His mother had a passion for Ancient Egypt, and Gaines considered a career in Archeology, participating in several digs in Alabama in his teenage years.

[3] Thanks to his dad's passion for theater, he also tried his hand at acting, participating in productions in community theatre all the way up to a professional role at the Alabama Shakespeare Festival in 1986.

Following in his parents’ footsteps he attended the College of William & Mary in Williamsburg, Virginia, and received a Bachelor of Science in Geology in 1995.

He took a class with his future PhD advisor, Dr. Mary L. Droser, on sabbatical from UC Riverside, who further instilled his passion for fossils and ancient ecosystems.

[10] He received multiple grants from government and private agencies for substantial expansion of the analytical facilities of the college and Geology Department.

He works on ancient sedimentary rocks all across the northern hemisphere; in British Columbia, South China, and American Great Basin.

[18] With his work around the world on the Burgess Shale he is helping to resolve one of the great mysteries relating to the Cambrian Explosion; the mechanism for the precise preservation of these fossils.

By collecting geochemical data from the many sites he has worked, he hypothesized that a combination of calcium carbonate deposits and lower levels of oxygen and sulfur in the Cambrian seas prevented the degradation of the fossils by microbes.

[13][19][20] Gaines's hypothesis with Shanan Peters relating the Cambrian Explosion to the Great Unconformity was featured on the cover of Nature in 2012.

[21] Using geochemical and stratigraphic data from 830 locations across North America they found evidence that the Great Unconformity affected ocean chemistry such that it may have triggered the evolution of Biomineralization, an essential factor of diversification of the Cambrian Explosion.

[22] In 2021, Gaines's work on the fossil records of early animal life was honored by the official naming of a species of hurdiid radiodont he helped to discover, Titanokorys gainesi.

[24] RUI: An Integrative Paleontological And Paleoenvironmental Study Of The Middle Cambrian Spence, Wheeler, And Marjum Soft-Bodied Faunas