The tilt of the earth changing would affect the distance to the sun. This, the radiation from the sun, and resulting temperatures, would change as well.
The species has a higher chance of survival as there are 3 plant types, even if 2 of those die out, there's a portion of the purple gorillas that can still eat the remaining plant type
photosynthesis: needs light to happen
Cellular respiration: waste products are carbon dioxide and water.
