Stanford Study Traces Human Origins To Southern Africa
STANFORD (CBS) — Modern humans may have originated in southern Africa, where hunter-gatherer populations had the greatest genetic diversity, a team of Stanford University researchers said Tuesday.
Their extensive studies indicate the region was the best location for the origins of modern man, challenging the school of thought that modern humans migrated from eastern Africa, the scientists said.
Genetic diversity is an indicator of longevity, said fellow Brenna Henn of Stanford’s Department of Genetics and biology Prof. Marcus Feldman, who led the research team.
“Africa is inferred to be the continent of origin for all modern human populations,” the team wrote in a paper published online Tuesday by the Proceedings of the National Academy of Sciences. “But the details of human prehistory and evolution in Africa remain largely obscure owing to the complex histories of hundreds of distinct populations.”
Feldman said this latest study included more extensive data on hunter-gatherer groups, like the Bushmen, than researchers have ever had before.
“We’ve just never had enough people represented in our studies before,” Feldman said. “Without the participation of these people, patterns of evolution within Africa can’t be determined.”
So, the new study provides “a much more satisfying answer,” he added.
Henn explained that populations in southern Africa have the highest genetic diversity of any population, suggesting “this might be the best location for (the origins) of modern humans.”
But there are still many other evolutionary mysteries, Feldman said, indicating that further research is ongoing based on the findings of the human origin study.
“There are lots of evolutionary problems that are still to be solved,” he concluded, “and analysis of DNA is our best chance to solve them.”
The scientists have analyzed and continue looking at variations in the individual nucleotide bases that make up DNA. They have genotyped 650,000 such individual changes or “single-nucleotide polymorphisms” in people from 25 African populations.
(Copyright 2011 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)