What did Darwin infer from his observations of organisms in South America and the Galápagos Islands?
A. The organisms on the Galápagos Islands were completely unrelated to mainland organisms.
B. The organisms on the Galápagos Islands were virtually identical to mainland organisms,
C. A small number of different plant and animal species had come to the mainland from the Galápagos Islands.
D. A small number of different plant and animal species had come to the Galápagos Islands from the mainland.
D. A small number of different plant and animal species had come to the Galápagos Islands from the mainland.
Darwin inferred that the different plant and animal species he observed on the Galápagos Islands had descended from a common ancestor and had adapted to their local environments over time. He also recognized that these organisms had most likely migrated from the mainland and evolved through natural selection.