adaptive radiation, which is the process where a single ancestral species evolves into many different species, each adapted to a specific set of environmental conditions or habitats. In the case of the Galapagos finches, the varied habitats on the different islands led to the evolution of different bill shapes and feeding behaviors in the finches, allowing them to exploit different food sources and niches. Darwin's study of the finches and their habitats was crucial in developing his theory of evolution by natural selection.