The concept of punctuated equilibrium was, to some, a radical new idea when it was first proposed by Stephen Jay Gould and Niles Eldredge in 1972. Now it is widely recognized as a useful model for one ...

Abrupt shifts in the evolution of animals – short periods of time when an organism rapidly changes size or form – have long been a challenge for theorists including Darwin. Now a newly published ...

It’s generally believed that evolution is a gradual process that takes place over significant periods of time. When it comes to fruit flies, however, researchers have long known that their ...

Charles Darwin's theory of gradual evolution is not supported by geological history, New York University Geologist Michael Rampino concludes in an essay in the journal Historical Biology. In fact, ...