somatic diversification theory

When immunologists discovered that antibodies were variable, they entertained various theories, including the somatic diversification theory that postulated that the genes for immunoglobulin were constant, and that they diversified in somatic cells. This turned out to be partly true, as somatic hypermutation is now well established. However, other theories were needed to explain other features of antibody diversity, including somatic gene rearrangement and isotype switching.