Simpson, George Gaylord, 1902-1984

Alternative names
Birth 1902-06-16
Death 1984-10-06

Biographical notes:

George Gaylord Simpson was a vertebrate paleontologist perhaps best known for his contributions to the founding and further articulation of the modern evolutionary synthesis. He studied at Yale University (Ph.D. 1926), having initially worked at the American Museum of Natural History in 1924. He returned to work the AMNH as a curator (1927-1942) and later as chairman of the Department of Paleontology and Geology (1942-1959). Simpson accepted an Alexander Agassiz Professorship from Harvard's Museum of Comparative Zoology (1959-1967), and taught courses in geology and biology. From there the Simpsons relocated to Tucson, Arizona, where George taught geology at the University of Arizona (1967-1984) while continuing his scientific writing.

From the description of Papers, 1918-1984. (American Philosophical Society Library). WorldCat record id: 154297997

One of the seminal figures in the emergence of the Modern or Neo-Darwinian Synthesis during the mid-twentieth century, George Gaylord Simpson (1902-1984) helped define the unique contribution made by vertebrate paleontology to the life sciences. A specialist in Mesozoic and early Cenozoic mammals, Simpson's contributions to the fusion of Darwinian natural selection and Mendelian genetics were both empirical and theoretical, culminating in his major works Tempo and Mode in Evolution and The Meaning of Evolution. From his posts at the American Museum of Natural History (1927-1959), Columbia University (1945-1959), Harvard (1959-1967), and the University of Arizona (1967-1984), Simpson became one of the most influential paleontologists of the century, helped in part by his ability to write successfully for both a technical, professional audience and a popular audience.

From the guide to the The Meaning of Evolution: A Study of the History of Life and of Its Significance for Man, 1949, (American Philosophical Society)

The vertebrate paleontologist and evolutionary biologist George Gaylord Simpson (1902-1984) was one of the seminal figures in the emergence of the Modern of Neo-Darwinian Synthesis during the mid-twentieth century. Born in Chicago, Illinois, Simpson was raised mostly in Denver, Colorado. Entering the University of Colorado in 1918, Simpson transferred to Yale in 1922, where he received both his B.A. (1923) and doctorate (1926). His dissertation, American Mesozoic Mammalia (1929), was among the first exhaustive analyses of the early evolutionary diversification of mammals, and began what would become a life-long interest in the subject.

During his formative years, Simpson was strongly influenced by his advisor Richard Swan Lull, Charles Schuchert, Carl O. Dunbar, Ross Harrison, L. L. Woodruff, and William Diller Matthew, and from the 1920s, and while he retained a traditional orientation toward field work and collection, Simpson was fluent in neontological approaches. From early in his career, he wrote that he consciously set out to lay "a basis for more theoretical and philosophical considerations of evolution."

After a post-doctoral year at the British Museum of Natural History, Simpson returned to the states in the fall, 1927, to take up a position with the American Museum of Natural History. The Museum proved an ideal spot to continue his work on Mesozoic and early Cenozoic mammals, and supported a series of important collecting expeditions, most notably his expeditions to Patagonia (1930-31, 1933-34) to study Eocene mammals. Out of one of these visits came Simpson's book Attending Marvels (1931), which was the first in a string of highly successful books on evolutionary and natural historical topics that Simpson wrote for a popular audience. In addition, Simpson and his second wife, Anne Roe (a childhood friend whom he married in 1938), co-wrote an unpublished mystery novel, "Trouble in the Tropics," during an unusually rainy season on their expedition to Venezuela in 1938-1939. More importantly, his South American experiences sharpened Simpson's understanding of the role of biogeography in evolutionary process.

In 1942, Simpson interrupted his career at the museum to enlist in the military. As a Captain, then Major, in Army intelligence, Simpson served with American forces in North Africa and western Europe until 1944, when he was forced to resign due to a severe bout of hepatitis. Upon his return home, two bronze stars in tow, he was promoted to chair of the Department of Geology and Paleontology at the American Museum, and accepted a cross appointment as professor of zoology at Columbia University (1945-1959), resuming his work on early mammals, concentrating on the rich Paleocene and Eocene faunas of the San Juan Basin, New Mexico.

