 As it is hereditary variations that are needed for evolution via natural selection, Jablonka and Lamb set out to study different inheritance systems (where system is understood roughly to mean a set of interacting factors and mechanisms) by identifying different kinds of hereditary variation (Jablonka 2001; Jablonka &amp; Lamb 1995, 2005/2014). Their approach can be described as focused on the mechanismic basis for different types of hereditary phenotypic variation. They have identified multiple inheritance systems, each with several modes of transmission, that have different properties, and that interact and coevolve (Jablonka 2001: 100; Jablonka &amp; Lamb 2005/2014). The systems are said to carry information, defined as the transmissible organization of an actual or potential state of a system. A detailed account of their mechanismic classification is presented in  section 3.3.