Question

darwin hypothesized that new species could appear gradually through small changes in an ancestral species. which observation that he made about finches most supports that hypothesis?
the finches all ate the same materials as the mainland population.
the finches were all relatively small compared to the mainland population.
the finches all appeared to be related but differed from the mainland population.
the finches were identical to the mainland population.

Explanation:

To support Darwin's hypothesis of new species forming through small changes in an ancestral species, we need an observation showing a relationship (ancestral connection) with differences (small changes over time).

• Option 1: Eating the same materials doesn't show evolutionary change.
• Option 2: Size comparison alone doesn't relate to species change from an ancestor.
• Option 3: Finches being related (ancestral link) but differing from mainland (small changes) matches the hypothesis.
• Option 4: Being identical would contradict the idea of new species forming via changes.

Answer:

C. The finches all appeared to be related but differed from the mainland population.