Glacial cycles drive rapid divergence of cryptic field vole species

Ecology and Evolution

Joana Paupério¹  Paulo C. Alves¹  Jeremy B. Searle²  Nicholas K. Fletcher²  Jeremy S. Herman³  Pelayo Acevedo⁴ 

[1] CIBIO/InBio, Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto, Campus de Vairão Vairão Portugal;Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA;Department of Natural Sciences National Museums Scotland Edinburgh UK;Instituto de Investigación en Recursos Cinegéticos, IREC (UCLM‐CSIC‐JCCM) Ciudad Real Spain;

关键词: environmental niche modeling;    genetic drift;    genotyping‐by‐sequencing;    glacial refugia;    Microtus agrestis;    speciation;   

DOI  :  10.1002/ece3.5846

来源: DOAJ

【 摘 要 】

Abstract Understanding the factors that contribute to the generation of reproductively isolated forms is a fundamental goal of evolutionary biology. Cryptic species are an especially interesting challenge to study in this context since they lack obvious morphological differentiation that provides clues to adaptive divergence that may drive reproductive isolation. Geographical isolation in refugial areas during glacial cycling is known to be important for generating genetically divergent populations, but its role in the origination of new species is still not fully understood and likely to be situation dependent. We combine analysis of 35,434 single‐nucleotide polymorphisms (SNPs) with environmental niche modeling (ENM) to investigate genomic and ecological divergence in three cryptic species formerly classified as the field vole (Microtus agrestis). The SNPs demonstrate high genomic divergence (pairwise FST values of 0.45–0.72) and little evidence of gene flow among the three field vole cryptic species, and we argue that genetic drift may have been a particularly important mechanism for divergence in the group. The ENM reveals three areas as potential glacial refugia for the cryptic species and differing climatic niches, although with spatial overlap between species pairs. This evidence underscores the role that glacial cycling has in promoting genetic differentiation and reproductive isolation by subdivision into disjunct distributions at glacial maxima in areas relatively close to ice sheets. Future investigation of the intrinsic barriers to gene flow between the field vole cryptic species is required to fully assess the mechanisms that contribute to reproductive isolation. In addition, the Portuguese field vole (M. rozianus) shows a high inbreeding coefficient and a restricted climatic niche, and warrants investigation into its conservation status.

【 授权许可】

Unknown