Michael: History's biggest winners weren't the smartest people or the strongest armies. They were just the luckiest. Their secret weapon? Not genius, but geography. And the deadliest weapon of all wasn't a sword—it was a pig. Kevin: A pig? What are you talking about? That sounds like the beginning of a very strange fairy tale. Michael: It's the explosive argument at the heart of Jared Diamond's Pulitzer Prize-winning book, Guns, Germs, and Steel: The Fates of Human Societies. And it’s less a fairy tale and more of a global detective story. Kevin: Right, and Diamond isn't even a historian, is he? He's a biologist and geographer who spent decades in New Guinea. That's where this whole idea started, right? With a question from a local politician named Yali. Michael: Exactly. Yali asked him a simple but profound question: "Why is it that you white people developed so much cargo and brought it to New Guinea, but we black people had little cargo of our own?" It’s a question about global inequality, and it sent Diamond on a 25-year quest for an answer that had nothing to do with race. Kevin: A quest that led him to a pig. I'm still stuck on the pig, Michael. Michael: We'll get to the pig, I promise. But to test his theory, Diamond first needed to find a kind of "natural experiment" in human history—a place where you could see his ideas play out in miniature. He found it in the vast expanse of the Pacific Ocean.

Kevin: Okay, so what does a natural experiment in history even look like? You can't exactly put two societies in a petri dish. Michael: You can't, but history sometimes does it for you. Around 1200 B.C., a group of people, the ancestors of modern Polynesians, started spreading out from the Bismarck Archipelago near New Guinea. They were the same people, with the same culture, the same tools, and the same domesticated plants and animals. They were a perfect baseline. Kevin: Like a control group. Michael: Precisely. Now, one group of these Polynesians settled in New Zealand around A.D. 1000. It was a huge, diverse land, perfect for the tropical crops they brought with them. They became the Maori. They farmed, their population boomed, and they developed complex technology, political structures, and, crucially, a tradition of fierce, chronic warfare. Kevin: Makes sense. More resources, more people, more competition. Michael: But a small offshoot of that same group, just a few hundred people, kept sailing east and landed on the Chatham Islands, about 500 miles away. These islands were cold, windy, and completely unsuitable for their tropical crops. Farming was impossible. Kevin: Oh, that sounds rough. What did they do? Michael: They had to revert to being hunter-gatherers. They became the Moriori. Because the islands could only support a small population—about 2,000 people—they had to learn to get along. They were scattered, isolated, and had no resources to spare. So they made a conscious decision. They outlawed war. Kevin: Hold on, they just... outlawed war? How does a whole society do that? Did they just vote on it? Michael: It became a core principle of their culture. They developed rituals for resolving disputes peacefully. For centuries, it worked. They were a small, peaceful, technologically simple society of hunter-gatherers. Meanwhile, their cousins back in New Zealand, the Maori, were becoming some of the most formidable warriors on the planet. Kevin: I have a bad feeling about where this is going. Michael: You should. In 1835, an Australian sealing ship stopped at the Chatham Islands and then sailed on to New Zealand. The crew told the Maori about these islands to the east, full of food, and inhabited by people who had forgotten how to fight. Kevin: Oh no. Michael: A few weeks later, a ship carrying 500 armed Maori arrived. They announced that the Moriori were now their slaves and began killing anyone who resisted. The Moriori elders held a council. They were horrified, but they stuck to their principles. They decided not to fight back, but to offer peace, friendship, and a share of the resources. Kevin: And did the Maori accept? Michael: They never got the chance to hear the offer. The Maori attacked, slaughtering hundreds. A Moriori survivor later recounted, "They commenced to kill us like sheep." They cooked and ate many of the bodies and enslaved the rest. Within a few decades, the Moriori culture was effectively extinct. Kevin: Wow. That's... just awful. So Diamond is saying the Maori weren't 'better' or 'stronger' people, they were just the product of an environment that was better for developing the tools of conquest? Michael: Exactly. Same people, different environments, radically different outcomes. The Moriori weren't morally or genetically inferior; they were just dealt a very different geographic hand. It’s a tragic, brutal, but perfect microcosm of the book's entire argument.

