By the year AD 802,701, humanity has evolved into two separate species: the Eloi and the Morlocks, whereof the Eloi live a banal life of ease on the surface of the earth, while the Morlocks live underground, tending machinery and providing food, clothing, and inventory for the Eloi. The narration suggests that the separation of species may have been the result of a widening split between different social classes. Having solved all problems that required strength, intelligence, or virtue, the Eloi have slowly become dissolute and naive: they are described as smaller than modern humans, with shoulder-length curly hair, pointed chins, large eyes, small ears, small mouths with bright red thin lips, and sub-human intelligence. They do not perform much work, except to feed, play, and mate; and when Weena falls into a river, none of the other Eloi helps her (she is rescued instead by the Time Traveler). Periodically, the Morlocks capture individual Eloi for food; and because this typically happens on moonless nights, the Eloi are terrified of darkness.
A portion of the book written for the New Review version, later published as a separate short story, reveals that a visit by the Time Traveller to the even more distant future results in his encountering rabbit-like hopping herbivores, apparently the descendants of the Eloi. They are described as being plantigrade, with longer hind legs and tailless, being covered with straight greyish hair that "thickened about the head into a Skye terrier's mane", having human-like hands (described as fore feet) and having a roundish head with a projecting forehead and forward-looking eyes that were obscured by lank hair.
In the 1960 film version of the book, the Eloi are depicted as identical to modern humans but small, blond, and blue-eyed. The Morlocks use an air raid siren to lure them into their caves. One of the Eloi is motivated to beat a Morlock to death when it attacks the Time Traveller.
In the 2002 movie adaptation of The Time Machine, the Eloi are depicted as identical to modern humans, with a hunter-gatherer lifestyle and appear to be an ethnic amalgamation of various indigenous races but maintain the English language as an intellectual exercise.