Final answer:
Life on the Galápagos Island evolved through natural selection and unique adaptations in species, a process known as adaptive radiation, which helped shape Darwin's theory of evolution by natural selection.
Step-by-step explanation:
The statement that summarizes what happened to life on Galápagos Island is: "Life on Galápagos Island evolved through natural selection, with unique adaptations in species observed among different islands." This concept is exemplified by the fact that on the Galápagos Islands, a range of species such as finches, iguanas, and giant tortoises have developed distinct characteristics suited to their specific environments, displaying a process known as adaptive radiation. Much of this understanding stems from Charles Darwin's observations during his visit to the islands, which contributed to his formulation of the theory of evolution by natural selection.