Genetic Complexity. Lewin equates genetic complexity with the extent of non-repetitive DNA as identified by reassociation experiments   (p74 Genes VII), i.e. exons present at low repetition frequency that may be unique or present in a small number of copies. By this definition of genetic complexity there is a tendency for it to increase over evolutionary time, from E.Coli to C.Eligans to D.Melanogaster to Mammals (p74 ibid).

Unit of Evolution. The following criteria are defined by JMS (1987). (1) Multiplication. Entities should give rise to more entities of the same kind. (2). Like begets like: A type entities produce A type entities, B type entities produce B type entities, and so on. (3). Variability. Heredity is not exact; occasionally A type objects give rise to A' type objects (it may be that A' = B).   Natural Selection occurs if objects of different types have a hereditary difference in their survival. A Unit of Selection possess characteristics (1) and (2) but is missing (3).