Did Malaria Jump To Humans From Chimpanzees?

This CNN piece is one of several posts today documenting the recent discovery of the genetic similarity between Plasmodium reichenowi - the form of Plasmodium (the malaria parasite) common to chimps - and Plasmodium falciparum, the form common to humans and the cause of over 1 million deaths a year. It appears to be a complete vindication of the scientific argument of Ajit Varki, reported in chapter 5 of NOT A CHIMP - called "Less Is More". Nathan Wolfe has isolated and sequenced DNA from both malaria parasites and suggests, as did Varki before him, that falciparum evolved from the common chimp parasite, reichenowi, and spread, via mosquito vector, from chimps to humans. In fact, Varki's take on this event, which could have happened at any time between 10s of 1000's of years ago to 2 or 3 million, is more interesting because it suggests that, back in Homo erectus days, reichenowi was THE common malaria parasite to humans and chimps and that humans underwent drastic evolution to their immune systems in order to counter it. For some reason, reichenowi appears to be relatively harmless to chimps today and it may have been forever thus - so chimps never did evolve resistance to it. Eventually, Plasmodium countered human resistance by evolving the falciparum form from reichenowi, though whether or not chimps were the seat of this parasite evolution - and why - remains to be seen.
If you want to read up on this in more detail the source paper is Open Access in PNAS. The URL is http://www.pnas.org/content/early/2009/07/31/0907740106.full.pdf+html The authors specifically echo Varki's argument that humans inactivated the CMAH gene in a classic "less is more" mutation to prevent the sialic acid precursor Neu5Ac making Neu5Gc - which coats chimpanzee cells. A mutation converting P. reichenowi to P. falciparum then allowed it to target the now over-abundant Neu5Ac on human cells - accounting for its extreme pathogenicity in humans today.