had no advantage or disadvantage, as the mutation for sickle cell is beneficial only in regions where malaria is common. In areas with malaria, carriers of the sickle cell mutation have an advantage as they are less likely to die from malaria compared to individuals without the mutation. However, if the mutation first appeared in a region without malaria, there would have been no selection pressure for the mutation, and the carrier would have had neither an advantage nor disadvantage.
