Tuesday, June 14, 2011

Not a smart way to evolve

From The Philadelphia Inquirer:
Today, our most fearsome natural enemies aren't big, fierce animals. They're microscopic invaders, with names like O104:H4. Their weapon is evolution.

O104:H4 is the label given to the strain of E. coli responsible for the food-borne outbreak currently sweeping through Europe. The organism is so good at infecting us that a deadly case could start with just 10 to 50 cells. Once ingested, this new E. coli multiplies into the billions, using various tricks to evade the immune system.

A benign form of E. coli inhabits all of us, but unlike these friendly bacteria, the new strain forms clumps that adhere to human intestines, where it secretes a deadly substance called Shiga toxin. In the worst cases, the toxin invades the bloodstream, where it massacres blood cells and eventually destroys the kidneys.

I was just thinking that this isn't a smart way to evolve.

Of course, evolution isn't directed. There's no goal, not for bacteria and not for us. And nothing shows it better than this.

If bacteria were intelligent, if they planned their evolution, they wouldn't become deadly at all. The "smart" strains of E. coli are those benign forms. They thrive without giving us any reason to attack them. Indeed, when we accidentally kill off our intestinal bacteria, as a side-effect of medication, we often take deliberate steps to repopulate them again. That's because they're not just harmless, but beneficial.

That's the way bacteria would evolve, if they were smart, and if evolution were directed in the first place. A deadly form of bacteria gets our attention. For our own survival, we must fight our hardest to destroy it. But even before we had the capability to fight with science, when we were still in the same boat as other animals, being deadly was not a smart move for bacteria, not in the long run.

The more deadly a bacteria, the quicker its host will evolve defenses - or go extinct, entirely. Neither is good, from the point of view of the bacteria. Ideally, you'd want to help your host survive and reproduce, because then you'd do well, too. At the very least, you should hope to do no harm.

But evolution isn't like that. Evolution isn't a guided process, and it doesn't look at the long term. Evolution will take life down a dead-end path if that's what works over the short-term, at every step along the way.

Bacteria can't look at the long-term, and can't choose, one way or another. Human beings can do that. We have the capability to look at the long-term, to even sacrifice over the short-term for our long-term benefit.  We're smart enough to have that ability. We're not smart enough to actually do it, normally, but we could.

It's a shame, isn't it? Unlike bacteria, we have the ability to make smart choices. But all too often, we don't. We have the ability to recognize global warming and the ability to do something about it, but we simply refuse to do either. It's easier, over the short-term, to follow the path of least resistance.

It may be a path that leads to disaster - it's certainly not the path to an optimal result - but we take it anyway, because we don't choose to use our intelligence. Evolution brought us to the point where we can make conscious decisions, so it's up to us now. We even have the ability - or will have it, shortly - to guide our own biological development - not natural selection, but self-directed artificial selection.

But will we make the right decisions? Will we make any real decisions at all? Bacteria don't have this choice. No other life on Earth has this choice, just human beings. So it really seems a shame to squander it, to automatically do what's easiest over the short-term, despite having the capability to do otherwise, don't you think?

Bacteria are tough competitors, but I wouldn't bet on this new strain of E. coli. I'd bet on human scientists, instead. Some humans will die, but we'll likely defeat these new enemies in the long-run. This is not a smart move for them. But there's nothing willful about it. They simply don't have a choice.

We do.

3 comments:

Jim Harris said...

Great post Bill. Evolution is not willful, but it seems to have a direction toward ever great complexity. Now I'm sure that's accidental, but why does it happen, do you think?

Chimeradave said...

I agree, this was a great post!

WCG said...

Thanks guys!

Re. the evolution of ever greater complexity, I don't know what else we'd expect. Mutations continue all the time, and evolution builds on what has come before. So it would be like continually working to add to a house. You might have started with a simple structure, but it's unlikely to stay that way.

Without natural selection weeding out the unfit, living things would be even more Rube Goldberg devices than we already are. Well, that's clear evidence that we weren't designed, because no intelligent designer would do some things that way. (The panda's thumb is the usual example cited, although there are plenty of features of human beings that are similar.)

On the other hand, I'm not sure how much the appearance of complexity is just that, appearance. After all, there are far more bacteria, slime molds, and worms and such than "advanced" life.