Learning Log 5

Most Challenging Concept

            I do not really get why they consider sickle cell anemia a textbook definition of natural selection in humans. Even though there is a little bit good coming out of sickle cell anemia, wouldn’t it still eventually die off? Natural selection is something that gets rid of bad traits, not keeps them. I can understand why the disease has lived for a long time, but I do not understand why is hasn’t already died as a disease. It’s characteristics make me believe that it would not last as a disease, yet it still is living.