natural selection

Skeletons of domestic pigeons facing each other. The left skeleton has a short beak, the right one has a long beak.

Darwin’s short-beak enigma solved

A mutation in the ROR2 gene is linked to beak size reduction in numerous breeds of domestic pigeons. Surprisingly, mutations in ROR2 also underlie a human disorder called Robinow syndrome.

Sex, lice and videotape

Biologists drove the divergence of different-sized feather lice from a single population. In four years the evolved lice had trouble mating with each other, a sign of speciation and they caught it on tape.