Laws Can’t Bind Us: Natural Selection and Evolution
We had some really interesting conversations about evolution at the Xmaz table, there being a pretty much even mix of scientist non-christians and christian non-scientists there.
It made me think on evolution, and want to publish what I see as the logical sibling of the “Laws Can’t Bind Us: Species” post from whenever ago.
First of all, evolution. Charles Darwin did not come up with evolution. Evolution as a concept had been around, and had been popular among the conspiracy theory set, for quite a while when Darwin heard of it. He travelled around the world with it on his mind, among other things.
But it was kind of a useless idea, because no one could think of a good way to explain how it could work. What Darwin did that blew everybody’s minds (after a while, and after someone else had proposed it too) is he came up with a mechanism by which evolution could work. Darwin rules because doing this is really hard, and then looks really easy afterwards!!
The mechanism Darwin came up with is natural selection. It is really famous but usually kind of misunderstood. ie I used to misunderstand it before I read this book (http://www.goodreads.com/book/show/40941.The_Scientists).
Turns out that natural selection: ‘survival of the fittest’, does not refer to fitness in a cardiovascular neo-fascist or jock kind of way, but in a ‘key fits in a lock’ kind of way. So survival of the fittest does not guarantee that situps will help you survive the apocalypse, unless situps are the exact skill that will give you an edge in the post-apocalyptic world. If that world requires webbed toes, the situp folks would be out of luck unless they also happened to have webbing. So there is hope for us all.
And this is the value of having a diverse population- you want a slew of weird characteristics in a given gene pool out there so that someone will survive!
Natural selection suggests that in a given environment, the individuals that have the greatest fitness for that environment (eg owning a sports car in modern society) will propagate more, passing on those good features. This can lead species who stay in the same environment to become really adapted to that environment over time, like chameleons. And after a while, different lineages start to look and be quite different, making what we perceive to be different species.
This is the general vibe.
But it leads to somewhere we have not really gone yet, at least to me.
Since the bible and the ancients, species have been seen as pretty much fixed. A dog is a dog, a cat is a cat, etc. Which makes sense when you consider how we perceive the world. But when you apply the concept of evolution, everything gets weird.
If evolution is correct, and everything we know suggests that it is, then species are really kind of a blur. Humans are one part of a blur going from (before) an ancestral ape through chimpanzees, neanderthals, australopithecus, and us. Really humans are just a point in transition from modern humans to whatever we will appear to be in a few millenia or eons. And all ‘species’ are like this. Nothing is fixed when evolution comes to town.
This makes the idea of speciousity even weirder! How can we speak of species when they are all just ephemeral and transient evolutionary entities?