Neo-Darwinian theories of cultural evolution are apt to be criticized on the grounds that they merely borrow from the theory of natural selection concepts that are then metaphorically applied to conventional historical narratives to which they add no more, if anything, than an implicit presupposition of progress from one predetermined stage to the next. Such criticisms, of which a particularly forceful example is a recent article in this journal by Fracchia and Lewontin, can however be shown to be seriously misconceived. (...) The fundamental process of heritable variation and competitive selection of information affecting phenotype underlies both biological and cultural evolution despite the obvious differences between the mechanisms of information transfer by genetic inheritance and by exosomatic imitation and learning. Information transfer is in neither case a metaphor standing for any other thing, and in neither case does change over time proceed in accordance with developmental laws from which the future evolution of either species or cultures could be predicted in advance. For all the unresolved questions that remain, neo-Darwinian evolutionary theory has demonstrated the mutual compatibility of idiographic and nomothetic explanation in the study of species and of cultures alike. (shrink)