Genetic heterogeneity and evolutionary demographic history of the endemic Colombian Saguinus Leucopus (Primates) by means of dna microsatellites and coalescence methods

The Colombian bare-face tamarin, Saguinus leucopus (Callitrichinae, Cebidae, Primates), is a small primate, which has the smallest distribution range of any of the Saguinus species known. This is only the second molecular population study of this species. Our analysis of 10 DNA microsatellites provided four main findings. 1- The microsatellites we used basically evolved following the uni-step mutation model; 2- In a previous study, Ruiz-García et al., (2014a) determined two different genetic populations within the range of this species (corresponding to the Colombian Departments of Antioquia and Tolima). Herein, we estimated the possible effective population sizes of these two populations as well as the total species by means of three procedures (Nielsen, 1997; Griffiths and Tavaré, 1994; O'Ryan et al., 1998). These methods showed similar amounts ranging from 5,600 to 14,000 individuals and were relatively similar to the census population size estimate of 10,000 individuals for this species; 3- The method of Ciofi et al., (1999) showed that the two populations considered were more affected by gene drift than by gene flow, although the populations were only partially isolated; 4-Three scenarios were considered trying to explain when the genetics fragmentation occurred between these two populations, 100, 500, and 2,000-4,000 years ago. The procedure of O'Ryan et al., (1998) provided the most probably scenario of fragmentation for the last 2,000-4,000 years (or before) showing the influence of Pleistocene-Holocene climatic changes generating genetic diversity. However, the genetic fragmentation in the last 100-500 years cannot be totally excluded.