The aim of this dissertation is to explore the nature of scientific progress and to broaden existing theories of what constitutes progress in science. I do this by means of a close analysis of the main post-Kuhnian philosophical accounts of scientific progress, namely those put forward by Imre Lakatos, Larry Laudan and Philip Kitcher. I test these three accounts by reconstructing a series of scientific episodes in evolutionary ecology in terms of each account and then assessing the degree to which each account incorporates what is progressive. The episodes I have selected concern the resource competition research of Dolph Schluter on Galapagos finches and related work leading up to it. After distinguishing between macroscopic and mi...