Advanced extraterrestrial civilizations manipulated extant species on Earth. Erich von Däniken postulates that these were created to survive hostile off-world conditions. Ancient tales are fraught with strange mixed creatures such as the sphinx, minotaurs, centaurs and others which terrified burgeoning human civilizations. With our modern understanding of genetics, we know that the pairing of two distinct species to yield such results would not be possible. Perhaps the only plausible solution, if we accept that such creatures were real, is that they were the result of extraterrestrial genetic manipulation.