Digest: White-eye birds provide possible answer to the paradox of the great speciator.

When organisms colonize a new area, they can come into secondary contact with closely related species. Consequent hybridization can lead to homogenizing gene flow and prevent genetic divergence. However, some lineages, like the White-eye birds examined in this study, can speciate rapidly while colonizing a wide geographic area. The authors suggest that this "paradox of the great speciator" may be solved through unusually rapid evolution of reproductive isolation.