ACT I
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Our story has reached the evolution of farming.
People have coevolved with plants. We plant seeds and help them grow, and we get food from the plants. They need us and we need them.
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In the Middle East, China, Central America, the Andes Mountains, and the Mississippi River valley, people took that all the way to planting crops and tending them continuously. People might’ve also done that on the Island of New Guinea, in northeastern Africa, inland west Africa, and coastal west Africa. In many other parts of the world people found other ways to manage their environments to increase its food production.
Not counting the evolution of our species in the first place, the development of farming was the most important thing people have ever done. We fundamentally changed our environment, and it’s led to our changing the global environment.
The development of farming led to the development of writing. But the first people to develop writing lived 5,000 years after the development of farming. That means written history doesn’t tell us anything about the development of farming.
But environmental science tells us a lot about about the most important event in human history.
ACT II
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The first place in the world people started farming full time was a place called Mesopotamia. That’s the land between the Tigris and Euphrates Rivers, in the Middle East.
Most of Mesopotamia is now part of Iraq. Unfortunately a lot of important archeological discoveries got destroyed in the war.
The second place in the world people started farming full time was in China, between the Yellow and Yangtze Rivers.
Mesopotamia and central China had the two most favorable environments in the world for farming at the time. They had the most productive combinations of land and plants. Even though farming might’ve been developed in seven other places, it was more labor intensive in all of them.
Eventually Mesopotamian agriculture became the fuel for Europeans’ colonization of almost everything in the world except for China.
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Once people start farming, it’s fairly easy to domesticate more local plants. It’s also easy to bring in plants from other places to grow. It’s also easy to plant the original crops in nearby land that has similar growing conditions.
Now look at the world map. Look at the Middle East, China, and the Americas. North and South America are longest north to south, and fairly narrow east to west. Asia, Europe, and North Africa, on the other hand, is the biggest landmass in the world, and it’s longest east to west.
Crops travel much more easily east and west than they do north or south. Because when they go east or west they get the same cycles of sunlight. That also means that for people who plant crops, the easiest farmland to expand into, and the most valuable land to conquer, is east or west, not north or south. When they move north or south they have to breed new plants for the sunlight cycles there, but they don’t have to do that when they move east or west.
The approximate latitude of Mesopotamia reaches from the coast of Portugal to the coast of China. That’s over 8,000 miles, or a third of the Earth’s circumference. That meant the Mesopotamian plants could grow in many of those places, and the seeds from many of those places could grow in Mesopotamia. China got part of that benefit too, but it was at one end of that stretch of land.
The agriculture in the Americas couldn’t travel nearly that far east or west.
The Maya, in southern Mexico and northern Central America, lived in one of the narrowest parts of the Americas.
For the Inca, the Andes are a mountain range that runs north and south. To the west was the coast, and to the east was the Amazon rain forest. Even though the sunlight cycles were the same there, the environments weren’t.
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Corn was domesticated by the Maya about 9,000 years ago. It spread to the Incan Empire and the Mississippi River civilization. The Wampanoag people fed corn to the Pilgrims in Massachusetts at the first Thanksgiving in 1621. By then people were growing it as far south at Chile.
We think of tomatoes as a staple of Italian food, and potatoes as one of the main crops of Ireland. But that only started after 1492. They were both domesticated by the Inca.
Crops can travel north and south, but not as easily.
The Isthmus of Panama was a barrier between the Maya and Inca. It’s only 40 miles wide, and it was covered in dense jungle. Neither empire tried to expand into it, because doing that would depend on them breeding plants that could grow in the environment on a very small piece of land that would’ve been very hard to farm. Their empires were only 700 miles apart, but there’s no evidence that they had direct contact with each other. Or even knew about each other.
700 miles is less than the distance between England and Spain. Or less than the length of California.
The Incan and Mayan areas were connected by trade networks. They each grew some of the plants the other domesticated. But their connections were either by boat or through that narrow strip of jungle.
Inventions from Mesopotamia spread all the way to Ireland, 3,000 miles away, within a few thousand years. The fact that some similar inventions didn’t get from the Maya to the Inca, or vice versa, in a similar amount of time, even though they were a quarter of the distance apart, shows us how much of a barrier the Isthmus of Panama was.
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Africa had a similar situation to the Americas.
Africa is the only continent that the equator runs through the middle of. The north coast of Africa and the south coast of Africa have similar growing conditions because they’re about the same distance from the equator.
