Résumé
Introgressive hybridization is now recognized as a widespread phenomenon,
but its role in evolution remains contested. Here we use newly available
reference genome assemblies to investigate phylogenetic relationships and
introgression in a medically important group of Afrotropical mosquito
sibling species. We have identified the correct species branching order to
resolve a contentious phylogeny, and show that lineages leading to the
principal vectors of human malaria were among the first to split.
Pervasive autosomal introgression between these malaria vectors means that
only a small fraction of the genome, mainly on the X chromosome, has not
crossed species boundaries. Our results suggest that traits enhancing
vectorial capacity may be gained through interspecific gene flow,
including between non-sister species.