Neanderthals were a relatively modern species of man-like creatures, first appearing on earth about 350,000 years ago and becoming extinct only 30,000 years ago. Neanderthal man was so named for the Neander valley in Germany where the first remains of this species were discovered in 1829, just a few years before Darwin's publication of The Origin of Species. It is thought that their existence overlapped that of modern man, Homo Sapiens, by about 15,000 years on the European continent, leading to much fantastic speculation, especially in modern fiction, that the two species interacted and even interbred with each other. In reality, Neanderthal Man was replaced by extinction by modern man as he migrated from Africa to Europe.
Whatever the interaction between the two species, gazing into a Neanderthal's eyes must have been a chilling look back into some primordial mirror for modern man. There was the contemporary version of the species looking at a previous version of himself, unrefined, relatively unskilled and less sexually differentiated in outward appearance than modern men and women.