Evolution by jerks or by creeps: Stephen Jay Gould's famous fossil fight
Critics mocked the theory Stephen Jay Gould championed as evolution by jerks. Gould shot back that the older view, in which species change smoothly and steadily, deserved the name evolution by creeps. Behind the joke lay a serious question about what the fossil record actually shows.
The idea, punctuated equilibrium, was set out by Gould and Niles Eldredge in 1972. It holds that most lineages stay much the same for long stretches, with change packed into comparatively brief bursts when new species branch off. Eldredge had first presented the pattern in his doctoral work on Devonian trilobites, but Gould coined the name. He argued it revised a pillar of Darwinian logic; some colleagues countered that it only tweaked existing theory, while others said the sheer amount of stasis had surprised most biologists.
Gould's own fieldwork centred on land snails, especially the genera Poecilozonites and Cerion. His book Ontogeny and Phylogeny drew wide praise for exploring how shifts in the timing of development, such as retaining juvenile features, can reshape organisms. He also pushed back against giving natural selection credit for everything and against claims that human behaviour is biologically fixed.
The spark came early. Born in Queens on 10 September 1941, he was five when his father took him to see Tyrannosaurus rex at the American Museum of Natural History, and he decided on the spot to become a palaeontologist. At Antioch College he was active in civil rights, and as a visiting student at Leeds he organised weekly protests outside a Bradford dance hall that turned black people away, until it dropped the policy. After a doctorate at Columbia he joined Harvard in 1967 and stayed for life.
Most readers knew him through 300 essays in Natural History magazine, peppered with asides about the New York Yankees, Gilbert and Sullivan and antiquarian books. A vocal opponent of creationism, he described faith and science as non-overlapping magisteria, each with its own domain of authority. The Library of Congress named him a Living Legend in 2000, and he died on 20 May 2002.
Source: Stephen Jay Gould
