Evolutionary hotspots in the middle and lower reaches of the Yangtze River Basin

Geographic areas that contain high genetic divergence among populations may be regions of evolutionary potential and conservation importance. Following the methods for mapping patterns of genetic divergence and diversity in a Geographic Information Systems (GIS) framework, we combined genetic landscapes across nineteen co-distributed species in the middle and lower reaches of the Yangtze River Basin (MLYRB) to identify important regions of evolutionary potential and assess whether these hotspots have high conservation importance. Diversity hotspots were mainly distributed in the Tai Lake sub-basin of the MLYRB. Several areas of high genetic divergence were located in the Dongting Lake, Hanshui and other lower mainstream sub-basins. Additionally, two areas of low divergence (coolspots) were identified in the lower mainstream sub-basin. In total, our results identified 14 evolutionary hotspots in the MLYRB. Our study provides a first assessment of the diversity and divergence patterns across a wide variety of species in the habitats of the MLYRB and, therefore, a working hypothesis for determining geographical areas of high evolutionary potential and conservation importance in the MLYRB.