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 In addition, Simpson and his second wife, Anne Roe (a childhood friend whom he married in 1938), co-wrote an unpublished mystery novel, "Trouble in the Tropics," during an unusually rainy season on their expedition to Venezuela in 1938-1939.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.

A major resource for the study of vertebrate paleontology in the twentieth century, and a critical resource for understanding the modern evolutionary synthesis, the Simpson Papers offer a comprehensive perspective on the life and work of George Gaylord Simpson. Trained at Yale and employed by the American Museum of Natural History, Columbia, Harvard, and the University of Arizona, Simpson made important empirical and theoretical contributions, helping to define his discipline for a generation of paleontologists.

The Simpson collection includes a comprehensive assemblage of professional correspondence (36 linear feet), with some personal correspondence as well, representing Simpson's varied scientific interests throughout his career. Written with charm, wit, and a sense of literary style, the correspondence touches on all aspects of modern paleontology, providing an important perspective on the emergence of contemporary evolutionary theory, biogeography, systematic theory and methodology, the relationship of science and religion, and creationism, as well as more general issues in scientific epistemology and social and political issues.

Among the notable correspondents are Simpson's fellow collaborators in the Modern Synthesis, Theodosius Dobzhansky, Ernst Mayr, and Julian Huxley, but the collection includes a laundry list of important vertebrate paleontologists, from his dissertation advisor, Richard Swan Lull, to Alfred Sherwood Romer, Bjorn Kurten, William Berryman Scott, Henry Fairfield Osborn, Glenn Jepsen, and to the younger generation of Philip Gingerich, Gareth Nelson, Elwyn Simons, and Joel Cracraft. Reflecting his interdisciplinary approach, Simpson also maintained extensive correspondences with geneticists, ecologists, biogeographers, ethologists, and several other varieties of neontologists. In addition to offering insight into his classic work on the early evolution of mammals and the evolution of equuids, Simpson's correspondence provides a fascinating look into his fieldwork in South America during the 1930s and on the development of paleontology in Argentina and Venezuela. Supplementing the correspondence is the rich material documenting his expeditions to Patagonia (1930-1931, 1933-1934), and Venezuela, 1938-1939. In addition to his fieldnotes and related manuscripts, the collection includes an extensive series of photographs providing key visual documentation.

The details of Simpson's own life and his attitudes toward science are laid out in some detail through his autobiographical writings, but also, in an intellectual sense, through the lengthy series of lectures, class notes and papers, research data, and publications. The carbon copy typescripts of his travel diaries, 1930-1979, are also an important source (his original field notebooks are at the American Museum of Natural History).

Finally, the collection includes a small, but important body of personal correspondence, including his letters home while serving in Army intelligence during the Second World War. A separate, smaller collection of Simpson letters (B Si5) is comprised of letters written by Simpson to his sister, Martha Lee Simpson Eastlake, 1918-1962. Predominantly personal, these recount his travels and experiences on scientific expeditions to New Mexico, Arizona, Argentina, and Chile.

Provenance

Subcollection I was presented by Anne Roe Simpson, 1985.

Subcollection II was a gift of Martha Lee Simpson Eastlake, 1975, and Leo Laporte, 1976.

Preferred citation

Cite as: George Gaylord Simpson Papers, American Philosophical Society.

Processing information

Catalogued, 1984; revised 2002.

Separated material

All books and medals were removed from the collection for more appropriate storage. Books removed include:

As of April 1989, the medals were not cataloged. A rough inventory is available from the Manuscripts Librarians.

1. Christian Morgenstern, The Moon Sheep (Insel-Verlag Wiesbaden, 1953)
2. Harald Stumpke, The Snouters, Form and Life of the Rhinogrades (Chicago: Doubleday & Co.), 2 copies in English, 1 German.

Related material

The APS houses a separate collection of papers of Anne Roe (B R621) relating primarily to research for her book, The Making of a Scientist. Her correspondence with her husband is included in the Simpson Papers.

The originals of Simpson's travel diaries and his original field notebooks are housed at the American Museum of Natural History.

Material on the evolutionary synthesis appears in the papers of Theodosius Dobzhansky (B D65) and in the collection assembled by Ernst Mayr (B M451) to document the Princeton Conference on the Common Problems of Genetics, Paleontology, and Evolution and the Conference on Evolutionary Synthesis sponsored by the American Academy of Arts and Sciences and held in Boston in May and October 1974.

Genetics Note

This collection contains materials which relate to the history of genetics.

Conservation note

All metal fasteners were removed, and plastic clips were used to keep pages together.

