These islands are volcanic in origin and were never attached to any continent. Galapagos Wildlife arrived here in one of three ways: flying, floating or swimming. Where in most environments larger mammals are normally the predators at the top of the food chain, these animals were unable to survive the journey. Thus the giant Galápagos tortoise became the largest land animal on the islands, and due to the lack of natural predators, the wildlife in the Galápagos is known for being extremely tame without instinctual fear.