So as far back as the mid-to-late 1800’s, scientists noticed that crab-like animals were oddly commonplace. It seems that, for one reason or another, evolution favors crab-like body structures over other crustacean body types. Well, maybe “favors” is the wrong word. I wouldn’t want to imply that evolution plays favorites or that evolution has any sort of intended outcome. That would be misleading.
When I read articles in the popular press about carcinization (the surprisingly common process of evolving a crab-like body), I feel like there’s a fundamental misunderstanding at work, not just about carcinization itself but about evolution in general. Evolution doesn’t “prefer” this and it certainly doesn’t “intend” that. There is no end-goal to the evolutionary process.
Evolution works by trial and error. Organisms have problems, problems like “how do I find food?” or “how do I avoid becoming food?” Some organisms manage to solve these sorts of problems; others do not. The ones who solve their problems get to live, and they have the opportunity to pass their genes on to the next generation; the others? They do not get to do that.
There are a surprising number of crab-like animals out there. That must mean that being a crab helps you solve certain problems. It does not mean that you’re evolution’s favorite, that evolution “wants” to create more crab-like creatures like you, or that being a crab is some sort of evolutionary end-goal.
All that being said, I have to admit it’s hard to avoid anthropomorphizing the concept of evolution just a little bit. I mean, look at the stuff I do on this blog. I anthropomorphize everything from atoms and molecules to planets and stars. I imbue all sorts of things with wants and needs and strange personality quirks. It’s only natural for me to say evolution “wants” this or “prefers” that, and I totally understand why so many other science writers fall into a similar trap.
So I guess what I’m saying is this: whenever you hear people talk about evolution’s “preferences” or “intentions,” bear in mind that those words are really just shorthand for something else.