Do you mean REM? If so it’s an abbreviation for Rapid Eye Movement; the deepest point in your sleep where dreams occur.
Answer:
decreases competition between members of the two different butterfly populations.
Explanation:
The choice of different habitats may be beneficial for the populations of butterflies since it enables to both groups to survive and reproduce without the need to compete for limited resources (in this case, the host plants)
If you cut a flatworm in half, both halves can grow into a new individual by fission.