File talk:Haplogroup D (Y-DNA) migration.png

Why is it African? --Yomal Sidoroff-Biarmskii (talk) 06:13, 10 October 2019 (UTC)[reply]

@Sidoroff-B:,@Yomal Sidoroff-Biarmskii:: The map depicts the proposed migration route based on the most recent research (Haber et al. 2019) involving the recent discovery of basal D (haplogroup D-CTS3946) which has been hypothesized to have an African origin, not its descendant, D-M174, which is generally considered to have originated in Asia (as the map shows). "D" on this map refers, not to D-M174 (which is previously what was meant by "D"). Haplogroup D-CTS3946 (what is now meant by "D") is the common ancestor of D-M174 (now also known as D1) and the recently-discovered haplogroup D0 (D0 is now also known as "D2"). Haplogroup D-CTS3946 is a very old haplogroup (significantly older that its descendent D-M174) and is believed to have diverged from DE around 73,000 years ago, before the Out-of-Africa migration of the ancestors of modern Eurasians/non-Africans.

D-CTS3946 (after its split from DE) is proposed to have spread both within and outside of Africa: with one branch diverging into D0 in Africa, and another branch outside Africa eventually diverging into D-M174 (i.e. with the M174 mutation later arising from the D-CTS3946 that had spread to Asia)—and D-M174 then diversifying in Asia.

See this new page recently created for basal D, which describes the recent research: https://en.wikipedia.org/wiki/Haplogroup_D-CTS3946

Skllagyook (talk) 07:32, 10 October 2019 (UTC)[reply]

@Skllagyook: My maternal half-brother is the Syrian D2. As I understand, all African D are extremely close to each other and they branch with the Saudi ones. Haber doesn't seem to favor a specific scenario. --Yomal Sidoroff-Biarmskii (talk) 07:56, 10 October 2019 (UTC)[reply]

@Sidoroff-B:,@Yomal Sidoroff-Biarmskii:: Haber (et al.) does/do favor an African origin for DE as well as basal D (now known as D-CTS3946) and for D2, positing that DE originated in Africa and that the split between D0(D2) and "D"("D" meaning the ancestor of D-M174) occurred in Africa (that split being from their common ancestor basal D/D-CTS3946). Haber et al. say: "Considering both the Y-chromosomal phylogenetic structure incorporating the D0 lineage, and published evidence for modern humans outside Africa, the most favored model involves an origin of the DE lineage within Africa with D0 and E remaining there, and migration out of the three lineages (C, D, and FT) that now form the vast majority of non-African Y chromosomes. The exit took place 50,300–81,000 years ago (latest date for FT lineage expansion outside Africa – earliest date for the D/D0 lineage split inside Africa), and most likely 50,300–59,400 years ago (considering Neanderthal admixture)." He/they say(s) this elsewhere in the study as well.

Although the known African D2 are close to each other, current distributions of haplogroups do not necessarily/always reflect their origins, and the origin of the D2 clade (the D2/D split) is calculated to be old (by Haber et al.) at around 71,000 years ago (with D-CTS3946 being about 73 kya, and DE being about 76 kya), before the date of the migration of the ancestors of modern Eurasians from Africa (which Haber et al. 2019, and other recent research, calculate at about 50-60,000 years ago, or more precisely according to Haber about 50,300–59,400 years ago), this being one of the reasons Haber et al. favor an African origin for DE and its immediate subclades (E, basal D, and D2/D0). They explain:

"All non-Africans carry around 2% Neanderthal DNA in their genomes (Green et al. 2010), and Neanderthal fossils have only been reported outside Africa. The geographical distribution of Neanderthals thus suggests that the mixing probably occurred outside Africa, and the ubiquitous presence of Neanderthal DNA in present-day non-Africans is most easily explained if the mixing took place once, soon after the migration out. This mixing has been dated with some precision using the length of the introgressed segments in the 45,000-year-old (43,210- 46,880 years) Siberian (Ust’-Ishim) to 232-430 generations before he lived, i.e. 49,900-59,400 years ago assuming a generation time of 29 years (Fu et al. 2014). If this date represented the time of the migration out of Africa, it would exclude the first two scenarios (Figure 2B and 2C) [2B and 2C being the scenarios involving a Eurasian back-migration of E and D0, and 2D being the third, and according to the authors more likely, scenario involving an African origin of E and D0 as well as DE]. Thus the combination of Y phylogenetic structure and dating of the out-of-Africa migration based on the 45,000-year-old Siberian fossil (Fu et al. 2014) favors the third scenario (Figure 2D) involving the migration out of C, D and FT between 50,300 years ago (lower bound of the FT diversification, Table S2) and 59,400 years ago (upper bound of the introgression; see Figure 3) which is in accordance with suggested models incorporating an African origin of the DE lineages."

https://www.genetics.org/content/212/4/1421

Skllagyook (talk) 08:02, 10 October 2019 (UTC)[reply]