Evolving with the enemy
The alteration or mutation in the human genome due to bacteria, viruses, and other freeloaders is discussed. Increase in thalassaemia mutations in areas where malaria is endemic, provided carriers protection against the parasite. Various genes have been identified as major players in conferring different degrees of susceptibility to a wide range of bacterial and viral infections, including tuberculosis, leprosy, HIV/AIDS, and hepatitis. The studies of infectious disease from its evolutionary aspect suggest gradual moulding in the genetic make-up due to the continuous struggle against infective agents.