Evolutionary evidence is important scientific background for appreciating the theory of evolution. We describe a STEAM-based lesson plan that uses paleontological drawings and a modern evolutionary database to explore and understand fossil, morphological, and molecular evidence. Together, with a focus on arthropods and the Cambrian explosion, students experience a heuristic process common in scientific reasoning, guiding them toward practices that synthesize knowledge and invite questioning in the life sciences.
Keywords: Cambrian fossil; TimeTree; arthropods; drawing heuristic; evolution; molecular characters; morphological characters; storytelling.