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.
Examples of endemic diseases include chicken pox that occurs at a predictable rate among young school children in the United States and malaria in some areas of Africa. The disease is present in a community at all times but in relatively low frequency. By contrast, there are the related terms epidemic and pandemic: 1  An epidemic is a sudden severe outbreak within a region or a group, as with AIDS in Africa or AIDS in intravenous drug users.  A pandemic occurs when an epidemic becomes very widespread and affects a whole region, a continent, or the entire world.