Lewis Smith Lake (or Smith Lake) is located in North-Central Alabama about 20 miles northwest of Birmingham in state of Alabama (U.S.) counties of Cullman, Walker and Winston. The 300-foot high dam, completed in 1961 by Alabama Power Company, impounds the Sipsey Fork of the Black Warrior River to form the lake.
Because the malaria species Plasmodium vivax normally uses DARC to enter red blood cells, people who carry this mutation are resistant to one strain of malaria. This particular strain of malaria is not a major killer in Africa today, but was likely more threatening in the past. Biologists reason that the DARC mutant arose in Africa through random mutation and began to spread through the process of natural selection.
Plasmodium, a genus of parasitic protozoans of the sporozoan subclass Coccidia that are the causative organisms of malaria. Plasmodium, which infects red blood cells in mammals (including humans), birds, and reptiles, occurs worldwide, especially in tropical and temperate zones. The organism is transmitted by the bite of the female Anopheles mosquito. Other insects and some mites may also transmit forms of malaria to animals.