ABSTRACT
As we have seen with the pandemic COVID-19 (caused by the virus SARS-CoV-2), viruses continue to affect human health. The chapter begins with a comparison of the COVID-19 pandemic with the influenza pandemic a century before. After a discussion of the nature of coronaviruses in general and SARS-CoV-2 in particular, we discuss the likely ways this virus spilled over into humans. We then explore how evolution has been used to track SARS-CoV-2. Next, we turn to the evolution of the properties of SARS-CoV-2, including the new, more infectious Delta variant. We also investigate the genetic factors that can affect susceptibility to COVID, including the intriguing prospect that we obtained both predisposing and protective variants from Neanderthals. Next, we consider the history of vaccines starting with smallpox and ending with COVID-19. The principles of evolution can be used to address the best strategies for vaccination schedules given limited resources. Finally, we turn to the AIDS pandemic with discussions about how evolution has been used to trace the evolution of HIV, the virus that causes AIDS, and how the evolutionary principles inform treatment.
