Lamarckism and ageing.

Although it is usually assumed that Lamarckian inheritance does not and cannot occur, molecular mechanisms by which non-mutational changes acquired in one generation can be transmitted to the next are now known. These mechanisms involve changes in chromatin structure, rather than changes in DNA base sequence. It is argued that some parentalage effects and Lansing effects may be due to inherited changes in chromatin structure. Methods of testing this idea are suggested.