Ghost World

We’re all ghosts. We all carry, inside us, people who came before us. — Liam Callanan, The Cloud Atlas

What a wondrous modern world we live in!

Ask Google a question and you can now immediately receive an AI-generated answer, based on a synthesis of multiple authoritative web pages. For example, here’s one that popped into my head the other day for no particular reason: How many generations would one have to go back to get to a common ancestor for all human beings alive today? This is what my laptop spit out in less time than it took me to type this sentence:

You only need to go back about 2,000 to 5,000 years (roughly 80 to 200 generations) to find a point where everyone alive shares the exact same ancestors. At that threshold every person who left descendants is an ancestor to all humans living today.

Researchers like mathematician Joseph T. Chang have proven that as populations mix across geographic regions, the Last Common Ancestor (the most recent person from whom all living people descend) likely lived between 2,000 and 4,000 years ago. If you trace lineage back just a bit further, you hit the Identical Ancestors Point. This means that every single person alive at that time (about 5,000 to 7,000 years ago) is either the direct ancestor of every living human today, or their ancestral line went completely extinct.

Let that settle in. For there is something almost offensively intimate about the idea. And also pretty beautiful.

Not the usual Hallmark-card, kumbaya, Michael row the boat ashore version of intimacy, either, with its soft-focus implication that we’re all connected in some vague spiritual sense. Rather, a kind of statistical intimacy, an intimacy enforced by arithmetic. The sort of intimacy that arrives not with violins but with a spreadsheet.

You begin with what seems like a harmless fact about ancestry: two parents, four grandparents, eight great-grandparents. Then sixteen, thirty-two, sixty-four. The numbers double with the steady confidence of compound interest and, because the human brain is exquisitely bad at exponential growth, everything feels manageable right up until it suddenly doesn’t.

Thirty generations ago — roughly the High Middle Ages — you should have, in theory, over a billion distinct ancestors. I did the math on this but feel free to check my work.

A billion. At which point the math itself begins to look embarrassed. Because there were not a billion people in the relevant population from which your ancestors could have come. There were nowhere near enough people. The arithmetic has run ahead of reality and smashed directly into it.

The only possible resolution is overlap. Your family tree is not a tree. It is a lattice. A web. A vast tangle of lines crossing and reconnecting like airline routes drawn by someone having a nervous breakdown.

The same people appear again and again. The branches fold back on themselves. The ancestors repeat. And then the implications begin arriving in waves.

One of the strangest consequences is that history’s apparently rigid categories — nations, races, tribes, kingdoms, castes, dynasties, bloodlines — start to look less like permanent structures and more like temporary weather patterns. Not illusions exactly. Weather is real. A hurricane can certainly kill you.

But weather is not geology. It is movement within a larger system. Human groups have always imagined themselves as bounded entities, and often fought and died over those boundaries. Yet viewed from the perspective of genealogical time, those boundaries become astonishingly porous.

This is something for the Himmler-Mengele-Lindbergh-Musk-Trump “foreign races are poisoning our inheritance of European blood” crowd to think about. Not that they ever would. That would involve thought rather than blind autolatry, humility rather than hubris.

Listen.

A merchant’s daughter in a Levantine port marries a traveller. A soldier survives a campaign and settles somewhere unexpected. A slave escapes. A refugee crosses a mountain range. A fisherman drifts to the wrong coast. A widow remarries. A child lives. Another child lives. And a hundred generations later, the consequences are everywhere.

History books are full of kings and conquests because kings leave records. What they leave less often is perspective. The actual machinery of ancestry operates at a much lower level. It is made not of empires but of marriages, births, migrations, accidents, seductions, famines survived by inches, diseases escaped by luck. Above all, innumerable moments that appeared utterly insignificant to the people living them.

The Last Common Ancestor — the most recent individual from whom every living person descends — already sounds like a figure from mythology. One imagines a shepherd standing beneath a Mesopotamian sky, or a woman carrying water somewhere in Iron Age India, utterly unaware that every person who will one day build skyscrapers, write symphonies, launch satellites, doomscroll social media or eat gas-station burritos for breakfast will descend from them.

But the truly destabilizing concept is the Identical Ancestors Point. Because beyond that point, the categories change. The question is no longer whether someone is your ancestor. The question is whether they are everyone’s ancestor.

Picture a village five thousand years ago. A real village. Mud walls. Smoke. Dogs. Arguments. Children chasing one another between huts. Maybe a hundred people. Some hopeful, some cruel, some wise, some tedious, some desperately in love, some desperately lonely. Every personality type currently alive was probably represented there in embryonic form.

Now imagine freezing that village in time and drawing a circle around every resident whose descendants persist into the present. They are not just your ancestors. Not just mine. Our ancestors. Every living human’s ancestors.

The village blacksmith. The woman who sold grain. The local gossip. The child with the crooked smile. The person everyone secretly disliked.

If their line survived, it did not survive merely into one nation or ethnicity or continent. It exploded outward through history until it reached literally everyone.

Everyone.

The implication is almost impossible to hold in mind because human cognition evolved for tribes, not billions. We are equipped to understand kinship at the scale of cousins and clans. We are not equipped to understand that, genealogically speaking, every stranger is a cousin in a sense so profound that it renders the word cousin nearly meaningless.

And yet there is another side to this realization, one that feels oddly melancholy.

The Identical Ancestors Point is not merely a story about universal ancestry. It is also a story about extinction. For every ancestral line that survives, countless others vanish. Entire branches disappear without fanfare.

A family has one child instead of three. A village dies during a plague. A lineage reaches a daughter who never has children. A thousand years pass. The line ends. No monument marks the occasion. No cosmic alarm sounds. The genetic and genealogical future simply flows around the missing branch like water around a stone.

The overwhelming majority of people who have ever lived are remembered by no one. Most did not leave books, monuments, inventions or names. Many left nothing except descendants. And even those descendants eventually become absorbed into the immense convergence of ancestry until individual lines blur into a shared human inheritance.

This creates a strange inversion of how we normally think about significance. We tend to imagine historical importance flowing downward from famous people. Great leaders, conquerors, inventors. Yet ancestry flows upward from ordinary people. The further back you go, the more history belongs to the anonymous.

Civilization itself begins to look like a giant machine for converting individuality into universality. The woman weaving baskets in 3000 BCE is gone. Her language may be gone. Her culture may be gone. Her village may be buried beneath layers of sediment. But if her descendants persisted, then some microscopic piece of her story sits inside everyone alive. You. Me. Everyone.

Not metaphorically.

Literally.

Maybe this is why the idea feels so unsettling. Modern life trains us to think in terms of separation. Separate nations. Separate identities. Separate interests. Separate destinies. We experience ourselves as discrete units moving through a world of other discrete units.

The mathematics of ancestry proposes something far stranger.

It suggests that beneath all visible divisions exists a hidden architecture of relatedness so dense that individuality itself becomes difficult to isolate. Every face contains echoes of migrations, marriages, betrayals, survivals and improbable encounters stretching backward through thousands of years. Every person is a crossroads. Every crowd is a family reunion so large that nobody recognizes anyone.

And somewhere beyond the reach of memory, beyond written history, beyond myth itself, there existed a moment when the distinction between “your ancestors” and “my ancestors” and “everyone’s ancestors” dissolved completely. As someone once said, I am he as you are he as you are me and we are all together.

Not spiritually. Not poetically. Mathematically.

Well, OK. Poetically as well.

Indonesian philosopher Toba Beta put it this way: “You are the fairy tale told by your ancestors.”