Statistical theory versus biblical history

 The familiar story of Adam and Eve - statistically allows for the "birth" of a single human tribe, which one day became 8 billion modern people. But the Mathematical Junta suggested calculating "the other way around" and got the result that if we assume that there are two people in the world who do not have common ancestors in the 40th generation, it turns out that they were born then by 2 trillion 198 billion ancestors. It is impossible to assume the simultaneous existence of so many people. We are talking about a period of history of only one or two millennia. Therefore, the conclusion is - we cannot consider history as the existence of people like us. I understand that such a statistical theory is unusual, but try to prove the opposite!