Three U.S. biologists share the Nobel Prize in Medicine for their research into the molecular mechanism that drives circadian rhythm.
How many Neanderthals were there? Archaeology and genetics have given very different answers. A new study reconciles them and reveals the lost history of these ancient people — including an early brush with extinction.
Hybrids, once treated as biological misfits, play a vital role in the evolution of many animal species. Now conservationists are trying to reconcile that truth with policies.