The late 1940s, however, were among the most productive years of Simpson's long career. Just prior to his enlistment, he had completed two important works, Tempo and Mode in Evolution (1944) and Principles of Classification and a Classification of Mammals (1945). As a guiding force in the Committee on the Common Problems of Genetics, Paleontology, and Evolution of the National Research Council, he, along with the geneticist Theodosius Dobzhansky, the biologist Ernst Mayr, and a handful of other scientists, crafted a persuasive argument showing the theoretical consistency of Mendelian genetics and Darwinian natural selection. Simpson's Tempo and Mode in Evolution, in particular, was a critical work in catalysing what Julian Huxley called the Modern Synthesis in evolutionary biology, the wedding diachronic data derived from paleontological study of the fossil record with neontological field data, and the empirical data of contemporary genetics. In The Meaning of Evolution (1949) Simpson provided a popular account of modern evolutionary theory -- popular in every sense of the word -- emphasizing the data provided uniquely by the fossil record.

Less successfully, at least in retrospect, Simpson's Evolution and Geography (1953) attempted to provide a coherent overview of paleobiogeography, rejecting the nascent theory of continental drift in favor of more traditional interpretations. Simpson's views on continental drift and biogeography changed radically with the accumulation of new data on sea floor spreading in the 1960s. In 1953, Simpson also completed The Major Features of Evolution, a synthetic overview of evolutionary theory.

An increasing slate of professional commitments provided a full schedule for Simpson during the decade. He traveled around the world with UNESCO in 1951, took part in two conferences on behavior and evolution (1955-1956), and in 1956, traveled to Brazil, where he almost lost his right leg when he was struck by a falling tree. Although his fieldwork was curtailed due to his protracted convalescence and continuing pain in his leg, he remained typically productive, putting out a textbook, Life: An Introduction to Biology in 1957.

Resigning his positions in New York in 1959, Simpson became Alexander Agassiz Professor in the Museum of Comparative Zoology at Harvard University (1959-1967). His later works, both professional and popular, revisited many of the themeshe had elaborated in the previous two decades, touching on systematics ( Principles of Animal Taxonomy, 1961), evolution ( This View of Life, 1964), and paleobiogeography ( The Geography of Evolution, 1965). Anne Roe, a psychologist, simultaneously employed as full professor in the Department of Education.

The Simpsons relocated to Tucson, Arizona, in 1967, when George accepted a professorship in geology at the University of Arizona (1967-1984). He continued to publish until the end of his life, including Penguins (1976), Splendid Isolation (1980), and his autobiography Concession to the Improbable (1978). He died in Tucson on October 6, 1984.

The laurels of an academic life fell abundantly on Simpson. A founder and president of the Society of Vertebrate Paleontology (Pres., 1942) and Society for the Study of Evolution (Pres., 1946), he was president variously of a number of professional organizations, ranging from the American Society of Mammalogists and American Society of Zoologists to the Society of Systematic Zoology. He was, as well, member of the American Academy of Arts and Sciences and the American Association for the Advancement of Science, and was elected to the the American Philosophical Society (1936), the Linnean Society of London, the National Academy of Sciences (1941), and the Royal Society of London (1958). He also received honorary degrees from the University of Colorado, the University of New Mexico, the University of Chicago, Yale University, and York University.

From the guide to the George Gaylord Simpson Papers, 1918-1984, (American Philosophical Society)


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Ark ID:


  • Scientific expeditions
  • Evolution
  • Paleontology
  • Evolutionary synthesis
  • Darwinism
  • Religion and science--20th century
  • Biology--Classification
  • Genetics
  • Evolution (Biology)
  • Horses--Evolution
  • Extinction (Biology)
  • Behavior evolution
  • Mammals--Evolution
  • Biogeography
  • Paleontology--Argentina--Patagonia
  • Creationism
  • Mammals, Fossil
  • World War, 1939-1945
  • Paleontology--Venezuela
  • Evolution--Religious aspects
  • Natural selection


not available for this record


  • Patagonia (Argentina and Chile) (as recorded)
  • Venezuela (as recorded)
  • Chile (as recorded)
  • Patagonia (Argentina and Chile) (as recorded)
  • New Mexico (as recorded)
  • Argentina (as recorded)
  • Argentina--Patagonia (as recorded)
  • Venezuela (as recorded)
  • Arizona (as recorded)