 In the introduction of the term “interactor”, it was observed that the previous theory has replicators interacting with their environments in two distinct ways: they produce copies of themselves, and they influence their own survival and the survival of their copies through the production of secondary products that ultimately have phenotypic expression (Hull 1980). The term “interactor” was suggested for the entities that function in this second process. An interactor denotes that entity which interacts, as a cohesive whole, directly with its environment in such a way that replication is differential—in other words, an entity on which selection acts directly (Hull 1980: 318). The process of evolution by natural selection is 