I'm not sure what the "green butterfly" example is, but here are some things that may help if you take them into consideration:
- Did butterflies of another colour survive? Did this have to do with the environment?
- What caused the population to increase or decrease?
I don't know about the green butterflies, but...
There are more green butterflies today than in the past. This is due to natural selection. One example of natural selection is that the green butterflies are less likely to be seen by their predators because their color allows them to blend in with their habitat easily.
