Malaria in antiquity: a genetics perspective

Historical texts provide credible evidence regarding the occurrence of malaria in recent human history but how far this antiquity stretches back through our hominid ancestors is questionable. Genetic analysis of the Plasmodium falciparum genome sequence has thus far failed to clarify the issue, but available evidence suggests a recent expansion of this Plasmodium species within the last 6,000 years. This coincides with an expansion of both human and mosquito populations brought about by the advent of agriculture. The shift from small groups of hunter-gatherers to larger settled populations was crucial in sustaining P. falciparum transmission and it is noteworthy that a number of malaria-protective polymorphisms also have origins in this timeframe. The antiquity of other Plasmodium species is more uncertain, but preliminary studies of Plasmodium vivax suggest it is considerably older than its more deadly relative.