Soft inheritance

Soft inheritance is a term coined by Ernst Mayr to contrast ideas about inheritance. Mayr argued that the concept of inheritance posits that the hereditary material is 'hard' and impervious to environmental influences. In soft inheritance "the genetic basis of characters could be modified either by direct induction by the environment, or by use and disuse, or by an intrinsic failure of constancy, and that this modified genotype was then transmitted to the next generation." Concepts of soft inheritance are usually accociated with the ideas of Lamarck and neo-Lamarckian evolution. There is also an opposite concept of hard inheritance.

Recent work in plants and mammals on the role of the environment on epigenetic modifications of DNA have led to the argument that inherited epigenetic variation is a kind of soft inheritance.