Trip Lamb, John C. Avise, J. Whitfield Gibbons, Phylogeographic Patterns in Mitochondrial DNA of the Desert Tortoise (Xerobates agassizi), and Evolutionary Relationships Among the North American Gopher Tortoises, Evolution, Vol. 43, No. 1 (Jan., 1989), pp. 76-87
No takes yet. Share an insight, caveat, or question.
Lamb et al. (1989) studied this question.