Climatic Niche Divergence and Conservatism Promote Speciation in Snake-Eyed Skinks (Sauria: Scincidae): New Insight into the Evolution and Diversification of Ablepharus Species

The degree to which closely related species conserve or diverge in their niche characteristics may provide insight into evolutionary and diversification processes, as well as some understanding of broad-scale biogeographic patterns. In this study, we used an ensemble of 10 algorithms to predict the distributions of 12 Ablepharus species in geographical (G)-space for the recent time and the future (2081–2100) climate conditions. Niche overlap, equivalency, and similarity tests in environmental (E)-space were used to test niche divergence and conservatism. The consensus model showed that temperature seasonality (n = 6) and annual precipitation (n = 3) were the major factors predicting the distribution of 75% (9 out of 12) of the species. The ensemble models based on ssp585 predict that 83.33% of the species (n = 10) may have contracted their ranges, especially at lower altitudes along their southern margins. They may have also expanded northward during this period. However, in the ssp126, most species’ distribution ranges may remain unchanged despite contractions and expansions. Based on multivariate niche analyses, the distributions of 28 and 11 paired comparisons explored in this study significantly diverged and conserved. We found that closely related species inhabit different habitats and respond to their climatic characteristics, indicating that ecology has a significant influence on speciation.