Failure to replicate a genetic signal for sex bias in the steppe migration into central Europe
Year: 2017
Type: letter
Abstract: Goldberg et al. (1) used genome-wide ancient DNA data (2) from central European Bronze Age (BA) populations and their three ancestral sources of steppe pastoralists (SP), Anatolian farmers (AF), and European hunter-gatherers (HG) to investigate whether the SP migration into central Europe after 5,000 years ago (3, 4) was sex-biased.By estimating a lower proportion of SP ancestry on the X chromosome (36.6%),which is primarily carried in females, than on the autosomes (61.8%), they suggest that the migration involved a ratio of 5-14 SP males for every female.We attempted to replicate this finding using qpAdm (3), which leverages allele frequency correlations between the admixed (BA) and source (SP, AF, and HG) populations with distant outgroups to eliminate potential biases due to genetic drift between the true source populations and the ones used as surrogates for them.Our outgroups are Mota (5), Ust_Ishim (6), Kostenki14 (7), GoyetQ116-1 (7), Vestonice16 (7), MA1 (8), AfontovaGora3 (7), and Levantine Neolithic farmers (9).We ran qpAdm with allsnps: YES and Mota as the basis population.The model fits the data (P = 0.072 autosomes and P = 0.747 chromosome X).For the BA population, we estimate 61.4 ± 2.9% SP, 31.0 ± 1.2% AF, and 7.6 ± 2.9% HG ancestry using all autosomal SNPs and 67.5 ± 17% SP, 26.5 ± 6.9% AF, and 6.0 ± 16.4% HG using all X-chromosome SNPs; thus, we do not find less SP ancestry on the X chromosome.To diagnose why we do not replicate the finding of ref. 1 we simulated pseudo-BA individuals with known admixture proportions and then used supervised ADMIXTURE (10)-the method used in ref.
Authors: Iosif Lazaridis, David Reich
Language: English
Subfield: Genetics
Domain: Life Sciences
SDG: Reduced inequalities
Open Access status: bronze
OpenAlex ID: W2953077176