Thread by @Aabhas24

1/n How peopling happened in world?

This thread shows the sequence rubbishing AIT through scientific evidences established so far.

Although it may change with time but the given researches state that Homo Sapiens first emerged in Africa some 300 KYA. (KYA=thousand years ago).

2/n This claim of Homo Sapiens emergence in Africa is based on thermoluminescence dating of remains & artifacts found at Jebel Irhoud, Morocco.

The studies were published in 2017.

The study can be read here. researchgate.net/publication/32…

3/n This is an image of remain from the Jebel Irhound.

More details including the skull contained in this report nature.com/articles/natur…

4/n Then we have Florisbad (South Africa) Homo-sapiens Skull dated to around 259±35 kya.

This paper contains the research ncbi.nlm.nih.gov/pmc/articles/P…

5/n In 2019, interesting studies came up.

In September of 2019, It was a computer based study referring 260 CT scans, of a virtual skull shape of the last common human ancestor & anatomically modern humans.

6/n The study suggested that modern humans arose between came in being around 260-350 kya through a merging of populations in East and South Africa.

The paper can be read here ncbi.nlm.nih.gov/pmc/articles/P…

7/n In the July of 2019, there was another interesting study.

The remains of Homo Sapiens were found in Apidima Cave in southern Greece, which were 210 kya.

Does this find, reinforces AIT? Not really. We will se this further.

Research can be read here nature.com/articles/d4158…

8/n The early expansions to Eurasia seem highly negligible & certainly it did not continue for long.

But the expansion kept happening in southern & central Africa by even bringing divergence in Human Population. ncbi.nlm.nih.gov/pmc/articles/P…

9/n Well, people must have heard of Acheulean Industry.
The term comes from the site of Saint-Acheul (an industry of stone tool manufacture characterized by distinctive oval and pear-shaped 'hand-axes' associated with HomoErectus & derived species such as Homo heidelbergensis.

10/n It appears that the Early modern human expansion in sub-Saharan Africa had contributed to the end of late Acheulean industries around 130kya.

11/n Interestingly we have arguments for the West Africa in particular about the very late coexistence of archaic and early modern humans, until as late as 12KYA
oxfordre.com/africanhistory…

12/n The studies reflect that the ancestors of the modern Khoi-San group had expanded to Southern Africa before 150 kya (possibly as early as before 260 kya).

Details in this report science.sciencemag.org/content/358/63…

13/n 130KYA, MIS 5 (Marine Isotope Stage 5) Megadrought had occurred. Then there were two ancestral population clusters in Africa:
1)mt-DNA haplogroup L0 in southern Africa (ancestral to the Khoi-San)
2)Haplogroup L1-6 in central/eastern Africa (ancestral to everyone else)

14/n A significant back-migration of bearers of L0 towards eastern Africa occurred between 120-75 kya.

Study in this paper:
ncbi.nlm.nih.gov/pmc/articles/P…

15/n The ancestors of the African Pygmies expanded to Central Africa most between 130-60 KYA.

Studies here ncbi.nlm.nih.gov/pmc/articles/P…

16/n Mostly it is very tough to analyse situation in West Africa for the lack of fossils.

Still, studies speak that Homo sapiens had reached the Western Sahelian zone & Tropical West African by 130 KYA.

17/n The Archaic Middle Stone Age sites of Africa appear to persist until very late, down to the Holocene extent, ie 12 KYA, guides us to a possibility of late survival of archaic humans, and late hybridization with Homo Sapiens in West Africa.
oxfordre.com/africanhistory…

18/n The Homo Sapiens migrated to the Levant and Europe around 130-115 KYA. Possibly the earliest waves had occurred 185 KYA.

Studies 👇science.sciencemag.org/content/359/63…

19/n Misliya Cave, Israel, A fragment of a jawbone with eight teeth was found & dated to around 185 KYA.

Levallois type (image) of Tools were found in the layers dating 250-140 KYA. If one could associate the tools with the jawbone, it would give date of earliest migration.

