soft inheritance

Soft inheritance is the term for a largely discredited set of theories. It was coined by Ernst Mayr to include such ideas as Lamarckism, that an organism can pass on characteristics that it acquired during its lifetime to its offspring. It contrasts with modern ideas of inheritance, which Mayr called hard inheritance. Since Mendel, modern genetics has held that the hereditary material is impervious to environmental influences (except, of course, mutagenic effects). 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 associated with the ideas of Lamarck and Geoffroy.