 For example, Dawkins argues at some length that genes and only genes can function as replicators in biological evolution. He adds that “all adaptations are for the preservation of DNA; DNA itself just is” (Dawkins 1982a: 45). But, DNA itself exhibits adaptations. Anyone who has spent much time examining the molecular structure of DNA soon realizes that it is adapted to replicate. In addition, the proliferation of junk DNA, transposons, and meiotic drive are three examples in which the only phenotypes that matter are phenotypic characteristics of genes (Brandon 1996; Sterelny 1996: 388). Dawkins’ characterizations of replicators, vehicles, and the relations between the two are too closely tied to genes, organisms, and development. DNA can certainly replicate itself, but it can also function as a “vehicle”, even though it cannot code for, ride around in, or direct itself. In sum, a more general characterization of selection is needed, a characterization that does not assume that the only causal connection between replicators and vehicles is development from embryo to maturity. Such a generalization was offered by Hull (1980, 1981, 1988), who proposed that the relevant notion is “interactor” rather than “vehicle”, as interactors are causal and active while vehicles are passive entities.