Final answer:
Adaptive radiation is the process where a single species evolves into multiple new species by adapting to various niches and habitats, often due to environmental changes and geographical isolation. The Hawaiian honeycreeper is an exemplary case of adaptive radiation.
Step-by-step explanation:
Adaptive radiation refers to the rapid branching through speciation of a phylogenetic tree into many closely related species. This process often occurs when a population of a single species disperses and finds distinct niches or isolated habitats, leading to the evolution of multiple new species from that single founder species. Factors that spark adaptive radiations include environmental changes, availability of new niches, and geographical isolation—as seen in island archipelagos—where each island provides unique living conditions that promote divergent evolution. One classic example of adaptive radiation is the Hawaiian honeycreeper, which has evolved into numerous species from one ancestral species. Other examples include the Darwin's finches in the Galápagos Islands and the cichlid fishes in East Africa's lakes.