Fission and fusion are nuclear reactions that produce energy, though they are not the same. Fission is the splitting of a heavy and unstable nucleus into two lighter nuclei. Fusion is the process where two light nuclei combine together releasing vast amounts of energy.
Answer:
The population of predators will decrease as well because without their prey they won't have anything to feast on for nutrition. So they will decrease without prey.
People's daily experiences can contribute to their belief that earth/ species do not change because we are changing with it as it is happening. Also the changes happen gradually so you can't constantly see to believe it.