Kevin: Okay, that's a powerful story for two islands. But how does this scale up to entire continents? Why did Eurasia get the 'Maori' treatment and the Americas, for instance, get the 'Moriori' one? Michael: This is where Diamond gets to the "ultimate causes." He argues that certain continents won a kind of geographic lottery thousands of years ago. It comes down to two main things: the shape of the continents and the raw materials they offered. Kevin: The shape of the continents? How does that matter? Michael: It matters immensely. Think about Eurasia. It's a massive landmass that is spread out primarily East to West. Now think about the Americas, or Africa. They are oriented North to South. Kevin: Okay, I'm picturing a map. Why is East-West better? Michael: Because locations at the same latitude share a similar climate, day length, and seasons. A crop domesticated in the Fertile Crescent, like wheat, could spread relatively easily all the way from Portugal to China. The climate was similar enough. But a crop domesticated in Mexico, like corn, had a much harder time spreading south to the Andes or north to the eastern United States. It had to cross tropics, deserts, and adapt to completely different day lengths and climates. Kevin: So ideas, crops, and animals could spread across Eurasia like a superhighway, while in the Americas, it was more like a series of winding, disconnected mountain roads. Michael: A perfect analogy. That diffusion of crops, animals, and technology gave Eurasia a massive head start. But it wasn't just the shape; it was the raw materials. The Fertile Crescent, for example, wasn't home to some kind of super-genius population. It was just blessed with an incredible variety of wild plants that were easy to domesticate: wheat, barley, peas, lentils, chickpeas. It was a jackpot of high-protein, high-calorie, storable crops. Kevin: And what about animals? Michael: This is where the lottery gets even more lopsided. Diamond introduces what he calls the "Anna Karenina Principle," borrowing from Tolstoy's famous line. "Happy families are all alike; every unhappy family is unhappy in its own way." He says the same is true for domesticable animals. Kevin: I love that. What does it mean for animals? Michael: It means that to be successfully domesticated, a wild animal has to tick a whole bunch of boxes. It needs to have a good diet—you can't domesticate a carnivore, it's too inefficient. It needs to grow fast. It needs to breed in captivity. It needs a reasonably placid disposition. It can't have a terrifying tendency to panic and flee. And crucially, it needs to have a social structure, a herd hierarchy that humans can co-opt. Kevin: So humans become the 'lead animal'. Michael: Exactly. Out of 148 large, terrestrial, herbivorous mammal species on Earth, only 14 have ever been domesticated. And of those 14, 13 were native to Eurasia. The Americas had only one: the llama/alpaca. Kevin: Wait, only one? What about all the other animals? Why couldn't Native Americans domesticate bison or bears? Michael: Anna Karenina Principle. Bison are incredibly dangerous and have a nasty disposition. Bears are carnivores. Think about zebras in Africa. They look like horses, they live in herds. Why didn't we domesticate them? Because they have a vicious streak, a powerful kick, and an innate ability to avoid capture that makes them impossible to tame. Every undomesticable animal is undomesticable in its own way. Eurasia just happened to have the sheep, goats, pigs, cows, and horses that were willing to play along. Kevin: This feels very deterministic, though. It's a point critics often raise. Are we just puppets of our geography? It seems to minimize the role of human culture and ingenuity. Michael: Diamond's response to that is fascinating. He argues it's not that people weren't ingenious everywhere. New Guineans and Native Americans were incredibly clever at mastering their environments. The issue is that geography gave Eurasians a much better set of raw materials to be ingenious with. It's hard to invent the wheel without a large domestic animal to pull the cart. It's hard to develop steel without the intense heat of furnaces that large, sedentary, food-producing societies can support.

