ANCIENT SINGLE ORIGIN FOR MALAGASY PRIMATES

We report new evidence that bears decisively on a long-standing contro versy in primate systematics. DNA sequence data for the complete cytoc hrome b gene, combined with an expanded morphological data set, confir m the results of a previous study and again indicate that all extant M alagasy lemurs originated from a single common ancestor. These results , as well as those from other genetic studies, call for a revision of primate classifications in which the dwarf and mouse lemurs are placed within the Afro-Asian lorisiforms. The phylogenetic results, in agree ment with paleocontinental data, indicate an African origin for the co mmon ancestor of lemurs and lorises (the Strepsirrhini). The molecular data further suggest the surprising conclusion that lemurs began evol ving independently by the early Eocene at the latest. This indicates t hat the Malagasy primate lineage is more ancient than generally though t and places the split between the two strepsirrhine lineages well bef ore the appearance of known Eocene fossil primates. We conclude that p rimate origins were marked by rapid speciation and diversification som etime before the late Paleocene.