Dinosaurs of a Feather, Flap Together.

Dinosaurs of a Feather, Flap Together.

We tend to forget how truly mysterious the mechanism of evolution is, and how clunky, funky, and wildly erratic the whole business can be. The funny part to me, is how the process tends to do the most with the least. Evolution is the classic overachiever. When it finds something that works, meaning the chance for survival has improved, it likes to go hog wild, so to speak, and keep pushing the limits until whatever change took place is no longer viable or something even better comes along.

It's why we see such Hollywood-like creatures in the prehistoric record. When teeth came along, it was like, let's make the biggest teeth possible. When horns came along, let's make lots of them, lots of big ones. When physical size helped, it was time to get humongous sizewise. So on and so forth. The same was true when a favorable mutation caused a scale to be slightly like a feather.

We know that feathers evolved from reptilian scales. Why? Because a feather is sort of like a scale on steroids; it's lighter and offered buoyancy to animals who made a living chasing other animals. You were faster and lighter on your feet if you had some feathers instead of all scales. At the molecular and genetic level, both scales and feathers also share a lot in common. A lot. Feathery scales were just an ultra cool development that quickly became a game-changer in totally unexpected ways. From added warmth in winter, to brighter, fancier colors, to that one other fringe benefit nobody saw coming -- flight.

Fast forward to when feathers made flying not only possible, but commonplace. Well, if you've got feathers on your arms, which were simply a pair of limbs, and they're working for you just fine, then let's add them to that other pair of limbs -- your legs. To not have feathered legs as well as arms would have been just plain dumb in evolutionary terms. And when you're running, chasing, and grabbing, (much like swimming) it comes natural almost to stroke with your arms and kick with your legs. Or if you were a dinosaur, flapping your feathery legs as well as your feathery arms was definitely the way to fly -- and literally so.

So what happened to feathered legs? They're still around. Pigeon fanciers have for years bred feathery legs for show. But the genes were already there to work with. What happened in prehistoric times was that feather design got really, really good. And at some point, feathers on your legs were actually a drag on airspeed because the arms were now so efficient that aerodynamics and wind resistance trumped the extra "lift" you got from your legs. It's a little like why the Flying Wing airplane is superior to those with extra fins, rudders and so forth on the hind end. All you need is a really efficient wing and the power to move it. Or move air over and past it. It's also why reptile tails changed into a bunch of birdlike steering feathers only.

The appearance of feathers is probably one of evolution's greatest achievements, if not the single greatest. We don't think about it much, which is why I took the time to mention it. Oh, and by the way, if you wouldn't think of eating a fried lizard, I suggest you stop eating chicken.