From Will Dunham at Reuters,
Genetic data from the skeletal remains of seven people who lived centuries ago in South Africa’s KwaZulu-Natal Province is offering intriguing new evidence that our species, Homo sapiens, is older than previously believed.
Scientists said on Thursday they sequenced the genomes of the seven individuals including a boy who lived as a hunter-gatherer at Ballito Bay roughly 2,000 years ago. In doing so, they were able to estimate that the evolutionary split between Homo sapiens and ancestral human groups occurred 260,000 to 350,000 years ago.
Until recently, the prevailing belief was that Homo sapiens arose a bit before 200,000 years ago. The new study and fossil discoveries from Morocco announced in June indicate a much older origin.
There is broad agreement among scientists that Homo sapiens originated in Africa. But the recent discoveries have suggested our species arose not in one locale like east Africa but in multiple places, a more complex so-called pan-African origin that the new genetic research seems to support. More.
But what exactly does it mean to say that “our species arose not in one locale like east Africa but in multiple places”? That human beings might have different original ancestors despite our being, for all practical purposes, pretty much the same worldwide?
That level of convergence points to frontloading, if not design. If not, what do they mean?
Abstract: Southern Africa is consistently placed as a potential region for the evolution of Homo sapiens. We present genome sequences, up to 13x coverage, from seven ancient individuals from KwaZulu-Natal, South Africa. Three Stone Age hunter-gatherers (about 2000 years old) were genetically similar to current-day southern San groups, while four Iron Age farmers (300 to 500 years old) were genetically similar to present-day Bantu-speakers. We estimate that all modern-day Khoe-San groups have been influenced by 9 to 30% genetic admixture from East Africans/Eurasians. Using traditional and new approaches, we estimate the first modern human population divergence time to between 350,000 and 260,000 years ago. This estimate increases the deepest divergence among modern humans, coinciding with anatomical developments of archaic humans into modern humans as represented in the local fossil record.Paper. (paywall) – Carina M. Schlebusch, Helena Malmström, Torsten Günther, Per Sjödin, Alexandra Coutinho, Hanna Edlund, Arielle R. Munters, Mário Vicente, Maryna Steyn, Himla Soodyall, Marlize Lombard, Mattias Jakobsson, Science
See also: Researchers: Evidence of life 3.95 billion years ago
Stasis: When life goes on but evolution does not happen