summary of the currently understood branching order is as follows: P. gondori - Asian clade P. fieldi, P. simiovale, P. vivax, P. simium, P. cynomolgi, P. inui - P. fragile, P. coatneyi, P. knowlesi, P. hylobati P. vivax/P. simium - P. fieldi, P. simiovale, P. cynomolgi, P. inui P. cynomolgi/P. inui - P. fieldi/P. simiovale P. fragile/P. coatneyi - P. knowlesi/P. hylobati This branching order may have to be revised as more data becomes available. The timing of these events is still rather uncertain. The African species P. georgesi appears to be a close relation of P. gondori. Another paper suggests that P. coatneyi and P. knowlesi are sister species while P. hylobati and P. inui are also sister species. This analysis supports the grouping of P. fieldi and P. semiovale as sister species with their closest relation being P. cynomogli. It also agrees with previous analyses that place P. simium and P. vivax as sister species. It also agrees that P. gondori is the African species most closely related to the Asian clade. This branching order may have some difficulties. A deletion of the LS1 rRNA gene of P. gonderi P. cynomolgi and P. simiovale has been reported. This mutation was not found in the other species of this group that were examined - P. fragile, P. knowelsi, P. simiae and P. vivax. These mutations are rare and suggest a relationship between the first three species to the exclusion of the others. Host relations P. cynomolgi, P. inui and P. knowlesi infect primates of the genus Presbytis. P. cynomolgi, P. fieldi, P. inui, P. knowlesi and P. semiovale infect primates of the genus Macaca. P. georgesi and P. gondori infect primates of the genus Cocerebus. P. gondori infects primates of the genus Mandillus. Additional species Within the 'Asian' clade are three unnamed potential species. One infects each of the two chimpanzee subspecies included in the study (Pan troglodytes troglodytes and Pan troglodytes schweinfurthii). These appear to be related to the P. vivax/P. simium clade. A new species - yet to be formally described - has been reported from orangutans (Pongo pygmaeus) in Indonesia. This species was identified from mitochondrial DNA in the blood of the hosts. It appears to be related to the other members of the Asian clade. Another as yet unnamed species likely to belong to this group has been identified in the mandrill (Mandrillus sphinx). Plasmodium: