[ILLUSTRATION OMITTED] Evolution, due to its importance in science, holds a prominent place in national science standards and many state standards. Scientists nearly universally agree that the theory of evolution best explains the unity and diversity of life. Accordingly, numerous science, science education, and religious organizations support the teaching of evolution (Sager 2008). Nonetheless, evolution remains controversial (Hermann 2008) with a third of American adults stating that the theory is false (Miller, Scott, and Okamoto 2006). Given this controversy, teachers should know about the legal implications of teaching evolution in public schools. In v. Kurtzman (403 U.S. 602 [1971]), the U.S. Supreme Court developed a to determine whether a state action, such as the Tennessee law against teaching evolution that was the basis of the famous Scopes monkey trial of 1925, violates the Establishment Clause of the First Amendment to the Constitution. This clause prohibits the government from passing legislation that establishes an official religion or prefers one religion over another. The so-called Lemon test states: (1) the act must have a bonafide secular purpose, (2) the act's principal or primary effect must be one that neither advances nor inhibits religion, and (3) the act must not result in an excessive entanglement of government with religion (Lofaso 2009). Below are four approaches to teaching evolution along with legal implications of using them in public school classrooms. Teachers are encouraged to engage all students in learning evolution--even those most reluctant to do so--while using best teaching practices consistent with current science and legally protecting oneself and school system. Approaches to teaching evolution Reiss (1992) reported on three possible instructional approaches, modified from Bridges (1986), for addressing controversial issues in science classrooms: advocacy, affirmative neutrality, and procedural neutrality. Hermann (2008) extended this framework to include avoidance. Avoidance Teachers avoid teaching evolution for many reasons, including: * they do not believe evolutionary theory and do not want to teach it, * they may want to avoid controversial issues to minimize discipline problems (Nicholls and Nelson 1992) and parental pressure, or * they lack training in teaching controversial issues (Levinson 2002). Teachers may omit instruction altogether or avoid using the term evolution in favor of the phrase change over time to introduce some general tenets such as adaptation and natural selection. Students may not even notice that evolution was omitted from the class. Teachers may not violate any laws if they avoid teaching evolution without the perception that they did so for religious reasons. However, teachers who omit evolution are not adhering to national standards and, in most cases, state standards. These teachers may be challenged for not adequately addressing the standards and can be required to do so by their school district (Peloza v. Capistrano Unified School District, 37 F 3d 517 [9th Cir. 1994]). Advocacy Advocating for evolution Public school science teachers advocate for evolution by teaching the science of evolution and not addressing related religious or political issues. Teachers advocating for evolution may explicitly or implicitly state that alternative explanations to evolution are unscientific or otherwise inferior. Some teachers advocate for evolution simply by teaching evolution without acknowledging that some students may hold beliefs they perceive to conflict with evolution. Advocates for evolution can defend science to the point that they alienate students by making them feel their own reasoning is inferior. However, students perceiving a conflict with their beliefs are often not vocal and internalize the conflict, which can result in disdain or complete withdrawal (Scharmann 1994). …