Multicellularity

Embryonic cells can self-assemble into new living forms that don’t resemble the bodies they usually generate, challenging old ideas of what defines an organism.

Studies of collective behavior usually focus on how crowds of organisms coordinate their actions. But what if the individuals that don’t participate have just as much to tell us?

A recently unearthed fossil and new genomic discoveries are filling important gaps in scientists’ understanding of how primitive green algae eventually evolved into land vegetation.

Researchers agree it’s a long shot, but transmissible cancers could theoretically evolve into independent species. Certain weird parasites might be living proof.

Theories about how animals became multicellular are shifting as researchers find greater complexity in our single-celled ancestors.

A single genetic change and some clever geometry show how single-celled organisms can band together to form cooperative multicellular entities.

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

An interview with the developmental biologist Cassandra Extavour on the origins of multicellular organisms and the evolution of cooperation.