High-resolution characterization of genetic markers in the Arabian Peninsula and Near East

In this work, I analysed the maternally transmitted mtDNA and biparentally inherited genome-wide polymorphisms to shed light on successive migrations into and from the Arabian Peninsula, at the crossroads between Africa, Europe and Asia. I focused on three main issues: 1- The first descendants of the out-of-Africa migration: My phylogeographic analysis on 385 complete mtDNA N1, N2 and X sequences showed their common origin in the Gulf Oasis region at ~57-65 ka. Instead of isolation, I identified a continuous gene flow between Arabia and Near East. Genome-wide data supported the strong clustering of Arabian and Near Eastern populations. 2- Major population expansions in the Arabian Peninsula: My data on the rare N(xR) lineages supported a continuous settlement of the Peninsula, while my founder analysis of other N lineages suggested Near Eastern lineages arriving continuously from the Late Glacial (31%-46%; some U and N1 lineages), Younger Dryas (24-28%; R0a and HV), Neolithic (20-25%; J and T; supported by my new complete 44 sequences) and till recently (10-15%; derived lineages). These results again challenge the hypothesis of long-term isolation between these two regions. 3- Genetic exchanges across the Red Sea: Phylogeographic analysis of L4 and L6 mtDNA complete sequences and HVS-I founder analysis from Africa into Arabia/Near East indicated that the Arab maritime dominance and slave trade (0.5-2.5 ka) were the main contributors (~60-70%) to the African input, but the entrance began with the establishment of maritime networks in the Red Sea by 8 ka. Genome-wide analyses supported this recent introduction (ROLLOFF estimates of 30-40 generations) suggesting that Arabia has 6% eastern African and 3% western African input. The HVS-I founder analysis for the back-to-Africa migrations showed that the Late Glacial period dominated introductions into eastern Africa, while the Neolithic was more important for migrations towards North Africa.