 Although such critics of Dawkins as Sterelny, Smith, and Dickison (1996) declined to join with Dawkins in his demotion of environmental interaction, they did agree with him that replicators are special. They play a special role in development. However, they do not limit replicators to genes, even in biological evolution. Sterelny et al. propose to extend the replicator to include nonstandard entities: “the set of developmental resources that are adapted from the transmission of similarity across the generations” (Sterelny 2001: 338). For example, the sort of burrow that a particular organism digs is influenced by its genetic makeup; however, if these burrows are used over and over again, characteristics of these burrows can themselves be viewed as replicators. The effects of these burrows get passed on from generation to generation, but not via the DNA.