Niles 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 challenging 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.
