A botanist and historian of science at the University of Pennsylvania, Conway Zirkle published on the history of evolutionary thought and genetics, with a particular interest in the discipline as practiced in the Soviet Union. The Zirkle Papers consist of approximately one linear foot of materials accrued by Zirkle during research for his book on Lysenko-era biology in the Soviet Union, The Death of Science in Russia (1949). Among the miscellaneous materials in the collection are four volumes (0.5 linear feet) of pressed specimens of ferns and algae.

Arthur J. Cain is an evolutionary biologist whose research interests have included genetics, natural selection, biogeography, and systematics. Based at Oxford University and, later, the University of Liverpool, much of Cain's research was field-based, focusing on terrestrial gatsropods. This collection contains correspondence, grant applications, reports, programs for scientific meetings, unpublished papers and lectures, research notes, charts, graphs, maps, and manuscript reviews of journal articles and books. The Cain Papers is divided into three series: I. Correspondence ; II. Subject Files ; and, III. Papers by Colleagues. Arrangement is alphabetical by folder title, and chronological within each folder.

The psychologist and behavioral geneticist Bronson Price made important contributions to the study of the genetics of mental traits in twins. Receiving his doctorate from Stanford in 1934, Price began down a research path that led him to study under Aleksandr R. Luria in Moscow from 1934-1935, and thereafter to the Department of Psychology at Ohio State. In 1941, Price changed course professionally, entering into war-time government service, never to return to academia, working first with the National Office of Vital Statistics and later as a statistician with the Children's Bureau and the Office of Education. The Price Papers contains one linear foot of correspondence relating to Bronson Price's interests in genetics and eugenics, with an emphasis upon Price's post-doctoral experiences in the Soviet Union and his long-term interests in the genetic study of twins. In addition to fairly extensive correspondence with H. J. Muller and Lewis Terman, the collection includes interesting materials relating to the Foundation for Germinal Choice, eugenic sterilization, and an extensive bibliographic card file used by Price in his research on twins post-1940. This note is currently under review for revision.

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. The Simpson Papers include a comprehensive assemblage of professional and personal correspondence, reflecting nealy all phases of Simpson's 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. The collection also includes autobiographical data and writings, lectures, class notes and papers, research data, material on his scientific expeditions (diaries in carbon form, photos, notes, etc.), publication material (he was author of some 800 publications), extensive photographic material, diplomas, and medals.