> There are lots of things that have tried to be cats—other groups of mammals that have evolutionarily converged on cats. Marsupials have tried to be cats. An extinct group of carnivorans called creodonts have tried to be cats. Weasels have tried to be cats. There’s all kinds of stuff that has tried to be a bit catlike in different ways—mongooses, things like that. But they kind of dip in and dip out of being cats, and they can’t really outcompete cats in their space. They haven’t lasted. All of those things that have tried to be cats, they do other things, too, and those things are fine. But there aren’t a lot of things that are around today that do a very good job of being a cat.

Er... okay? And what exactly does this mean?

I wish they defined "catness," in this sense, so we knew what it meant for a species to approach it. As it is, the above paragraph essentially tells us nothing.