Gaunce Lewis earned his AB from Harvard in 1971, was a junior officer in the US Navy 1972-1975, and earned an SM in 1976 and a Ph.D. in 1978 from the University of Chicago, writing a dissertation under J. Peter May. He was a T. H. Hildebrandt Research Assistant Professor at the University of Michigan-Ann Arbor 1978-1981, joined SU as an assistant professor, and was promoted to associate professor 1984 and to professor in 1993. He was an Alexander von Humboldt Fellow 1989-1990.

His research interests were in algebraic topology, specifically equivariant homotopy theory and stable homotopy theory, and algebra, specifically Mackey functors and representation theory. He has published 15 papers, many very long and deep, and with coauthors the 503 page Springer Lecture Notes in Mathematics vol. 1213 entitled Equivariant Stable Homotopy Theory in 1986. He gave AMS special session talks at South Bend 1991, Syracuse 1993, and Baltimore 1998, and one at the Canadian Mathematical Society in Kingston 1998. He gave a talk at the NSF/CBMS Regional Research Conference in Fairbanks in August of 1993. He also spoke at AMS Summer Research Institutes in Seattle 1996 and Boulder 1999, the Midwest Topology Conference in February 2000, and a "by invitation only" workshop at Stanford in August 2000. He had NSF grant support 1983-1985 and has had two Ph.D. students: Melda Oruc (1987) and Kevin Ferland (1999). In March of 1996, the Ph.D. advisor of Florian Luca, a graduate student in topology at the University of Alaska, Fairbanks, died unexpectedly. Gaunce served as a replacement advisor for Florian until he completed his Ph.D. late that summer.

Gaunce served on the department's Executive Committee 1992-1994, 1995-1997 and 2001-2002, Graduate Committee 1990-1991 and Undergraduate Committee 1985-1988 and 2000-2001. In the College of Arts and Sciences he served on the Academic Committee 1994-1995 and the Promotion and Tenure Committee 1997-1998.

Gaunce Lewis died May 17, 2006 at the age of 56.

Sources: Dr. Lewis's CV dated May 2001; Philip Church (05/26/2010).

An article Memorial Tribute: L. Gaunce Lewis Jr. (1949–2006) and Mark Steinberger (1950–2018) by J. Peter May was published in Notices of the AMS.