3 ms·

>It's been known for a very long time that there were earlier migrations out of Africa, specifically to the Levant. That is contradicted by the findings below.

>It's been known for a very long time that there were earlier migrations out of Africa, specifically to the Levant. That is contradicted by the findings below. Genetic Discrepancies – Some non-African populations (e.g., Australo-Melanesians and East Asians) possess archaic DNA from unknown hominins not found in Africans, implying deep regional continuity rather than a complete replacement by recent African migrants. Multiple Ancestral Lineages – The discovery of distinct ancient hominin populations, such as the Denisovans and Red Deer Cave people, suggests a complex web of interbreeding rather than a single-origin replacement model. MtDNA & Y-Chromosome Inconsistencies – While mitochondrial DNA (mtDNA) is often cited in support of OOA, recent studies indicate that some deep-rooted Y-chromosome lineages (e.g., haplogroup D found in Tibetans and Andamanese) show ancient divergence outside Africa, inconsistent with a recent African bottleneck.

Tor3 2y ago
I don't see why the early Levant migration should in any way be contradicted by what you list. As for the list, all of that is consistent with the accepted interbreeding with Neanderthals, Denisovans and possibly other (related or unrelated to N or D) earlier migrants. It's about acquiring some genes from those people, which in no way contradicts Out of Africa and the African bottleneck. How could acquiring some genes from earlier populations be inconsistent with an African bottleneck affecting Sapiens? BTW there were apparently more than one bottleneck, at different times.
- willmadden 2y ago
  The issue isn’t just interbreeding. It’s that the fossil and genetic evidence suggest a far more complex human history than the standard OOA model allows. If Homo sapiens left Africa ~60,000 years ago, why do we find fossils in China that are 260,000 years old? In Greece we found 210,000 years old fossils, and the Levant at 177,000 years old? These predate the major OOA migration and suggest independent regional evolution. Non-African populations, especially Australo-Melanesians, carry archaic DNA not found in Africans. Where did that archaic DNA originate? It was not Africa. Again, this shows a regional continuity rather than a simple migration-plus-interbreeding scenario. If an African bottleneck occurred, why do we see deeply divergent lineages like Y-DNA haplogroup D in Tibetans and Andamanese? These suggest lineages of non-African ancestry survived bottlenecks. Stone tools in India ~74,000 years ago show no signs of disruption, contradicting the idea that a major migration replaced existing populations. The OOA model does not fully explain this evidence. A more nuanced model including persistent non-African lineages is the only thing that makes sense.
  - Tor3 2y ago
    1 - Is there scientific consensus that there are 260,000 year old Homo Sapiens fossils in China? Other fossils, yes (after all, Erectus and possibly more left Africa nearly two million years ago) 2 - Are you saying that Australo-Melanesians carry DNA which is not just Denisovan and Neanderthal and not that other archaic unknown species suggested? Denisovan and Neanderthal DNA isn't found in Africa either, generally, but that statement of course just means that what makes Neanderthals and Denisovans _different_ from the originating African populations isn't found in Africa. Neanderthals and Denisovans are still considered an "Out of Africa" population. I can't see anything in what you listed which is different from Out of Africa, plus a little intermixing with earlier migrations (e.g. Neanderthals and Denisovans, and potentially others). That would fully explain why you see some "old" DNA in some populations. It's still Out of Africa, again because 96-98 % of the DNA of any person on Earth is from a (relatively) recent exodus out of Africa. This is still extremely different from the older multi-regional hypotheses.

Tor3 2y ago

I don't see why the early Levant migration should in any way be contradicted by what you list. As for the list, all of that is consistent with the accepted interbreeding with Neanderthals, Denisovans and possibly other (related or unrelated to N or D) earlier migrants. It's about acquiring some genes from those people, which in no way contradicts Out of Africa and the African bottleneck. How could acquiring some genes from earlier populations be inconsistent with an African bottleneck affecting Sapiens? BTW there were apparently more than one bottleneck, at different times.

willmadden 2y ago
The issue isn’t just interbreeding. It’s that the fossil and genetic evidence suggest a far more complex human history than the standard OOA model allows. If Homo sapiens left Africa ~60,000 years ago, why do we find fossils in China that are 260,000 years old? In Greece we found 210,000 years old fossils, and the Levant at 177,000 years old? These predate the major OOA migration and suggest independent regional evolution. Non-African populations, especially Australo-Melanesians, carry archaic DNA not found in Africans. Where did that archaic DNA originate? It was not Africa. Again, this shows a regional continuity rather than a simple migration-plus-interbreeding scenario. If an African bottleneck occurred, why do we see deeply divergent lineages like Y-DNA haplogroup D in Tibetans and Andamanese? These suggest lineages of non-African ancestry survived bottlenecks. Stone tools in India ~74,000 years ago show no signs of disruption, contradicting the idea that a major migration replaced existing populations. The OOA model does not fully explain this evidence. A more nuanced model including persistent non-African lineages is the only thing that makes sense.
- Tor3 2y ago
  1 - Is there scientific consensus that there are 260,000 year old Homo Sapiens fossils in China? Other fossils, yes (after all, Erectus and possibly more left Africa nearly two million years ago) 2 - Are you saying that Australo-Melanesians carry DNA which is not just Denisovan and Neanderthal and not that other archaic unknown species suggested? Denisovan and Neanderthal DNA isn't found in Africa either, generally, but that statement of course just means that what makes Neanderthals and Denisovans _different_ from the originating African populations isn't found in Africa. Neanderthals and Denisovans are still considered an "Out of Africa" population. I can't see anything in what you listed which is different from Out of Africa, plus a little intermixing with earlier migrations (e.g. Neanderthals and Denisovans, and potentially others). That would fully explain why you see some "old" DNA in some populations. It's still Out of Africa, again because 96-98 % of the DNA of any person on Earth is from a (relatively) recent exodus out of Africa. This is still extremely different from the older multi-regional hypotheses.