Friday, December 26, 2014

Science, convergent evolution, birdsong and personal contact

From Pfenning et al. illustrating the regions of Human and
Songbird brains that are involved in song and speech and
which have similar gene expression specializations.
Two amazing papers in Science exploring:
These demonstrate some of the genetic basis of singing in songbirds, which has evolved independently several times in birds and of course has also evolved independently in humans.
Nevertheless there is convergent evolution not merely in the "morphology" as one might expect but in the actual genetic basis of singing. The full papers incidentally are well worth reading even though they are highly technical. They also compare, for controls, a vocal non-learning bird (chicken) and a vocal non-learning primate (macaque).

This not only provides (much) more fascinating detail on the basic point, which I first learned from Iain McGilchrist's wonderful book The Master and his Emissary, that speech must have evolved from song, but also it illustrates in a fascinating way Simon Conway Morris's key point about convergent evolution. Indeed I'm not sure that even Simon would have expected such a dramatic finding. Truly the idea that evolution is "random" needs to be re-thought given the many striking instances of convergent evolution.

There is another completely different but also fascinating paper in that issue of Science called When contact changes minds: An experiment in transmission in support for gay equality which demonstrates the enduring influence of one personal contact on opinions (in California) in support of gay marriage. They compared gay and straight canvassers on the subject but didn't compare the effect of telephone or virtual contact with the direct personal contact they studied. Still it seems very plausible that it was the direct contact that mattered. All fascinating.

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