Multilocus phylogeny suggests a distinct species status for the Nepal population of Assam macaques ( ): implications for evolution and conservation.

Phylogenetic relationships within the -group of macaques based on morphological, behavioral, and molecular characteristics have remained controversial. The Nepal population of Assam macaques ( ) (NPAM), the westernmost population of the species, is morphologically distinct but has never been used in phylogenetic analyses. Here, the phylogenetic relationship of NPAM with other congeners was tested using multiple mitochondrial and Y-chromosomal loci. The divergence times and evolutionary genetic distances among macaques were also estimated. Results revealed two major mitochondrial DNA clades of macaques under the -group: the first clade included , , and eastern subspecies of Assam macaque ( ); the second clade included together with species from the eastern and central Himalaya, namely, , , and NPAM. Among the second-clade species, NPAM was the first to diverge from the other members of the clade around 1.9 million years ago. Our results revealed that NPAM is phylogenetically distinct from the eastern Assam macaques and closer to other species and hence may represent a separate species. Because of its phylogenetic distinctiveness, isolated distribution, and small population size, the Nepal population of -group macaques warrants detailed taxonomic revision and high conservation priority.