The document contains definitions for 61 terms related to evolution, including adaptation, adaptive radiation, ancestral trait, artificial selection, biodiversity, biogeography, convergent evolution, derived trait, directional selection, disruptive selection, ecosystem diversity, evolution, extinction, fitness, fossil, genetic diversity, genetic drift, geographic isolation, molecular clocks, natural selection, normalizing selection, population genetics, punctuated equilibrium, radioisotope dating, relative dating, reproductive isolation, speciation, species diversity, stabilizing selection, and vestigial structure. Each term is defined in 1-2 sentences.