EVOLUTION is a complex beast, but it can operate in breathtakingly simple ways. Just a single pair of incompatible genes can help prevent closely related species from hybridising, experiments on a pair of fruit fly species have revealed.
Geneticist Daniel Barbash and colleagues at Cornell University in New York studied Drosophila melanogaster and Drosophila simulans, two species that although related are unable to fully hybridise. Male offspring produced by female D. melanogaster and male D. simulans die before hatching, and this barrier to genetic interchange helps keep the two species distinct.
By manipulating variants of different genes in each species,…
