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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.
The discovery that viruses move between species unexpectedly often is rewriting ideas about their evolutionary history — and may have troubling implications for the threat from emerging diseases.
With electrical signals, simple cells organize themselves into complex societies and negotiate with other colonies.
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.