Equatorial Africa is a dense jungle. Agriculture might’ve been developed independently in three separate places in North Africa, all of them at least 5,000 years ago. But back then nobody had maps of any of the continents. For agriculture to travel from the north to the south at that time, people would’ve had to clear jungle to turn into farmland. Then they would’ve had to breed plants to grow all the way down to the equator.
Nobody ever felt like going to that much trouble, so it didn’t happen. Farming was brought to the south coast of Africa by the Dutch.
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The agriculture that originated on New Guinea had obstacles of its own. That’s the only center of agriculture that was on an island. That meant it had the fewest local plants available of any center of agriculture. Even though people figured out how to domesticate plants and how to produce more food by farming than they could by hunting and gathering, it was harder for them to produce well balanced diets than it was for the people of any other center of agriculture in the world.
That meant the least population growth, which meant the fewest people spreading out looking for more places to farm. It also meant the least land available to farm. Even though there are many other islands around New Guinea, all that land is separated by ocean where no one can farm.
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Farming in China spread quickly along the rivers.
The Yangtze River is the third largest in the world, and the Yellow River is sixth. The Mississippi River is the fourth largest in the world. The agricultural center in northeastern Africa had the Nile River nearby, which is the second largest in the world.
But the Yangtze and Yellow Rivers run east and west, while the Nile and the Mississippi Rivers run north and south.
ACT III
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Separate from, but related to, the domestication of plants is the domestication of animals. People all over the world, some of whom never domesticated plants, domesticated various animals.
First was the dog, which was domesticated from wolves somewhere in Europe or Asia at least 20,000 years ago. But all the other animals that people domesticated began around the times people domesticated plants.
People used animals for food, labor, and other purposes, from dogs to cats to rodents to birds to silkworms.
But large mammals were the most valuable ones. They produced a lot of meat, milk, leather, wool, and fertilizer. They could be ridden, or used to carry cargo. They could also be used to pull plows, carts, wagons, sleds, and chariots.
There were large mammals all over the world. People domesticated 14 species of them in all.
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Today Africa has the most exciting animals, because they’re so big, or so ferocious, or they run so fast. That’s because they evolved on the same continent as humans. Domesticating animals means breeding animals for qualities that make them more useful to humans.
To domesticate animals first you have to tame some wild animals. To tame wild animals you have to get close to them without them running away or attacking you. But if you can get close to an animal without it running away or attacking you, that also makes it easy for you to kill the animal and eat it.
Killing animals and eating them takes a lot less brainpower than taming and domesticating them. Carnivores have been eating other animals for as long as animals have existed.
In Africa, unlike any other continent, our ancestors hunted animals for 7 million years while their brainpower was evolving. African animals being big, ferocious, or fast, are all different ways of them being hard to kill with spears. Because all the ones that were easy to kill with spears got eaten a million years ago. The one species that survived long enough in a form that could be domesticated was the donkey, in northeastern Africa, which evolved from horses that migrated in from the Middle East more recently.
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When people reached Australia and the Americas they had a similar situation. The people had highly developed hunting skills, and the animals there had no natural fear of humans. There were large animals there that were easy for people to get close to.
At that point, big animals that were easy to get close to were easy to kill and eat. In Australia and North and South America, a number of species went extinct soon after the first people arrived.
Other large mammals, like deer, moose, elk, and buffalo had natural defenses against other animals that also worked well against people. No one ever managed to domesticate them.
People didn’t domesticate any large mammals in Australia or North America. In South America one species survived long enough for people to domesticate them. That was the llama, in the Andes mountains.
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The other 12 large mammals that people domesticated lived in Asia and Europe. Earlier species of humans spread into those places about a million years ago. So those animals had been evolving along with them. When behaviorally modern humans got there, those animals had defenses against humans that worked well enough to keep them alive long enough for people to figure out how to domesticate them.
Once again, Mesopotamia had the best combination of animals. Goats, pigs, sheep, cattle, and Arabian camels— the ones with one hump— were domesticated in Mesopotamia. Horses were domesticated in Ukraine, just to the north of Mesopotamia. Donkeys were domesticated in northeastern Africa, just to the west.
That means around the time Mesopotamians domesticated plants, they also got seven of the 14 species of large animals that were ever domesticated in the world.
