Data from: Cryptic phylogeographic history sheds light on the generation of species diversity in sky-island mountains

Biodiversity hotspots should be given high priority for conservation under
the situation of global climate change. The sky islands in southwestern
China are characterized by extraordinarily high species diversity and are
among one of the world’s top biodiversity hotspots. However, neither the
actual species diversity in this region or mechanisms generating this
diversity are well explored. Here, we report on the phylogeographic
analysis of the long-tailed mole (Scaptonyx fusicaudus), a semi-fossorial
mammal that inhabits the montane cool forests across the Chinese sky
islands and is considered to represent one species divided into two
subspecies. Analyses using DNA sequence data from one mitochondrial and
six nuclear genes revealed that populations inhabiting different mountains
exhibited exceptionally strong geographic structure. The lowlands and
large rivers act as “soft” and “hard” barriers to dispersal, respectively,
isolating evolutionary lineages for up to 11 million years. Our results
suggest that the mountain ranges act as interglacial refugia buffering
populations from climate fluctuations, further facilitating allopatric
diversification. Strikingly, species delimitation analyses suggests that
the long-tailed mole may comprise 18 operational taxonomic units and 17
putative species. Our results suggest that for low-vagility species, the
complex topography of the Chinese sky islands has shaped genetic diversity
and structure and promoted exceptional diversification through a
combination of eco-environmental stability as well as geographic
fragmentation. The patterns observed in S. fusicaudus may be
representative for other cold-adapted species, reflecting the generation
of mammalian faunal diversity in the sky-island mountains of southwestern
China.