The way we present things often shapes our thoughts. How often do we say that a group of animals belongs to a particular family because they have such and such characteristics. Kind of like, all cats are cats because they all have a set of cat features that make them cats.
Now, this sounds all very good, but in a sense, we're getting it backwards. Instead of cats being cats because they share traits, they share traits because they're cats. Confusing, right? What the biologists are saying by this is that cats have feline characteristics because they have inherited them from the ancestor of all cats. All the cat traits are doing is allowing us to recognize the descendants of that common ancestor—it's the ancestry that really counts, not the characteristics.
The cheetah that roamed the American West during the last ice age
presumably lacked fully retractable claws, like its Old World living relative. This
un-cat-like feature, though, doesn't remove it from the family of cats. It merely
records a cat that marches—or runs—to a different drummer.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.