Fig. 1

Sampling locations and genetic clusters of different populations used in this study (a) and the dendrogram based on microsatellites using Nei’s genetic distance (b). The map of China shows the locations of sampled rat populations, the Tea Horse Ancient Road, the Chuan-Zang Highway, and primary rivers in China. The coloured pie charts represent distinct genetic clusters found via Bayesian clustering analysis for each population, with red representing cluster I, yellow presenting cluster II and green for cluster III. The map is downloaded from the website of National Administration of Surveying, Mapping and Geoinformation of China (http://bzdt.nasg.gov.cn/index.jsp)