future breakfast by caching food from the night before only if they had been treated in a curmudgeonly fashion the day before. The question, as ever, with these studies, is what degree of theory of mind the chimp needs to be able to enact such strategies. It is not necessary for him to be thinking "I will hide the stones here because they will not think that the hay is hiding missiles" thereby profiting from the human visitors' false state of knowledge.

Because the paper is published in PLoS 1 it is freely available for those who want to read in full. The URL is:
 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0036782

Otherwise a good precis of the research can be accessed here:

http://www.alphagalileo.org/ViewItem.aspx?ItemId=120108&CultureCode=en

Tuesday 8 May 2012

Psychopathy linked to specific structural abnormalities in the social brain

In the chapter INSIDE THE BRAIN in NOT A CHIMP I detail significant anatomical and cell differences between humans and chimps relating to parts of the brain responsible for social cognition: the so-called 'social brain'. Here, Nigel Blackwood, from King's College, London, reveals results from MRI studies of prisoners with the 'cold' or psychopathic form of anti-social personality disorder and shows structural abnormalities in parts of the prefrontal cortex and the temporal pole. he claims this is the first detailed study to relate psychopathy to deficits in the 'social brain' .http://medicalxpress.com/news/2012-05-psychopathy-linked-specific-abnormalities-brain.html

Friday 4 May 2012

Extra gene drove instant leap in human brain evolution

http://medicalxpress.com/news/2012-05-extra-gene-drove-instant-human.html

In NOT A CHIMP I devote one chapter, called MORE IS BETTER, to the extent to which phenomena like gene duplication have driven human evolution and widened the genomic gap between humans and our near neighbours - chimpanzees. Evan Eichler's work was heavily mentioned in the book and in this recent report on his work with Franck Polleux, an expert in brain development at The Scripps Research Institute, they make trenchant claims for the dramatic effects of gene duplication at crucial points in our hominin evolutionary history that may have been very important in brain growth and development - and unique human brain anatomy. The gene in question is SRGAP2. Here's a section of this Medical Express report which encapsulates what happened and why it may be very important:

""There are approximately 30 genes that were selectively duplicated in humans," said Franck Polleux. "These are some of our most recent genomic innovations."

Intriguingly, many of these genes appear to play some role in the developing brain. Polleux and Evan Eichler, a genome scientist at the University of Washington, focused their expertise and attention on one of the genes known as SRGAP2. This gene has, in fact, been duplicated at least twice during the course of human evolution, first about 3.5 million years ago and then again about 2.5 million years ago.

The new work shows that the second and relatively recent duplication event produced only a partial copy of the gene. This copy acts at exactly the same time and place as the original, allowing it to interact with and block the ancestral gene's function.

"This innovation couldn't have happened without that incomplete duplication," Eichler said. "Our data suggest a mechanism where incomplete duplication of this gene created a novel function 'at birth'."

Interestingly, the novel gene appears to have arisen just as the fossil record shows a transition from human's extinct Australopithecus ancestors to the genus Homo (as in Homo sapiens), which led to modern humans. That's also when the brains of our ancestors began to expand and when dramatic changes in cognitive abilities are likely to have emerged."

The gene is involved in neuronal migration to appropriate parts of the developing brain from the epithelium from which neurons bud off. It also seems to govern the complexity of projections any neuron can develop - a key factor in eventual complexity of interconnectivity of neurons - network.

Tuesday 1 May 2012

Josh Klein's TED talk on the intelligence of crows

A fascinating and well delivered TED talk on the intelligence of crows that mirrors the information in the CLEVER CORVIDS chapter of NOT A CHIMP. Well worth a watch.

Monday 23 April 2012

Ravens remember relationships they had with others

In the chapter CLEVER CORVIDS in NOT A CHIMP I mention the research, on ravens, of theory of mind in ravens by Tomas Bugnyar and colleagues. Here is yet another offering from this camp that points to extensive memory of social relationships in ravens and yet another example of he casual denigration of avian minds by the use of the term "bird-brained"!!

A quote from the Physorg article sums it up:-

"Ravens respond to calls from previously unknown individuals with even lower and rougher calls and thus try to increase the acoustic perceivable body-size – also in humans larger people have lower voices than smaller ones and angry humans rougher voices. While it was known that mammals change their voices based on the relationship they share with others, the researchers were now able to show for the first time that also birds change their calls according to relationship quality.
The duration of the memory is beyond the previously estimated ability for birds; the ability to remember relationship valence has been shown for the first time in animals."

Thursday 23 February 2012

Our Missing Genes

In a chapter titled LESS IS MORE in my book NOT A CHIMP I talk about a number of loss-of-function mutations in the human genome where a gene that functions in our primate cousins has become silenced in us. Turned into a pseudogene. Sometimes this can lead to disease and sometimes it can be shown that it is adaptive - part of the evolution of our genome. In this report on a recent SCIENCE paper, the research group found over 1000 genuine loss-of-function mutations in the human genome and suggested every European has at least 20 of them.

Friday 27 January 2012

Tame Theory: Did Bonobos Domesticate Themselves?

In NOT A CHIMP I devote a chapter to the idea, first suggested to me by Richard Wrangham, that humans may have self-domesticated. I mention at length Wrangham's work with Brian Hare on the differences between bonobos and chimpanzees and their suggestion that self-domestication processes were very important in deriving those differences. Here, in Scientific American, is a useful article going over that ground, following a scientific paper co-authored by Wrangham, Hare and Wobber.

Saturday 14 January 2012

Scientists find link between gene and sensitivity to emotional environment

In NOT A CHIMP I detail research that looked at the tie-up between anxious personality traits and the carriage of a short repeat variant of the gene for the serotonin transporter molecule at the synapse. Here a group of scientists, principally at the University of Essex, carry the research forward in a very gratifying way. They find that carriers of the short repeat have a negative cognitive bias which can be trained by cognitive therapy to be more positive. So they tend to take more notice of negative or threatening information, and, conversely, blossom when they are subject to very supportive social experiences.

"Professor Elaine Fox, who led the study, explained: "Our findings suggest that people with a short serotonin transporter gene are likely to be far more reactive to both very negative situations, such as a car crash, and very positive ones, such as a very supportive relationship. This supports the idea of short serotonin transporter genes as 'adaptability', rather than 'vulnerability', genes. They may not only increase the risk of an individual developing emotional vulnerability in a negative environment but also increase the chances of them benefiting from a supportive environment, compared to people with the long form...People with a long serotonin transporter gene are likely to be less influenced by their emotional environment, which may help to protect them from negative events but could also mean that they are less able to benefit from a positive environment."

Their studies support work from Oxford which suggests that "drugs used to treat anxiety and depression by lowering serotonin levels at the gap between nerve cells (such as selective serotonin reuptake inhibitors) might work by reducing a patient's negative attention bias, causing them to adopt a more positive outlook on life that leads to a decrease in anxiety and depression."

""This opens the door to the idea of personalized treatments for anxiety disorders. Information about the genotype and cognitive biases of a patient could be used to inform decisions about which treatments, such as ABM and cognitive behavioural therapy, are likely to be most effective," Professor Fox said."