The molecular evolutionary basis of species formation revisited.

How do new species arise? This is among the most fundamental questions in evolutionary biology. The first genetic model for how reproductive barriers lead to the origin of new species was proposed nearly 90 years ago. However, empirical evidence for the genetic mechanisms that cause reproductive barriers took many decades to accumulate.

Admixture mapping reveals evidence for multiple mitonuclear incompatibilities in swordtail fish hybrids.

How barriers to gene flow arise between closely related species is one of the oldest questions in evolutionary biology. Classic models in evolutionary biology predict that negative epistatic interactions between variants in the genomes of diverged lineages, known as hybrid incompatibilities, will reduce viability or fertility in hybrids. The genetic architecture of these interactions and the evolutionary paths through which they arise have profound implications for the efficacy of hybrid incompatibilities as barriers to gene flow between species.