Final answer:
Sickle cell trait, the Duffy null-allele, and the G6PD mutation demonstrate how human populations evolve genetic adaptations to survive diseases like malaria. The sickle cell trait and G6PD mutation can offer protection against malaria, but they can also lead to health issues such as anemia. If malaria was eliminated, the frequency of these genetic traits might decrease due to the lack of a selective advantage.
Step-by-step explanation:
Sickle Cell Trait and Genetic Adaptations
The sickle cell trait, the Duffy null-allele, and the G6PD mutation are all examples of how human populations adapt to environmental stressors such as diseases. Mutations that cause these conditions offer insights into the complex relationship between genetic variation and environmental pressures.
G6PD Mutation
The G6PD mutation can lead to a form of anemia, which while disadvantageous, also confers resistance to malaria. In areas where malaria is endemic, individuals with this mutation may have a higher fitness due to their reduced susceptibility to the disease. If malaria was eradicated from these regions, the selective advantage for carriers of the G6PD mutation would likely diminish, leading to a potential decrease in the frequency of this gene variant over time.
Sickle Cell Trait and Anemia
Individuals with one copy of the sickle cell gene (heterozygous) have a trait that offers protection against malaria. However, individuals with two copies (homozygous) suffer from sickle cell anemia. The presence of the sickle cell gene in high frequencies among certain populations, despite its potential to cause severe health issues, underscores the strong selective pressure exerted by malaria.
Should malaria be eliminated in a region with a high frequency of the sickle cell allele, the fitness benefits conferred by the trait would no longer be relevant. This could result in a decrease in the allele's frequency as the protective benefit is offset by the health risks associated with sickle cell anemia in homozygous individuals.