SREL Reprint #1902

A molecular phylogeny of the gopher tortoises, with comments on familial relationships within the Testudinidae

Trip Lamb1 and Charles Lydeard2

1Department of Biology, East Carolina University, Greenville, North Carolina 27858
2Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29802

Abstract: Sequences from the mitochondrial cytochrome b gene were obtained to examine molecular phylogenetic relationships among the North American gopher tortoises. Data from 352 aligned positions generated a single most-parsimonious tree for each of three analytical approaches: (1) equal weighting, all substitutions; (2) equal weighting, third position changes limited to transversions; and (3) transversions weighted 10 times transitions. Identical topologies for the resulting trees depict the gopher tortoises as a monophyletic group comprising two well-defined clades. Observed sequence divergence (7.0%) between the agassizii (Gopherus agassizii; G. berlandieri) and the polyphemus (G. flavomarginatus; G. polyphemus) clades suggests an Early Miocene separation of these lineages. The cytochrome b phylogeny complements some previous systematic interpretations, including formal taxonomic recognition of the two distinct groups, but is at odds with the most recent morphological analysis. Additional sequence comparisons of selected testudinoid (batagurid, emydid, and testudinid) taxa yielded a phylogeny consistent with a morphologically based hypothesis demonstrating close phylogenetic affinities between the Testudinidae and the "Bataguridae."

SREL Reprint #1902

Lamb, T. and C. Lydeard. 1994. A molecular phylogeny of the gopher tortoises, with comments on familial relationships within the Testudinidae. Molecular Phylogenics and Evolution 3:283-291. 

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).