Some Thoughts on Family Trees, Ancestry and Logical Conclusions
Some things to talk about... Let’s start with a discussion about ancestors, or family trees. So, if you start by looking at your own family tree, and drawing out all of your relatives/ancestors, you quickly get overwhelmed with the size and scope of the non-immediate family members. So, if you think about simplifying, (which is a good thing to think about anyway), then you can start by just looking at your direct heritage, like your mother and father. Here’s a fact; everyone has a mother. Another fact; everyone has a father. Here's a picture of your family tree at its best! Hard to argue with those facts. It's for you, or any of the other 6.7 billion of us on the planet right now. So, if you just take the fact that everyone has a mother and a father (by serious definition), then start going back further in time to the next few generations... it looks like this: Which means that each generation back, just multiply by two and you get the total number of your direct ancestors in that generation, right? If you just keep multiplying by two... it goes exponential and it takes 34 times (generations) before the total number of your direct ancestors exceeds the Current total population of the Earth (6.7 billion, remember?) (34 time gets you to 8,589,934,592 people). Hmmmmm...this is interesting. So, there must be something flawed with the logic. If you look at a plot of this, starting with you, and going backward in time...it looks like this;
This is making the gross assumption that the average age of when the "Mothers" give birth is 20 years old. I should stop at this point and note that so far, I'm not talking about anything but some basic facts. No discussion of biology, genetics, religion, mathematics, planetary science or flat thumbnails. (I just threw in that last part). So if you go back 34 generations, with mothers giving birth on average at the age of 20, you get back to the year 1350 AD, and a total number of ancestors of 8,589,934,592. Well, this can't be true. Your total "direct" ancestry can't exceed the number of people on earth at the current time. If fact the estimated total population of the earth in 1350 is roughly 443,000,000.
Check the Wikipedia source here:
It's pretty hard to argue with this fact. Not that you or I would want to get into any argument... So, there are two "facts." One is the total population of the earth and the other is the total ancestors "limit." I'll call this a limit since if there was a world of unlimited population, there would be less and less "interdependency" in the ancestry. Or, each generation's "Mothers and Fathers" would not be related to each other.
Combining the two plots.... So, coming from the present time and working backward with the total upper (unrealistic) limit of your ancestors, and coming from past time and looking at the total population of the earth bounds the two limits. Bounds the two limits of what? What are these two facts telling us?
There is obviously some level of inter-dependency on direct lineage. If you go back to whenever the definition of "humans" started (without getting into ethics, genetics, religion, biology, gene pools, etc.) the earliest population would have had some inter-family/clan relationships. So your (and my) ancestors would have been a "small" number.
Starting with you (or me) our ancestors start with our mother and father, two, and expand from there. The Total number of your ancestors will be increasing as you go back in time or generations. This is acknowledging that there is some level of interdependence of ancestral heritage. So, the total number of ancestors must be some number under the two limiting curves, like;
So, what I find interesting, is that there is a maximum number of ancestors. Just from the two basic facts of:
- The World's Total Population
- The Limit of Total Independent Ancestors
From the basic nature of the curve, it seems that your, my and everyone's maximum number of ancestors peaks out around the period of 1300 - 1500 AD. That's when your total number of ancestors must start decreasing to get to two; your mother and father.
So, what in the world was going on around 1300 - 1500 AD? Literally. This period of time seems very interesting in all parts of the world; Europe, Asia, North America, South America...Hmmmm.
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