Fig. 2.

Schematic representation of the major radiations amongst Plasmodium species. Since becoming parasites of vertebrates, the genus Plasmodium has expanded to infect a wide variety of hosts. Only a handful of these species, those referred to specifically in the text as well as some other major groupings, are represented here. The precise relationships between the species are not always known, so branch positioning is indicative rather than definitive – more detailed analyses are available elsewhere (Martinsen and Perkins, 2013). Human parasites originate from Plasmodium clades that have expanded in related groups of hosts, including the Laverania radiation in African apes, which includes the most deadly form of human malaria, P. falciparum, and an expansion of P. vivax-related parasites in African apes and Southeast Asian monkeys. The other two major human malaria parasites, P. ovale and P. malariae, also have relatives in African apes, but the full diversity and relationship between these species is not currently known. Recent works indicates that rodent and bat Plasmodium parasites are closely related, with possible host switching occurring on more than one occasion (Schaer et al. 2013).