Early in The Greatest Show on Earth: The Evidence for Evolution, Richard Dawkins raises the question of why the idea of evolution took so long to emerge. The basic concept that life forms change as successful ones multiply and unsuccessful ones die off didn’t require any technology to come up with. So why did it emerge so much later than abstract ideas about mathematics, physics, etc?
One explanation he gives – and which I find interesting – is that people were captivated by a Platonic notion of essential forms. Dawkins convincingly uses the example of rabbits to illustrate what he means:
There is no permanent rabbitness, no essence of rabbit hanging in the sky, just populations of furry, long-eared, coprophagous, whisker-twitching individuals, showing a statistical distribution in size, shape, colour, and proclivities.” (p. 22 hardcover)
What we call ‘a rabbit’ now is just a kind of snapshot in the development of that organism, between the ancient emergence of chordates and mammals and the emergence of whatever it is the descendantâ€™s of todays rabbits will become. Given enough time, they will surely include creatures that no modern person would put into the category of ‘rabbit.’
Dawkins suggests that the categorical way in which children learn has something to do with why the Platonic view is so intuitively appealing. Presented with the overwhelming complexity of the world, they begin to put this and that into different conceptual boxes. That habit, useful as it is for making do in the world, may have blinded humanity to one of the most powerful explanations to the very nature of our world and the beings in it.
It is, of course, equally true to say that there is no permanent â€˜humanness.â€™ As a species, we are only human temporarily. Over time, we will inevitably change; and if we were separated into groups that strictly did not interbreed, we would eventually become incapable of doing so. Indeed, given the limitation of the speed of light, that may be precisely the rate of any humans who leave our solar system in order to try to colonize planets orbiting other suns.