This study focused on whether a teacher's personal beliefs impacted how the state standards for evolution were taught in a middle and high school science class. This research followed a collective case study design that was conducted on a population of middle and high school science teachers in the State of Georgia. Educators were asked fifteen semi-structured interview questions. Thematic analysis of data was conducted to address two research questions. Research question one aimed to address what the personal beliefs of middle and high school science teachers revealed about the practice of teaching evolution. Furthermore, research question two was designed to address how the educational beliefs of middle and high school science teachers influenced their instruction of teaching evolution. Four themes were developed from the thematic analysis. Theme one emerged from overwhelming data in the semi-structured interviews: Evidence was used to support teaching the theory of evolution in the secondary science classroom. Theme two was centered around the teacher's pedagogy as it related to effectively teaching the theory of evolution and addressed any religious conversations that might occur. It stated that teachers who supported teaching the theory of evolution could effectively address any religious conversations. Data from the thematic analysis showed an overall lack of teacher bias in teaching the standards related to evolutionary teaching. As a result, theme three stated that limitations in teaching the theory of evolution were not derived from a teacher's personal belief system. Lastly, theme four communicated how a teacher's educational beliefs positively impacted the way the standards were taught, because there was no deviation from the standard. Gaps in the literature indicated the need to research if the individual beliefs of secondary science educators influenced teaching evolutionary content and how that impacted life science students. Results from this qualitative study provided evidence to decrease the challenges in evolution education despite any potential personal and educational beliefs held by the teacher. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]