A disease is just what it says: a “dis” - “ease”; meaning something is keeping you from being at ease, or your normal state. From a system theory approach, disease is a stressor that moves the body ou...A disease is just what it says: a “dis” - “ease”; meaning something is keeping you from being at ease, or your normal state. From a system theory approach, disease is a stressor that moves the body out of homeostasis. There are many kinds of diseases that are important to human evolutions. We've already discussed genetic diseases, but here we are going to look at human variation as a response to infectious disease.
