British scientists unveiled research indicating that the human brain grew slowly over millions of years, occurring gradually within each species of ancient humans and contradicting previous beliefs of ...

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 ...

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, ...

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.