With the advent of technological innovations, humans are now capable of modifying the environment at a previously unprecedented level. Advances in medicine, such as the development of penicillin, have saved countless lives. Modern agricultural methods have vastly improved the amount of food that can be harvested. Building towns and infrastructure has ensured that people are no longer isolated from each other. At first glance it may seem as though these recent changes in human history would halt evolutionary change. However, modern humans certainly still face challenges to survival and exhibit varying reproductive success - the fodder for evolution.