Abstract

Northeast India, with its variety of geographical features and topography, provides a plethora of niches for species to evolve and thrive. Among a multitude of factors, past climate change is one of the important factors influencing primate speciation in this region. Populations of various species could have risen or declined in response to these climatic fluctuations. Recent advances in climate modelling as well as genomic data analysis has paved the way for understanding how species accumulate at a particular geographic region. We utilized these methods to explore the primate diversity in the unique region of northeast India. To ascertain these population level changes, we inferred demographic history of nine species of primates found in northeast India with MSMC2 and compared it with species distribution models using past climate data of Pliocene and Pleistocene period. Through this study, we are able to give a detailed picture of how past climatic changes have affected the present species diversity and we show that the primate diversity in northeast India is a mix of species either originated there or have dispersed from mainland southeast Asia. We observe that effective population size has decreased for all the species, but distributions are different for all the four genera, Macaca, Trachypithecus, Hoolock and Nycticebus, and this provides important insights pertaining to present primate diversity in the region. It also gives an idea about how each species is affected differently by climate change, and why it should be given emphasis in framing species-wise conservation models for future climate change.