All the finches on the Galapagos islands

Options

A. are unrelated but descended from a common ancestor.
B. are descended from a common ancestor and therefore related.
C. rarely compete for the same food source.
D. are related but not descended from a common ancestor.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the finches on the Galapagos Islands and their relationships to each other and their common ancestor.

2. **Identifying the Options**: The options provided in the question likely include statements about the finches being related, descended from a common ancestor, and competing for the same food sources.

3. **Analyzing the First Option**: The first option states that all the finches are unrelated but descended from a common ancestor. This is incorrect because if they descended from a common ancestor, they must be related.

4. **Analyzing the Second Option**: The second option states that the finches are descended from a common ancestor and therefore related. This is correct, as the finches on the Galapagos Islands evolved from a common ancestor.

5. **Analyzing the Third Option**: The third option suggests that the finches are adapted to compete for the same food source. This is also correct, as different species of finches have evolved various beak shapes and sizes to exploit different food resources available on the islands.

6. **Analyzing the Fourth Option**: The fourth option claims that the finches are related but not descended from a common ancestor. This is incorrect, as they are indeed descended from a common ancestor.

7. **Conclusion**: The correct answers are the second and third options, as they accurately describe the relationships and adaptations of the finches on the Galapagos Islands.

### Final Answer:
The finches on the Galapagos Islands are related and descended from a common ancestor (Option 2), and they have adapted to compete for the same food sources (Option 3).

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