Human evolution; from several starting points in Africa (Introduction)

by David Turell , Saturday, July 14, 2018, 01:09 (2324 days ago) @ David Turell

A new theory proposes H. sapiens sprung up in several places in Africa and gradually coalesced into our current form:

https://www.theguardian.com/science/2018/jul/11/no-single-birthplace-of-mankind-say-sci...

" a team of prominent scientists is now calling for a rewriting of this traditional narrative, based on a comprehensive survey of fossil, archaeological and genetic evidence. Instead, the international team argue, the distinctive features that make us human emerged mosaic-like across different populations spanning the entire African continent. Only after tens or hundreds of thousands of years of interbreeding and cultural exchange between these semi-isolated groups, did the fully fledged modern human come into being.

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"This continental-wide view would help reconcile contradictory interpretations of early Homo sapiens fossils varying greatly in shape, scattered from South Africa (Florisbad) to Ethiopia (Omo Kibish) to Morocco (Jebel Irhoud).

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"The latest analysis suggests that this patchwork emergence of human traits can be explained by the existence of multiple populations that were periodically separated for millennia by rivers, deserts, forests and mountains before coming into contact again due to shifts in the climate. “These barriers created migration and contact opportunities for groups that may previously have been separated, and later fluctuation might have meant populations that mixed for a short while became isolated again,” said Scerri.

"The trend towards more sophisticated stone tools, jewellery and cooking implements also supports the theory, according to the paper...

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“'Someone finds a skull somewhere and that’s the source of humanity. Someone finds some tools somewhere, that’s the source of humanity,” she said, describing the latest approach as: “‘Let’s be inclusive and construct a model based on all the data we have available.”

"The analysis also paints a picture of humans as a far more diverse collection of species and sub-populations than exists today. Between 200,000 and 400,000 years ago, our own ancestors lived alongside a primitive human species called Homo naledi, found in southern Africa, a larger brained species called Homo heidelbergensis in central Africa and perhaps myriad other humans yet to be discovered."

Comment: It is a strange thought to imagine various types of humans evolving everywhere from their ape-like ancestors, all to end up as one surviving type. Sounds like a purposeful drive. A major problem is the paucity of wide-spread homo fossils to fill in the story.