How did the mockingbird species of the Galapagos help Darwin come up with his theory?

The Galápagos mockingbird species played a crucial role in Charles Darwin's development of his theory of evolution by natural selection. He observed that these birds varied significantly between different islands, each adapted to their specific environments. This variation suggested that species could change over time based on their surroundings, leading him to propose that species evolve through a process of adaptation and natural selection. Ultimately, these observations helped him formulate the idea that all species share a common ancestor and evolve through gradual changes.