 Culture cannot be atomised into discrete units: Ideas stand in logical relations to each other. Whether an individual is able to acquire some belief, for example, depends on their related conceptual competencies. It is impossible to believe in the theory of relativity without understanding it, and one cannot understand it without holding many additional beliefs relating to physics. The same is true for non-technical beliefs. Depending on which religion one is talking about, belief in God is likely to be related to various other beliefs concerning forgiveness, retribution, love and so forth. This has led some critics to argue that it is a mistake to take a view of culture which atomises it into discrete units, assigning replicative power to them individually. The anthropologist Adam Kuper complains that ‘Unlike genes, cultural traits are not particulate. An idea about God cannot be separated from other ideas with which it is indissolubly linked in a particular religion’ (Kuper 2000, 180). Memeticists are likely to respond by saying that although ideas are inter-linked, this does not undermine the meme-gene analogy: O’Brien et al. (2010) have argued that a more mature view of the role of genes in evolution and development re-instates the meme-gene parallel. For there is a sense in which genes, too, need to be studied in a context that takes other genes, and their broader developmental and environmental settings, into account. A DNA sequence can have different effects in different organisms, depending on the network of relations it enters into with other genetic and developmental resources. Just as the significance of belief in God can vary with social context, with the result that it can make little sense to think of ‘belief in God’ as a meme, so the function of some DNA sequence can vary with organic context, with the result that it makes little sense to identify some sequence type as a gene for the purposes of evolutionary analysis.