When Time Became History - The Human Era
Imagine someone coming into your kitchen and taking a few tools, a pan, and your garbage. Then they bury everything in the woods. 12,000 years later, an archaeologist is trying to figure out who you were, what was important to you, what video games you played, what you believed in, and what informed your decisions because you happened to live during a remarkable time in human history—the planetary revolution, when humanity transitioned, becoming a multiplanet species.
In that time, our numbers would explode by orders of magnitude; our technology and standard of living would improve to levels previously thought impossible, and our self-conception would change forever. And all the future archaeologist has to learn about is your junk in the woods. While we can only hope that this will be someone's problem in 12,000 years, we have the same problem today. We're trying to reconstruct a revolution that took place 12,000 years ago. Today, only shadows remain of the people who experienced our distant past as their present.
What remains from our past? We can look at our present in crispy 4K, in color and sound. Three generations ago, the world was just black and white. One more generation, and we see the world through blurred photographs. Further back, paintings and texts become our main way of experiencing the past. A mere 20 generations before us, every written word had to be copied by hand, and reports became more scarce and less reliable. The first historian lived a mere 100 generations ago; before him, there were only epics and legends and dead kings bragging on pieces of stone.
250 generations ago, there are only fragments left in the ground and images stripped of their original meaning. Eventually, humanity becomes basically invisible. Still, we do know some things about our ancestors. Let's try to tell their story and what it means for us today—the greatest transition in human history. For some 2 million years, or roughly 880,000 generations, the life of our ancestors was basically the same. It was around 20,000 years, or 800 generations ago, that the behaviorally modern humans began a process that would change our lifestyle forever.
At first, gradually for some of us, then faster for more of us, and then suddenly for almost all of us, back then, there were about 1 million modern humans on Earth. Most other human species had died out, probably with a little help from us. Our ancestors' biology had given them the necessary tools: a general intelligence to understand things, a social intelligence to understand each other, and language to express abstract ideas and create new concepts.
These were people just like you. They suffered and experienced joy, were bored, cried, and laughed. They lived in communities of a few dozen people. They controlled fire and had tools made from wood, stone, and bone. They told stories, mourned their dead, and created art. They traded with other tribes, from obsidian to shellfish. Some hunted big game and were very mobile; others relied more on plants they collected, and others mostly stayed in one area with an abundance of seafood. This was the common state of humanity for most of our history until a slow transition, step by step, turned into a revolution.
Step by step, the first solid evidence for this stands from the Jordan Valley, where our ancestors collected wild wheat more than 20,000 years ago. They noticed that seeds in the ground made more plants the next year if they put good ones in one place. The next year, they had more of the good ones. This was a great supplement to hunting and gathering; you could prepare some crops, return next year, build a temporary settlement, and have a secure food supply.
Our ancestors used these bonus crops to bake the first bread and brew the first beer. With every generation, they gathered deeper knowledge about the plants and animals around them and how to manipulate them to their advantage. But there was a lot to learn. Very slowly, from generation to generation, pockets of knowledge expanded and were passed along to be expanded again. This early agriculture started to drastically reduce the space our ancestors needed to feed one individual, which made it possible to stay in one place longer.
Around 12,000 years ago, these little pieces of progress had reached a critical mass. Most of the calories we consume today stem from about 15 different founder crops that humans began to domesticate in earnest in the next few thousand years. What we call the Agricultural Revolution was not a thing that began suddenly one day; it was a slow process driven by small groups over many generations. Eventually, gradual change gave rise to a new era—the human era.
During the next few thousand years, progress would speed up and turn hunter-gatherers into farmers who lived in villages, towns, and then cities. When farmers moved into new areas, they replaced the nomadic tribes or turned them into farmers too. This was neither easy nor painless. In the early days, people had a diverse diet made up of up to 250 different plants and animals. For some of the groups transitioning to agriculture, the variation in their diets declined drastically, and some even seemed to have been undernourished. Living close together, with animals created a breeding ground for disease. Virtually every infectious disease caused by microorganisms that have adapted to humans arose in the last 10,000 years: chera, smallpox, measles, influenza, chickenpox, and malaria.
Mortality, especially among children, rose drastically. Still, our numbers grew because living in the same place enabled women to bear far more children than before. For a farmer, more kids mean more hands to work the fields. Even with more people dying younger, villages and towns grew. The number of humans on Earth exploded. About 100 generations after the beginning of the human era, there were already 4 million of us. This increased the need for food and forced people to come up with ever more efficient ways of producing calories, solidifying our new lifestyle. Going back to hunting and gathering would have just meant death by starvation for most.
One question remains unanswered: why? Why would people exchange the freedom of living off nature with a huge variety in food for the grind of agriculture and often more limited diets? Nobody knows for sure. Climate change seems to have made the transition possible, and some scientists argue that it was caused by external factors like undernourishment or overpopulation—both highly contested today. The most widely accepted idea is that it was a deliberate choice made by countless communities around the globe.
Maybe it's also connected with what makes us human—the ability to come together, develop shared identities, and exchange stories and knowledge. Some archaeologists think the groups of hunter-gatherers traveled long and far to celebrate, to hold feasts and rituals. They would have used these occasions to talk about their version of innovation, better hunting and tool-making techniques, how to catch and breed animals, and which plants could be collected and multiplied.
Maybe they even exchanged seeds. It's not unlikely that these gatherings were the catalyst that spread the knowledge of agriculture through the many isolated groups of humanity, ultimately ending a lifestyle that was common to our species for thousands of generations. So, by being able to come together, celebrate, share, and learn from one another, these humans might have taken the steps that led to our modern world, and we have much to be grateful for.
We are still the same humans today, even if it often doesn't feel that way. Maybe it's time to come together to share what we know and celebrate our existence once again. To begin another peaceful transition—the planetary revolution that will change everything once more. So, hopefully, in another 12,000 years, our descendants will look back on us today with gratitude for the amazing world they are able to inhabit.