One of the core conceits of the Howardian Universe of Kull and Conan is that magic and other forms of "Strange Science" have been around forever. The Valusians, a group of serpent-men and the children of Yig, who became known as Set the Serpent God, once ruled the entire world and modified animals and plants to serve their ends. They mapped the stars and developed crazy technology before they pissed off the Gods by not -cloning- or -modifying- an animal, but creating one whole-cloth, usurping the power of the Gods. (Not that the gods were happy with them, anyhow, what with them wiping out their Frog-People neighbors in their world-conquest and using genetic modification to make all the other planetary inhabitants into serpenty things).