January 05, 2008

Abstract on Y-haplogroup J1-M267

From the XVII Congresso Degli Antropologi Italiani (thanks to the reader who brought this to my attention).

Dispersal patterns of M267-derived Y chromosomes in the Mediterranean

Sergio Tofanelli (1), Gianmarco Ferri (2), Laura Caciagli (1), Luca Taglioli (1), Donata Luiselli (3), Giorgio Paoli (1), Cristian Capelli (4)

Human Y chromosomes belonging to haplogroup J1 (International Society of Genetic Genealogy 2007) share a derived state (G) at the M267 mutation site. It has been argued (Semino et al., 2004) that this mutation originated some 24,000 years ago in the Near East or North-East Africa and spread in the Mediterranean by means of at least two temporally distinct migrations: the first would have occurred towards Aegean and Italian coasts in Neolithic times; a more recent one (estimated time bounds 8.7–4.3 Ky) would have diffuse M267-G in Northern Africa. According to other authors (Nebel et al., 2001; Al-Zahery et al., 2003; Di Giacomo et al., 2004), however, M267-G would have arisen as early as 10,000 years ago and would mark the historical expansion of Arabian tribes in the northern Levant and southern Africa.
We investigated the variability of M267-G chromosomes from 23 different Mediterranean populations (original and published data) at a total of 20 Y STR loci. Three different sets of markers were considered: the “Y-filer” set (DYS456, DYS389I, DYS390, DYS389II, DYS458, DYS19, DYS385a, DYS385b, DYS393, DYS391, DYS439, DYS635, YGATA-H4, DYS437, DYS392, DYS438, DYS448) allowed to more accurately reconstruct time and space of the main dispersal events associated with this mutation; the “MH” (DYS19, DYS388, DYS390, DYS391, DYS392, DYS393) and the “DL3” (DYS388, YCAIIa, YCAIIb) sets allowed the origin and diffusion of local modal haplotypes to be better defined.
The results depict a more complex and deeper stratification of haplotype-clades than thought before. In fact, we could observe both, geographically structured and even lineages, that could be associated to pre-agricultural, Neolithic and historical demographic events.

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