The influence of migration on the maintanance of assortative mating
(English)Manuscript (preprint) (Other academic)
Rapid speciation has been shown plausible without the need for extreme founder events, complete geographic isolation, the existence of distinct adaptive peaks or selection for local adaptation. However, standard theory predicts that extremely low migration rates are enough to hinder divergence between populations, and thus speciation. Our question to be answered is at which migration rates divergence, and hence speciation is still possible. Is it really as strict as theory predicts? We show that assortative mating can be upheld for several generations in populations experiencing immigration rates of up to eight percent, or 13-15 immigrants per generation, despite the lack of adaptive divergence and trade-offs between the exchanging populations. Since assortative mating vanishes after some generations of extensive gene flow without selection against hybrids, we conclude that selection is likely to be an important factor in speciation in the face of gene flow.
Parapatric speciation, migration, assortative mating, Callosobruchus maculatus, experimental evidence
Research subject Biology with specialization in Animal Ecology
IdentifiersURN: urn:nbn:se:uu:diva-130378OAI: oai:DiVA.org:uu-130378DiVA: diva2:349499