A gene known as HbS was the center of a medical and evolutionary detective story that began in the middle 1940s in Africa. Doctors noticed that patients who had sickle cell anemia, a serious ...

A single base change can create a devastating genetic disorder or a beneficial adaptation, or it might have no effect. How do mutations happen, and how do they influence the future of a species?

Can we predict that natural selection will weed out genetic disease over time? Sickle-cell trait haplotype distribution shows the genetic advantages of this mutation. In the deoxygenated ...