There are theories galore as to how speech originated, but there are no primitive languages to test the theories on—no “fossil languages” as counterparts of the imprints in rock or the fragments of bone that have provided geologists or anthropologists with their knowledge of prehistoric life. There are still some Stone Age peoples in existence—modern remnants of very primitive cultures, hidden away in the world's backwaters—but none is without language, and all speak highly complex languages.