Final answer:
Studying lice provides insights into human evolution, such as when early humans began wearing clothing and their move from Africa. Lice genetics also offer data on epidemiology, indicating a role in disease transmission throughout history.
Step-by-step explanation:
Studying lice can provide significant insights into human evolution. Dr. David Reed's research into the coevolution of lice and humans suggests that lice, due to their close association with humans throughout history, can fill important gaps in the fossil record. By examining lice genetics and the types of lice associated with humans (— the head louse, body louse, and pubic louse —), scientists have been able to estimate key historical events, such as when humans started wearing clothes and became less hairy.
For example, the divergence of body lice from head lice corresponds with humans beginning to wear clothing. This is supported by the fact that body lice live in clothing, compared to head and pubic lice, which live in hair. Furthermore, the genetic diversity of African lice is higher than that found in lice from other regions, backing the Out of Africa model which suggests that both humans and their parasitic counterparts originated in Africa.
Additionally, the study of human lice has implications for understanding disease transmission. Lice have been implicated in the spread of diseases such as typhus and potentially the plague, indicating that clothing practices and lice could have played a role in historical pandemics.