BIOB51H3 Lecture Notes - Lecture 16: Multiple Drug Resistance, Viral Load, Natural Selection
20 Mar 2019
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Document Summary
Hiv can quickly evolve resistance to drugs within the body of a single host. Why is hiv fatal? (evolutionary causes: why is hiv fatal, natural selection within a host (rapid replication, natural selection for viral transmission between hosts, humans have not evolved resistance to hiv. Short-sighted evolution organisms adapt to a certain environment or they are selected to replicate at a particular rate in that environment. For every individual, the replication rate increases over the time that they are hiv positive. There is selection for rapid replication in the body of each individual. Within the body of one host, hiv evolves to more virulent over time. Natural selection favours increased virulence of sexually transmitted diseases when transmission to new hosts is frequent (and favours decreased virulence when transmission to new hosts is infrequent) Also see story of cholera outbreak in south america in 1990"s in the documentary: the evolutionary arms race. Aids occurs more rapidly if viral load is high.
