While traveling in South America in 1831, Charles Darwin observed many huge fossils of extinct animals and similar living animals that were much smaller.

Question

Which of the following would be Darwin's explanation for his observations?
The environment that these animals lived in changed, and traits for smaller body size were an advantage.
The environment that these animals lived in has never changed; all animals have been created independent of each other.
The giant fossil animals and the smaller living animals are not related to each other.
The giant fossil animals are the remains of the parents of the smaller living animals.

Answer 1

Darwin's explanation for his observations would most likely be:

The environment that these animals lived in changed, and traits for smaller body size were an advantage.

This aligns with Darwin's ideas about evolution and natural selection, where changes in the environment can lead to changes in the traits that are favorable for survival and reproduction. Over time, these traits become more common in a population, leading to smaller body sizes in the living relatives of the extinct giants.