The genetic demographic history and phylogeography of the Andean bear(Tremarctos Ornatus) by means of microsatellites and mtDNA markers

Herein I show new molecular data (microsatellites and mtDNA sequences) for theAndean bear based on a larger sample size (286 individuals) than previously analyzed byRuiz-GarcÍa (2003, 2007) and Ruiz-GarcÍa et al., (2003, 2005). This sample wascomposed of individuals obtained in Venezuela, Colombia, Ecuador, Peru and Bolivia.Four main results came out of this study. 1- The evolutionary microsatellite dynamics ofthe markers applied to the spectacled bear revealed 20% of multiple-step mutations andan overall historical effective number of around 10,000 individuals; 2- Microsatellitesdetected a significant genetic heterogeneity for a large fraction of the comparisons madeamong the different populations considered, although this genetic differentiation wassmaller than that obtained in previous studies; 3- No tests detected any significantbottleneck event in the history of the overall population nor in the spectacled bearpopulations of Colombia and Ecuador. In contrast, some tests detected historicalpopulation expansions in this species. This was contrasted with the possible climaticchanges during the late Pleistocene. 4- The phylogeographic analysis by means of themitochondrial control region sequences showed, in contrast to the microsatellites, littledegree of differentiation among the Andean bears from Venezuela, Colombia andEcuador. However, two Peruvian exemplars were relatively differentiated from all theother sequences analyzed. This paper discusses the integration of both sets of molecularmarker results.