David Elson Sheppard, aged 82 , passed away on July 28, 2020, in Glen Mills, Pennsylvania, from complications due to pancreatic cancer. He was born on January 16, 1938, in Chester, Pennsylvania, the only child of Ruth Crosier Sheffield Sheppard and Howard Blew Sheppard. He attended the Chester Public Schools through ninth grade and graduated from the Mount Hermon School for Boys in 1955. He received the Bachelor of Arts (Biology) from Amherst College in 1959 and a PhD (Biology-Genetics) from Johns Hopkins in 1964. He taught at Reed College from 1963 to 1965 and held a NSF postdoctoral fellowship in Biology Sciences at the University of California–Santa Barbara from 1965 to 1966. He taught courses in Genetics and Biochemistry and performed research in the Department of Biological Sciences at the University of Delaware from 1967 until his retirement in 2005. His research interests were in the area of the control of gene expression in bacteria. David embraced the non-theological fellowship of the First Unitarian Society of Wilmington, Delaware, and was an active member for over 50 years. He was particularly proud of his involvement in the new Unitarian congregations started by First Unitarian in southern New Jersey and the Delmarva Peninsula. David married the love of his life, Gayle Lea Drummey, on August 20, 1960. His devotion to her was always foremost in his actions. They were together until his death. David is survived by his wife; their children Rebecca Jean Sheppard (Christopher Michael Mark), Paul Owen Sheppard (M. Sharon Davis Sheppard), and Marc Andrew Sheppard (SJ Thoreson); their grandchildren Daniel Crosier Siders, Benjamin Davis Sheppard, Joshua Paul Sheppard, and Thoreson Liam Sheppard. At the request of the deceased, no memorial service is planned at this time. Family and friends are encouraged to post photos and reminisces at https://professorsheppard.com. In lieu of flowers, the family suggests donations in Dave's name to the Sheffield Scholarship Fund at Northfield Mount Hermon School. Contributions can be sent through the following link: https://www.nmhschool.org/give Sheffield Scholarship Fund should be noted in 'Gift Instructions. Contributions noted for the Fund can also be mailed to NMH Advancement Office, One Lamplighter Way, Mount Hermon, MA 01354. Online condolonces may be made by visiting (www.paganofuneralhome.com).