Self-evidently, the gravity on the surface of a planet limits the maximum size of large terrestrial organisms.
James Lovelock has pointed out that atmospheric levels of oxygen much above about 25 percent, let alone 30 percent, would cause raging conflagrations today.
As we have seen so far in this series, fire was an absolutely crucial component in humanity’s rise to civilization and technology.
All these elements of fitness in nature for the development of technology, crucial to mankind’s rise to civilization, long preceded man’s arrival on Earth.
The combustion of wood or coal may seem so familiar as to be unworthy of any comment.