Answer:
The first living things on Earth, single-celled micro-organisms or microbes lacking a cell nucleus or cell membrane known as prokaryotes, seem to have first appeared on Earth almost four billion years ago, just a few hundred million years after the formation of the Earth itself.
With a certain species out of the food chain this leaves other animals population to dwindle because of them feeding off of the migrating animals. Meanwhile other plants and animals might flourish because these animals would no longer be a threat to their species.
