(Picture from here.)
Mostly I think evolution speaks for itself.
But I'd be remiss if I didn't talk at least a little about people's difficulty with it.
Personally, I think evolution has sufficiently proved itself to move from the scientific concept of theory to the scientific concept of fact. No scientist of any integrity disputes the fact that we got here by a natural mechanism that we call evolution. The component parts of the mechanism are in dispute, argument and enthusiastic debate. But no one disputes that evolution happened.
It's the same way the no one disputes the facts explained by Maxwell's Equations or Newton's Laws of Motion. Maxwell's equations explain the phenomenon he observed regarding electricity and Newton's equations explain the operation of the phenomenon of motion. That neither model is complete does not refute the fact that there is electricity or the fact there is motion.
Natural selection is the model. Evolution is the fact.
But unlike electricity and motion, evolution strikes at the heart of human exceptionalism-- not too terribly different from American exceptionalism which I spoke about here. Human exceptionalism is the belief that we are special beyond our natural endowments. It usually takes the form that humans are endowed of their abilities by God.
This should not be surprising.
A species by its definition must distinguish between like and not like, otherwise propagation is impossible. Arising from that, reproductive groups distinguish between mine and not mine-- horses, cows, lions and gorillas all make that distinction. Chimpanzees make war against other bands, showing that they have made the leap from reproductive group to societal abstraction. From mine to my people.
One of the human abilities we so prize is the ability to abstract-- the ability to simplify and categorize like things together. The ironclad concept of species itself is a human invention. Reproductive isolation in the wild is much more complex and interesting. (What's the nature of the species boundary between dog and wolf, for example?)
Abstraction is an enormously powerful tool. From it we have deduced cosmology, Euclidean geometry and evolution.
We apply this ability to ourselves and derive nations, states, political ideology and religion which, I submit, are all examples of human exceptionalism. Democrats are better than Republicans. Americans are better than Canadians. Southerners are better than Yankees. Christians are better than Moslems. On and on and on.
I wonder sometimes if we would benefit as a species if we would just stop thinking about ourselves all the time. We're a tiny piece of life on the world that through bizarre happenstance developed abilities that give us inordinate power.
We've been to the moon, cracked the atom and moved machinery with only the circuits of our brain. We've also not managed to make it back in thirty years, burn the atom like it was coal and are figuring out how to better manipulate our brain to make us buy more things from China.
Our view of our exceptional selves was advantageous for the last several thousand years. (For a fun view of this, see Milo Manara's Man. NSFW.) But at some point in the recent past we reached a tipping point, a point beyond which considering ourselves as the sole important group on the planet, made things worse instead of better. I'm not sure when it began but it is unmistakably true now.
The philosophical worth of human beings has been paramount throughout our history. The corollary of that is the worth of human effort has been valued over the natural world. James Watt said in an interview I heard years ago that it wasn't that he didn't value wildlife; it was that he valued human beings more. By extension, he valued human property as symbolic of human worth since he had no trouble developing public land for private interest. Humans, as exceptional creatures, have decided they have the moral right to exploit the living world as they see fit.
I think it's time to change that outlook. And I think it begins by not thinking of ourselves as a special creation outside the operations of nature but as something that evolved directly by the operations of nature.
I don't mean that we are part of everything in the world in some subjective spiritual way. I mean it in an objective mechanism. As Tom Lehrer sang in Pollution:
The breakfast garbage that you throw in to the bay,Or perhaps we should quote Benjamin Franklin:
They drink at lunch in san jose.
We must all hang together, or assuredly we shall all hang separately.