In the thesis I will argue that some models of evolutionary epistemology provide an extremely illuminating and original explanation of the workings of the scientific process. Evolutionary approaches to the growth of scientific knowledge have been criticised because of the putative existence of fundamental disanalogies between biological and scientific selective processes. I will show that these criticisms are largely misguided. I will distinguish two main kinds of evolutionary models. EEM models, which focus on the evolution of human cognitive mechanisms by natural selection (e.g. that developed by Ruse), do not provide a satisfactory basis on which to explain the nature of scientific selection processes, which are cultural rather than biological in origin. EET models, by contrast, focusing on the cultural and social origins of the selective systems operating in science, are better suited to this task. I will focus mainly on the EET models proposed by Donald Campbell and David Hull. Two general themes emerge from their analysis: the emphasis on the general validity of the variation-selection model of knowledge acquisition (i.e. trial-and-error), and the view that science is a socially adaptive and adapted system, governed by the action of peculiar selective mechanisms that partially lead to epistemic success. On the basis of the critical examination of these EET models I will argue for three main conclusions. First, EET approaches are correct in rejecting the methodological individualism so central to many alternative epistemologies. Second, EET models offer us genuinely normative epistemological insights, particularly where social epistemology is concerned. Third, EET provides a viable naturalistic alternative to social constructivism, by justifying epistemic standards as "evolutionary constructions" (i.e., products of selection processes).