The earliest recorded beliefs about heredity were provided by ancient Greeks who observed that animals gave birth to other animals of the same species and that children tended to resemble their parents. They deduced the “particulate theory” from this observation, suggesting that some information from body parts of each parent passed directly into the corresponding body parts of their offspring. Aristotle (384–322 BCE) posited that the father provided a miniature organism and the mother provided the necessary conditions for its growth. He refuted the notion of a simple, direct transfer of body parts from parent to offspring by observing that animals and humans who had been mutilated or lost body parts did not confer these losses to their offspring. Aristotle described a process he called epigenesist, in which the offspring was gradually generated from an undifferentiated mass by the addition of parts [1].