Final answer:
Charles Darwin gathered plants, animals, and fossils at every opportunity during his time on the HMS Beagle. He made detailed notes and drawings of his observations, which were key to his theory of evolution through natural selection.
Step-by-step explanation:
Charles Darwin, while on the HMS Beagle, gathered plants, animals, and fossils at every opportunity. He explored various locations during the expedition and kept a diary, making detailed notes and drawings of his observations. Darwin's observations and collections played a crucial role in the development of his theory of evolution through natural selection.