"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Here’s what you’ll learn when you read this story: Is evolution a gradual process or a punctuated one, ...

Until recently, details about this group's most distant past have been elusive. But a UC Riverside-led team has now identified the oldest known ecdysozoan in the fossil record and the only one from ...

A representation of single-cell RNA sequencing data from two species of worms, C. elegans (left) and C. briggsae (right). Each point represents a single cell, arranged such that cells from the same ...

Scientists found the 500-million-year-old fossil of a "penis worm" in the Grand Canyon—and reconstructed how the creature would have used its strange mouth to feed. The newly discovered species of ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." “It may be doubted,” Darwin wrote, “if there are any other animals which have played such an important ...