The majority of the US public rejects evolution, yet evolutionary approaches grow increasingly important in solving the world’s most pressing problems such as global food security, curing and preventing diseases, coping with climate change, and preserving ecosystems. One of the major challenges in teaching evolution is overcoming preset beliefs that are held even in the face of conflicting evidence. People are more receptive to information that opposes existing beliefs when asked to make their own conclusions based on explanatory evidence, a processes inherent in the scientific process. Authentic science is a pedagogic approach in which students conduct the scientific process as if they were practicing scientists, but it is not used to teach evolution because of the time and resources required to observe evolution. We worked with local seventh-grade teachers to develop an authentic science program using live Trinidadian guppies from populations with different evolutionary histories, which allowed students to observe the end points of evolution rather than the process. We implemented this weeklong program in two Northern Colorado schools for two consecutive years reaching over 600 students. In the second year, we administered pre- and post-assessments that showed significant increases in both knowledge and acceptance of evolution in program participants as compared to a control group. Mounting evidence suggests that empirical evidence alone is ineffective at teaching evolution and must be paired with content on the nature of science. As suggested by the success of our program, authentic science may be the tool that allows us to overcome preset beliefs, transforming evolution education in the US.