Southwest China, the last refuge of continental primates in East Asia

Knowledge of primate evolutionary history from the Late Miocene to the present in East Asia is necessary to develop a conservation strategy for primates today and future. This background is especially evident from the distributions of fossil-bearing sites in the Pleistocene and historical records over the past 800 years. We illustrate catarrhines' early dispersal and radiation routes, paths, and later shrinking trajectories, providing robust evidence and information for making or amending conservation strategies. Catarrhines (apes and Old-World monkeys) in East Asia are analyzed in this study. The results indicate that their spread during the Pleistocene from the west to east remarkably involved the three river systems (Yangtze, Yellow, and Pearl) and the coastlines, resulting in broad distributions in the Far East (Taiwan, Korea, and Japan). Unfortunately, their continental taxa significantly suffered reductions from ancient to modern Holocene, leading to a tremendous biodiversity loss in East Asia. These events corresponded to major periodic social upheavals and anthropogenic activities, particularly in the first half of the last century and the post-war period after 1950 that has involved unparalleled environmental devastation and natural resource depletion. Except for the taxa in Taiwan and Japan, primates in East Asia will finally be confined to Southwest China, especially a Convergence-Divergence Center (CDC) that has played a unique role in shielding primates and other animals, as well as the plants since the Later Miocene. Thus, developing a specific conservation priority is critical for the CDC and its adjacent regions to mitigate primate extinction in East Asia.