Your 600 millionth great-grandfather

I’ve been studying the family tree for some time now, and given it quite a lot of thought. For you to be born today from 12 previous generations, 4094 ancestors over the last 400 years needed to have had intimate relations.

Think for a moment; How many struggles? How many battles? How much sadness? How much happiness? How much tragedy? How many victories? How much joy? How many love stories? How much romance? How much melancholy? How much hostility or hatred? How many expressions of hope for the future? Or confidence in times to come? How much doubt? How much disappointment? How much was left undisclosed? How many secrets? How many clandestine journeys? How many furtive diaries or disguised journals just decayed without ever being read? How much distress? How much satisfaction? – did your ancestors have to undergo for you to exist in this present moment? And how spiritually diverse would be their thoughts?    

But I’m not just looking at 12 previous generations, I’m going way back. If you took a picture of yourself, and then placed a picture of your dad on top of it.  Then found a picture of your Grandad, and placed it on top of that, and if you did the same with his father, your great-great-grandfather, on top of these, a character who you can only picture as a sort of shadowy figure, and if you just carried on piling the pictures on top of each other, going back through more and more and more great-great-greats, you could keep on doing this even before photography was invented. After all, how many ‘greats’ would you need for a decent experiment?

Well, I don’t expect you to be able to answer that because I haven’t yet said what the experiment is yet. But let’s pick a number out of mid-air, say, a mere 185 billion or so will do nicely.

Mere?

It isn’t easy to imagine a pile of 185 billion pictures. How high would it be? Well, if each picture was printed as a normal picture postcard, 185 billion pictures would form a tower about 220,000 feet high: that’s more than 180 skyscrapers standing on top of each other. Too tall to climb, even if it didn’t fall over (which it would). So, let’s tip it safely on its side, and pack the pictures along the length of a single bookshelf. How long is the bookshelf? About forty miles. The near end of the bookshelf has the picture of you. The far end has a picture of your 185 billionth great-grandfather.

What did he look like? An old man with wispy hair and white side whiskers? A caveman in a dinosaur skin? Forget it. We don’t know exactly what he looked like, but fossils give the scientific community a pretty good idea. Believe it or not, your 185 billionth great-grandfather was ….. a fish.

So was your 185 billionth great-grandmother, which is just as well or they couldn’t have mated with each other, and you wouldn’t be here at all.

So, when people say we descended from the apes, we have to ask who the apes are descended from, right?

Let’s now walk along our forty-mile bookshelf, pulling pictures off it one by one to have a look at them. Every picture shows a creature belonging to the same species as the picture on either side of it. Everyone looks just like its neighbours in the line, or at least as much alike as any man looks like his father and his son, as any woman looks like her mother and daughter. Yet if we walk steadily from one end of the bookshelf to the other, we’ll see a human at one end and a fish at the other. And lots of other interesting great-great-grandparents in-between, which include some animals that look like apes, others that look like monkeys and so on. Each one is like its neighbours in the line, yet if we pick any two pictures far apart in the line, they are very different, and if we follow the line from humans back far enough, we come to a fish. And from there, if we turned around to go forwards in time, it’s what happened when our fish ancestor had a fishy child, who had a fishy child, who had a fishy child ..… who, 185 billion (gradually less fishy) generations later, turned out to be you.

So it was all very gradual – so gradual that you wouldn’t notice any change as you walked back a thousand years, or even ten thousand years, which would bring you to somewhere around your 400th great-grandfather. Or rather, you’d notice lots of little changes all the way along, because nobody looks exactly like their father, but you wouldn’t notice any general trend. Ten thousand years back from modern humans is not long enough to show a trend.

A portrait of our ancestors of ten thousand years ago would be no different from modern people, if we set aside superficial differences in dress and hair and whisker style. He would be no more different from us than modern people are different from other modern people. How about a hundred thousand years, where we might find your 4000th great-grandfather? Well, now, maybe there would be a just noticeable change. Perhaps a slight thickening of the skull, especially under the eyebrows. But it would still only be slight.

Now let’s push a bit further back in time. If you walked the first million years along the shelf, the picture of your 50,000th great-grandfather would be different enough to count as a different species, the one they call Homo erectus. We today, as you know, are Homo sapiens. Homo erectus and Homo sapiens probably wouldn’t have wanted to mate with each other, or, even if they did on a really bad Saturday night after 12 pints of stella and a kebab, the baby would probably not have survived or been able to have babies of its own.

We’re Homo sapiens and our 50,000th great-grandfather was Homo erectus. But there never was a Homo erectus who suddenly gave birth to a Homo sapiens baby. So, when you ask, ‘Who was the first person in my family tree, and when did they live?’ there’s no precise answer. It’s all kind of fuzzy.

At some point, probably less than a million years ago but more than a hundred thousand years ago, our ancestors were sufficiently different from us that a modern person wouldn’t have been able to breed with them even if they had met.

But looking for a starting point for your family tree, you’d find yourself stumped because to go back further, say, to your 185 million great-grandfathers would, no doubt, make an interesting read, but the research would prove rather taxing. No records were kept of that particular fish, or what happened to his or her offspring, or where in the world he lived. Not even oral tradition survived from one generation to another. At least, not that we know of. So, as you can see, you’d be kind of flummoxed as to where to start.

And then, who was that fish’s dad? Who or what were his ancestors? Well, we’re probably looking at sharks because they evolved about 450 million years ago, which means they were around at least 90 million years before trees and 190 million years before dinosaurs. And during that time, they survived four of five global mass extinctions.

Respect!

Scientists seem to agree that sharks descended from small leaf-shaped fish that had no eyes, fins or bones, and these themselves evolved from some kind of single celled organisms, which, truth be told, would have been your 500 millionth great-grandfather.

Mate, you’re not even descended from a leaf or a rotting piece of wood. More than likely, your 600 millionth great-grandfather ‘existed’ as part of the heavier layers of foul, decomposing matter in a handful of waterlogged dirt.

Basically, your 600 millionth great-grandfather was nothing than sludge!