Answer:
This question has little context, but I understand what you are trying to say.
The reason why dark moths survived while light moths weren't able to survive is due to the dark moths having conditions that allowed them to camouflage better than the light moths. An environmental condition that would allow this would be the dark moths and the light moths living in the same dark environment.
Explanation:
When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes in biomes at different latitudes.
20kg piece of pure gold, i think........
