Evolutionary medicine
There are some adaptations that have changed our traits over time. Some of these adaptations have made people more healthy. But there are constraints that keep some traits from changing. The presence of constraints means that adaptations that could make people more likely to be healthy are not able to happen. Also, sometimes adaptations can happen but with trade-offs. This could mean changes in one trait that make people healthy might lead to changes in other traits that make people sick.<ref></span>a b Stearns SC (2005). "Issues in evolutionary medicine". American Journal of Human Biology. 17 (2): 131–40. doi:10.1002/ajhb.20105. PMID 15736177. S2CID 42756608.</ref>