Originally posted by: conjur
No, they're based upon mutations seen in DNA (mitochondrial DNA and the Y-chromosome) as studied and corroborrated by many different scientists.Originally posted by: Riprorin
This date is based on "molecular clock" assumptions which are based on evolutionary beliefs regarding when certain events occured.Originally posted by: conjur
Question #2 was:
How long have homo sapiens been on earth?
That would be ~200,000 years with the mitochondrial Eve having lived about 150,000 years ago (she wasn't the first homo sapiens)
It's all based on ASSUMPTIONS of the rate of mutational substitutions.