 There has also been a profound reconception of the evolution by selection process, which has rejected the role of replicator as misconceived. In its place the role of “reproducer” is proposed, which focuses on the material transference of genetic and other matter from generation to generation (Griesemer 2000a,b; see Forsdyke 2010; see  section 3.5).  On this approach, thinking in terms of reproducers incorporates development into heredity and the evolutionary process. It also allows for both epigenetic and genetic inheritance to be dealt with within the same framework. The reproducer plays a central role, along with a hierarchy of interactors, in work on the units of evolutionary transition (see  Evolutionary Transition;  Griesemer 2000c). This topic concerns the major transitions of life from one level of complexity to the next, for example, the transition from unicellularity to multicellularity. More recently, another notion was introduced of a “reproducer” that is more broadly inclusive, in that it relaxes the material overlap requirement and focuses on an understanding of “who came from whom, and roughly where one begins and another ends” (Godfrey-Smith 2009: 86).