Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

Question: What phenomenon is crowding out other species and making all the other causes of extinction worse? Answer: human overpopulation
Human overpopulation, which is crowding out other species. It also makes all the other causes of extinction worse.

Question: What are genes that are close together on the same chromosome called? Answer: linked genes
Linked genes are genes that are close together on the same chromosome. Linked genes are inherited together.

Question: What system includes lymph organs, lymph vessels, lymph, and lymph nodes? Answer: immune
The immune system includes lymph organs, lymph vessels, lymph, and lymph nodes.