Reindeer were domesticated in northern Europe and Asia. Bactrian camels— with two humps— were domesticated in central Asia. Water buffalo, yaks, and two relatives of cattle, called the Bali cattle and the mithan, were domesticated in different parts of Asia.
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The Inca had llamas, which are very good pack animals for the mountains. But a horse is four or five times bigger than a llama so they have a lot more muscle power. Llamas are too small for adults to ride.
Native Americans had dogs that their ancestors brought with them across the Aleutian Islands. One sign that the Inca and the Maya didn’t know about each other, is that there weren’t llamas in North America, in spite of how valuable they would’ve been.
Mayan and Mississippi agriculture spread to many other places in North America. Large animals can be used to pull plows. That lets people farm land that’s too hard to plow by hand. It also makes it easier to farm land they can plow by hand.
The Inca also raised llamas for meat and wool, which would’ve been valuable to farmers anywhere.
There were extensive trade routes all over North America. People using llamas for pack animals would’ve been valuable for farming and trading. They would’ve been valuable to nomadic people, to carry their possessions when they moved.
The Maya, along with the Aztecs and the other empires in that area, had large armies that waged wars against each other from time to time. But their ability to wage wars and conquer territory was always limited by how much food they could carry with them while walking on foot. Llamas would’ve been valuable for that too.
Many people in North America could’ve put llamas to good use in many ways, but the biggest animals they had were dogs.
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For many people it’s hard to imagine that in 1491 Natives in North America walked everywhere on foot. That’s because soon after Europeans came with their horses, Natives got hold of some.
Horses spread through the Americas faster than European explorers. When Europeans encountered many of the Natives, European horses were already an important part of their lifestyles.
This story takes us for a real twist.
Horses evolved in North America. The world’s oldest fossils of horse skeletons are from Wyoming.
Horses crossed the Bering Land Bridge into Asia about 4,000,000 years ago, sometime when the ocean levels were low. They encountered proto-humans for the first time there. That’s where they evolved defenses against humans.
They spread all the way into Europe and Africa. In Africa they evolved into zebras and donkeys.
When the first humans crossed into the Americas, the horses they found here never had contact with humans before, so they hadn’t evolved defenses against them. The people soon ate all the horses here, along with a number of other species. When Europeans brought horses with them across the Atlantic, their species had circumnavigated the globe!
Part of the reason horses would’ve spread among Native American so quickly is because they were well adapted to living here. That made them very valuable.
Today in the US we have feral horses, mostly in the west. They do well here because they’ve returned to their native habitat.
ACT IV
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Farming leads to population growth. Producing more food lets people have more children who grow up to have more children. Farming on the most fertile land in the world produced the most food of anywhere in the world. That meant Mesopotamia could support the most people of any land in the world.
That difference in the number of people made that society more physically powerful than its neighbors. That meant a lot of people with seeds spreading out, looking for more places to grow food. They had the most soldiers to conquer neighboring land, and the most farmers waiting to move onto the land and start farming.
All the other original centers of agriculture got that advantage too. China, the Maya, and the Inca all had empires.
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Farming also leads to trade routes.
A physically powerful society, with a lot of food, is going to attract people who want to trade for some of what they have. That brought in plants, animals, raw materials, finished products, people, and ideas. Every agricultural society had that.
Again, Mesopotamia being in the middle of the biggest land mass in the world meant it was in the middle of the biggest trading network.
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Farming leads to a lot of new ideas.
Population growth means more people to think of ideas. Conquest and trade networks bring in more people with ideas from outside. Every agricultural society had a high concentration of brainpower and ideas. Again, Mesopotamia having the biggest population size and being in the middle of the biggest landmass and biggest trading network in the world meant it had the highest concentration of brainpower and ideas.
Mesopotamians didn’t think of more ideas than any other group because they were smarter than anyone else. They thought of more ideas because there were more people there to think of ideas.
ACT V
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This part of the story can be found in Jared Diamond’s book Guns, Germs and Steel. Also in his Guns, Germs, and Steel video series on You Tube.
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The domestication of plants and animals, and the population growth it led to, led to further developments. Like the specialization of labor, cities, kingdoms, metal tools, writing, and organized religion. Each of these things made societies more physically powerful. Since farming and population growth happened at different times and in different amounts in different parts of the world, so did the other things that they led to.
That began the clashes of cultures that have happened around the world for the past 10,000 years. That’s the next chapter in our story of Being Human on Planet Earth.