• American Humanist Association
• American Society of Mammalogists
• American Society of Zoologists
• Columbia University -- Faculty.
• Geological Society of America.
• Harvard University--Faculty
• International Commission on Zoological Nomenclature
• National Academy of Sciences (U.S.)
• Society for the Study of Evolution
• Society of Systematic Zoology (U.S.)
• Society of Vertebrate Paleontology.
• University of Arizona--Faculty

• Diplomas.
• Field notes.
• Medals
• Photographs
• Photonegatives
• Slides.

• Patagonia (Argentina and Chile) -- Description and travel
• Venezuela -- Description and travel

• Arambourg, C. (Camille), 1885-1969
• Ayala, Francisco Jose, 1934-
• Barbour, Thomas, 1884-1946
• Bebe, William, 1877-1962
• Beck, William Samson, 1923-2003
• Bennett, Wendell Clark, 1905-1953
• Bordas, Alejandro F.
• Boucot, A. J. (Arthur James), 1924-2017
• Cabrera, Angel, 1879-1960
• Clark, Wilfrid E. Le Gros (Wilfrid Edward Le Gros), 1895-1971
• Cloud, Preston, 1912-
• Cockerell, Theodore D. A. (Theodore Dru Alison), 1866-1948
• Colbert, Edwin Harris, 1905-
• Couturier, Marcel A. J., 1897-
• Cracraft, Joel
• Crompton, Alfred W., 1927-
• De Beer, Gavin, Sir, 1899-1972
• De Camp, L. Sprague (Lyon Spra
• Dobzhansky, Theodosius Grigorievich, 1900-1975
• Dunbar, Carl O. (Carl Owen), 1891-1979
• Edinger, Tilly, 1897-
• Elias, Maxim K. (Maxim Konrado
• Epling, Carl, 1894-
• Ford, E. B. (Edmund Briscoe),
• Freeman, Derek
• Gazin, Charles Lewis, 1904-
• Gingerich, Philip D.
• Gould, Stephen Jay, 1941-2002
• Grant, Verne
• Gregory, Joseph Tracy, 1914-
• Gregory, William K. (William K
• Hall, E. Raymond (Eugene Raymo
• Heberer, Gerhardt, 1901-1973
• Hibbard, Claude William, 1905-
• Hoffstetter, Robert
• Hooijer, Dirk Albert
• Hopwood, Arthur Tindell, 1897-
• Huxley, Julian, 1887-1975
• Jenkins, Farish A., 1940-
• Jepsen, Glenn Lowell, 1904-
• Kellogg, Remington, 1893-
• Kermack, K. A. (Kenneth A.)
• Kuhn-Schnyder, Emil
• Kurtén, BjC6rn
• Laporte, Léo F.
• Lattimore, Owen, 1900-
• Lavocat, René
• Leakey, L. S. B. (Louis Seymour Bazett), 1903-1972
• Lewontin, Richard C., 1929-
• Lillegraven, Jason A., 1938-
• Lull, Richard Swann, 1867-1957
• Marshall, Larry G.
• Matthew, William Diller, 1871-
• Mayr, Ernst, 1904-2005
• McGrew, Paul Orman, 1909-
• McKenna, Malcolm C.
• Montagu, Ashley, 1905-1999
• Morgan, Arthur Ernest, 1878-19
• Muller, H. J. (Hermann Joseph), 1890-1967
• Nelson, Gareth J.
• Newell, Norman Dennis, 1909-2005
• Olsen, Stanley John, 1919-
• Olson, Everett Claire, 1910-
• Osborn, Henry Fairfield, 1857-
• Ostrom, John H.
• Pascual, Rosendo
• Patterson, Bryan, 1909-
• Phelps, William Henry
• Reig, Osvaldo
• Rensch, Bernhard
• Reynolds, Thomas Emmett, 1892-
• Riggs, Elmer Samuel, 1869-
• Roe, Anne, 1904-
• Romer, Alfred Sherwood, 1894-1973
• Russell, Loris Shano, 1904-
• Scaglia, Galileo J.
• Schaeffer, Bobb
• Schuchert, Charles, 1858-1942
• Scott, William Berryman, 1858-1947
• Simons, Elwyn L.
• Simpson, George Gaylord, 1902-1984
• Stebbins, G. Ledyard (George Ledyard), 1906-2000
• Stirtin, Ruben Arthur, 1901-19
• Tieje, Arthur Jerrold, 1889-
• Van Valen, Leigh
• Westoll, T. Stanley
• Wilson, Edward Osborne, 1929-
• Wood, Albert Elmer, 1910-
• Wood, Horace
• Woodward, Arthur Smith, 1864-1

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