Evolution

For decades, researchers have commonly assumed that higher oxygen levels led to the sudden diversification of animal life 540 million years ago. But one iconoclast argues the opposite: that new animal behaviors raised oxygen levels and remade the environment.

An unlikely team offers a controversial hypothesis about what enabled animal life to get more complex during the Cambrian explosion.

A newfound pair of giant viruses have massive genomes and the most complete resources for building proteins ever seen in the viral world. They have refreshed the debate about the origins of these cellular parasites.

Modelers find evidence that a combination of competition, predation and evolution will push ecosystems toward species diversity anywhere in the universe.

The neuroscientist Erich Jarvis found that songbirds' vocal skills and humans' spoken language are both rooted in neural pathways for controlling learned movements.

Near an Australian desert mining camp, wild dingoes are losing their fear of humans. Their genetic and behavioral changes may echo those from the domestication of dogs.

Compact genomes and tiny cells gave flowering plants an edge over competing flora. This discovery hints at a broader evolutionary principle.

Evolution settled on a genetic code that uses four letters to name 20 amino acids. Synthetic biologists adding new bases to DNA will be free to improve on nature — if they can.

Corina Tarnita deciphers bizarre patterns in the soil created by competing life-forms.