What observations did Darwin make on the Galápagos Islands that helped convince him that evolution occurs? a. the existence of animals that did not fit into Linnaeus's classification system; b. the similarities and differences among cacti and tortoises on the different islands; c. the presence of species he had seen on other tropical islands far from the Galápagos; d. the radioactive age of the rocks of the islands; e. fossils of human ancestors

Verified step by step guidance

1. Identify the key observations Darwin made during his visit to the Galápagos Islands, which are crucial for understanding his theory of evolution.
2. Consider how the unique species on the islands, such as the finches and tortoises, varied from one island to another in terms of physical characteristics.
3. Analyze how these variations could suggest that species adapt to their environments, which could lead to changes in species over time.
4. Evaluate the significance of these observations in the context of the theory of natural selection, where traits that enhance survival and reproduction become more common in a population over generations.
5. Reflect on how these observations challenged existing views of the time, which largely supported the idea that species were unchanging and created exactly as they are seen today.

Key Concepts

Natural Selection

Natural selection is a fundamental mechanism of evolution proposed by Charles Darwin. It posits that individuals with traits better suited to their environment are more likely to survive and reproduce, passing those advantageous traits to the next generation. This process leads to gradual changes in species over time, as advantageous traits become more common within a population.

Adaptive Radiation

Adaptive radiation refers to the evolutionary process where organisms diversify rapidly into a variety of forms to adapt to different environments. This concept is exemplified by the finches on the Galápagos Islands, which evolved distinct beak shapes and sizes to exploit different food sources, illustrating how species can adapt to specific ecological niches.

Biogeography

Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Darwin's observations of species on the Galápagos Islands, particularly their similarities to species on the mainland and their unique adaptations, provided critical evidence for the idea that geographic isolation can lead to speciation and evolutionary change.