MtDNA variation in North, East, and Central African populations gives clues to a possible back-migration from the Middle East.
A.D. Holden et al.
The general timeline for human occupation of Africa has been studied extensively. However, questions involving Upper Palaeolithic migrations still persist. One remaining question is the presence of the mitochondrial M1 haplogroup in North and East Africa. Some (Quintana-Murci et al. 2004, 1999) argue that the presence of M1 in modern Africans is a remnant of the original M haplogroup that left Africa 60 kya via the Horn of Africa. Others (Forster, 2004) propose that it is instead the result of a back-migration from the Arabian Peninsula from 20 kya. This research aims to test these two competing hypotheses.
We analysed mtDNA variation in ~250 persons from Libya, Somalia, and Congo/Zambia, as representatives of the three regions of interest. Our initial results indicate a sharp cline in M1 frequencies that generally does not extend into sub-Saharan Africa. While our North and especially East African samples contained frequencies of M1 over 20%, our sub-Saharan samples consisted almost entirely of the L1 or L2 haplogroups only. In addition, there existed a significant amount of homogeneity within the M1 haplogroup.
This sharp cline indicates a history of little admixture between these regions. This could imply a more recent ancestry for M1 in Africa, as older lineages are more diverse and widespread by nature, and may be an indication of a back-migration into Africa from the Middle East. Further research on this topic includes more extensive population samples from the Middle East, as well as possible correlations of M1 to the Afro-Asiatic language family.
I’m still looking for the full text on this one. Another mt DNA study placing M1 as Asian.