Nat. Selection and Sickle cell Anemia
This is where biological traits become more or less common in a population with a factor of different reproduction. Which supports evolution.
Sickle Cell Anemia
Sickle cell anemia is a disease passed down through families in which red blood cells form an abnormal sickle or crescent shape.
Sickle cell anemia and Natural selection go hand and hand. If you have a carrier that mates with a carrier the offspring is greatly at risk to get this diesease. Were if you have a non carrier mate with a non carrier then the chances of the offspring having this disease is low, and if you have a carrier mate with a non carrier the the offspring has purty much the same chances of not getting it as to getting it.