They result in population decline. They are all observable in the fossil record. They occur slowly over long periods of time. They are more likely to be observed in plants.
I gave my students this multiple choice question: Physical features help animals survive. Which statement best describes physical adaptations that occur through natural selection in changing environments?

Only one answer is correct among these 4 choices:
- They result in population decline.
- They are all observable in the fossil record.
- They occur slowly over long periods of time.
- They are more likely to be observed in plants.

Could you tell me which one is correct?

They occur slowly over long periods of time.