Contact Us

Ricklefs RE, Outlaw DC (2010) A molecular clock for malaria parasites. Science 329(5988): 226-229.

DOI: 10.1126/science.1188954
EID: 2-s2.0-77954593415
PMID: 20616281

DOWNLOAD PDF

ABSTRACT
The evolutionary origins of new lineages of pathogens are fundamental to understanding emerging diseases. Phylogenetic reconstruction based on DNA sequences has revealed the sister taxa of human pathogens, but the timing of host-switching events, including the human malaria pathogen Plasmodium falciparum, remains controversial. Here, we establish a rate for cytochrome b evolution in avian malaria parasites relative to its rate in birds. We found that the parasite cytochrome b gene evolves about 60% as rapidly as that of host cytochrome b, corresponding to ~1.2% sequence divergence per million years. This calibration puts the origin of P. falciparum at 2.5 million years ago (Ma), the initial radiation of mammalian Plasmodium at 12.8 Ma, and the contemporary global diversity of the Haemosporida across terrestrial vertebrates at 16.2 Ma.