20/n Study related to 19/n
sciencedaily.com/releases/2018/…

21/n The evidences suggest that these early migrations do not led to long colonization and got dispersed by 80 KYA. ncbi.nlm.nih.gov/pmc/articles/P…

22/n Not very sure but there is a possibility that the first wave of expansion had reached China & North America around 125 KYA (read source of 21/n), but would have dispersed without leaving any trace in the genome of contemporary humans. nature.com/articles/natur…

23/n Interestingly, as per most prominent evidences:

Modern humans left Africa at least 125KYA using two different routes:
A)Through the Nile Valley heading to the Middle East, B)Through the present-day Bab-el-Mandeb Strait on the Red Sea crossing to the Arabian Peninsula

24/n Red Sea at that time, was at much lower level and narrower extension.
The study ncbi.nlm.nih.gov/pmc/articles/P…

25/n Through the second route, they settled in present-day UAE, (125KYA ) ( science.sciencemag.org/content/331/60…)Oman (106KYA) ( sciencedaily.com/releases/2011/… ),Reaching the Indian Subcontinent (Jwalapuram, 75KYA).

No human remains are found but only India has strongest evidences.

More from 26/n

26/n We have no human remains in any of the three sites.

But the similarities between the stone tools found at Jebel Faya, those from Jwalapuram and some from Africa suggest the dispersal to India very strongly. sciencenews.org/article/hints-…

27/n We got evidences of Peopling in India at least 80kYA
nature.com/articles/s4146…

28/n These studies also somehow buttress the claim that modern humans from Africa arrived at southern China about 100 KYA.

Consider arrival in Zhiren Cave, Zhirendong, Chongzuo City through this study ncbi.nlm.nih.gov/pmc/articles/P…

29/n Then we have Liujiang hominid (in Liujiang County), ambiguously dated 139-111 KYA. Study Link: sciencedirect.com/science/articl…

The Liujiang men are among the earliest Homo sapiens found in East Asia.

This picture was taken at the Smithsonian Natural History Museum.

30/n The dating results of the Lunadong (Bubing Basin, Guangxi, southern China) teeth hint that it may be as old as 126 KYA.

PS: the journey had certainly happened through India.
nature.com/articles/natur…

31/n All the initial expansions from Africa didn't leave traces in the results of genetic analyses based on the Y chromosome & on MtDNA (represents only a small part of the human genetic material).

32/n And hence it appears that those HS didn't survive in large numbers and were actually assimilated by our major ancestors.

Scholars generally argue that Toba Eruption might be the reason for extinction (small genetic imprint).

33/n But there are some strong argue Toba Eruption hardly impacted human population.

Study 👇science.sciencemag.org/content/327/59…

34/n The most recent dispersal of Human Sapiens took place 70-50 KYA.

Studies:
1) cell.com/current-biolog…
2)ncbi.nlm.nih.gov/pmc/articles/P…
3)ncbi.nlm.nih.gov/pmc/articles/P…

35/n As discussed earlier, around 75KYA a small group of around 1000 from East Africa, bearing mitochondrial haplogroup L3 crossed the Red Sea strait at Bab el Mandib, to what is now Yemen.

Study:
1)ncbi.nlm.nih.gov/pmc/articles/P…
2)science.sciencemag.org/content/331/60…

36/n As discussed earlier, some studies also supports for the northern route through Sinai/Israel/Syria (Levant). Their descendants spread along the coastal route around Arabia and Persia to the Indian Subcontinent 55 KYA.

37/n Other research supports a migration out of Africa between about 65-50 KYA.
cell.com/current-biolog…

38/n These coastal migrations between approx 70-50 KYA is associated with mitochondrial haplogroups M & N (both derivative of L3).

As Homo Sapiens migrated, they interbred with Neanderthals and Denisovans. sciencedirect.com/science/articl…

39/n Denisovan DNA makes 0.2% of mainland Asian & Native American DNA.
ncbi.nlm.nih.gov/pmc/articles/P…

40/n Will be pointing more details of specifically Peopling in India from 41/n tomorrow.

But so far it has been clearly established that first wave of migration from Africa had people reach India.