Discussions on the history and historiography of Australia's New England

Monday, August 07, 2017

More DNA data, the impact of cold on human survival

In the constant turmoil that is modern prehistory I missed this September 2016 Nature paper, The Simons Genome Diversity Project: 300 genomes from 142 diverse populations. The abstract reads:
Here we report the Simons Genome Diversity Project data set: high quality genomes from 300 individuals from 142 diverse populations. These genomes include at least 5.8 million base pairs that are not present in the human reference genome. Our analysis reveals key features of the landscape of human genome variation, including that the rate of accumulation of mutations has accelerated by about 5% in non-Africans compared to Africans since divergence. We show that the ancestors of some pairs of present-day human populations were substantially separated by 100,000 years ago, well before the archaeologically attested onset of behavioural modernity. We also demonstrate that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans; instead, their modern human ancestry is consistent with coming from the same source as that of other non-Africans.
Cold, cold, cold. That was the story of long periods of the hominid past. In a comment in Current Anthropology, Robert Hosfield responds to criticisms of his work on the impact of cold on the human species, including especially the possible impact of hypothermia as compared to frostbite.  It seems to come back to questions of clothing as compared to other physiological modifications. I had only seen references to this controversy, how did early hominids survive with poor tool kits and limited clothing, in very cold environments?  This popular piece provides a 2016 input reporting on Horsfield's work.

 Wikipedia piece on this issue points to the disagreements but also suggests that it was rather a long time ago.
One of the issues is the date of the domestication of fire. Many of the presentations such has this Wikipedia diorama are actually very stylized. This example will make you shiver!

 I think the reality is threefold: the human body has considerable capacity to adapt if it is given time; if you have fire and shelter, you can get warm or at least warmer when external conditions are very harsh;  and you may have access to skins or other coverings to keep you warm.

All these things have then to be adjusted to local conditions. For example, you will not go outside if a blizzard is raging unless you absolutely have to. So you will store food if you can to accommodate.  This may be no more than leaving it outside if temperatures are that low.

Your age also determines your response to climatic extremes. If you are younger, it is easier to cope. people may just die earlier.

This total mix determines the group's response It's important from the viewpoint of Australian history because it helps us make judgement about the impact of the Last Glacial Maximum.The Aborigines survived in Tasmania in glacial conditions. Clearly, they had the culture and equipment to respond, although it may have reduced populations and life expectancy. Beyond this, we just don't know what the actual story was.

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