 The classical molecular gene concept was closely related to the notions of genetic information and the genetic code (see  §1.3  and entry on  biological information).  While some philosophers have described these terms as potentially misleading metaphors (Sarkar 1996), many see these concepts either as used in a literal sense and hence justified (Godfrey-Smith 2000), or as metaphorical, but productive (Levy 2011). The details of an adequate explication are much debated (e.g., Stegmann 2005), but on the level of molecular phenotypes (mainly proteins) the information concept is seen as relatively uncontroversial. More debated is the question if information, or the notion of causal specificity that it implies, is a unique property of DNA or if it applies to other cellular and extra-cellular components as well (Baxter 2019; Bourrat 2020; Griffiths &amp; Stotz 2013: Ch. 4–6; Griffiths et al. 2015; Waters 2007; Weber 2017; Woodward 2010). On the level of whole organism phenotypes, genetic information has been explicated in terms of teleosemantic theories borrowed from philosophy of mind and emphasizing the selected function of genes (Maynard Smith 2000; Sterelny et al. 1996). The parity thesis, stating that non-genetic factors can carry information in the same sense has been suggested on this level as well (Griffiths 2001). Other philosophers have discussed the question of whether selected function would not be better located on the level of the developing organism as the receiver of information (Jablonka 2002) or if a notion of genetic representation can be reformulated in terms of transmission in an intergenerational information producer and consumer system (Shea 2013; cf. Kõiv 2020; Planer 2016).