Biology

A technique based on genetic bar codes can easily map the connections of individual brain cells in unprecedented numbers. Unexpected complexity in the visual system is only the first secret it has revealed.

Using a brain-computer interface, scientists are beginning to learn why learning is hard.

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.

Researchers are building a case that long before the nervous system works, the brain sends crucial bioelectric signals to guide the growth of embryonic tissues.

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.

The long, variable times that some diseases incubate after infection defies simple explanation. An idealized model of tumor growth offers a statistical solution.

The computer scientist Barbara Engelhardt develops machine-learning models and methods to scour human genomes for the elusive causes and mechanisms of disease.

Even with no one in charge, army ants work collectively to build bridges out of their bodies. New research reveals the simple rules that lead to such complex group behavior.