ABSTRACT
This chapter examines genetic influences on disease incidence or prevalence incidence is the number of people who develop a disease during a particular period, e.g., their lifetime, and is distinguished from prevalence, which is the number who have it at any one time. It explores the use of evolutionary information in identifying disease genes and outlines the importance of evolutionary information for medical treatments. Evolutionary forces, including drift, mutation and selection, have been important influences in several of the cases. The chapter considers how differences between individuals, arising through neutral processes or selection, contribute to our health and disease. In addition, there are features of our evolutionary past with health implications that arose before the appearance of modern humans and are thus shared by all people. The change in allele frequencies can have important health implications.
