Sunday, October 11, 2015
The R1 haplogroup probably originated in Africa.
The phylogeography of R1 in Africa makes it clear that this y-chromosome is spread globally across Africa and includes the genetic structure of diverse African populations including Berber, Chadic, Cushitic, Khoisan,Pygmy, Niger-Congo, Nilo-Saharan and Semitic speaking African populations (Berniell-Lee et al, 2009; Cruciani et al, 2010; Wood et al, 2009). The fact that Dravidians carry the R haplogroup illustrate the recent introduction of R y-chromosome to Eurasia.
Abu-Amero et al (20009) reveal the fact that Dravidians carry the R haplogroups illustrate the recent introduction of Ry-chromosomes to Eurasia. The frequency of haplotype M173 in Eurasia is as follows: Anatolia 0.19%, Iran 2.67%, Iraq 0.49% Oman 1.0%, Pakistan 0.57% and Oman 1.0% . This contrast sharply with the widespread distribution of R1 in Africa that ranges between 7- 95% in various parts of Africa, especially Cameroon (Coia et al, 2005). Coia et al (2005) has revealed that no maternal Eurasian lineages have been found among Sub-Saharan Africans with a R1- M173 profile.
Haplogroup V88 has the greatest frequency in Africa. It is predominately carried by Chadic speakers, ranges between 2-60% among Central African Niger-Congo speakers (Cruciani et al, 2010). Researchers have found that the TMRCA of V88 was 9200-5600 kya (Cruciani et al, 2010).
The phylogenetically deep haplogroup R1b is mainly found in West Africa and the Sahel, where the frequency ranges between 5-85% among various Niger Congo speakers (Cruciani et al, 2010). The paternal record of M173 on the African continent illustrates a greater distribution of this y-chromosome among varied African populations than, in Asia.
The greatest diversity of R1b in Africa is highly suggestive of an Africa origin for this male lineage. Archaeological (Lal, 1963), genetic (Winters, 2008;2010a), placenames (Balakrishnan, 2005) and linguistic data group (Aravanan,1979,1980; Upadhyaya, 1976,1979; Winters 1985a,1985b, 1989) linking Africans and Dravidian support the recent demic diffusion of SubSaharan Africans and gene flow from Africa to Eurasia. An early colonization of Eurasia 4kya by Sub-Saharan Africans and Dravidian carriers of R1-M173 is the best scenario to explain the high frequency and widespread geographical distribution of this y-chromosome on the African continent (Winters, 2010c). Given the greatest diversity of R1- M173, this is the most parsimonious model explaining the frequency of R-M173 in Africa.
In conclusion, the R haplogroup probably originated in Africa. In my paper POSSIBLE AFRICAN ORIGIN OF Y-CHROMOSOME R1-M173 , I argue that the P clade originated in Africa because 1) the age of R-V88 and 2) the widespread nature of R1 in Africa. Researchers have found that the TMRCA of V88 was 9200-5600 kya (Cruciani et al, 2010). Eurasians carry the M269 (R1b1b2) mutation. The subclades of R1b1b2 include Rh1b1b2g (U106) (TMRCA 8.3kya) and R1b1b2h (U152) (TMRCA 7.4kya). The most recent common ancestor for R1b1b2 is probably 8kya (Balaresque et al, 2010).
In Africa we find R-M269 and V88. Clearly, R-V88 is older than R-M269 there is no evidence of archaeological evidence of a back migration or haplogroup R into Africa, but there is evidence of the migration of the Kushites and Proto-Sahara into Eurasia from Middle Africa. The diversity of R1 haplogroups in Africa supports the proposition that the R macrohaplogroups originated in Africa, not Eurasia.