   This aspect of the adaptationism debate is connected with a general epistemological issue in philosophy of science: underdetermination of theory by evidence. Evolutionary hypotheses are typically underdetermined by available evidence. In principle, rival hypotheses make different commitments about the nature of evolutionary history, but in practice these hypotheses are empirically indistinguishable given the available evidence. Philosophers argue about the consequences of this underdetermination for our understanding of biological science (Turner 2005, Stanford 2006). Yet, there is agreement that the problem of underdetermination should be addressed by developing and using tests that discriminate between rival hypotheses.