What is George Gaylord Simpson?
'''George Gaylord Simpson''' (16 June 1902 – 6 October 1984) was an [[Americans|American]] [[paleontologist]]. Simpson was perhaps the most influential paleontologist of the twentieth century, and a major participant in the [[modern evolutionary synthesis]].<ref>Simpson G.G. 1944. ''Tempo and mode in evolution''. Columbia, N.Y.</ref><ref>Simpson G.G. 1953. ''The major features of evolution''. Columbia, N.Y.</ref> He was an expert on [[extinct]] [[mammal]]s and their migrations, especially the [[Great American Interchange]] between the [[Americas]].<ref>Simpson G.G. 1940. Mammals and land bridges. ''Journal of the Washington Academy of Sciences'' '''30''': 137{{ndash}}163. See Charles H. Smith's website for full text. [http://people.wku.edu/charles.smith/biogeog/SIMP940B.htm]</ref> Simpson opposed [[Alfred Wegener]]'s theory of [[continental drift]], so his work on animal migration lacked this idea.<ref>Simpson G.G. 1953. ''Evolution and geography: an essay on historical biogeography with special reference to mammals''. Oregon State System of Higher Education, Eugene, Oregon.</ref> Simpson dispelled the myth that the [[evolution]] of the [[horse]] was a linear process culminating in the modern ''Equus caballus''. He coined the word ''hypodigm'' in 1940,<ref>A [[Sample (statistics)|sample]] from which the characters of a population are to be inferred.</ref> and published extensively on the [[taxonomy]] of fossil and living mammals.<ref>Simpson G.G. 1940. Types in modern taxonomy. ''American Journal of Science'' 238, p418</ref> == Biography == Born in [[Chicago, Illinois]], Simpson was raised mostly in [[Denver, Colorado]]. He got his degrees from [[Yale University]] in 1923 and 1926. His dissertation, ''American Mesozoic Mammalia'' (1929), was the first step in his lifelong interest in the evolution of mammals. After a post-doctoral year at the British [[Natural History Museum]], Simpson returned in 1927 to take up a post in the [[American Museum of Natural History]].<ref name=AmPhil/> In 1942, Simpson enlist