mass extinction. global warming. gene dominance. natural selection.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Edith's checkerspot butterfly is a non-migratory species found in distinct populations from Canada to Mexico. Today, populations in southern regions are declining while new populations push the northern limit further north. This range shift provides evidence for the theory of
Possibilities:
- mass extinction.
- global warming.
- gene dominance.
- natural selection.

global warming.