a response to one of the most riveting history books you'll ever read,

"The Columbian Exchange," by David Crosby.

He had a good year in 1969. Published "The Columbian Exchange," played Woodstock, he

was still on his first liver. What? It was Albert Crosby? Gah! History. Never being as

interesting as I want it to be.

Right, so, it was Alfred Crosby Jr. And in that book, he wrote:

"The big questions are really the only ones worth considering, and colossal nerve has

always been a prerequisite for such consideration." I love it!

Before 1492, we couldn't really talk about a world history at all. We could only talk

about the different histories of separate regions. But, Columbus changed all of that,

and everything else.

The Columbian Exchange irrevocably homogenized the world's biological landscape. Since Columbus,

the number of plant and animal species has continually diminished.

And the variation in species from place to place has diminished dramatically.

I mean the first European visitors to the Americas had never seen a tomato or a catfish.

Native Americans had never seen a horse.

And by making our planet biologically singular, the Columbian Exchange completely remade the

populations of animals, particularly humans.

And vitally, this cross-pollination also made possible such wonders as contemporary pizza.

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So we're going to break Columbian exchange down into four categories: diseases (boy,

you're looking good, smallpox, I'm glad you've been eliminated), animals, plants, and people.

Mr. Green, Mr. Green. People are animals.

Yeah, that's true, Me from the Past, but just for the sake of simplicity--

Also, if you think about it, microbes are kind of animals and plants are too, I mean—

OH MY GOD SHUT UP BEFORE I KILL YOU AND CREATE A TIME TRAVEL PARADOX.

Microbes, like those hairy blokes back there, were a definite negative in terms of the Columbian

Exchange.

Terminology is hard here, but the majority of Caribbean Islanders or Native Americans

or Amerindians had exactly one response to the arrival of Europeans: death.

We can't be sure how many natives died as a result of European arrival, but it was definitely

more than 50%, and some estimates place it as high as 90%.

Historians used to blame European brutality, which was definitely was a factor, but the

main culprit was disease.

Smallpox is usually seen as the villain of this story, but it's more likely that a series

of diseases in combination did the damage.

Along with smallpox, Americans were killed by measles, and mumps, typhus, chicken pox,

none of which they had been previous exposed to.

This astonishing decrease of population was definitely the worst effect of these diseases,

both psychologically and demographically, but the secondary effects were almost as bad.

For one thing, the deaths of Aztec and Incan rulers touched off wars, which in turn made

it easier to spread disease, because, you know, the number one way to catch smallpox

is via hand-to-hand combat.

Plus, leaders kept dying. Huayna Capac, the leader of the Inca Empire succumbed to smallpox

before Pizarro even arrived.

His death led to a violent succession struggle between his sons, which was won by Atahualpa

who, in turn, was captured and killed by Pizarro.

And, without that war, the Inca would have had a much better chance against the Spaniards,

whose numbers were comparatively tiny.

A similar thing happened to the Aztecs. The Moctezuma who eventually lost to Cortes was

the nephew of a much more powerful king who died of smallpox.

And, the death of that great king encouraged some of the smaller states in the Aztec empire

to rebel and some of them even fought for the Spaniards.

And, another side effect of disease was starvation because there simply weren't enough people

left to grow crops to feed the living.

And then malnutrition made survivors that much more susceptible to disease. In short,

it sucked.

The transmission of disease largely went one way, from the Old World to the New, but the

Americans did have one gift for Europe: venreal syphilis.

It showed up in Europe around 1493. And even though Europeans are very fond of ascribing

syphilis to each other—

Italians called it the French Disease; the French called it the disease of Naples; Poles

called it the German disease; Russians called it the Polish Disease—

The truth is, venereal syphilis was spread by sailors who'd returned from the Americas.

In fact, in his book "The Columbian Exchange," Crosby tells it like this:

"Sailors, by the nature of their profession, are men without women and therefore men of

many women. we can imagine no group ... more perfectly suited for guaranteeing that venereal

syphilis would have worldwide distribution."

Who says history books are boring?

