Evolution

An infection sweeping through Australia’s struggling koala population provides an unprecedented opportunity to explore how retroviruses insert themselves into the genome.

A new solution to the prisoner’s dilemma, a classic game theory scenario, has created new puzzles in evolutionary biology.

All life on Earth is made of molecules that twist in the same direction. New research reveals that this may not always have been so.

Microscopic creatures called bdelloid rotifers have thrived without mating for millions of years. How they did it could reveal why sex is so essential for almost everyone else.

A study of diverse colonies of spiders supports a controversial idea in evolution — that natural selection can act on communities as well as on individuals.

The movement of lizards around the Caribbean is forcing researchers to account for human activity in even their most basic ecological models.

A massive statistical study suggests that even though genetic changes happen at random, the final evolutionary outcome — fitness — is predictable.

Despite swapping DNA through interbreeding, butterflies and other animals can maintain distinct species.

Bacteria may have helped single-celled organisms make the leap to multicellular animals.