Stephen Stearns, teaching Yale's Evolution and Medicine course, uses this short segment to trace how the concept of a patient has changed in recent history. Drawing on the 2015 Sinauer textbook Evolutionary Medicine that anchors the course, he walks through shifts in how doctors and societies have defined who counts as sick, how diagnosis has been institutionalized, and how the modern clinical encounter took shape. The talk sits within a larger unit asking what evolutionary biology can add to medicine, and this piece supplies the historical grounding before Stearns brings evolutionary reasoning to bear on disease and treatment. It runs about fourteen minutes and functions as one building block in a numbered lecture sequence rather than a stand-alone survey, useful mainly for students following the course in order.