Demographic history shapes genomic ancestry in hybrid zones
Citations Over Time
Abstract
Demographic factors such as migration rate and population size can impede or facilitate speciation. In hybrid zones, reproductive boundaries between species are tested and demography mediates the opportunity for admixture between lineages that are partially isolated. Genomic ancestry is a powerful tool for revealing the history of admixed populations, but models and methods based on local ancestry are rarely applied to structured hybrid zones. To understand the effects of demography on ancestry in hybrids zones, we performed individual-based simulations under a stepping-stone model, treating migration rate, deme size, and hybrid zone age as parameters. We find that the number of ancestry junctions (the transition points between genomic regions with different ancestries) and heterogenicity (the genomic proportion heterozygous for ancestry) are often closely connected to demographic history. Reducing deme size reduces junction number and heterogenicity. Elevating migration rate increases heterogenicity, but migration affects junction number in more complex ways. We highlight the junction frequency spectrum as a novel and informative summary of ancestry that responds to demographic history. A substantial proportion of junctions are expected to fix when migration is limited or deme size is small, changing the shape of the spectrum. Our findings suggest that genomic patterns of ancestry could be used to infer demographic history in hybrid zones.
Related Papers
- → Characterizing the admixed African ancestry of African Americans(2009)194 cited
- → Genetic admixture, self‐reported ethnicity, self‐estimated admixture, and skin pigmentation among Hispanics and Native Americans(2008)78 cited
- → Analysis of genetic ancestry in the admixed Brazilian population from Rio de Janeiro using 46 autosomal ancestry-informative indel markers(2012)68 cited
- → The Impact of Modern Admixture on Archaic Human Ancestry in Human Populations(2023)25 cited
- → Genetic ancestry and radical prostatectomy findings in Hispanic/Latino patients(2024)3 cited