The Concepts of Inheritance and Hereditary Variation

Abstract

The idea of extended inheritance has become a leitmotif of what has been called 'extended synthesis'. This idea, meanwhile, leads to ignoring one of the distinctive marks of what has been classically understood as hereditary transmission: its close association with the process of reproduction. Without considering such an association, the notion of inheritance, rather than being extended, in fact, dissolves; and accepting such a dissolution would bring too many difficulties for the discourse of biological sciences. One of these difficulties has to do with the concept of 'hereditary variation'. With the dissolution of the notion of inheritance, this concept would also dissolve; and, without it, the Theory of Natural Selection would become unreliable. But, as there are no valid reasons to accept such a theoretical cost, here I want to show that both concepts, that of inheritance and that of hereditary variation, may and should be elucidated without accepting the idea of extended inheritance.