Malaria

Certainty Style Key
Hover over keys for definitions:
True   Likely   Speculative
Human Uniqueness Compared to "Great Apes": 
Absolute Difference
Human Universality: 
Population Universal (Some Individuals Everywhere)
MOCA Domain: 
MOCA Topic Authors: 

Among the human malarias, P. falciparum is the most virulent and associated with the largest number of deaths. Chimpanzees are hosts to a closely related pathogen (P. reichenowii) and can be experimentally infected with human P. falciparum without exhibiting any symptoms of severe disease. Conversely, an old study indicated that humans could not be infected by P. reichenowii. One study comparing the merozoite stage EBA-175 receptors of these two pathogens and their respective binding preferences to host target molecules on red blood cells indicates that human P. falciparum evolved to exploit the uniquely human sialic acid content of target attachment molecules - possibly explaining the difference in virulence of P. falciparum in humans and apes. More recent studies show that all extant P. falciparum strains are likely derived from a single "great ape" to human transfer event.  A likely explanation is that the loss of expression of the Neu5Gc sialic acid in hominin ancestors made them partially or completely resistant to the extant P. reichenowii, and that one strain later evolved to bind the Neu5Ac-rich erythrocytes of humans, eventually becoming P. falciparum

Timing

Timing of appearance of the difference in the Hominin Lineage as a defined date or a lineage separation event. The point in time associated with lineage separation events may change in the future as the scientific community agrees upon better time estimates. Lineage separation events are defined in 2017 as:

  • the Last Common Ancestor (LCA) of humans and old world monkeys was 25,000 - 30,000 thousand (25 - 30 million) years ago
  • the Last Common Ancestor (LCA) of humans and chimpanzees was 6,000 - 8,000 thousand (6 - 8 million) years ago
  • the emergence of the genus Homo was 2,000 thousand (2 million) years ago
  • the Last Common Ancestor (LCA) of humans and neanderthals was 500 thousand years ago
  • the common ancestor of modern humans was 100 - 300 thousand years ago

Possible Appearance: 
3,000 thousand years ago
Probable Appearance: 
1,000 thousand years ago
Definite Appearance: 
50 thousand years ago

References

  1. Evolutionary history of human Plasmodium vivax revealed by genome-wide analyses of related ape parasites, Loy, Dorothy E., Plenderleith Lindsey J., Sundararaman Sesh A., Liu Weimin, Gruszczyk Jakub, Chen Yi-Jun, Trimboli Stephanie, Learn Gerald H., MacLean Oscar A., Morgan Alex L. K., et al. , Proceedings of the National Academy of Sciences, 2018/08/15, (2018)
  2. Origin of the human malaria parasite Plasmodium falciparum in gorillas, Liu, Weimin, Li Yingying, Learn Gerald H., Rudicell Rebecca S., Robertson Joel D., Keele Brandon F., Ndjango Jean-Bosco N., Sanz Crickette M., Morgan David B., Locatelli Sabrina, et al. , Nature, 2010/09/23, Volume 467, Issue 7314, p.420 - 425, (2010)
  3. Human-specific evolution of sialic acid targets: explaining the malignant malaria mystery?, Varki, A., and Gagneux P. , Proc Natl Acad Sci U S A, Sep 1, Volume 106, Number 35, p.14739-40, (2009)
  4. The origin of malignant malaria, Rich, Stephen M., Leendertz Fabian H., Xu Guang, LeBreton Matthew, Djoko Cyrille F., Aminake Makoah N., Takang Eric E., Diffo Joseph L. D., Pike Brian L., Rosenthal Benjamin M., et al. , 2009/09/01, Volume 106, Issue 35, p.14902 - 14907, (2009)
  5. Evolution of human-chimpanzee differences in malaria susceptibility: relationship to human genetic loss of N-glycolylneuraminic acid, Martin, M. J., Rayner J. C., Gagneux P., Barnwell J. W., and Varki A. , Proc Natl Acad Sci U S A, Sep 6, Volume 102, Number 36, p.12819-24, (2005)