If You have 2 parents, 4 grandparents, 8 great parents, so if you go back 40 generations you’d have a supposed 1 Trillion ancestors, But only 100B humans have ever existed. Explain.
In: Biology
People have shared ancestors. They might not be mating with their close relatives, like shared grandfathers or even great-grandfathers, but if you look far enough back everyone is going to be related.
This seems obvious from a practical standpoint, how are you going to be able to know that a prospective mate shares no ancestors with you *for all time*? There is no way of knowing, so such relationships occur. In fact how far removed one must be to mate varies by culture, with some middle eastern cultures viewing first cousins as ideal mate prospects.
Latest Answers