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The genetic evidence proves that pharaohnic northeast Afrika and modern West Afrika are linked via Sahelian E-M2 subclades.
The differentiation of E-Z15941 dates back to 10.53 ± 0.72 – 7.34 ± 1.00 kya. The frequency map of this clade (figure 20, panel D) shows that this haplogroup is found around lake Chad, along the Niger river and northward as far as Morocco and Egypt. In order to shed light on the past events of this lineage, we compared our SNPs with those found in the Y chromosomes from the 1000 Genomes Project (Appendix 1), which mainly come from western Africa (Poznik et al. 2016). In this in silico analysis, we only considered the 1000 Genomes Project SNPs within our sequenced 3.3 Mb. The other Sahelian/Saharan clade, E-L516, differentiated
between 8.42 ± 0.97 and 6.43 ± 0.82 kya in a broad area ranging from the central Sahel to the western coast. It was found with different frequencies in different populations with different linguistic affiliations, with no clear link with a single ethnic group (figure 20, panel G).
Interestingly, we found a clade restricted to northeastern Africa, namely E-V5001. More specifically, this clade is found at low frequencies (1-5%) in the Siwa and Baharia oasis in the Egyptian Sahara, where it arrived between 10.53 ± 0.72 and 3.81 ± 0.86 kya (figure 14 and Appendix 2). This can be interpreted as the footprint of a wider and more ancient distribution across the Sahara, which was erased and segregated in the small saharan oasis after the desertification of the region.
The geographic distribution and dating of E-Z15941, E-L516 and E-V5001 seems to suggest an extensive occupation of the
Saharan/Sahelian region from lake Mega-Chad and northward during the Green Sahara in a time window from ~ 10 kya to ~ 4 kya, followed by a massive movement southward and, to lesser extent, northward due to the advancing desertification(Atanasio; 2017).
