Admixture of evolutionary rates across a butterfly hybrid zone

Admixture of evolutionary rates across a butterfly hybrid zone

Blog Article

Hybridization is a major evolutionary force that can erode genetic differentiation between species, whereas reproductive isolation maintains such differentiation.In studying a hybrid zone between the swallowtail butterflies Papilio syfanius and Papilio maackii (Lepidoptera: Papilionidae), we made the Sinus Mist unexpected discovery that genomic substitution rates are unequal between the parental species.This phenomenon creates a novel process in hybridization, where genomic regions most affected by gene flow evolve at similar rates between species, while genomic regions with strong reproductive isolation evolve at species-specific rates.Thus, hybridization mixes evolutionary rates in a way similar to its effect on genetic ancestry.

Using coalescent theory, we show that the rate-mixing process provides distinct information about levels of gene flow across different parts of genomes, and the degree of rate-mixing can be predicted quantitatively from relative sequence divergence ([Formula: see text]) between the hybridizing species at equilibrium.Overall, we demonstrate that reproductive isolation maintains not only genomic differentiation, but also Sit-Stand the rate at which differentiation accumulates.Thus, asymmetric rates of evolution provide an additional signature of loci involved in reproductive isolation.