Transposable elements: possible catalysts of organismic evolution.

Mutation is the ultimate source of all genetic variation in natural populations and is generally considered a prerequisite for evolution. Although transposable elements are acknowledged as a major source of spontaneous mutations, the evolutionary significance of these mobile pieces of DNA remains the subjects of some debate. In this perspective, I discuss the biology of transposable elements with particular emphasis on their potential to produce mutations that have dramatic effecs on organismic evolution.