Dykes graduated from Auburn University with a degree in electrical engineering in 1969. After graduation, he served as a commissioned officer in the U.S. Army Signal Corps. He received a master's degree in business administration in 1981 from Emory University and a master's degree in management from Stanford University in 1986. He is the retired chief financial officer of BellSouth Corporation, where his career spanned 35 years. He joined Southern Bell, the predecessor company, in Atlanta in 1971 and held a series of positions in the company's network operations and network planning and engineering groups. He is a past director of Cingular Wireless and served as its chairman of the board.
Dykes, currently a director of American Tower Corporation, previously served as a trustee of St. Joseph's Health System, Atlanta, and as a director of Burger King Holdings, Inc. A member of the Alabama Engineering Hall of Fame, he currently serves on the Electrical and Computer Engineering Advisory Board, and he has been recognized as a Distinguished Auburn Engineer by the Auburn Alumni Engineering Council.
Dykes is a member of Auburn's 1856 Society, as well as the Ginn Society and the Engineering Eagles Society in the Samuel Ginn College of Engineering. He is also a life member of the Auburn Alumni Association. He is married to Anne and has two children: John, a 2005 Auburn graduate, and Brian.