Evolution: it works!

So evolution is really important. Whether you want to believe it or not, all living things are evolving all the time. If they didn't, they wouldn't be here today. When most people think about evolution, they think about apes turning into humans or, if they're really nerdy, dinosaurs turning into birds. And while that's cool and all, there are examples of evolution all around us that happen in short enough spurts that we can see them (and their consequences) within our measly human lifespan. 

The first thing to get past, though is this idea of nature vs. nurture. I see this idea come up a lot when people talk about evolution and biodiversity and whatnot. The truth is, the influences of nature and nurture are split pretty evenly. For example, you can have two tall parents, but if your environment restricts your access to proper nutrients, you probably won't end up looking like an NBA player. Nature (your genes) and nurture (your environment) need to work together in order for any genetic predisposition to come out. 

Where you really should be thinking about nature and nurture is when it comes to natural selection. Evolution happens within a population of living things when that population's environment changes. As long as the change isn't something totally devastating, like--oh, I don't know, an asteroid or something--then the population as a whole will adapt genetically to it. If an area gets, say, colder, then organisms with traits that protect them from cold will be more likely to survive and thus pass those genes on to future generations. After some time, you'll have a shiny new population of tulips or caribou or whatever that has evolved to better withstand cold.

But it's important to remember that evolution is not predictive. It can only work with what's already there. A great example that my professor brought up in one of our first classes is the human spine. Our backs kind of suck. That's why there's a thriving industry dedicated to alleviating back pain. We have chiropractors, we have special painkillers, we have those pathetic commercials with the miserable-looking wooden puppets. And why do our backs suck? Because they're meant for quadrupeds, not bipeds. Throughout the course of human evolution, it became advantageous for us to walk on two legs instead of four. It's awfully convenient, isn't it? But our backs have no way to catch up. We have a mutated quadruped spine, and that's the best our genes can do unless we go out and mate with--I don't know, T-rexes? No magic bipedal gene has or ever will pop up in our species that will give us a better spine design, and people with especially crappy backs can still reproduce and pass on their crappy-back genes. Chiropractors, rejoice. 

So that's a long-term example. But what about that short-term, within-our-measly-human-lifespan business? Well, for a great example of that, let's look to Australia. Australia has a bunny problem. (Not a terrible problem to have, but then again, I'm not a farmer. I just really like bunnies.) Scientists have tried again and again to introduce a variety of specialized bunny plagues in the hopes of reducing the population. And it works--sort of. But in the long run, it causes more problems than it solves. Why is that? Well, inevitably, you'll have some bunnies that just so happen to be naturally resistant to the plague of the week. While the other bunnies are busy dying painfully, the plague-resistant bunnies continue to mate and reproduce as usual. Before you know it, you've got a fully restocked continent of bunnies that are immune to your fancy plague, because now that's a genetic trait advantageous to survival. 

That's an awful lot of words I just typed up there. In a nutshell, evolution is the change over time in a population of living things as helpful genetic traits are passed on. Without it, life on Earth would not be able to cope with our ever-changing environment. And then we'd all be dead. And that would suck. For those of a religious persuasion who are hesitant to accept the theory of evolution, why not think of it this way: isn't your God smart enough to come up with something like this? It's efficient and (mostly--pandas, I'm looking at you!) effective.

Evolution: the ultimate time-saver!