A federal court in Pennsylvania will begin hearing arguments on Monday in a trial to determine how the theory of evolution is taught in US public schools.

Parents have sued the school system in Dover, Pennsylvania, for requiring the teaching of "intelligent design", which holds that nature is so complex and perfectly made that it must have been created by an intelligent being. Evolutionary theory, as set out by Charles Darwin, argues that small mutations give certain animals an advantage in the battle for survival and cause the formation of new species over time.