Where the antelope play

If you will be so kind as to look back in my blog a month ago, you will see something I did on vestigial traits- The odds and ends of your body that serve no good today, but may have been useful in your deep past.

Today, I think I'll show how these traits can be more than just extra teeth or a misplaced bone. Take the Antelope that live on the plains of America, for example. These little powerhouses may look a little like a midget deer, but they can run like the dickens. Where most animals living on the North American plains can't run more than about 25 mph, an antelope can almost reach highway speeds.

Why is this?

As it turns out, the antelope's ability to run like a Kenyan triathlete on crack is rooted in their species' birth, a mere 3 million years ago. During this period of American History, cheetahs stalked the plains of Kansas.

Well, they weren't cheetahs, exactly, they were a relative of pumas called Miracinonyx, (that's a post for later) but a cat that is perfectly engineered for running is still a major threat to an antelope's survival. What happened? Only the fastest antelopes would survive. After the Miracinonyx's still unknown demise, the antelope retained it's running speed.

The more things change, the more they stay the same. You might have seen this situation 3 million years ago in Kansas. Picture courtesy of Jerry Friedman

Because the antelope can outrun any predator alive today by a healthy margin, it is thought that their top speed will eventually be lower. Evolution works on a "just good enough" function, and the amount of muscle needed to run at highway speeds simply takes too much energy to grow.