Darwin Day

I must interrupt these grand musings to acknowledge the birthday of Charles Darwin (which also happens to be the birth date of Abraham Lincoln). There are various Darwin Day celebrations going on but rather than focus on the individual I'd like us to think about the intellectual revolution he kick-started and what it has meant both culturally and scientifically. If you are interested in a well-organized set of informational and educational resources you can find one here.

Copernicus and Galileo removed the earth from the center of the universe. While that was very upsetting to the Pope and Bishops, and got Giordano Bruno burned alive, among other nasty consequences carried out in the name of Jesus, it didn't actually shatter the smug conception that God made humans in his own image and built the universe for our benefit, heliocentric though it may be. (Of course now we know it isn't even that -- the sun and the stuff that goes around it aren't even anything special or even hardly anything at all.)

I think I can understand why lots of people have trouble accepting the idea of evolution. While there are understandable mechanisms that drove it over the 3 1/2 billion years or so since the Last Common Ancestor, they underlie a stochastic process -- that is, one that depends on chance. It didn't have to end up where we are now, or even anywhere much like it. That includes us. We're accidental.

A few things we aren't. We are not descended from monkeys. We are more closely related to bonobos than to any other species, and almost as closely related to chimpanzees, but the last common ancestor of bonobos and humans is long extinct. (We are also descended from fish, by the way, although the specific fish is also extinct.) We are not the culmination of some progressive process that led to somehow better and better or more and more capable organisms. It is fair to say that we're quite unusual in our behavioral adaptability, language capacity and ability to invent and plan. But it's looking as though we can't plan well enough to assure we'll still be around, at least in large numbers and enjoying the kinds of technical capacities we have now, for very much longer.

Looking at that graph of human population in the previous post, we do see that we are the species for whom something happened in the late 18th Century that resulted in an unprecedented population explosion -- unprecedented, that is, for a large animal. A bacterium in a pond can undergo a much faster population explosion, but we've done it on a global scale. Then the bacteria die in their own excrement.

Human evolution into our unique state was driven by a combination of our manual dexterity (which required bipedalism to be possible), ability to plan, behavioral flexibility which made cultural transmission of knowledge and behavioral strategies possible, and language which enabled cultural transmission and social cooperation. All of these capacities evolved together and depended on each other for much of their value. But no guiding intelligence or purpose is necessary for all this to have happened. This blog isn't an evolutionary biology class and I'm not going to argue for the preceding assertion. There are a few books that do it very clearly.

But the point is, we're on our own. If anybody is going to save our sorry asses, it's us. Nobody else cares. But I hope we do.