Biology 1001A Lecture Notes - Lecture 21: Species, Homo Sapiens, Denisovan
16 Aug 2017
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Document Summary
Competing theories about where modern humans (homo sapiens) evolved, and which is best supported by available evidence. Perhaps through competition, h. sapiens eventually drove archaic humans to extinction: this hypothesis suggests that all modern humans are descended from a fairly recent. African ancestor: as of 2011, genetic data generally supported the african emergence hypothesis. Further work on the y chromosomes of thousands of men from africa, europe, asia, australia, and the americas has confirmed that all modern humans are the descendants of a single migration out of africa. Populations of h. erectus and archaic humans had spread through much of europe and asia by 500 thousand years ago and modern humans (h. sapiens) evolved from descendants of these earlier dispersals. Although these geographically separated populations may have experienced some evolutionary differentiation, gene flow between them prevented reproductive isolation and maintained them as a single but variable species, h. sapiens.
