Data from: Genomic diversity and geographical structure of the Pyrenean desman

The Pyrenean desman (Galemys pyrenaicus) is a small semi-aquatic mammal
endemic to the Iberian Peninsula. The species has recently experienced a
strong decline and some of its populations are severely threatened with
extinction. To help in the preservation of this species, it is critical to
understand its genetic structure and main evolutionary units, as these may
have specific local adaptations and could be of great conservation value.
Sequencing reduced representation libraries (ddRAD) from 26 specimens
selected from across its entire range, we obtained around 45,000 loci per
specimen and 1185 single nucleotide polymorphisms. Heterozygosity varied
substantially among individuals from different areas. Interestingly,
specimens from the southeastern Pyrenees had some of the lowest
proportions of heterozygous positions inferred from genome-wide data in
mammals so far. In addition, we estimated a tree reflecting genomic
divergence, performed a principal component analysis, and carried out a
Bayesian analysis of the population structure. Combined evidence supported
the existence of five distinct genomic clusters largely coincident with
the main mountain ranges where the species occurs, with few specimens
presenting relevant admixture levels. There was good correspondence
between these populations and the mitochondrial lineages detected in a
previous study, yet substantial differences in some areas demonstrate the
importance of performing genomic analysis to reveal the whole population
history. Although the analysis of further specimens is necessary to better
characterize the distribution of the different evolutionary units, the
distinctive geographical structure of this species revealed by the genomic
data should be considered in future conservation plans.