As this blog site is pretty much dedicated to Apocalypse, and we have an interest here in human population and survival in general, I found myself thinking about the trajectory of the human race over time. And that got me thinking about how many relatives I have… or not, and how many progenitors came before me to make my existence possible. Of course, that also led to some random thoughts, one being how likely it is that I am more racially diverse than my skin, hair, and eye color might make me assume.
I mean, I’m pretty white. Blonde and blue-eyed, too. So many people might expect me to be Scandinavian. My parents claimed the Schleswig Holstein area to be their homeland… my father from the German side, and my mother from the Danish side. Far northern Germany, the base of the Danish peninsula. And they would be correct in the short term. I’m pretty sure. Well, kinda. Pretty much. Maybe…
There is a family story on my maternal side, though, an explanation for my mother’s dark hair and deeply dark eyes. It is said that there is gypsy blood running through the family veins.
But there is a possible twist, recently discovered, that sheds some doubt.
My sister’s son, my nephew, just got the results of one of the DNA tests that are recently so popular. It says that he has an ancestor from Mali. That isn’t where gypsies originated, from India. Mali is central Africa.
The sleuth in me has been cogitating over the variables ever since I was told. Of course, it is possible my nephew’s Mali genes came from his father… but what other explanation is there for my mother’s coloring? I have an old picture of her as young woman, and unless my bias is playing tricks on me, she definitely looks like she might be of African heritage. I remember my maternal grandfather, blonde and blue-eyed, and my grandmother, unusually dark. And I have a memory of her mother, my great-grandmother… frail and elderly, brushing her white hair and speaking to me in Danish as her blue eyes twinkled.
So my great-grandfather must have been dark. Where else would my mother’s black hair and eyes come from?
Which leads me back to the numbers. I have two parents, just like you. I have four grandparents, and eight great-grandparents, just like you, too. The numbers stay the same for all of us. Only the spacing of the generations varies, the length of each. The average length of time between generations in our modern society is about twenty-five years. That means four generations per century. Of course, we all know that ancient peoples, even a hundred years ago, procreated at a much earlier age. A century ago the average generational turn-over was twenty years.
So that got me thinking. How many ancestors do I have? How many… say… in forty generations? At an average of twenty-five years, to be conservative, how many ancestors would my grandkids have in the year 1000 (roughly, starting at the year 2000 for easy understanding)?
I’m reminded of that old story, the one where a man says he will perform a task for a king every day for a month, paid in a single grain of rice the first day, but doubled each day thereafter. By the end of the month, he owns the kingdom.
And so it goes…
In my assumed scenario, my mother’s dark-complected ancestor would be my great, great, great grandparent. Five generations, and thirty-two progenitors. To my grandchildren, seven generations and a hundred twenty-eight progenitors.
Starting and working backward from the year 2000, ten generations in the past, someone would have over a thousand ancestors. Twenty generations in the past? Over a million ancestors. Thirty? Over a billion. And forty generations in the past? How many could there be, really? A trillion, thirty-five billion, five hundred eleven million, six hundred twenty-seven thousand, seven hundred and seventy-six.
Somewhere in that line of descent, we passed the number of humans that ever lived on Earth.
Wrap your head around THAT. I’ll say it again, another way. Somewhere before we get to the fortieth generation, probably somewhere around the thirty-fifth, we passed the number of possible progenitors that every individual on earth has… using every possible individual ever born. EVER born. All the way back to the first human.
Let’s put a little perspective on this.
If you’ve looked at the graph, you’ll also see that population growth stayed fairly steady until the advent of well thought out medical intervention, finally starting to curve up in about the year 1000. Steadily improving medicine really made the population take off in the early 1800s, and antibiotics in the early 1900s made the world population explosion possible.
What does all this mean in the context of numbers concerning progenitors and generations? Well, it means we are all much more closely related than we modern clueless human beings realize.
After all, those generations on the far side of the year 1000 had the same numbers. They had as many progenitors in the thousand years that preceded them as we have in the last thousand years.
How can this be, if there were so few people?
Well, there was a lot more inbreeding. Our ancestors were far less genetically diverse than the present population. Some of our ancestors traveled to the next village to find a mate, but there were a lot of first cousins with identical progenitors fooling around. Lends a whole different perspective to the phrase, “Kissin’ cousins,” doesn’t it?
But this doesn’t mean genetics weren’t being mixed in these prehistoric cultures. There is some evidence of seafaring watercraft as far back as forty-five thousand years ago. And remember, this wasn’t some guy in a boat landing once in present-day New York to spread his seed among millions. This was likely a trader with a route, landing in small, sparsely populated villages where his genetic contribution made an impact, and sometimes spending weeks, months or even years among strangers.
Natural barriers concentrated genetic characteristics, but enough genetic diversity occurred to keep humans viable.
This limited contact all changed several centuries ago. Large ocean-going craft paralleled civilization and the construction of larger cities. As population centers grew on land, sea transport carried larger crews.
We all know what the first profession is claimed to be, don’t we? This is well before birth control and legal abortion, although they had their ways. Genetic diversity was rampant around the seaports of the last five thousand years.
But this is the crust of the biscuit. There are no pure strains of human lineage. We are all related. If you extrapolate from the numbers, understanding how closely genetic strains are related even today, we are all practically cousins. And as for racial “purity”? ROTFLMAO…
And remember, we started out using conservative numbers. The actual figures are likely much higher, even twice or more as much.
Now, I wonder where my Neanderthal DNA fits into all of this?