Every aquarium owner hopes for one thing. A perfectly clean tank that somehow takes care of itself. It sounds ideal, but ...

In Lake Malawi, hundreds of species of cichlid fish have evolved with astonishing speed, offering scientists a rare opportunity to study how biodiversity arises.

If every face tells a story, this one might have a sorry tale to relate about the time a golf ball landed in its pond. But there’s been no tragic sporting accident here. The enormous swollen forehead ...