Stephen Jay Gould
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Gould's most significant contribution to evolutionary biology was the theory of punctuated equilibrium developed with Niles Eldredge in 1972. The theory proposes that most evolution is characterized by long periods of evolutionary stability, infrequently punctuated by swift periods of branching speciation. The theory was contrasted against phyletic gradualism, the popular idea that evolutionary change is marked by a pattern of smooth and continuous change in the fossil record.
Most of Gould's empirical research was based on the land snail genera ''Poecilozonites'' and ''Cerion''. He also made important contributions to evolutionary developmental biology, receiving broad professional recognition for his book ''Ontogeny and Phylogeny''. In evolutionary theory he opposed strict selectionism, sociobiology as applied to humans, and evolutionary psychology. He campaigned against creationism and proposed that science and religion should be considered two distinct fields (or "non-overlapping magisteria") whose authorities do not overlap.
Gould was known by the general public mainly for his 300 popular essays in ''Natural History'' magazine, and his numerous books written for both the specialist and non-specialist. In April 2000, the US Library of Congress named him a "Living Legend". Provided by Wikipedia