We throw the word “species” around a lot. Endangered species this. New species that. But just what is a species, anyway? 

We thought we knew: It’s any organisms that can mate and produce fertile offspring. That’s true, but it’s not the whole truth. There are, as science educator and Brain Scoop host Emily Graslie explains in the video above, dozens of definitions of the word “species,” and scientists are using them all. It’s total taxonomic chaos. Even Charles Darwin, whose most famous work has "species" right there in the title, threw up his hands when it came to defining the word.

“Fine,” you might be thinking, “but who cares?” You should. Identifying species is a critical part of habitat conservation, exploration, and public health. If the plight of endangered plants and animals doesn’t move you, think of your own skin (and all the species that call it home).

Header image from YouTube // thebrainscoop