Question

several species of finch live on the galapagos islands. they are very similar in appearance, but have adapted beaks of different sizes and shapes based on their major food source. finches with large beaks eat mainly large seeds and cacti. finches with small beaks eat mainly small seeds and insects.
which of the following best explains the variety of beaks found in finches on the galapagos islands?
a. biological evolution does not have any effect on the species diversity of an ecosystem.
b. evolution through natural selection can increase the species diversity of an ecosystem.
c. evolution through natural selection always causes a decrease in the species diversity of an ecosystem.
d. biological evolution only affects the species diversity of plants in an ecosystem.

Explanation:

• Option A: Incorrect. Biological evolution (like natural selection in finches) does affect species diversity.
• Option B: Correct. The finches' beak variations are due to natural selection (adapting to food sources), leading to new species and increased diversity.
• Option C: Incorrect. Natural selection here increased diversity, not always decrease.
• Option D: Incorrect. Evolution affects all organisms, not just plants (finches are animals).

Answer:

B. Evolution through natural selection can increase the species diversity of an ecosystem.