Paleontologist Stephen Jay Gould is dead. Gould is best-known for his co-development of the theory of punctuated equilibrium in evolutionary biology, which challenged the intellectual hegemony of gradualism and paved the way for a much more dynamic view of evolutionary history. (Though some would say that Gould didn't go far enough.)
Stepping beyond the relatively safe realm of punctuated equilibrium, I've recently discovered the altogether bizarre landscape of catastrophism. This line of thinking was originated in recent times by Russian scientist Immanuel Velikovsky, who seems to have become something of a cult figure (info: 1 | 2 | 3). SF writer James P. Hogan, whom I respect, has been intrigued enough about Velikovsky's claims to write about them on his website, use them as the imaginative basis for his novel Cradle of Saturn, and link to a recent extension of Velikovsky's ideas. Although I'm normally skeptical about dogmas of science (including gradualism in geology and evolutionary biology), I must say that some of these catastrophist views are simply fantastical and beyond what I find believable based on the evidence. So follow the links in this paragraph at your peril. :)