1. Population genetics is all about gene frequencies Evolution = a change in gene frequencies No change = genetic equilibrium = absence of evolution

5. Hemoglobin Structure 2 alpha chains (C 16):141 aa 2 beta chains (C. 11):146 aa Natural selection in humans E.g., hemoglobin

6. Sickle cell anemia Sixth code word from one end of the beta gene. HbA  HbS Possible genotypes HbA/HbA HbA/HbS HbS/HbS

7. Relationship : malaria and sickle cell anemia Distribution of HbSDistribution of malaria

8. Malaria HbA/HbS Resists malarial parasite