You can categorize every single living being. This classification system allows scientists to study plant and animal diversity and to group closely related species. From horses to insects to worms, ...

I thought kingdoms were at the top of the taxonomy tree. I understand "life" , to separate it from non-living things, but "domain" is a new one to me, and for good reason -it was introduced in 1990 .

The animal kingdom is on its last legs, at least when it comes to taxonomy. Kingdoms are not such a big deal after all. Carl Woese's method for organizing life is a departure from Carl Linnaeus ...