 The debates over adaptationism in the 1980’s made philosophers familiar with the complex interactions between explanations of traits in evolutionary biology and explanations of the same traits in developmental biology. Developmental biology throws light on the kinds of variation that are likely to be available for selection, posing the question of how far the results of evolution can be understood in terms of the options that were available (“developmental constraints”) rather than the natural selection of those options (Maynard Smith, Burian et al. 1985). The debate over developmental constraints looked at developmental biology solely from the perspective of whether it could provide answers to evolutionary questions. However, as Ron Amundson pointed out, developmental biologists are addressing questions of their own, and, he argued, a different concept of constraint is needed to address those questions (Amundson 1994). The emergence in the 1990’s of a new field promising to unite both kinds of explanation, evolutionary developmental biology, has given rise to a substantial philosophical literature aimed at characterizing this field from a methodological viewpoint (Gray 1992; Griffiths and Gray 1994; Oyama 2000a, 2000b; Oyama, Griffiths, and Gray 2001; Maienschein and Laubichler 2004; Robert 2004; Amundson 2005; Brandon and Sansom 2007). For example, developmental systems theorists (Gray 1992; Griffiths and Gray 1994; Oyama 2000a, 2000b; Oyama, Griffiths, and Gray 2001) argue for “parity” between genes and non-genetic factors. First, organisms inherit a “developmental matrix” and not just genes (e.g. “epigenetic inheritance”). Second, the role of genes is in the development of traits is not causally unique – insofar as genes “carry information” or are “copied” the same can be said of other factors. That is, genes and developmental factors causally covary with phenotypic traits. However, defenders of “extended replicators” argue that genes uniquely carry information in a teleosemantic sense (Sterelny et. al. 1996). Another source of philosophical controversy in developmental biology concerns whether any traits are innate and what innateness might be (Ariew 1999; Griffiths 2002; Mameli and Bateson 2006). Philosophers have contributed to clarifying the difference concepts at issue. 