Multiplicity of Function

of organs and structures, the principle whereby every bodily organ or structure performs more than one function simultaneously or at different times in its individual development or ontogeny. For example, the wing of a bat is not only used for flying but also helps catch prey (by acting like a net) and regulate body temperature; in addition, its web participates in the production of vitamin D. Multiplicity of function is also characteristic of protozoan organelles and organoids in tissue cells. The principle of multiplicity of function underlies all changes in organs and structures in the course of evolution.