Write a correct answer to the given question based on its associated fact. Make sure that your answer is contained in the associated fact. Don't be creative and introduce any new word that is not mentioned in the associated fact! Remember that the associated fact has been rearranged to form the question. So, the correct answer words must lie within the associated fact. The correct answer can be a word, phrase, or even a sentence.

Fact: paleontologists study the remains of plants. 
Question: What do palentologists study?
plants.

Fact: Gene flow occurs when individuals migrate. 
Question: Migration increases what?
gene flow.

Fact: ethologists usually study observable behaviors in natural enviornments. 
Question: Who studies observable behaviors in natural environments.?

ethologists.