3.3 Historical evidence of gene flow from Levant into the Southwest Asia
We next calculated D-statistics to explore the Neolithic origin of all modern domestic goats, based on the previously published ancient genomic data from the Near East. Our results revealed that among all Neolithic goat groups from the Fertile Crescent, samples from Levant region have higher genetic affinity with modern African goats (Figure 3a ), that is in line with previous study of Daly et al. 2018. We further observed that among Asian modern goat groups, samples from IRQ and IRN have higher allele sharing with Neolithic Levant. However, we found that goat samples from South-Asia (BNG and PKS) have high genetic affinity with ancient samples from Neolithic East group (Figure 3a ). To estimate the possible time of gene flow from Levant into the SWA, we further performed outgroup f 3-statistics, f 3 (ancient IRN, ancient Levant; outgroup), using AdmixTools software (Alexander et al. 2009). The results indicate that among all ancient samples from IRN country, those from Chalcolithic period (~ 4,200 BC) have the closest genetic affinity with different ancient Levant populations (Figure 3b ), which provides a dating of the admixture event. This is confirmed by the D statistics, in the form of (Ancient IRN, Neolithic-East; EAFR, Outgroup) as well as (Ancient IRN, Neolithic-East; ancient Levant, Outgroup) (Figure S9 ). This again illustrates the high level of genetic continuity between Iranian goats with both EAFR and different Levant populations in Chalcolithic period.