Rita Gonc¸alves1, Ana Freitas1, Marta Branco1, Alexandra Rosa1,4, Ana T. Fernandes1,
A total of 553 Y-chromosomes were analyzed from mainland Portugal and the North Atlantic Archipelagos of Ac¸ores and Madeira, in order to characterize the genetic composition of their male gene pool. A large majority (78–83% of each population) of the male lineages could be classified as belonging to three basic Y chromosomal
haplogroups, R1b, J, and E3b. While R1b, accounting for more than half of the lineages in any of the Portuguese subpopulations, is a characteristic marker of many different West European populations, haplogroups J and E3b consist of lineages that are typical of the circum-Mediterranean region or even East Africa. The highly diverse haplogroup
E3b in Portuguese likely combines sub-clades of distinct origins. The present composition of the Y chromosomes in Portugal in this haplogroup likely reflects a pre-Arab component shared with North African populations or testifies, at least in part, to the influence of Sephardic Jews. In contrast to the marginally low sub-Saharan African Y chromosome component in Portuguese, such lineages have been detected at a moderately high frequency in our previous survey of mtDNA from the same samples, indicating the presence of sex-related gene flow, most likely mediated by the Atlantic slave trade.
Interesting from this
mtDNA haplogroups L0–L3 and M1 that are characteristic to sub- Saharan populations are present at ~12% and ~14.8% in the south of Portugal and Madeira, respectively.
…which assumes the M1 is from slaves, but I suspect this may have a much older date, like 20k or more from North Africa as some movement from North Africa is suggested at this point by mt DNA U6 and Y chr E1, and one L mt DNA hg.
TMRCA for Portuguese E1 lineages estimated as 22.9 ± 7.2 ky (Table 2) favours the first scenario, a possible parallel to mtDNA U6 cited in Gonzalez et al. (2003).
Which agrees with the observations that the North African Holocene population seem to be a patchwork of sub Saharan and Eurasian phenotypes, with the far West (Taforalt) showing as the least Sub Saharan, and Sudanese Nubia as the most. This supports an expansion from the North East of Africa that spread the Iberomaurussian culture as far as Portugal and Syria.
The paper also observes that J1 seems to have arrived on two separate occasions..
the divergence time of J1 in Central and South Portuguese populations (between 4.8 ky and 11.1 ky, Table 2) suggests that they were imported from distinct founding populations or even through different waves from different Middle-Eastern populations that had diverged much earlier elsewhere.
Which could be possible if the older J1 arrived with the Capsian transition in North Africa as was recently suggested.