The Hominidae (/hɒˈmɪnᵻdiː/), also known as great apes or hominids, are a taxonomic family of primates that includes seven extant species in four genera: Pongo, the Bornean and Sumatran orangutan; Gorilla, the eastern and western gorilla; Pan, the common chimpanzee and bonobo; and Homo, the human.

Several revisions in classifying the great apes have caused the use of the term "hominid" to vary over time. Its original meaning referred only to humans (Homo) and their closest relatives. That restrictive meaning has now been largely assumed by the term "hominin", which comprises all members of the human clade after the split from the chimpanzees (Pan). (See below, for a fuller discussion of related and very similar terms, at Terminology.) The current, 21st century, meaning of "hominid" refers to all the great apes including humans. Usage still varies, however, and some scientists and laypersons still use "hominid" in the original restrictive sense; the scholarly literature generally shows the traditional usage until around the turn of the 21st century.

The Neanderthal Parallax is a trilogy of novels by Robert J. Sawyer published by Tor. It depicts the effects of the opening of a connection between two versions of Earth in different parallel universes: the world familiar to the reader, and another where Neanderthals became the dominant intelligent hominid. The societal, spiritual and technological differences between the two worlds form the focus of the story.

The trilogy's volumes are titled Hominids (published 2002), Humans (2003), and Hybrids (2003). Hominids first appeared as a serial in Analog Science Fiction, won the 2003 Hugo Award for Best Novel, and was nominated for the John W. Campbell Award the same year;Humans was a 2004 Hugo Award finalist.

The initial contact between the two worlds takes place at the Sudbury Neutrino Observatory in Sudbury, Ontario, which is also the location of a scientific research facility in the Neanderthal world.

Terminology

As the books unfold, both species agree to use the Neanderthal terms to distinguish between them; thus a gliksin is a member of Homo sapiens, and a barast is of Homo neanderthalensis. Human refers to either species.