Genetic study The Persian plateau served as hub for Homo sapiens after the main out of Africa dispersal

[Tautalus]

Abstract

A combination of evidence, based on genetic, fossil and archaeological findings, indicates that Homo sapiens spread out of Africa between ~70-60 thousand years ago (kya). However, it appears that once outside of Africa, human populations did not expand across all of Eurasia until ~45 kya. The geographic whereabouts of these early settlers in the timeframe between ~70-60 to 45 kya has been difficult to reconcile. Here we combine genetic evidence and palaeoecological models to infer the geographic location that acted as the Hub for our species during the early phases of colonisation of Eurasia. Leveraging on available genomic evidence we show that populations from the Persian Plateau carry an ancestry component that closely matches the population that settled the Hub outside Africa. With the paleoclimatic data available to date, we built ecological models showing that the Persian Plateau was suitable for human occupation and that it could sustain a larger population compared to other West Asian regions, strengthening this claim.
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The Persian plateau served as hub for Homo sapiens after the main out of Africa dispersal - Nature Communications

The timing and chronology of the movement of Homo sapiens after migration out of Africa remains unclear. Here, the authors combine a genetic approach with a palaeoecological model to estimate that the Persian Plateau could have been a hub for migration out of Africa, suggesting the environment...

www.nature.com

Some excerpts:​

"On the basis of genetic and archaeological evidence, it has been suggested that the Eurasian population that formed the first stable deme outside Africa after ~70–60 kya can be characterised as a Hub population, from which multiple population waves emanated to colonise Eurasia, which would have had distinct chronological, genetic and cultural characteristics. It has also been surmised that the Hub population cannot be seen as simply the stem from which East and West Eurasians diverged. Instead, this was a more complex scenario, encompassing multiple expansions and local extinctions"

"The aforementioned scenario was grounded in evidence stemming from ancient genomes from West and Central Eurasia and China, indicating that the ancestors of present-day East Eurasians emerged from the Hub at ~45 kya (Fig. 1A, red branch). These emergent groups subsequently colonised most of Eurasia and Oceania, though these populations became largely extinct and were assimilated in West Eurasia by a more recent expansion that took place by ~38 kya (Fig. 1A, blue branch). The first of these two expansions, whose associated ancestry we name here the East Eurasian Core (EEC), left descendants in Bacho Kiro, Tianyuan, and most present-day East Asians and Oceanians. The second expansion, which we name the West Eurasian Core (WEC), left descendants in Kostenki14, Sunghir, and subsequent West Eurasians, and in the genome of palaeolithic Siberians"

"The outlined scenario is complicated by the need to account for the Basal Eurasian population (Fig. 1A, green), a group that split from other Eurasians soon after the main Out of Africa expansion, hence also before the split between East and West Eurasians. This population was isolated from other Eurasians and later on, starting from at least ~25 kya, admixed with populations from the Middle East. Their ancestry was subsequently carried by the population expansions associated with the Neolithic revolution to all of West Eurasia."

"With our work, we show that populations from the Persian Plateau carry an ancestry component that closely matches the population that settled the Hub outside Africa, therefore pointing to the Persian Plateau as suitable for human occupation throughout 60–40 kya, indirectly shedding light on the early interactions and admixture of our species with Neanderthals and the relationships between the main Eurasian and the elusive Basal Eurasian human population"

 

[norbert]

Can be complemented with this article in Reuters: https://www.reuters.com/science/whe...ng-africa-new-study-has-an-answer-2024-03-25/

One of the study's authors, Luca Pagani, claims the following: "The people inhabiting the hub at the time apparently had dark skin and dark hair, perhaps resembling the Gumuz or Anuak people now living in parts of East Africa."

Yes, they had dark skin and dark hair which is only logical. But does Mr. Pagani actually believe that the Gumuz or Anuak, both Nilotic peoples, haven't changed in the last 70.000 years? Or that they lived in East Africa for the same amount of time? The laws of evolution do not apply do the Gumuz or Anuak?

I think this article shows a more realistic rendering of what archaic humans looked like: https://medium.com/@civanekmekci/what-really-is-the-archaic-homo-sapiens-15c420f9b69

 

[Tautalus]

Can be complemented with this article in Reuters: https://www.reuters.com/science/whe...ng-africa-new-study-has-an-answer-2024-03-25/

One of the study's authors, Luca Pagani, claims the following: "The people inhabiting the hub at the time apparently had dark skin and dark hair, perhaps resembling the Gumuz or Anuak people now living in parts of East Africa."

Yes, they had dark skin and dark hair which is only logical. But does Mr. Pagani actually believe that the Gumuz or Anuak, both Nilotic peoples, haven't changed in the last 70.000 years? Or that they lived in East Africa for the same amount of time? The laws of evolution do not apply do the Gumuz or Anuak?

I think this article shows a more realistic rendering of what archaic humans looked like: https://medium.com/@civanekmekci/what-really-is-the-archaic-homo-sapiens-15c420f9b69

The people inhabiting the hub were homo sapiens sapiens, they were anatomically modern.
They were not the archaic humans pictured on the article that you indicate.

