Final answer:
HIV in humans is hypothesized to be derived from SIV in primates, specifically simian immunodeficiency virus. This jump to humans likely occurred in sub-Saharan Africa and has led to the development of HIV, which causes AIDS.
Step-by-step explanation:
It is hypothesized that HIV in humans is derived from SIV in primates. SIV stands for simian immunodeficiency virus. The transition from SIV to HIV likely occurred in sub-Saharan Africa where the simian virus was first transmitted to humans. Over time, this virus evolved into what we recognize today as HIV. HIV is a retrovirus that targets helper T cells and is the causative agent of acquired immune deficiency syndrome (AIDS), a condition that has led to the deaths of nearly 40 million people since it was first identified in 1981. Sub-Saharan Africa remains the most affected region, with the highest prevalence of infections worldwide.