I like cheetahs. I think they might be my favorite animal.

I read a book once (it was a picture book, but it still counts) that talked about how cheetahs all look alike. I never really noticed that, because all lions look alike, and all giraffes look alike, and basically any group of animals in the wild look a lot like each other.

But then I looked more closely at the pictures of the cheetahs. They really do look alike. I mean, alike-alike. They have the same markings. Not in the way that giraffes all have spots, or tigers all have stripes, but they really have the same markings. The same dark spots near their eyes, for starters.

Plus, they’re all built the same way. You don’t have big cheetahs and little cheetahs. Fast cheetahs and slow cheetahs. Pinheaded cheetahs and cheetahs with big old noggins. Cheetahs with longer or shorter limbs, or ears, or tails, or noses, or anything. They all look the same.

And it’s no accident.

Evidently, experts think that, during one of the ice ages long ago, the cheetah population got very low, almost to extinction. And I don’t mean only a few hundred cheetahs left in the world. I mean only a few cheetahs left. Like maybe fewer than five. Maybe even two.

And then, those Adam and Eve cats reproduced, and reproduced some more, and after a long line of inbreeding that doesn’t pay to think about when using the Adam and Eve analogy, their numbers went back up to healthy levels. Cheetahs were on the brink of extinction, possibly even more brinkish than any other species, but they made it.

Of course, since they all come now from the same basic family, they’ve lost the genetic diversity that once allowed them to survive at all. In other words, they’re all the same now. If there’s another environmental catastrophe, or even a major shift in environment or climate, it’s a coin-toss whether cheetahs will survive this time. Since they’re all fundamentally the same, there won’t be any outliers to adapt to the change.

I like cheetahs. They’re fast, sneaky, and beautiful. They manage to find their own mates and offspring among countless identical cheetahs, which you know is no small feat if you’ve ever tried to find your sister, one person among thousands wearing red coats, at the Day-After-Thanksgiving sales.