Pleistocene glaciations caused the latitudinal gradient of within-species genetic diversity

Abstract Intraspecific genetic diversity is a key aspect of biodiversity. Quaternary climatic change and glaciation influenced intraspecific by promoting range shifts population size change. However, the extent to which affected on global scale not well established. Here we quantify nucleotide diversity, common metric in more than 38,000 plant animal species using georeferenced DNA sequences from millions samples. Results demonstrate that tropical contain significantly nontropical species. To explore potential evolutionary processes may have contributed this pattern, calculated summary statistics measure demographic detected significant correlations between these latitude. We find are likely deviate neutral expectations, indicating they historically experienced dramatic fluctuations associated with Pleistocene glacial cycles. By analyzing most comprehensive data set date, our results imply climate perturbations be important as process driving latitudinal gradient richness previously appreciated.