Evolution is the underlying framework upon which all biology is based; however, when it comes to learning evolutionary concepts, many students encounter obstacles. There are many reasons as to why these obstacles occur. These reasons deal with evolution being treated as a discrete topic among many within a biology curriculum, misunderstanding the nature of science, and personal difficulties with understanding due to evolution's seemingly abstract nature. In this article, we propose a different way of thinking about and teaching evolution in grades K-12, and it surrounds four core areas essential to the understanding of evolution: variation, selection, inheritance, and deep time. Possibilities for how these areas can affect learning are described and implications for assessment are also discussed.Keywords Evolution education . Evolution teaching approaches . Learning progressions . Understanding evolution . Evolutionary beliefs . Evolution curricular approaches When Charles Darwin proposed his theory of natural selection in the 1800s, this profoundly changed the social and scientific landscape of the time. Few in society of the time could accept this paradigm shift, but the Darwinian shift had hallmarks of the scientific process, where competing explanations of the natural world were, and still, looked at through open-mindedness and a critical lens. A similar conflict occurred in geology over Wegener's theory of continental drift. Once mapping of the ocean floor revealed the mid-oceanic ridges and trenches that Wegener's theory required, the geology community quickly adopted the theory, which now forms the basis for understanding much of geology. Evolution holds a similar place in biology. The integration of genetics with evolution that started in the 1930s (Haldane 1932) provided the "missing link" in biology that mid-oceanic ridges had provided to geology. As a result, evolution is the overarching theory that provides the stable bedrock on which biological research and understanding are based. While new details and discoveries in evolution continue to emerge, evolution is the basis for our understanding of biology. Yet despite this centrality, evolution continues to be poorly understood by students, educators, and the public.