Earth will be overpopulared so all animals will be killed off to free space for people

Asimov Isaac : writer
Earth will be hidden under the metal shell of one of the huge city (probably after Nuclear war). Because of the overpopulation life will be perfectly balanced - the birth rate and death, food and waste, work and leisure, where there was no crime and misfortune. It was perfection, but the last non-human animals get killed off to make room for people

novel "2430 A.D.: Too Late For the Space Ark"