Intelligent design is the assertion that "certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection." It is a modern form of the traditional teleological argument for the existence of God, modified to avoid specifying the nature or identity of the designer. The idea was developed by a group of American creationists who reformulated their argument in the creation-evolution controversy to circumvent court rulings that prohibit the teaching of creationism as science. Intelligent design's primary proponents, all of whom are associated with the Discovery Institute, a politically conservative think tank, believe the designer to be the God of Christianity. Advocates of intelligent design argue that it is a scientific theory, and seek to fundamentally redefine science to accept supernatural explanations. The consensus in the scientific community is that intelligent design is not science. The U.S. National Academy of Sciences has stated that "creationism, intelligent design, and other claims of supernatural intervention in the origin of life or of species are not science because they are not testable by the methods of science." The US National Science Teachers Association and the American Association for the Advancement of Science have termed it pseudoscience. Others in the scientific community have concurred, and some have called it junk science.