Looking for a rigorous, no-prep way to teach evolution and natural selection? This Modern Horse Claim, Evidence, Reasoning (CER) activity transforms a classic evolutionary case study into a structured literacy exercise that hits both science and ELA standards. This resource guides students through the 55-million-year journey of the horse lineage—from the forest-dwelling Eohippus to the modern Equus. It is perfect for biology or middle school life science teachers looking to reinforce the