Santiago Ramírez studies the evolution, adaptation, and speciation of plant-pollinator mutualisms. His work includes comparative and population genomics of bees and their associated host plants, phylogenetics, chemical ecology, neuroethology, and natural history of insect-plant interactions. His research includes the evolutionary biology of the charismatic euglossine bees and the intricate associations they have as pollinators of orchids from the Neotropical Region, and the ecological genetics of native and introduced populations of the economically important honey bee, Apis mellifera.