The variety of life in all its forms, encompassing the diversity of species, genetic variation within species, and the range of ecosystems, from rainforests to meadows to farmland. In food systems, biodiversity is both a resource and a casualty: diverse crop varieties and livestock breeds provide resilience against pests, diseases, and climate change, while industrial agriculture’s focus on a handful of high-yield varieties erodes that genetic wealth. The loss matters practically, since the wild relatives of crops harbor genes for drought tolerance and disease resistance that breeders need. Diets also reflect biodiversity: traditional cuisines used hundreds of plant species where modern diets rely on dozens. Conserving agricultural biodiversity, in seed banks and on farms, is an investment in the future of food security.