So says this article about the Brotherhood of Man:
With the help of a statistician, a computer scientist and a supercomputer, Olson has calculated just how interconnected the human family tree is. You would have to go back in time only 2,000 to 5,000 years – and probably on the low side of that range – to find somebody who could count every person alive today as a descendant.
Unless that person didn’t reproduce. But it is a fascinating facet of human reproduction that it takes 2 people to make a new human. It’s kinda funny to think about – it’s a magical process, creating a human from nothing, springing forth new life in the womb of a woman.
Turn that idea around and you realize that we have a lot of relatives if you go back far enough:
It also means that all of us have ancestors of every color and creed. Every Palestinian suicide bomber has Jews in his past. Every Sunni Muslim in Iraq is descended from at least one Shiite. And every Klansman’s family has African roots.
How can this be?
It’s simple math. Every person has two parents, four grandparents and eight great-grandparents. Keep doubling back through the generations – 16, 32, 64, 128 – and within a few hundred years you have thousands of ancestors.
It’s nothing more than exponential growth combined with the facts of life. By the 15th century you’ve got a million ancestors. By the 13th you’ve got a billion. Sometime around the 9th century – just 40 generations ago – the number tops a trillion.
Of course, that 1 trillion figure include a lot of “overlap.” We’re all interrelated, which is a beautiful and scary thing.
I don’t think the math is 100% accurate simply because human history is more complicated than that. And there were efforts by many different peoples to ensure racial (or religious) purity by rigidly controlling who their sons and daughters could marry.
In fact, some of those pure lines could still be largely untainted even today. Who knows if that’s the case, but I’m not sure we have a common human ancestor unless you go all the way back to Abraham.
It means when Muslims, Jews or Christians claim to be children of Abraham, they are all bound to be right.
“No matter the languages we speak or the color of our skin, we share ancestors who planted rice on the banks of the Yangtze, who first domesticated horses on the steppes of the Ukraine, who hunted giant sloths in the forests of North and South America, and who labored to build the Great Pyramid of Khufu,” Olson and his colleagues wrote in the journal Nature.
Ideas like this tend to give the stories of Abraham a little more credence. Who knows, maybe we are all related to one guy. What a stud.