Niles EldredgeNiles Eldredge has been a paleontologist on the curatorial staff of the American Museum of Natural History since 1969. A specialist in mid-Paleozoic phacopid trilobites, Dr. Eldredge, along with Stephen Jay Gould of Harvard, formulated a theory challnging Darwin's premise that evolution occurs gradually. Their theory, known as Punctuated Equilibria, asserts that evolution occurs in dramatic spurts interspersed with long periods of stasis. Read More Read Less