MARMOSET PHYLOGENETICS, CONSERVATION PERSPECTIVES, AND EVOLUTION OF THE MTDNA CONTROL REGION

Marmosets (genus Callithrix) are a diverse group of platyrrhine primat es with 13-15 purported taxa, many of them considered endangered. Morp hological analyses constitute most of the basis for recognition of the se forms as distinct taxa. The purpose of this study was to provide a molecular view, based on mitochondrial control region sequences, of th e evolutionary history of the marmosets, concomitant with a molecular phylogenetic perspective on species diversity within the group. An add itional purpose was to provide the first comparative examination of a complete New World monkey control region sequence with those of other mammals. The phylogenetic analyses provide convincing support for a sp lit between the Atlantic forest and Amazonian marmosets, with the incl usion of the pygmy marmoset (Cebuella pygmaea) at the base of the Amaz onian clade. The earliest branch of the Atlantic forest group was C. a urita. In the Amazonian group, the analyses do not support the recogni tion of C. humeralifer and the recently described C. mauesi as distinc t taxa. They do, however, support a clear distinction between C. argen tata and a strongly supported mixed clade of C. humeralifer and C. mau esi. In the Atlantic forest group, the phylogenetic tree suggests mixi ng between C. penicillata, C. kuhli, and possibly C. jacchus. Most of the sequence features characteristic of other mammal control regions w ere also evident in marmosets, with the exception that conserved seque nce blocks (CSBs) 2 and 3 were not clearly identifiable. Tandem repeat units often associated with heteroplasmy in a variety of other mammal s were not evident in the marmoset sequences.