Thomas was born in 1933 at Russellville, Alabama. From Harvard University, he earned three degrees in biological science with a specialty in botany. He held several academic and administrative positions at the University of Alabama. He earned the rank of full professor of biology in 1966, and he served as vice president for student affairs between 1969 and 1975. He was a member of Phi Beta Kappa and Sigma Xi.
In 1975 Thomas became the second scientist to lead North Carolina State University. During his tenure enrollment passed 20,000 and the School of Veterinary Medicine was established. He resigned in 1981 to accept the presidency of the University of Alabama, a position he held until 1988. He also served as president of Pennsylvania State University from 1990 to 1995.


