Fire rivals breath as imagery for life. When we die, the fire of life goes out. Our ancestors who first tamed it probably thought fire a living thing, a god even. Staring into flames or embers, especially at night when the campfire warmed and protected them, did they commune in imagination with a glowing, dancing soul? Fire stays alive as long as you feed it. Fire breathes air; you can suffocate it by cutting off its oxygen supply, you can drown it with water. Wild fire devours the forest, driving animal prey before it with the speed and ruthlessness of a pack of wolves in (literally) hot pursuit. As with wolves, our ancestors could capture a fire cub as a useful pet, tame it, feed it regularly and clear away its ashy excreta. Before the art of firemaking was discovered, society would have prized the lesser art of husbanding a captured fire. Perhaps a live scion of the home fire was carried in a pot for barter to a neighbouring group whose own fire had unfortunately died.
Wild fires would have been observed giving birth to daughter fires, spitting sparks and live cinders up on the wind, like dandelion puffs, to land and seed the dry grass at a distance. Did ergastrine philosophers theorise that fire cannot spontaneously generate, but must always be born of a parent fire, either wild fire out on the plains, or domestic fire fenced in by hearthstones? And did the first firemaking sticks therefore rub out a world view?
Our ancestors might even have imagined a population of reproducing wild fires, or a pedigree of descent among domestic fires traced from a glowing ancestor bought from a distant clan and traded on to others. But still there was no true heredity. Why not? How can you have reproduction and a pedigree, yet no heredity? This is the lesson fire has for us here.
True heredity would mean the inheritance not of fire itself but of variations among fires. Some fires are yellower than others, some redder. Some roar, some crackle, some hiss, some smoke, some spit. Some have tinges of blue or green amongst the flames. Our ancestors, if they had studied their domesticated wolves, would have noticed a telling difference between dog pedigrees and fire pedigrees. With dogs, like begets like. At least some of what distinguishes one dog from another is handed down by its parents. Of course some comes in sideways too: from food, disease and accident. With fires, all the variation comes from the environment, none descends from the progenitive spark. It comes from the quality and dampness of the fuel, from the lie and strength of the wind, from the drawing qualities of the hearth, from the soil, from traces of copper and potassium that add touches of blue-green and lilac to sodium’s yellow flame. Unlike a dog, nothing about the quality of an adult fire arrives via the spark that gave it birth. Blue fires don’t beget blue fires. Crackling fires don’t inherit their crackle from the parent fire that threw up their initiating spark. Fires exhibit reproduction without heredity.
-Richard Dawkins, From The Ancestor’s Tale, chapter called Canterbury