 The alternative to this view begins with the observation that cultural inheritance is important, and it seeks to integrate cultural inheritance into traditional evolutionary models. But this general motivation leaves open the issue of whether cultural evolution requires the existence of cultural replicators. Clearly one can accept many of the criticisms of the meme concept, and still attempt to model the effects of cultural inheritance. Rather than seeking to show that there are cultural replicators, one can instead seek to build models that allow for error-prone learning, and that acknowledge that an individual’s beliefs are often the result of exposure to many sources, rather than copying from just one source. The interest of cultural evolutionary models in this tradition is sometimes simply to show how cultural change of various sorts—not necessarily adaptive cultural change—can subsequently affect genetic evolution, and vice versa. This is the general goal of models of gene-culture co-evolution. But cultural evolutionary models also aim to assess the role of cultural inheritance in the construction of adaptation: here, cultural evolutionary theorists are not merely seeking to explain distributions of traits in populations, they are seeking to explain the appearance of valuable cultural novelties (Godfrey-Smith 2012).