What did Charles Darwin while he was at the Galapagos islands?

During his visit to the Galapagos Islands in 1835, Charles Darwin observed a diverse range of species, particularly finches and tortoises, which exhibited unique adaptations to their specific environments. These observations led him to formulate key ideas about natural selection and evolution. The variations among species on different islands provided crucial evidence for his theories, ultimately contributing to the development of his landmark work, "On the Origin of Species." Darwin's insights from the Galapagos played a vital role in shaping modern Biology.