The results obtained from, and techniques used in, different fields of science, such as mathematics, physics and biology are selected, gathered and analyzed to provide an introduction to the developing field of research into the nonlinear physics of DNA. The DNA molecule, which has been traditionally studied by techniques developed through molecular biology, is considered here rather from a physicist's viewpoint, as a nonlinear dynamical system. This is a complimentary way of looking at the molecule, and is arrived at following both a theoretical analysis of interactions and motions in DNA,...