What is balanced polymorphism?

Balanced polymorphism:

1. The balanced polymorphism is the polymorphism provided by the selection against both homozygotes in favor of heterozygotes.
2. The recessive genotype is eliminated more than the dominant one
3. The differences in the elimination rate of those genotypes maintain the stable being of both alleles in the population with a specific rate for each.
4. The most studied systems are a system of hemoglobin selection by malaria (selection of abnormal hemoglobins affected by thalassemia, with defect of glucose-e-phosphate dehydrogenase).
5. The stability of these polymorphisms disappears because of the success of the fight against malaria.
6. Such balanced polymorphism becomes transitional. But, the elimination of pathological genes from the population requires time.