The most recent resurgence of philosophical attention to the so-called ‘functional talk’ in the sciences can be summarized in terms of the following questions: (Q1) What kind ofrestrictions, and in particular, what kind ofevolutionary restrictionsas well as to what extent, is involved in functional ascriptions? (Q2) How can we account for theexplanatory importof function-ascribing statements? This paper addresses these questions through a modified version of Cummins’ functional analysis. The modification in question is concerned with phylogenetical restrictions on causal role functions, and it stems from an analysis of some primary areas in molecular biology. I examine how evolutionary consideration affects the so-called ‘function-analytical explanatory strategy’ (Cummins [1975] 1998, 2002). Finally, I argue that the neo-functional analysis here proposed accounts for a certain convergence between the main rival theories of biological function.