Sickle Cell Anemia
Natural Selection
What is Sickle Cell Anemia?
A severe hereditary form of anemia in which a mutated form of hemoglobin distorts the red blood cells into a crescent shape.
Malaria Resistance
A carrier of sickle cell is malaria resistant, however if you are homozygous for sickle cell you have sickle cell anemia. Sickle cell anemia causes trouble with your red blood cells and your arteries. If both your parents are malaria resistant, their children have a 25% chance of getting sickle cell anemia.
Blood Cells
Normal Red Blood Cell
Sickled Red Blood Cell
Normal Red Blood Cell and Sickled Red Blood Cell
Mutation
In sickle cell anemia a single genetic mutation in the genetic code causes some parts of the body to be deprived of oxygen.
Natural Selection
The people of West Africa have developed a resistance to malaria, most cases of malaria are stopped there due to this genetic mutation that was developed. As this develops there is more of a chance that both children's parents will be carriers of this mutation. Which gives children a slightly greater chance of getting both parents genes for the mutation, which means they are homozygous for the mutation which causes sickle cell anemia.