Toward Understanding the Origins and Geographic Distribution of Genomic Diversity in Human Populations from Saudi Arabia and the Broader Middle East

Abstract

The Arabian Peninsula (AP) is a geographic region that has played an important role in human evolution. To understand patterns of genetic variation, including levels of Neanderthal ancestry, we analyzed whole genome sequence data from Saudi Arabia in the AP and the broader Middle East. Consistent with prior studies, we found that the indigenous Arab genomes formed a unique cluster from other Middle Eastern populations likely due to higher levels of endogamy compared to other populations. However, our data also showed that Arabian populations possessed more diverse African ancestry, while populations in the Levant and North Africa exhibited higher levels of European ancestry, leading to extensive genetic structure across the Middle East. Furthermore, we uncovered evidence of multiple waves of migration and admixture in the AP and the Levant from Africa. Interestingly, our analyses also showed that These results have potential implications for the incidence of complex disease in different populations across the Middle East. Additionally, our findings agree with other studies that reported have lower amounts of Neanderthal ancestry in the Middle East compared to European populations. However, our study showed that levels of Neanderthal ancestry varied across the Middle East with higher levels occurring in the Levant compared to the Arabian Peninsula. These genetic patterns are consistent with a single geographic origin of admixture in the Levant with subsequent spread of this ancestry across the Middle East.