The theory of evolution, which states that species have evolved over time, is a theory which must be taught in public schools. Lerner (2000) states that there are good standards for what school children should know about the theory, depending upon the child’s grade. He states that children from grades kindergarten to third grade should understand that living things reproduce, and that the offspring may not be exactly like their parents. They should also understand that a living things must grow up or change before reproducing. Another fact that they must learn is that the earth is over four billion years old. When children are between the ages of nine and twelve, they should be taught about how evolution results in competition and survival between and within species, and the factors that go into species survival, such as environmental, predatory and temperature factors. They should also learn that species adapt to different environments, and that genetic variation results in mutations that may help species adapt to this environment. Also, the theory of natural selection should be understood. When a child is between middle and high school, they should know about such concepts as genetic drift, sexual selection and the complex interactions of ecosystems (Lerner, 2000).
Evolutionary theory should be taught, despite the objections of religious individuals who object to the theory being taught, for a variety of reasons. The first set of these reasons address why the theory should be taught, despite the objections of religious individuals. The second set addresses why the theory is important, in general, to learn. For the first set, the first reason why evolutionary theory should be taught is that the United States has a firm tenet that church and state must be separated. In essence, if there is a statute that prohibits the teaching of evolution in the public school, and the basis for this is because the religious parents object on the grounds that teaching the theory runs contrary to their religious teaching, then the state is, in effect, giving support to these religious views (Emerson, 1960). Emerson (1960) compares to this type of prohibition to be the same as if a medical school was forbidden to teach about birth control methods because Roman Catholics object. This would mean that the state is siding with the Roman Catholics, which is tantamount to supporting this religion (Emerson, 1960). This argument makes sense, because all religions have different tenets and beliefs, so it is not the job of schools to design curriculums to make sure that nobody is offended. If a Christian can make a demand that the curriculum must be aligned with their beliefs, then so can the Muslim and the Jew, etc. Eventually, there would be nothing acceptable to teach in the public schools. The second reason why the prohibition of teaching evolution in schools would be wrong is because it would be a violation of the freedom of expression. Americans have the freedom of ex