The maize geneticist Barbara McClintock (1902-1992) is credited with the discovery of "jumping genes," that is chromosomal "crossing over" and translocation. She received the Nobel Prize in Physiology or Medicine in 1983. The collection is organized into six series: I. Correspondence, 1931-1991; II. Subject files, 1938-1989; III. Works by McClintock, 1944-1989; IV. Works by others, 1927-1991; V. Research notes, notebooks, and card files, 1930s-1990s ; VI. Photographs, 1928-1991.

This collection of correspondence, reports, and manuscripts concerns Stalker's research in genetics and evolutionary biology, particularly the evolutionary genetics of Drosophila. Most of the letters are scientific, although the usual academic politics in various departments is mentioned. There is also material on the Society for the Study of Evolution (1970).

A bacteriologist from MIT, Salvador E. Luria's work with Max Delbruck on bacteriophage demonstrated that bacterial resistance to certain phages arose through genetic mutations. His later work showed that phages also mutate genetically. He received the Nobel Prize in Physiology or Medicine in 1969 with Max Delbruck and Alfred D. Hershey. The collection is organized into seven series: I. Correspondence, 1938-1992 ; IIa. Subject Files, 1938-1990 ; IIb. Personal Material. 1923-1991 ; III. Works by Luria, 1938-1987 ; IV. Works by Others, 1944-1990 ; V. Research Notes and Notebooks, 1941-1979 ; VI. Course Material, 1931-1991 ; VII. Photographs and Negatives, 1957-1982. Arrangement: Alphabetical by folder title and then chronological within each folder.

One of the four horsemen of the evolutionary synthesis of the 1940s, Theodosius Dobzhansky played a crucial role in bridging the gap between theoretical and empirical approaches in genetics and in promoting the Neo-Darwinian synthesis. His contributions to the biological species concept and to an understanding the evolutionary dynamics of wild populations of Drosophila were fundamental to the development of modern population genetics and evolutionary thought. The Dobzhansky Papers are a remnant of the correspondence and writings of the geneticist and evolutionary biologist, Theodosius Dobzhansky. The correspondence (7.5 linear feet) provides insight into Dobzhansky's scientific, philosophical, and social views, particularly during the last decade of his life. Equally valuable are the 54 notebooks (ca.1917-1975) which comprise an almost uninterrupted self-commentary on Dobzhansky's career, replete with typescripts of personal letters and short essays sent to colleagues and friends. The collection also contains two unbound volumes of annotated "reminiscences" from the Columbia Oral History Project, 1962; two bound volumes of papers dedicated to him on his 70th birthday; and 1.5 linear feet of photographs.

The correspondence in this collection concerns behavior genetics, evolution, heredity, etc. There is material relating to the congresses of the Permanent International Committee on Genetics, and the IXth (Bellagio, 1953), Xth (Montreal, 1958), and XIth (The Hague, 1963) International Congress of Genetics. There is also correspondence pertaining to the Cold Spring Harbor Symposium on Quantitative Biology (1955), the Mendel Semi-Centennial Symposium (1950), the Soviet geneticists' visit to the U.S. in 1967, and to Anton R. Zhebrak.

The collection includes three accessions: (1) a portion of Lewontin's correspondence files (mainly A-L) and copies of papers acquired in 1979; (2) a 2003 accession with files on various subjects and correspondence with about 30 colleagues, and (3) a substantial 2018 accession of about 60 linear feet that includes correspondence, manuscripts, and subject files. The topics discussed in the letters are numerous, including much on contemporary scientific controversies such as race, Darwin, evolution, intelligence, and biological determinism.

Sewall Wright ranks among the most influential figures in the field of population genetics during the 20th century, and made important contributions to biostatistics, biometrics, and evolutionary theory. These papers contain much of Wright's professional correspondence, scattered research notes, and drafts of a small number of papers.