© Peter Watson 2017  The discovery must have come as a great shock. But did it happen overnight, so to speak? Were people immediately convinced? This seems unlikely and in any case they may have grasped the process only incompletely for quite some time. For example, as we shall see later, there did at this time emerge a focus on the penis (recorded in art) but there seems much less evidence – hardly any – that the importance of semen was understood. Humans would have known about semen in their own case, but may not have observed it directly in other species since ejaculation occurred inside the female mammal. What does seem to have occurred is that ancient people grasped that penetration mattered, but not necessarily penetration of the vagina. There is some evidence, which we shall come to, that piercing was thought to be important and to produce new individuals in some way. In other words, there appears to have been a transition time, a cross- over time, when the principle of paternity was grasped without a full understanding of the mechanism of sexual reproduction. Birth had hitherto been a mystery and woman had seemed magical. To early people, the newly discovered role of the father would have seemed equally magical though in a different way. The link between intercourse and birth in dogs need not immediately have led to the idea being transferred to humans, and other animals, but eventually the pennies would have dropped. From what we know, the whole process took about a thousand years, for early humans to have become convinced of the great link. Some rudimentary ‘genetics’ would have been learned, such as the fact that smaller animals (easier to control) tended to have smaller offspring. And that some men fathered more and better (stronger, healthier) offspring. All this would have been exciting for early humans but not as exciting, no doubt, as the changes the new ideas brought about in their own personal lives. For the new discovery must have changed early people’s psychology beyond recognition, and in at least four areas: the concept of God, the concept of the ancestor, the concept of the home, the concept of the individual in his or her family.