 

[norbert]

The people inhabiting the hub were homo sapiens sapiens, they were anatomically modern.
They were not the archaic humans pictured on the article that you indicate.

Of course but anatomically modern doesn't mean that any of today's human populations resemble these early humans. All modern phenotypes are the result of later adaptations and that includes the phenotype of the Gumuz and Anuak. Luca Pagani adding a "perhaps" is proof that his claim is based on nothing. It is more of a journalistic than scientific claim actually. No human population has remained unchanged over the last 70.000 years, yet he seems to make the argument that the Gumuz and Anuak are some kind of remnant of those ancient times. That is definitely not what the early modern humans looked like. Yes, they were anatomically modern but still comparably archaic. Dark skin, dark straight or wavy hair, prominent brow ridges. The Shkul V skull of an early human found in Israel displays a prominent brow bridge. The picture you saw in the link I posted before is not the actual representation of an early modern human. In fact, it shows a neanderthal. Despite the obvious differences (the brain case for instance), it still may give you an approximate idea of what the early humans looked like. And if there's a human population today that may come close to what the early modern humans looked like, I would point to the aboriginal Australians, but even they do not look like them because they too were subjected to a long period of change and adaptation since OoA.

 

[Tautalus]

Of course but anatomically modern doesn't mean that any of today's human populations resemble these early humans. All modern phenotypes are the result of later adaptations and that includes the phenotype of the Gumuz and Anuak. Luca Pagani adding a "perhaps" is proof that his claim is based on nothing. It is more of a journalistic than scientific claim actually. No human population has remained unchanged over the last 70.000 years, yet he seems to make the argument that the Gumuz and Anuak are some kind of remnant of those ancient times. That is definitely not what the early modern humans looked like. Yes, they were anatomically modern but still comparably archaic. Dark skin, dark straight or wavy hair, prominent brow ridges. The Shkul V skull of an early human found in Israel displays a prominent brow bridge. The picture you saw in the link I posted before is not the actual representation of an early modern human. In fact, it shows a neanderthal. Despite the obvious differences (the brain case for instance), it still may give you an approximate idea of what the early humans looked like. And if there's a human population today that may come close to what the early modern humans looked like, I would point to the aboriginal Australians, but even they do not look like them because they too were subjected to a long period of change and adaptation since OoA.

Skhūl V's skull is estimated to be between 120,000 and 80,000 years old. The initial time frame of the Hub study is between ~70–60 to 45 kya, so there is a significant temporal difference.

Also there is doubt as to whether the Skhūl hominids are partially of Neanderthal descent or whether they represent an extinct lineage.
In any case, the Hub populations belonged to a different lineage.

I don't know if Aboriginal people are the best example, and that's because Aboriginal people carry a significant percentage of Denisovan DNA, which should affect their phenotype.
Tianyuan, the East Eurasian descendant of the Hub's first expansion, lacks the levels of Denisovan DNA present in modern East Asians. Studies seems to indicate that this Denisovan admixture occurred in the Pacific region, so after the populations left the Hub, and not on the Asian continent.

Perhaps the best example of these early Hub individuals are the populations of the Andaman Islands, which the study authors classify as unadmixed South-East Eurasians.

Anyway, I doubt the Hub initial population had very pronounced archaic features like prominent brow ridges.

 

[norbert]

Skhūl V's skull is estimated to be between 120,000 and 80,000 years old. The initial time frame of the Hub study is between ~70–60 to 45 kya, so there is a significant temporal difference.

Also there is doubt as to whether the Skhūl hominids are partially of Neanderthal descent or whether they represent an extinct lineage.
In any case, the Hub populations belonged to a different lineage.

I don't know if Aboriginal people are the best example, and that's because Aboriginal people carry a significant percentage of Denisovan DNA, which should affect their phenotype.
Tianyuan, the East Eurasian descendant of the Hub's first expansion, lacks the levels of Denisovan DNA present in modern East Asians. Studies seems to indicate that this Denisovan admixture occurred in the Pacific region, so after the populations left the Hub, and not on the Asian continent.

Perhaps the best example of these early Hub individuals are the populations of the Andaman Islands, which the study authors classify as unadmixed South-East Eurasians.

Anyway, I doubt the Hub initial population had very pronounced archaic features like prominent brow ridges.

The Andamanese acquired their phenotype via convergent evolution. Isolation doesn't conserve previous traits. Think of the Galápagos Islands where all the animals descend from the mainland but have radically diverged from their ancestors due to isolation, on a much larger temporal scale, of course. The Andamanese today are not the same people that colonised those islands 26.000 years ago. They adapted to a very tropical environment over time and I don't see how they would have looked like that in the "Hub."

Nevermind. There is no point in pursuing this any further. It's just another paper published for grants with lots of maybes and perhapses. Who knows how much it's been politicised, too. Btw, the Andamanese are also said to harbour 1-2% neanderthal admixture. But mixing with other humans is not the main driving force behind changes in phenotype. It is the combination of many factors like climate, diet, subsistence etc.