Journal Article

High Risks of Losing Genetic Diversity in an Endemic Mauritian Gecko: Implications for Conservation

Groombridge, Jim J., Gallagher, Laura E., Buckland, Steeves, Cole, Nik C., Dawson, Deborah A., Küpper, Clemens, Harris, Stephen, Burke, Terry

2014

Overview

Genetic structure can be a consequence of recent population fragmentation and isolation, or a remnant of historical localised adaptation. This poses a challenge for conservationists since misinterpreting patterns of genetic structure may lead to inappropriate management. Of 17 species of reptile originally found in Mauritius, only five survive on the main island. One of these, Phelsuma guimbeaui (lowland forest day gecko), is now restricted to 30 small isolated subpopulations following severe forest fragmentation and isolation due to human colonisation. We used 20 microsatellites in ten subpopulations and two mitochondrial DNA (mtDNA) markers in 13 subpopulations to: (i) assess genetic diversity, population structure and genetic differentiation of subpopulations; (ii) estimate effective population sizes and migration rates of subpopulations; and (iii) examine the phylogenetic relationships of haplotypes found in different subpopulations. Microsatellite data revealed significant population structure with high levels of genetic diversity and isolation by distance, substantial genetic differentiation and no migration between most subpopulations. MtDNA, however, showed no evidence of population structure, indicating that there was once a genetically panmictic population. Effective population sizes of ten subpopulations, based on microsatellite markers, were small, ranging from 44 to 167. Simulations suggested that the chance of survival and allelic diversity of some subpopulations will decrease dramatically over the next 50 years if no migration occurs. Our DNA-based evidence reveals an urgent need for a management plan for the conservation of P. guimbeaui. We identified 18 threatened and 12 viable subpopulations and discuss a range of management options that include translocation of threatened subpopulations to retain maximum allelic diversity, and habitat restoration and assisted migration to decrease genetic erosion and inbreeding for the viable subpopulations.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adaptation / Animal Migration / Animals / Assisted migration / Biology and Life Sciences / Colonization / Conservation / Conservation of Natural Resources / Deoxyribonucleic acid / Differentiation / DNA / DNA, Mitochondrial - chemistry / Ecology / Ecology and Environmental Sciences / Endangered & extinct species / Endangered Species / Environmental protection / Environmental restoration / Evolution / Extinction / Extinction, Biological / Forests / Fragmentation / Geckos / Genetic diversity / Genetic markers / Genetic structure / Genetic Variation / Genotype / Habitat conservation / Haplotypes / Inbreeding / Lizards - genetics / Lizards - physiology / Management / Markers / Mauritius / Microsatellite Repeats / Microsatellites / Mitochondrial DNA / Mutation / National parks / Phelsuma / Phelsuma guimbeaui / Phylogenetics / Phylogeny / Phylogeography / Pinus taeda / Plant sciences / Population Density / Population Dynamics / Population genetics / Population growth / Population structure / Reproductive Isolation / Reptiles / Restoration / Risk factors / Subpopulations / Translocation / Trends