Kevin: Alright, so Eurasia has the better crops, more animals, and easier diffusion of ideas. Let's see the payoff. How did this actually look in a real historical collision? Michael: For that, we go to Cajamarca, Peru, on November 16, 1532. This is the ultimate case study. You have Francisco Pizarro with a tiny force of 168 Spanish soldiers, deep in foreign territory. And he's about to meet Atahuallpa, the absolute monarch of the Inca Empire, who is backed by an army of 80,000. Kevin: 168 versus 80,000. The odds are... not good for Pizarro. Michael: On paper, it's a suicide mission. But Pizarro had the direct products of Eurasia's geographic advantages. First, the obvious ones: guns and steel. His men had steel swords, armor, and a few primitive firearms. The Inca had clubs, stone axes, and cloth armor. It was a massive technological gap. They also had horses, which were terrifying to people who had never seen them and gave the Spanish a huge advantage in speed and shock value. Kevin: That's the "Guns and Steel" part of the title. But there's more, right? Michael: Much more. Pizarro had the advantage of writing. The Spanish were a literate society. Pizarro knew about Cortés's conquest of the Aztecs just a few years earlier. He had, in effect, a manual for conquest. Atahuallpa, on the other hand, knew almost nothing about the Spaniards. His society had a form of record-keeping with knotted strings called quipu, but not a system of writing that could convey detailed information and history. He was walking into a trap, completely blind. Kevin: So information was a weapon. But that still doesn't account for the numbers. 168 men can't defeat 80,000, no matter how good their swords are. Michael: You're right. And that brings us to the most powerful and invisible weapon of all. The one you were asking about. The pig. Or more broadly, the germs. Kevin: The pig's revenge! Michael: Exactly. For thousands of years, Eurasians had been living in dense, crowded cities, in close proximity to their domesticated animals—their pigs, their cows, their sheep, their poultry. The great killer diseases of human history—smallpox, measles, influenza, plague—are what scientists call crowd diseases. They are mutations of animal diseases. We got measles from cattle, flu from pigs and ducks, smallpox possibly from camels. Kevin: So living in dirty, crowded cities with lots of animals was... a good thing? Michael: In the long run, yes. It was a brutal, deadly process. For centuries, epidemics swept through Eurasia, killing millions. But those who survived passed on their genetic resistance. Over generations, Eurasians developed a powerful immunity to these diseases. Native Americans, on the other hand, had very few domesticated animals. They had no exposure, and therefore, no immunity. Kevin: So when the Europeans arrived... Michael: They brought this arsenal of germs with them. Smallpox actually arrived in the Americas before Pizarro did, spreading overland from earlier Spanish settlements. It's estimated that it killed up to 95% of the Native American population. It killed the reigning Inca emperor and his designated heir, which plunged the empire into a devastating civil war between Atahuallpa and his brother. Pizarro didn't just walk into an empire; he walked into an empire that was already collapsing from a biological apocalypse. Kevin: Ninety-five percent? That's not a conquest, that's cleaning up after a plague. The battle was over before it even began. Michael: That's Diamond's point. The capture of Atahuallpa wasn't a story of European bravery or genius. It was the inevitable result of 13,000 years of divergent history, all set in motion by the luck of the geographic draw.

Kevin: It's such a massive, all-encompassing theory. It feels like it explains... everything. Michael: And that's both its power and the source of the controversy around it. Diamond’s central argument is that the story of humanity isn't a race between peoples, but a story of how different environments equipped people with vastly different toolkits. The inequalities of the modern world have deep roots, not in biology or culture, but in the biogeographic luck of the draw thousands of years ago. Kevin: It's a powerful, and for some, an uncomfortable idea. It challenges our notions of progress and merit. It makes you wonder, if the continents were tilted differently, or if bison had been as placid as cows, what would our world look like today? Michael: It's a huge question, and one that has sparked a lot of debate since the book was published. We'd love to hear what you think. Does this explanation feel complete to you, or is something essential missing from the story? Let us know. Kevin: It definitely gives you a new lens to look at the world map. Michael: This is Aibrary, signing off.