PDA

View Full Version : More on "Out of Africa"



Angela
29-07-18, 17:38
See:
"Out of Africa by spontaneous migration waves View ORCID Profile (http://orcid.org/0000-0002-6469-3526)Paul D. Bons, Catherine Claudia Bauer, Hervé Bocherens, Tamara de Riese, Dorothée G. Drucker, Michael Francken, Lumila Menéndez, Alexandra Uhl, Boudewijn P van Milligen, Christoph Wißing"


https://www.biorxiv.org/content/early/2018/07/27/378695

"Hominin evolution is characterized by progressive regional differentiation, as well as migration waves, leading to anatomically modern humans that are assumed to have emerged in Africa and spread over the whole world. Why or whether Africa was the source region of modern humans and what caused their spread remains subject of ongoing debate. We present a spatially explicit, stochastic numerical model that includes ongoing mutations, demic diffusion, assortative mating and migration waves. Diffusion and assortative mating alone result in a structured population with relatively homogeneous regions bound by sharp clines. The addition of migration waves results in a power-law distribution of wave areas: for every large wave, many more small waves are expected to occur. This suggests that one or more out-of-Africa migrations would probably have been accompanied by numerous smaller migration waves across the world. The migration waves are considered "spontaneous", as the current model excludes environmental or other factors. Large waves preferentially emanate from the central areas of large, compact inhabited areas. During the Pleistocene, Africa was the largest such area most of the time, making Africa the statistically most likely origin of anatomically modern humans, without a need to invoke additional environmental or ecological drivers."

FIREYWOTAN
31-07-18, 21:58
Thank you for sharing this article that helps to better think about just what Out of Africa really could challenge and possibly add new support.
I keep finding this year dynamic in so so many ways. it's a real challenge to read and think and want to add to the conversations but it seems I'm getting there to late of a dollar short. Yet it's an important piece of a puzzle I so want to understand. There are so many new and eciting ideas that are being shared but at times it's more important to listen than to jump in without the right conversations but it's another question that these pieces made me think abou.


Assuming that migration waves did happen, the question arises what caused them,61 in particular the spread of AMH. Most authors favour some competitive advantage of AMH62 over other Homo species [31-33]. With climate change now central in the scientific63 discourse, many recent studies suggest that climate played an important role in the64 environmental changes making AMH more competitive than other Homo species, or65 allowing opening ecological corridors for dispersal of Homo sapiens out of Africa [34-42].

ihype02
09-08-18, 23:30
Majority of ape species are found in Africa, so I tend to be in favour of Africa being the birth of humans. I know nothing though.

Tamakore
13-05-19, 03:18
I agree. Despite various "out-of-Africa-then-back-to-Africa" theories, I think the obvious place of origin is still the most likely. When there was a significant gap in the fossil record of African ape evolution, there was a theory that the African great apes evolved in Asia then went back to Africa. Now that more African ape fossils have filled the gap that theory seems less likely. If I had to pick one place of origin I would call myself an African because I believe my ancestors lived in Africa for 39.94 out of the last 40 million years. If I had to pick one taxonomic label I would call myself an African ape because cladistically humans are just a branch of the African ape family tree. Chimpanzees are more closely related to humans than they are to gorillas. I could even call myself a monkey because cladistically apes are a branch within the monkey (simian) clade. So those who still dispute the proposition that humans evolved from monkeys will be shocked to hear that we didn't evolve from monkeys because we still are monkeys. We evolved from prosimian primates.