4. Discussion
This study, as expected, provides scientific evidence and information to identify bioclimate, land use, and human-induced activity (population density) variables that have significantly shaped, and would drive, macaques’ diversity and geographic distribution trajectories from the Pleistocene to the 2050s of the Quaternary. In addition to demonstrating how macaques have been evolutionarily changed in geographic distribution during the epoch, the results also provide scientific guidelines to amend the existing conservation strategies and management for macaques in the years to come, referring to their future geographical shifting directions and survival prospects in mainland East Asia, which would be shaped by the two greenhouse emissions scenarios (SSP2 and SSP5).