The genetic crisis of the Mexican Bolson Tortoise (Gopherus flavomarginatus: Testudinidae)

Abstract

Gopherus flavomarginatus (Testudinidae) is endemic to a series of discontinuous, isolated basins collectively known as the Bolson de Mapimí in the Chihuahuan Desert. Its numbers declined after catastrophic levels of exploitation during the mid-20th century. However currently, the Bolson Tortoise appears to be on a path to recovery owing to intensive, sustained conservation efforts. We sequenced an 842-bp-long fragment of the D-loop from 76 individuals distributed throughout the species' range. The results revealed only two haplotypes. An AMOVA showed that 95% of the variance occurred among populations, whereas the remaining 5% was explained by genetic differences within populations. Tectonic processes together with ecological transformation during the Pleistocene and Holocene may be responsible for the reduction in this species' genetic variation. A bottleneck during which a significant percentage of the haplotype diversity was lost would result in genetic homogeneity. Although there is demographic growth, the lack of genetic diversity is indicative of the potential crisis that the Bolson Tortoise is facing, and awareness must be brought to this situation. © 2012 Koninklijke Brill NV, Leiden.