Thursday, July 02, 2015

PBS "First Peoples": humans evolved rapidly by "interbreeding"

PBS has a new series from “Wall to Wall Media”, called “First Peoples”, tracing the origin of man. The major link for all the episodes is here.   The first three episodes dealt with Africa, Asia, and Australia.
The overriding theme is that modern man (“homo sapies”), came into contact with “archaic humans”, other species but close and recent enough to interbreed anyway.
In Africa, the oldest male fossil for homo sapiens seems to have been found for a male in Ethiopia.  Common male and female ancestors for everyone living today have been found dating back to about 200000 years.
But there is evidence that homo sapiens from Africa mated with Neanderthals in what is now the Middle East.  Modern Europeans and Asians have up to 2% Neanderthal genes.   Some Africans may have pygmy genes, and some Asians may have older “homo erectucs”.  Interbreeding allowed men to process Vitamin D, develop stronger T-cells or various other immune mechanism, and even process energy differently so as to be able to live with less hemoglobin (in Tibet and eventually the Andes).  In all cases, genetics encouraged the most capable human to live in a geographical area, so intellect always tended to improve, whatever the previous species.
Interbreeding provides much faster evolution than simple mutation.
Homo erectus has been around for 1.5 million years, so humans may be older than we think.  One of the biggest challenges has been natural climate change.
On Australia, aborigines had to adapt to drought after Ice ages ended. 
One could say, we are all black.


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