Final answer:
Darwin's understanding of Earth's ancient and changing nature was crucial as it supported his hypothesis that species evolve gradually over time in response to changing environments, laying the groundwork for the theory of natural selection.
Step-by-step explanation:
Charles Darwin's acceptance of an ancient, continuously changing Earth was pivotal for the development of his theory of evolution. Through the influence of geologists like Charles Lyell, who popularized the idea that small, gradual processes lead to significant geological changes over vast periods, Darwin understood that similar slow and steady processes could lead to substantial biological changes, given enough time.
This perspective was crucial for Darwin to hypothesize that species changed gradually over long spans of time, in response to their changing environments, thus explaining the diversity and adaptation of species he observed during his voyage on the HMS Beagle.
The correct answer to why Darwin's acceptance of an ancient, continuously changing Earth was so important in his development of his ideas about evolution is: c. Darwin hypothesized that species changed gradually, over long spans of time, in response to diverse and changing habitats. This understanding allowed Darwin to integrate his observations with the theory of natural selection, leading to the formulation of his insights into evolution.