Final answer:
HIV likely evolved from a virus that infected monkeys and crossed over to humans in sub-Saharan Africa. The virus's quick mutation rate, a hallmark of ongoing evolution, can lead to drug resistance.
Step-by-step explanation:
The Evolution of HIV
The Human Immunodeficiency Virus (HIV) likely evolved from a simian virus that was initially found in monkeys. This cross-species transmission to humans likely occurred in the early to mid-1900s, predominantly in sub-Saharan Africa. Over time, HIV has undergone numerous mutations, particularly during the process of reverse transcription, which is prone to errors. These mutations have contributed to the development of drug-resistant strains of the virus quickly, especially in scenarios where a patient is on antiretroviral therapy. This rapid mutation rate exemplifies evolution as an ongoing process, with the virus adapting to the selective pressures of the treatment.
Furthermore, it has been discovered that individuals carrying the CCR5-delta 32 mutation showcase a natural resistance to HIV. This mutation affects the CCR5 receptor, which most strains of HIV use to enter T cells.
SUMUP
- HIV likely evolved from a simian virus and jumped to humans in sub-Saharan Africa.
- It exhibits rapid mutation, particularly in treatment scenarios, illustrating ongoing evolution.
- CCR5-delta 32 mutation provides natural resistance to some people against HIV.