Genetic Assimilation and the Paradox of Blind Variation

This chapter confronts the neo-Darwinian core tenet of blind variation, or random mutation, with classical and recent models of genetic assimilation. We first argue that all the mechanisms proposed so far rely on blind genetic variation fueling natural selection. Then, we examine a new hypothetical mechanism of genetic assimilation, relying on nonblind genetic variation. Yet, we show that such a model still relies on blind variation of some sort to explain adaptation. Last, we discuss the very meaning of the tenet of blind variation. We propose a formal characterization of the tenet and argue that it should not be understood solely as an empirical claim, but also as a core explanatory principle.