What peculiar feature did Darwin observe in the tortoises on the Galápagos Islands?

• A. The shape of their shells varied depending on the island they inhabited.
• B. They had brightly colored shells to attract mates.
• C. They had webbed feet adapted for catching fish.
• D. They could swim long distances between islands.

Answer: (A)

Verified step by step guidance

1. Understand the context of the question: Charles Darwin observed various species on the Galápagos Islands during his voyage on the HMS Beagle. His observations contributed to the development of his theory of natural selection.
2. Focus on the tortoises: Darwin noticed that the tortoises on the Galápagos Islands exhibited differences in their physical characteristics, particularly the shape of their shells.
3. Relate the shell shape to environmental adaptation: The shape of the tortoises' shells varied depending on the specific island they inhabited. For example, tortoises on islands with lush vegetation had dome-shaped shells, while those on islands with sparse vegetation had saddle-shaped shells, allowing them to stretch their necks to reach higher vegetation.
4. Eliminate incorrect options: Brightly colored shells, webbed feet for catching fish, and swimming long distances are not features observed in Galápagos tortoises. These traits are not relevant to their adaptation or survival in the Galápagos environment.
5. Conclude the correct observation: The peculiar feature Darwin observed was the variation in shell shape among tortoises, which was influenced by the environmental conditions of the islands they inhabited.