“Out of Africa” Theory of Human Evolution Gets Further Confirmation! Saturday, May 12, 2007
Posted by Henry in Africa, anthropology, Australia, Australia Aborigines, evolution, genetics, homo erectus, human evolution, Melanesian, New Guinea, science, world.3 comments
The fascinating tale of human evolution gets another important story added to it, this time with a new DNA research done on Australian Aborigines and Melanesians from New Guinea, which further confirms the hypothesis that all humans originated from a group of people from Africa around 50,000 years ago. This is known as “Out of Africa” or the single origin theory.
Up till now the fossils and tools found in Australia have cast doubt on the Out of Africa hypothesis, since they differ significantly to South Asia. This implies that the early settlers in Australia might have interbred with the local homo erectus population that was already there (which migrated out of African some two to one million years ago), “or because there was a subsequent, secondary migration from Africa”.
But the research done using mitochondrial DNA (mtDNA) and Y chromosomes DNA shows that:
there was no evidence of a genetic inheritance from Homo erectus, indicating that the settlers did not mix and that these people therefore share the same direct ancestry as the other Eurasian peoples.
The researchers suggest that the variations in fossil and tool records can be explained with the thousands of years of isolation that the aboriginal population faced, since the land bridge joining Australia and Asia was submerged into water some 8,000 years ago.
This, in combination with an earlier report, further confirms that the Out of Africa hypothesis is becoming the firm theory of how humans have evolved. We can mainly thanks to the advancement in the science of genetics.
Below is a map of mtDNA migration, courtesy of Wikipedia:
Evolution Space 