Saturday, October 23, 2010

Weekend Edition: Evolution in Action

UC Davis: evolving mosquito
Somebody ought to show this post to that media clown Glenn Beck--who does quite well, thank you--broadcasting his stupidity to two millions everyday over the public airwaves. Because no one has shown him a "half monkey human" (or is it the other way around?) he does not accept evolution as a scientific fact. The British daily The Independent tells us that the most dangerous mosquito malaria carrier Anopheles gambiae is in the process of splitting into two distinct genetic variants that will develop eventually into two distinct species of mosquito. Gambiae, one of several mosquito species that can carry the Plasmodium bacteria which causes malaria in humans, is responsible for 500 million new cases each year throughout Africa. This evolutionary development poses new problems for eradication of the disease that kills almost one million people each year in Africa alone. Scientists at the Imperial College of London see the mosquito evolving more quickly than anticipated. Two strains, M and S have been known for years, but sequencing of their individual genomes has revealed the extent of the differences between the two variants. The S strain is the ancestral one because it is found all over sub-Saharan Africa whilst the M strain is concentrated in central and west Africa. The M strain also appears to have adapted to laying its eggs in rice paddies which are a recent introduction to the continent. A human strategy to eradicate one species may not work against another. It is not known what role mosquito control measures in their environment plays in the evolution toward two distinct mosquito species.