Evolution education in the United States remains controversial and challenging. This is in part due to the difficulty educators face when tryingto overcome students' preexisting beliefs about evolution, which can bias assimilation of information and inhibit learning. We propose that the most effective way to overcome such belief persistence is through an engaging, hands-on inquiry approach that mimics the scientific process used to study evolution. Although this teaching approach, known as authentic science, has gained recognition for its effectiveness in the classroom, it has not been widely applied to teach evolution. We describe how an authentic science approach can be used to teach evolution by natural selection, and provide a formula for the development of such programs. Following this blueprint, we developed a program using Trinidadian guppies and implemented it in 7th grade classrooms in Colorado. Pre- and post-program assessments revealed significant increases in both the understanding and acceptance of evolution among participants. Authentic science experiments using locally adapted populations of live organisms may be able to overcome belief persistence and improve student understanding of evolution.