" Evolution and Medicine
The ultimate goal of evolutionary medicine is to use insights from evolutionary biology to prevent and treat disease. Traditionally, medicine has has been concerned with understanding of their proximate causes of disease, but as Ernst Mayr said "No biological problem is solved until both the proximate and the evolutionary causation has been elucidated".
While established evolutionary fields and methodologies, such as population genetics and pathogen evolution, have made significant contributions to medicine, evolutionary (or Darwinian) medicine seeks to take this further, by addressing fundamental questions such as 'why natural selection leaves bodies vulnerable to disease?'
Although humans are still evolving rapidly, we change our environments even faster and many of the illnesses that are increasing in modern high-income urban environments are the consequence of "gene-environment misfit", where our genetics is not adapted to the new conditions. Notable examples are the high calorie western diet, lack of exercise, and the failing regulation of our immune systems due to lack of the microbial "teaching" inputs that the system evolved to require.