Evolution and humans: all over Africa (Evolution)

by David Turell , Friday, September 29, 2017, 14:41 (2610 days ago) @ David Turell

There seems to be several lines of African descent:

https://cosmosmagazine.com/palaeontology/bones-of-stone-age-boy-challenge-single-origin...

"The 2,000-year-old bones of a boy found on a beach in South Africa have provided more grounds to challenge the prevailing theory that modern humans had a single origin in north-eastern Africa.

"That fraying theory, based on fossils found at Omo Kibish and elsewhere in Ethiopia, dates the emergence of modern humans to about 180,000 years ago. However, by using DNA analysis as a ‘molecular clock’ to calculate the length of time since the boy’s ancestors diverged genetically from other groups of modern humans, scientists in South Africa and Sweden estimate that modern humans must have existed between 260,000 and 350,000 years ago.

"This pushing back of the estimated date of the emergence of modern humans by at least 100,000 years is roughly in line with research published in June that dated human remains and other artefacts found at the Jebel Irhoud archaeological site in Morocco as about 300,000 years old.

"The finding lends weight to the hypothesis there was not just a single cradle of modern humankind in north-eastern Africa but, rather, an entire continental nursery.

“'It seems that both genetics and archaeology are converging on this point that there might be multiple places in Africa that archaic humans transitioned from Homo erectus to H. heidelbergensis to modern humans,” says Carina Schlebusch of Uppsala University in Sweden, lead author of the new research, published in the journal Science.

"Scientists have been hesitant about alternatives to the single-origin idea because of the demise of a previous ‘multiregional’ theory that once competed with the ‘Out of Africa’ hypothesis, Schlebusch says. That theory, suggesting separate groups of modern humans evolved from ancient hominin groups around the world, was disproven by DNA analysis showing Homo sapiens fossils throughout the rest of world were much closer genetically to each otherthan those from Africa, and therefore could not have evolved independently.

“'The multiregional theory was wrong in terms of how the globe was populated,” Schlebusch agrees, “but it is not necessarily wrong about how humans evolved in Africa.”

***

"Given the lack of supporting archaeological artefacts, the only thing known with certainty about the boy is what his genes tell us: he was a member of the San branch of the Khoe-San peoples of southern Africa. He likely lived a hunter-gatherer lifestyle and spoke with the clicks that linguistically unify the San with the Khoe, who practised a nomadic form of pastoral farming.

"The Khoe-San are not only genetically distinct from Europeans and Asians but also from other Africans. Research suggests that they are a branch of modern humans that diverged early from our oldest common H. sapiens ancestors.

"What makes Ballito Bay A special, from a contemporary scientific perspective, is his relative genetic “purity’, meaning his ancestry involved fewer procreative liaisons with members of other human groups than the other specimens."

Comment: In my view the burst of human development all over Africa can be the result of a direction by God. No other branch of primates did that.