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 ...

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 ...

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, ...

Scientists have developed a theoretical model that uncovers the dual role of polyploidy -- organisms carrying extra genome copies -- in evolution. Their findings reveal that polyploidy can stabilize ...

In this video segment from NOVA: "Judgment Day: Intelligent Design on Trial," paleontologist Neil Shubin recounts a fossil discovery that added another compelling piece to the body of evidence that ...

An updated evolutionary model shows that living systems evolve in a split-and-hit-the-gas dynamic, where new lineages appear in sudden bursts rather than during a long marathon of gradual changes.