(Ne ~3000). Plasmodium Colobine and macaque monkeys migrated from Africa into the Eurasian continent 10 and 6 millions of years ago respectively and became the ancestors of the extant Asian Old World monkey species. Asian Old World monkey malaria parasite species infect both colobine and macaque monkeys. The existing divergence between the Asian and African clade of this subgenus seems likely to have been caused by intercontinental allopatric speciation along with that of their hosts. Malaria parasites of the lemurs are not traditionally grouped with the subgenus Plasmodium being placed rather within subgenus Vinckeia. This classification may not be correct. Based on an analysis of the mitochondria, these parasites seem to group with the others infecting primates. The origin of the primate infecting species (excluding those in the Laverina subgenus) may date back to the Eocene - a time when the primate radiation began. This analysis also suggests that the species infecting gorillas and humans may have originated in chimps. Plasmodium: Asian clade At least nine species belong to the 'Asian' clade of Plasmodium. These species include Plasmodium coatneyi, Plasmodium cynomolgi, Plasmodium fieldi, Plasmodium fragile, Plasmodium inui, Plasmodium hylobati, Plasmodium simiovale, Plasmodium simium and Plasmodium vivax. As a rule (with the noticeable exception of P. knowesli), the Asian species have a 72-hour intra erythroctytic life cycle. Analysis of the merozoite surface protein in ten species of the Asian clade suggest that this group diversified between 3 and 6.3 million years ago - a period that coincided with the radiation of the macques within South East Asia. The inferred branching order differs from that found from the analysis of other genes suggesting that this phylogenetic tree may be difficult to resolve. Positive selection on this gene was also found. In an analysis of the SSU rRNA gene it was found that all Asian simian Plasmodium species have a single S-type-like gene and several A-type-like genes. A 50 residue insertion in the V7 variable region near the stem 43 is shared exclusively by the S-type like sequences of the Asian simian Plasmodium species and the S- and O-type sequences of P. vivax. This is consistent with their shared ancestry. Plasmodium vivax may have originated in Asia and the related species Plasmodium simium appears to be derived through a transfer from the human P. vivax to New World monkey species in South America. This was proposed in a study of howler monkeys near