The adjective human derives first of all from the Latin word humanus, meaning "of a man." It, then, became an French word in the Middle Ages, and after the Norman Conquest of 1066, it found its way into Middle English a little later than the time of Geoffrey Chaucer. The Middle English word was humain, which, of course, resembles modern English's word humane.
The word seems to have its origins in the mid 15th century (the 1400's). It seems to have remnants of French, Old English, and Latin.
As a noun, from 1530s. Its Old English cognate guma (from Proto-Germanic *guman-) survives only in disguise in bridegroom. (etymonline)
However, it is a bit more complicated than this. The Latin word "humus" means "soil" in Latin. It kind of makes sense that the word for "human" would crop up from "soil" because humans depend a lot on soil in the beginning during our agricultural roots.
One way or another, the word has an interesting history. You can look in some other entomology dictionaries to find information.