THE BIOLOGY AND EVOLUTION OF HIV

Abstract This review examines the current state of knowledge about HIV/AIDSin terms of its origins, pathogenesis, genetic variation, and evolutionary biology. TheHIV virus damages the host’s immune system, resulting in AIDS, which is characterizedby immunodeficiency, opportunistic infections, neoplasms, and neurologicalproblems. HIV is a complex retrovirus with a high mutation rate. This mutation rateallows the virus to evade host immune responses, and evidence indicates that selectionfavors more virulent strains with rapid replication. While a number of controversialtheories attempt to explain the origin of HIV/AIDS, phylogenetic evidencesuggests a zoonotic transmission of HIV to humans and implicates the chimpanzee(Pan troglodytes troglodytes) as the source of HIV-1 infection and the sooty mangabeyas the source of HIV-2 infection in human populations. New therapies provide hope forincreased longevity among people living with AIDS, but the biology of HIV presentssignificant obstacles to finding a cure and/or vaccine. HIV continues to be a threat tothe global population because of its fast mutation rate, recombinogenic effect, and itsuse of human defenses to replicate itself.