Their research direction had always been wrong.
Everyone had assumed that in the Apocalypse, the soil and air were contaminated to various degrees, and so when cultivating seeds, they would take them to an indoor pollution-free environment and use grow lights to provide illumination. Little did they know that crops grown this way were actually not capable of naturally thriving in the harsh conditions of the Apocalypse.
Long before, Darwin had mentioned the rule of survival of the fittest in his theory of evolution, the so-called natural selection. Organisms compete for survival, with those who can adapt continuing to live, while those who can't are eliminated accordingly.
Just like the Special Ability Users, Mutated Plants, and Mutant Animals that had evolved in the post-apocalyptic environment, the same natural laws applied to seeds.
