Answer:
The best answer to the question: Earth has undergone some catastrophic changes from time to time. Which of these most likely explains why life on Earth continued following these catastrophes, would be, A: A wide variety of species existed.
Step-by-step explanation:
In trying to explain why Earth is still populated by animals and plant life, even though there have been several catastrophic events that should have ensured extinction, there have been several theories that have been formulated. One such theory is Darwin´s Theory of Natural Evolution, which explains how species with strong genetic traits that help them adapt to environmental conditions are more likely to survive and pass on their genetic makeup to future generations. However, there is another series of theories that explain speciation, meaning, the appearance of new species given changing conditions in the environment. This idea says that species may arise from a common ancestor when the need arises. It also explains that thanks to the existence of a wide variety of species, both animal and plant life were able to survive in the face of catastrophic situations, and since their genes were strong enough to survive, they were passed on to future generations, instead of reaching extinction.