Climatic Niche Differentiation Accompanied the Radiation of Leaf‐Eared Mice in the Phyllotis darwini Species Group (Sigmodontinae, Cricetidae)
Marcial Quiroga‐Carmona, José H. Urquizo, Naim M. Bautista, Guillermo D'Elía, Jay F. StorzABSTRACT
Aim
To characterise the evolution of climatic niches during the diversification of the
Location
South‐central Andes, surrounding lowlands and Patagonia, South America.
Methods
Species' climatic niches were characterised by sampling contemporaneous precipitation and temperature conditions across occurrence locations and entire distributional ranges. Climatic niches were analysed and modelled using multivariate analyses (PCA, PERMANOVA), a maximum entropy‐based algorithm and novel methods developed to explore levels of differentiation (niche overlap test) and divergence (niche divergence test) between realised and fundamental niches. Comparative phylogenetic methods were applied using a time‐calibrated phylogeny and integrating climate niche data to estimate ancestral environmental niches within geographic and environmental spaces.
Results
Comparisons revealed low levels of climatic niche overlap, both among species' realised niches and among their fundamental niches, suggesting high levels of niche differentiation during the diversification of Phyllotis species. Quantifications of niche overlap further showed that observed differences among species lay primarily in the multidimensional nature of climatic niches, as unidimensional quantifications exhibited higher levels of overlap. Evolved differences among species' climatic niches were better fitted to a Brownian motion model of evolution, but lacked phylogenetic signal and showed no significant association with species' phylogenetic distances.
Main Conclusions
Low levels of differentiation between ancestral climatic niches suggest that the early radiation of species in the