There are two fascinating new papers about language evolution in Nature Neuroscience (institutional access required). The first, by Rilling et al is a comparative MRI scan of human and primates, looking at the circuit level activation of the arcuate fasciculus, the neural pathway that links two major language areas of the brain, Wernicke’s Area and Broca’s area. It is this pathway that is lesioned in Aphasiacs. They found a significant difference in the levels of connectivity and the location of the terminations of the pathway across the species. In two other control pathways where no difference was predicted, they found reasonable uniformity across the species.
Archive for March, 2008
A new PLoS paper by Okanoya et al claims to show rats engaging in significant tool use. As you might expect, the paper is pretty extensive and convincing, clearly demonstrating that rats can not only use tools, but differentiate between different categories of tools in different contexts. This is another piece of evidence against the idea that only humans can use tools and that tool use is the product of some sort of higher cognitive function. Already tool use has been observed in a wide range of species, from chimpanzees to birds.
I had the pleasure of sitting next to Okanoya at dinner during Evolang. He was a lovely guy and he whipped out his laptop and showed us some of the videos in this paper. He said the paper had only really been done to prove that even rats could use tools. His team certainly wasn’t making a comment about rats in particular. As he says in the paper, this is just more evidence that “tool use is not a specific faculty resulting from higher intelligence, but is a specific combination of more general cognitive faculties”. It is important to bear in mind though that these rats were trained to use tools and we don’t have any evidence yet of natural tool use.
From The Guardian Science, by James Randerson
A fossilised jawbone and teeth found in a cave in northern Spain may have belonged to one of the first human ancestors to set foot in western Europe. The hominid has been identified as Homo antecessor, or pioneer man, a possible ancestor of both our own species and Neanderthals. The fossils date from between 1.1m and 1.2m years ago.
The next day brought a couple of plenary speakers who both spoke on fascinating topics but somehow managed to make them dull as hell or inpenetratable.
Rudolph Botha began by looking at exaptation and argued that it is a mechanism that is too frequently employed in accounts of language evolution. He painstakingly went through a series of examples in the literature where exaptation is heavily invoked and tried to show that it did not meet the standards for exaptation that most biologists would use. It was persuasive, and on an interesting topic, but somehow Botha contrived to make it duller than a Calvinist sermon. Come on Rudi, this subject is naturally cool, it shouldn’t have the life sucked out of it like this.
Okay, more biased rambling commentary on Evolang 08…
I’d never heard of Gary Marcus before but he presented one of the most stimulating presentations of the whole week. The title of his talk, “Language as Kluge”, was intriguing, but sounded a bit too technical to really whet the appetite. As he got into his talk I was very pleasantly surprised by the broad brush approach he used, and the attention-to-detail he used to back it up.
More evidence for language affecting cognition. Here’s a lovely long post at Mixing Memory about a PLoS paper showing language having a measurable influence on colour perception.
Well I’m back in the UK after a very pleasing Evolang 08 in Barcelona. It was an busy and fulfilling week of evolutionary linguistics, biology, primatology and cultural evolution. Our hosts were the University of Barcelona and CosmoCaixa, the fantastic local science museum. The beer and tapas certainly helped to make the week pass smoothly, although the conference threw up its usual raft of controversies.
There’s no way I can cover everything that was said in every talk, not least because lots of the sessions ran simultaneously. But I’m going to try to give you a brief outline of the plenary speakers and some of the more significant presentations I saw:
The workshop session kicked off with Duane Rumbaugh, legendary primatologist, who gave his standard talk about his primate research programme. He emphasised the importance of finding emergent behaviours in great apes, by which he meant behaviours that are insightful and synthesise learning experience without any apparent stimulus control or reinforcement. He pointed to lots of examples from Kanzi to reinforce this point. Ultimately this talk was interesting but familar.
Rumbaugh was followed by Dave Leavens, who I really couldn’t make my mind up on. He presented an argument that joint attention was essential for language competence, which seemed to fit neatly within the . However, his significant extrapolation was to present a range of evidence for pointing behaviour in primates. From this he concluded that the precursors of triadic pointing are present in other primates and therefore must (parsimonially) be in our common ancestor. I liked the argument but felt that the evidence he presented was a little bit rough around the edges, particularly his argument that environmental factors account for why we don’t see these behaviours as readily in captive chimpanzees. He drew an unnecessary and unpleasant comparison between caged primates and Romanian orphanage children, which failed to account for the differences in cognition found in these species under natural circumstances. research programme
This was followed by William Hopkins, another Yerkes researcher, who produced some excellent evidence that Chimpanzees are indeed lateralised, despite the scientific consensus. He showed some excellent studies of the differences in size of relevant brain areas, that reinforced extensive practical research performed on apes in captivity.
Many more to come as I get round to writing them up…