View Full Version : Levantine and southern Arabian populations have a shared population history

14-10-18, 19:21
Deven N. Vyas

"Analyses of Neanderthal introgression suggest that Levantine and southern Arabian populations have a shared population history"

"Objectives: Modern humans are thought to have interbred with Neanderthals in the Near East soon after modern humans dispersed out of Africa. This introgression event likely took place in either the Levant or southern Arabian depending on which dispersal route out of Africa was followed. In this study, we compare Neanderthal introgression in contemporary Levantine and southern Arabian populations to investigate Neanderthal introgression and to study Near Eastern population history. Materials and Methods: We analyzed genotyping data on >400,000 autosomal SNPs from seven Levantine and five southern Arabian populations and compared those data to populations from around the world including Neanderthal and Denisovan genomes. We used f4 and D statistics to estimate and compare levels of Neanderthal introgression between Levantine, southern Arabian, and comparative global populations. We also identified 1,581 putative Neanderthal-introgressed SNPs within our dataset and analyzed their allele frequencies as a means to compare introgression patterns in Levantine and southern Arabian genomes. Results: We find that Levantine and southern Arabian populations have similar levels of Neanderthal introgression to each other but lower levels than other non-Africans. Furthermore, we find that introgressed SNPs have very similar allele frequencies in the Levant and southern Arabia, which indicates that Neanderthal introgression is similarly distributed in Levantine and southern Arabian genomes. Discussion: We infer that the ancestors of contemporary Levantine and southern Arabian populations received Neanderthal introgression prior to separating from each other and that there has been extensive gene flow between these populations."

15-11-18, 23:52
Thank you for opening the doors to another chance and opportunity to explore the past and question the future. Neanderthal's fascination was awakened by Svante Paabo "Neanderthal Man"

Given the consistency of dates for the main OOA dispersal and Neanderthal introgression, as well as the fact that introgression is
present in all non-Africans,
it has been proposed that the introgression event occurred very soon after
the OOA dispersal and most likely somewhere in the Near East (e.g., Alves, Šrámková Hanulová, Foll, & Excoffier, 2012; Currat & Excoffier, 2011; Green et al., 2010; Lazaridis et al., 2016; Prüfer et al., 2014; Wall et al., 2013).
Despite Neanderthal introgression being present in all non-African populations,


from different parts of the world have different levels of introgression, with the highest levels in EastTwo main models to explain regional differences in Neanderthal introgression have been proposed, which we will refer to as the “multiple pulses” and “dilution” models,respectively.
The “multiple pulses” model was described by Vernot et al. (2016) based on whole genome
sequences from the 1000 Genomes Project along with novel genome Oceanian genome sequences (it should be noted that this dataset does not include any Near Eastern populations).