Figure 2.

Spread of Iran-like ancestry and Semitic languages

Map shows admixture dates in thousands of years ago (red) based on Table S2 and Semitic languages dispersals estimated by Kitchen et al. (2009) from lexical data (blue). Kitchen et al. (2009) estimate an Early Bronze Age origin for Semitic languages ~5.7 KYA in the Levant. Admixture also appears in non-Semitic speaking groups such as the Somalis, a Cushitic-speaking population. Kitchen et al. (2009) suggested that Semitic languages would have spread into East Africa with little gene flow, as Ethiosemitic-speaking populations share similar proportions of non-African ancestry and are genetically similar to Cushitic-speaking populations, confirmed by more recent analysis (Pagani et al., 2015). They proposed that the current distribution of Ethiosemitic languages reflect a language diffusion process through African populations, rather than gene flow. Our admixture tests Tables S3 and S4 also suggest an ancient Egyptian source of ancestry in East Africa, rather than from Arabia, although ancient DNA from Arabia is still missing to make a comparable analysis. See also Figure S2.