Data from: Historical environment is reflected in modern population genetics and biogeography of an island endemic lizard (Xantusia riversiana reticulata)

The restricted distribution and isolation of island endemics often
produces unique genetic and phenotypic diversity of conservation interest
to management agencies. However, these isolated species, especially those
with sensitive life history traits, are at high risk for the adverse
effects of genetic drift and habitat degradation by non-native wildlife.
Here, we study the population genetic diversity, structure, and stability
of a classic “island giant” (Xantusia riversiana, the Island Night Lizard)
on San Clemente Island, California following the removal of feral goats.
Using DNA microsatellites, we found that this population is reasonably
genetically robust despite historical grazing, with similar effective
population sizes and genetic diversity metrics across all sampling
locations irrespective of habitat type and degree of degradation. However,
we also found strong site-specific patterns of genetic variation and low
genetic diversity compared to mainland congeners, warranting continued
special management as an island endemic. We identify both high and low
elevation areas that remain valuable repositories of genetic diversity and
provide a case study for other low-dispersal coastal organisms in the face
of future climate change.