The phylogeographic structure of the mountain coati (Nasuella olivacea; Procyonidae, Carnivora), and its phylogenetic relationships with other coati species (Nasua nasuaandNasua narica) as inferred by mitochondrial DNA

摘要

Carnivores are important elements of Neotropical biomes that are in need of conservation efforts. However, successful conservation methods rely on the identification of accurate evolutionary taxa. Unfortunately, in the case of Procyonidae systematics, there has been little knowledge in some genera. Two of these genera areNasuellaandNasua, also known as the coatis. Herein, we analyzed a dataset obtained in South America and Central America, containing sequences of three mitochondrial genes (ND5, Cyt-b, andD-loop) collected from 42 mountain coati (Nasuella olivacea) specimens, plus 50 white-nosed coati (Nasua narica) and 51 ring-tailed coati (Nasua nasua) (total sample of 143). Our results support four main findings. (1) We detected four significantly different groups ofN. olivacea. There were two small groups, one distributed in the Central Colombian Andean Cordillera and Western Ecuadorian Andean Cordillera, and another in the Western Colombian and Ecuadorian Andean Cordilleras. The specimens of these small groups were phenotypically un-differentiable fromN. olivacea, but their mtDNA were more related to that ofN. nasuathan to the mtDNA of the otherN. olivacea. The other two groups ofN. olivaceacontained the major part of the specimens analyzed. One is in the Eastern Colombian Andean Cordillera and is molecularly un-differentiable from the proposed "new" endemic Venezuelan species,Nasuella meridiensis. The ancestor of this group gave origin to another expanded group in the Western and Central Colombian and Ecuadorian Andean Cordilleras. (2) Different analyses (network, temporal splits, genetic diversity analyses) showed that the mitochondrial haplotypes ofN. nasuawere the first to appear (temporal diversification during the Late Miocene, and Pliocene), followed by the haplotypes of the current groups ofNasuella(temporal diversification during the Pliocene and beginning of the Pleistocene), and then the haplotypes that of the Central AmericanN. narica(temporal diversification during the Pleistocene). WithinN. nasua, we detected, at least, four highly differentiated groups that contain cryptic species or highly differentiated subspecies. (3) All of the taxa we analyzed showed high levels of mitochondrial genetic diversity, butN. nasuashowed the highest levels, whereasN. naricashowed the lowest levels. (4) Some groups ofN. olivacea, andN. naricashowed Pleistocene population expansions, but all the taxa showed a very strong signal of population declination in the last 20,000 years ago (YA), which could be correlated with the drastic climatic changes in that epoch.