No abstract

The accurate identification of taxa of Aotus is essential for 1) the development of precise biomedical assays, 2) the determination of potential illegal traffic of this genus, and 3) conservation. Although many studies have contributed to what we know about the phylogenetics of Aotus, none used a sufficiently large number of samples to clarify its complexity. To address this need, we sequenced 696 base pairs of the mitochondrial cytochrome-oxidase II gene (mtCOII) in 69 specimens of 7 taxa of Aotus. We also analyzed 8 microsatellite loci in 136 individuals of 6 taxa. In contrast to previous studies, we sampled only wild individuals and have a precise geographical origin for each one. The mtDNA results showed that: 1) the northern gray-necked group of Aotus is genetically more homogeneous than the polyphyletic red-necked group of Aotus; 2) the ancestors of Aotus vociferans seem to be the original species candidate for the current Aotus; 3) Aotus azarae azarae and A. a. boliviensis are the most differentiated taxa, likely a result of extreme genetic drift during stasipatric speciation; 4) the first genetic splits found among taxa of Aotus occurred during the Pliocene (or even Miocene) while the most recent ones happened during the Pleistocene, when forest refugia may have played an important role in speciation. The mean number of microsatellite alleles was 3–5.33 alleles per locus. We found some private alleles that could be useful in helping to identify illegal trade, although a larger sample size is needed to ensure that these alleles are really private to the relevant taxa. These new findings increase our understanding of the phylogeny of Aotus and the level of genetic diversity within different taxa of Aotus.Fil: Ruiz García, Manuel. Pontificia Universidad Javeriana; ColombiaFil: Vásquez, Catalina. Pontificia Universidad Javeriana; ColombiaFil: Camargo Acosta, Emily Yineth. Pontificia Universidad Javeriana; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Leguizamón, Norberto. Secretaría Distrital Ambiental; ColombiaFil: Gálvez, Hugo. Instituto Veterinario de Investigaciones Tropicales y de Altura. Estación Experimental; Perú. Universidad Nacional Mayor de San Marcos; PerúFil: Vallejo, Adriana. Pontificia Universidad Javeriana; ColombiaFil: Pinedo, Myreya. Pontificia Universidad Javeriana; ColombiaFil: Castellanos Mora, Luisa. Fundación Omacha; ColombiaFil: Shostell, Joseph. University of Pennsylvania; Estados UnidosFil: Alvarez, Diana. Pontificia Universidad Javeriana; Colombi

We propose the first molecular systematic hypothesis for the origin and evolution of Cebus capucinus based on an analysis of 710 base pairs (bp) of the cytochrome c oxidase subunit II (COII) mitochondrial gene in 121 C. capucinus specimens sampled in the wild. The animals came from the borders of Guatemala and Belize, Costa Rica, and eight different departments of Colombia (Antioquia, Chocó, Sucre, Bolivar, Córdoba, Magdalena, Cauca, and Valle del Cauca). Three different and significant haplotype lineages were found in Colombia living sympatrically in the same departments. They all presented high levels of gene diversity but the third Colombian gene pool was determined likely to be the most ancestral lineage. The second Colombian mitochondrial (mt) haplogroup is likely the source of origin of the unique Central America mt haplogroup that was detected. Our molecular population genetics data do not agree with the existence of two well-defined subspecies in Central America (limitaneus and imitator). This Central America mt haplogroup showed significantly less genetic diversity than the Colombian mt haplogroups. All the C. capucinus analyzed showed evidence of historical population expansions. The temporal splits among these four C. capucinus lineages were related to the completion of the Panamanian land bridge as well as to climatic changes during the Quaternary Period.

Some previous genetic studies have been performed to resolve the molecular phylogenetics of the squirrel monkeys (Saimiri). However, these studies did not show consensus in how many taxa are within this genus and what the relationships among them are. For this reason, we sequenced 2,237 base pairs of the mt COI and COII genes in 218 Saimiri individuals. All, less 12 S. sciureus sciureus from French Guyana, were sampled in the wild. These samples represented all the living Saimiri taxa recognized. There were four main findings of this study. (1) Our analysis detected 17 different Saimiri groups: albigena, cassiquiarensis, five polyphyletic macrodon groups, three polyphyletic ustus groups, sciureus, collinsi, boliviensis, peruviensis, vanzolinii, oerstedii and citrinellus. Four different phylogenetic trees showed the Central American squirrel monkey (S. oerstedii) as the most differentiated taxon. In contrast, albigena was indicated to be the most recent taxon. (2) There was extensive hybridization and/or historical introgression among albigena, different macrodon groups, peruviensis, sciureus and collinsi. (3) Different tests showed that our maximum likelihood tree was consistent with two species of Saimiri: S. oerstedii and S. sciureus. If no cases of hybridization were detected implicating S. vanzolinii, this could be a third recognized species. (4) We also estimated that the first temporal splits within this genus occurred around 1.4-1.6 million years ago, which indicates that the temporal split events within Saimiri were correlated with Pleistocene climatic changes. If the biological species concept is applied because, in this case, it is operative due to observed hybridization in the wild, the number of species within this genus is probably more limited than recently proposed by other authors. The Pleistocene was the fundamental epoch when the mitochondrial Saimiri diversification process occurred.

We analyzed 115 Saguinus leucopus, from four Colombian departments (Antioquia, Bolivar, Caldas and Tolima ), for 701 bp of the mt COII gene and at 10 microsatellite loci to estimate gene diversity levels, possible molecular subspecies and historical demographic changes in this species. This endemic Colombian species showed an elevated gene diversity in this gene, although its geographical distribution is very restrictive and extremely threatened by habitat fragmentation. The mt COII gene did not show any geographical structure in the distribution of the haplotypes within this species, but it did show a noteworthy population expansion throughout the history of this species. A Bayesian analysis showed that the haplotype diversification of this species began around 1.6 million years ago (MYA), whilst a haplotype network gave the beginning of this diversification at around 0.5-0.6 MYA. Forty-seven individuals out of the 115 were analyzed for 10 DNA microsatellites. The genetic diversity was relatively elevated for this kind of marker too, and comparable to that found in other Neotropical monkeys with a wider geographical distribution. Two gene pools were detected with the microsatellites, one in the northern distribution area (Antioquia) and the other in the southern distribution area (Tolima). No tests detected any bottleneck affecting this population; however, two procedures (k test and Kimmel et al. 1998 test) detected significant population expansion for the microsatellite markers, like that seen with the mt COII gene.