What is the relationship between the sickle cell anemia and the malaria?

Sickle cell anemia is a genetic diseases that causes red blood cells to be shaped like sickles while normal red blood cells are shaped more like a cylinder. Malaria works by going into the red blood cells until they burst. Because of the strange shape of the red blood cells in people who have sickle cell anemia, malaria can't enter in the cells that have the sickle trait, but it can enter in the others. This way, people with sickle cell wouldn't be as adversely effected then those without it. Having one copy of chromosome mutation in the hemoglobin gene will be protective against malaria and while having two copies of mutation in the hemoglobin gene will cause the individual to suffer from sickle cell anemia. Actually there is no causation between two diseases. Sickle cell anemia is a natural barrier in front of the malaria. Normally diseases are harmful in all ways. However sickle cell anemia prevents malaria as an advantageous situation for this correlation. A sickle cell anemia carrier is in a advantageous situation while fighting with malaria. Through the natural selection, people might become resistant to the malaria.