Survival of the fittest would prevent any transformations.
来自SA
He mistakenly ascribes the expression "survival of the fittest" to Charles Darwin.
他错误地认为“适者生存”是查尔斯·达尔文说的。
Natural selection ensures only the fittest survive to pass their genes on to the next generation.
自然选择确保只有最适应环境的物种得以存活下来，把基因传给下一代。
With the changes in the world's climate, dinosaurs died, but many smaller animals lived on. It was the survival of the fittest.
随着世界气候的变迁, 恐龙绝迹了, 但许多较小的动物却继续活了下来. 这就是适者生存.
It's not the fittest team in the world.
来自THETIMES