"Neocatastrophism is a collective term. It was coined by Schindewolf sometime in the sixties. He was a paleontologist. But all kinds of scholars in the natural sciences have taken party in the debate. What they agree on is that the earth— and, in particular, its biology—has not evolved at an even pace but in leaps, which have been directed by great natural catastrophes that favor the survival of species. Meteor showers, comets, volcanic eruptions, spontaneous chemical disasters. The core of the debate has always been the question of whether these catastrophes occur at regular intervals. And if they do, what determines the frequency?
-Smilla's Sense of Snow
All of this is a long-winded and particularly obtuse way of saying "fits-and-starts."