Phylogenetic relationships among Brazilian howler monkeys, genus Alouatta (Platyrrhini, Atelidae), based on gamma(1)-globin pseudogene sequences

The genus Alouatta (howler monkeys) is the most widely distributed of New W orld primates, and has been arranged in three species groups: the Central A merican Alouatta palliata group and the South American Alouatta seniculus a nd Alouatta caraya groups. While the latter is monotypic, the A. seniculus group encompasses at least three species (A. seniculus, A. belzebul and A. fusca). In the present study, approximately 600 base pairs of the gamma(1)- globin pseudogene were sequenced in the four Brazilian species (A. seniculu s, A. belzebul A. fusca and A. caraya). Maximum parsimony and maximum likel ihood methods yielded phylogenetic trees with the same arrangement: {A. car aya [A. seniculus (A. fusca, A. belzebul)]}. The most parsimonious tree had bootstrap values greater than 82% for all groupings, and strength of group ing values of at least 2, supporting the sister clade of A. fusca and A. be lzebul. The study also confirmed the presence of a 150-base pair Alu insert ion element and a 1.8-kb deletion in the gamma(1)-globin pseudogene in A. f usca, features found previously in the remaining three species. The cladist ic classification based on molecular data agrees with those of morphologica l studies, with the monospecific A. caraya group being clearly differentiat ed from the A. seniculus group.