the most recent common ancestor of the extant strains that has been published is 452,000 years ago. A review of this subgenus has been published Based on the analysis of the cytochrome b gene the relationships in this subgenus appear to as follows: P. falciparum and P. reichenowi are sister species. Their closest relation is P. billcollinsi. P. gaboni and P. billbrayi are sister species whose closest relation is P. gora. P. gorb is more closely related to the P. falciparum/reichenowi/billcollinsi clade than the P. gaboni/billbrayi/gora clade. This putative taxonomy will need confirmation from other DNA studies. A second study seems to confirm this proposed grouping. Another estimate puts the divergence between falciparum and reichenowi at ~200,000 years before present. The dates of the evolution of the species within the subgenus Laverania have been estimated as follows: Laverania: (Mya) (95% estimated range: - ) P. falciparum in humans: (range: - ) P. falciparum in Pan paniscus: (range: - ) P. falciparum in humans and Pan paniscus: ( - ) P. reichenowi - P. falciparum in Pan paniscus: (range: - ) P. reichenowi - (range: - ) P. billbrayi - P. falciparum (range: - ) P. billcollinsi - (range: - ) P. praefalciparum - P. falciparum in gorilas 40,000-60,000 years ago Another estimate using the mutation rate (1.2 x 10−8 subsititutions/site/year) of the cytochrome b gene placed the spread of P. falciparum to humans at 365,000 years ago (95% credible interval: 112,000 to 1,036,000 years). Revised names have been proposed for the P. gora and P. gorb species - Plasmodium blacklocki and Plasmodium adleri respectively. These names were chosen to honour the malariologists Saul Adler (1895–1966) and Donald Blacklock (1879–1953). It has also been proposed that the P. falciparum strains infecting gorillas should be renamed Plasmodium praefalciparum. This proposal appears to have been accepted. The species P. billbrayi seems to be synonymous with earlier named P. gaboni. Host-parasite relations: P. falciparum has been isolated from chimpanzees, gorillas and humans. The non human strains may be reclassified as P. praefalciparum. P. reichenowi has been isolated from chimpanzees. P. billcollinsi has been isolated from chimpanzees. P. billbrayi has been isolated from chimpanzees. P. gaboni has been isolated from chimpanzees. P. adleri has been isolated from gorillas. P. blacklocki has been isolated from gorillas. P. lomamiensis has been isolated from bonobos. P. praefalciparum has been isolated from gorillas. Another analysis has proposed the following