Human fishing affects the size of the fish population, and over generations, the size of the fish. Scientists have found that when fisheries go after mostly large fish, they create evolutionary pressure that favors the survival of smaller fish. Eventually, intense pressure from fishing could lead to food supply issues. In this video, Mikko Heino, a biologist at the University of Bergen, speaks with Knowable Magazine to explain how this effect works and what we can do to minimize human impacts on fish evolution.