Ancestry-assortative mating in admixed human populations

Non-random mating is an important source of genetic structure in natural populations. In a variety of species, positive correlations have been observed in trait values between mates, a phenonenon termed "assortative mating". In admixed human populations, which derive recent ancestry from multiple source populations, a number of studies have observed positive correlations in ancestry proportion between spouses. However, what this means about how humans choose partners remains unclear.

Population genetic models of ancestry-assortative mating typically consider ancestry proportion as a continuous variable and assume that individuals are directly biased in selecting mates by similarity in ancestry proportion. In my ongoing work, we consider an alternative sociologically-motivated model in which individuals instead choose their partners based on shared group identity. Using forward-in-time simulations written in the SLiM framework, we compare the impacts of different strategies for defining mate choice on observed ancestry tracts.

View my poster from the 2023 Society for Molecular Biology and Evolution conference in Ferrara, Italy.