The radical contingency thesis (RCT) claims that evolved biological traits are contingent in the sense that are unpredictable, because their evolution depends on the happenings of previous evolutive states, which, despite ending in some specific biological forms, could have derived in very different ones. This paper offers a new version about evolutive contingency, understood as the sharp distinction between function and biological form. There are enough elements for supporting the idea that, given the way natural selection works, in which the environment plays a key role, there is a clear distinction between biological form and function. This view implies contingency regarding the strategies that natural selection uses for accomplishing the varied required functions, but convergence in the general functions that traits are intended to fulfill. This view sheds light on the very nature of biological contingency in the sense that it shows that contingency is impossible if some general and basic functional effects are posited for every living organism.