RESUMEN
This research examines phylogenetic relationships between members of the Atelinae subfamily (Alouatta, Ateles, Brachyteles, and Lagothrix), based on analysis of three genetic regions. Two loci, cytochrome c oxidase subunit II (COII) and the hypervariable I portion of the control region, are part of the mitochondrial genome. The other is a single-copy nuclear gene, Aldolase A Intron V. Analysis of these genetic regions provides support for tribe Alouattini containing the Alouatta species, while tribe Atelini contains the other three genera. However, these three genetic regions produce conflicting results for relationships among tribe Atelini members. Previous genetic studies supported grouping Brachyteles with Lagothrix, leaving Ateles in a separate subclade. The present data sets vary based on the genetic region analyzed and method of analysis suggesting all possible cladistic relationships. These results are more consistent with investigations of morphology and behavior among these primates. The primary cause of discrepancy between this study and previous genetic studies is postulated to reside in increased sampling in the present study of genetic variation among members of the Atelinae, specifically Ateles. The present study utilized samples of Ateles from all postulated species for this genetically variable primate, while previous studies used only one or two species of Ateles. This paper demonstrates that shifting relationships are produced when different species of Ateles are used to reconstruct phylogenies. This research concludes that a trichotomy should still be supported between members of tribe Atelini until further analyses, which include additional Atelinae haplotypes are conducted.