Scivillage.com Casual Discussion Science Forum

https://arstechnica.com/science/2017/07/...of-africa/

EXCERPT: [...] The picture painted by nuclear DNA (nDNA) is that, between 765,000 and 550,000 years ago, our ancestors in Africa diverged into two groups. One group would eventually lead to our own species [...] The other group would lead to Neanderthals and the closely related Denisovans. This proto-Neanderthal/Denisovan group left Africa for Eurasia at some point; sometime around 430,000 years ago, they diverged into distinct Neanderthals and Denisovans. But the picture painted by mtDNA is different. Neanderthal mtDNA is more similar to modern humans than it is to Denisovan mtDNA. And the divergence date between us and them, when estimated based on mtDNA, is much more recent—between 498,000 and 295,000 years ago. Some researchers have suggested that you can explain this mixed genetic evidence if Neanderthals interbred with another, more recent African group of humans. This would provide them with different mtDNA after they split from Denisovans. And that, in turn, means that there must have been humans, closely related to our own species, who left Africa for Europe far earlier than previously suspected....

MORE: https://arstechnica.com/science/2017/07/...of-africa/

I'm inclined to think that the history of human life is a lot more complex than we currently imagine. If we knew the details, a lot of current theorizing would seem laughably simplistic.

So I suspect that there might have been lots of out-of-Africa episodes, or alternatively none at all. The reason I say that is that I don't imagine everyone suddenly saying 'Let's all leave Africa!' and then doing so in one huge mass-migration. It's more likely that early hominins were kind of leaking out of Africa in small mobile hunter-gatherer bands for a very extended period.

Nor do I hold to any orthodoxy that all human evolution has to take place in Africa or that if any human evolution took place out of Africa, it was always abortive (the Neanderthals, the Denisovans, the Flores 'hobbits') and didn't lead to us. That 'only-in-Africa' faith just seems inherently unlikely to me.

There was probably lots of evolving going on in lots of different places (reproductive isolation associated with long migrations and movements into new ecological environments would almost guarantee that), resulting in lots of human variants widely dispersed around Africa and Eurasia, resulting in turn in lots of gene mixing as bands encountered each other. So the fine-details of human genetic history are probably going to be complicated.

Not trying to sound like I denigrate women....I would never do that and if this sounds like I am then buddy you need to get a life......Remember the movie Quest for Fire. The male group of travellers comes across a different tribe that has a female who willingly submits to having sex with the alpha stranger. I'm kind of wondering whether we should think consensual sex was the norm for interbreeding. Something leaves me to think it was forced sex that was the prime mechanism for spreading human genes around. What that is probably still with us, in our genetic makeup. This may sound awful but it's as if life doesn't care about how the job gets done, just keep making more life anyway you can. We really don't need to follow that script any longer, but some do.