The idea of a niche in natural history is ancient: many writers noticed that animals and plants live in places where they are well adapted to live. The word "niche" was first used in biology by naturalist Roswell Johnson, but in 1917 Joseph Grinnell was the first to use it in a research program. Later, he described the niches of a variety of species. Grinnell was the first to offer the "exclusion principle" in which only one species could occupy a particular niche at any one time.