Aaron Swartz has a nice article about how chemical companies looking to sell their product and conservatives who want to smear environmentalists have been spreading the myth that banning DDT caused millions of deaths from malaria. As it turns out, the reason that people stopped using DDT a lot in poor countries wasn't because of Rachel Carson's baneful influence -- it was because mosquitos started becoming DDT-resistant:
DDT use has decreased enormously, but not because of a ban. The realreason is simple, although not one conservatives are particularly fondof: evolution. Mosquito populations rapidly develop resistance to DDT,creating enzymes to detoxify it, modifying their nervous systems toavoid its effects, and avoiding areas where DDT is sprayed — and recentresearch finds that that resistance continues to spread even after DDTspraying has stopped, lowering the effectiveness not only of DDT butalso other pesticides.
An article from Current Biology describes how flies with DDT resistance not only become able to resist other insecticides, but also gain unexpected super powers:
