This is something I find very cool and fascinating, but may bore other people silly if they can even work up enough interest to care that much.
Starting with yourself - and only biology and genetics matter in this exercise - go back one generation. There will be two parents, one mother and one father. Go back two generations, and there will be four grandparents, two grandmothers and two grandfathers. Another generation will bring eight sets of genes.
The doubling up happens every generation. A mere ten generations gives you 1024 great (x9) grandparents. Twenty generations brings us to 1,048,576. Thirty will be 1,073,741,824. And we'll end at forty, which will be 1,099,511,627,776 great (x39) grandparents, more people than have ever existed throughout history.
Of course this means that certain sets of couplings will duplicate many, many times - more and more as you go back and there were fewer people living.
Remembering that people use to have children at much younger ages than is common today, if we assign an average age of 20 to each generations, 40 generations is only approximately 800 years. Even if you want to raise that average age, it's still a remarkably short time in human history. Go back a thousand years, five thousand, ten thousand, the numbers will both be mindboggling large yet increasingly small.
One thing science agrees with the major religions on is that we have a common ancestor. Judeo-Christian-Islamic mythology starts with Adam and Eve (or even Noah, but his sons all had wives who had parents, so we need to go back to Eden for this to work, and unlike the Torah-Bible-Quran, I'm not about to ignore mothers when it comes to begatting). Depending on what sort of time frame you accept if you're a muddle-headed young earth creationist, if you go back six to ten thousand years, we go from one set of parents to one set of ultimate grandparents. Maybe. We'll come back to this later.
Of course in reality the world is not only much older than that, so is humanity. However, this is where things get muddier for the exercise. Do we only count human ancestors? I wouldn't. Why should we discount our non-human ancestors, without whom we wouldn't exist? We shouldn't!
Therefore we get to back even further. Millions of years further. When we do the doubling now, the numbers are astronomical and very hard to comprehend. Other numbers are changing too. You think going back far enough we'd end with one pair of ancestors. You'd be wrong. We go back further than that. We have one set of birth parents, two people. But the number at the start is even less than that. Despite all the doubling that has gone on, once we go back far enough it gets down to one. One single cell organism. We can go even further to proteins and stuff, but to me, one ancestor is good enough. From this all life as we know it sprang. Yes, we are closely related to chimpanzees and gorillas, but we are also distantly related to goldfish and tigers. And pigs too, but damn it, I'm still going to enjoy a good pork chop.
I mentioned getting back to Genesis later. If you think about it, even then we go back down to one. Adam. The patriarchal nonsense contained in that book says Adam was created from dust, but Eve was made from one of Adam's ribs, essentially making her his clone. Unfortunately you don't get the really great related to all life part of this if you accept Genesis as literal truth.
That said, one thing we can all agree on (except for the most racist fantasist) is that if you go back far enough, we are all related. So, cousins, please be nice to each other. We're the only family in this universe we've got.Labels: ancestry, generations, relationship to each other
posted
by Tabby at 11/15/2008 09:44:00 p.m.
