Wednesday 2 July 2014

Wednesday Science Limerick - Our Ancestral DNA



Lifelike figure of a Neanderthal Man in the Neanderthal Museum in Germany
It would seem a Neanderthal man
Met a sweet little Denisovan
And their child’s DNA
Is still with us today
As a part of our genetic plan
Denisova cave in Altai Mountains, SIberia, viewed from the road
Remains of Denisovans, Neanderthal and modern humans have been found in the Denisova cave, and genetic testing has proved that the three sub-species of Homo interbred - with, for example - the Australian aborigines having more Denisovan genes than  do Europeans. It could well be that human evolution is typified by the formation of separate groups, probably with different cultures and way of gathering food. The most successful groups prospered. Climate change, driven by the Ices Ages, would cause groups to migrate and any cross-breeding would allow the more useful genetic changes in the different groups to be shared.

New research results are appearing all the time and only a week ago there was a detailed press report Skulls with mix of Neandertal and primitive traits illuminate human evolution from the American Association for Science about 400,000 year old skeletons found in a Spanish cave. At the same time a paper in Science, The genetics of Mexico recapitulates Native American substructure and affects biomedical traits, suggests that some indigenous Mexican groups are as genetically different from one another as Europeans are from East Asians. This paper suggests that some groups have been isolated for hundreds of thousands of years. [However I am waiting to see other comments on this claim as it is thought that humans only reached America about 15,000 years ago!]

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