Evolutionary medicine, also called Darwinian medicine, is the application of modern evolutionary theory to understanding health and disease.
"The dominant metaphor for the body has been a machine... Disease has been viewed as a defect arising in an otherwise perfect device. An evolutionary view offers a richer and more nuanced view of the body as a product of natural selection: extraordinary in many ways, but also flawed in many ways, for good evolutionary reasons."
"The key principles of evolutionary medicine are that selection acts on fitness, not health or longevity; that our evolutionary history does not cause disease, but rather impacts on our risk of disease in particular environments; and that we are now living in novel environments compared to those in which we evolved."
A common medical misconception is to assume that any organ or body part is meant to be perfect by design, ultimately to ascertain longevity, whereas the view offered by Darwinian evolution is that organisms are ‘designed’ to secure the propagation of genes coded in the DNA... Thus, the human body (like all other living organisms) comprises a set of design trade-offs of often conflicting adaptive mechanisms.
Why We Get Sick - book by Randolph M. Nesse and George C. Williams