Syphilis would go on to infect a veritable who's who of Europe, from Baudelaire to Gauguin

to Nietzsche, not to mention numerous family members of the famously infertile Tudor and

Valois families, meaning that Syphilis may be responsible for many of those miserably

boring dynastic power struggles of post-Columbus Europe.

Anyway, nothing against syphilis, but it pales in comparison to the devastation wrought by

Old World diseases arriving in the New World. But the New World did have one gift for the

Old World that was pretty destructive: Tobacco.

Oh, it's time for the Open Letter? And there's been a costume change? That doesn't bode well.

An Open Letter to Tobacco.

But first, let's see what in the secret compartment. Don't be cinnamon, don't be cinnamon, don't

be--dang it!

I guess that I'm going to do the cinnamon challenge. Oh...I'm not happy about this,

Stan. For the record. Alright. I'm going to do the cinnamon challenge, one tablespoon

of cinnamon in my mouth, no water.

Ah, boy. That sucked. I regret doing that, to be honest with you.

Dear Tobacco, I just did something really stupid. But at

least it was cheap.

I'm going to tell you two stories about smoking. The first comes from my high school history

teacher, Raoul Meyer, who also writes Crash Course. When I was a senior in high school,

he walked up to me and he said, "I want you to keep smoking. I want you to smoke until

the day after your 65th birthday, and then I want you to die so that I collect all of

your social security."

That inspired me, Mr. Meyer, to quit smoking just eight short years later.

Here is an amazing statistic, cigarettes were handed out to American service men during

World War II.

And more soldiers, who started smoking during the war, died from smoking than died from

the war.

So if the New World was looking to extract some measure of revenge for smallpox and measles

and chicken pox, mission accomplished. Best wishes, John Green.

Now, onto animals. American animals like llamas and guinea pigs never really caught on in

Eurasia.

But, imports to the Americas—like pigs, cows, and horses—were revolutionary. Let's

go to the Thought Bubble.

First of all, these animals, especially pigs, completely remade the food supply.

Pigs breed really quickly, they eat anything, and they turn into bacon—which made them

heroes to the New World just as they are today heroes to the Internet.

Here's how quickly pigs breed: When Hernando de Soto arrived in Florida in 1539, he brought

13 pigs. By the time of his death, there were 700. That was three years later.

The abundance of meat and plentiful land for agriculture and grazing meant that Europeans

in the Americas very rarely experienced famine, and despite what you may have learned about

religious and political freedom, the main reason Europeans came to America was to eat.

Large European animals also changed the nature of work in the Americas. Before Europeans,

the largest beast of burden was the llama and at best it could carry, like, 100 pounds.

This meant that for the long distance travel that the Inca engaged in, the primary transportation

animal was...Incas.

Oxen, when combined with their plows made it possible to bring more land under cultivation,

and also made transportation easier and more efficient.

And plus, European animals remade culture. The grossly stereotypical American Indian,

like from the movies, riding the Great Plains with an eagle feather headdress and war paint.

Well, he didn't exist before the Columbian Exchange because there were no horses for

him to ride.

And the introduction of horses allowed many native Americans to abandon agriculture in

favor of a nomadic lifestyle, because riding around hunting buffalo made them far richer

than farming ever had.

Thanks, Thought Bubble. While animals and diseases completely reshaped the New World,

it was New World plants that had the biggest effect on Eurasia.

Sure, Europeans brought over some crops that we now grow here in the Americas, like wheat

and grapes, both of which are necessary for Catholic mass.

But New World plants radically changed the lives of millions, maybe hundreds of millions

of Africans, Asians, and Europeans. Specifically, by making pizza possible.

I mean, until 500 years ago, Italians lived without tomatoes—without modern pizza or

marinara sauce or pizza or ketchup or pizza or even pizza.

Indians lived without curry, which contains chilies, a New World food.

Persians lived without corn, which is a New World food. As are beans and potatoes and

avocados and peanuts and blueberries. The list goes on and on.

And these New World crops led to probably the greatest population increase in history.

To quote Crosby:

"It is crudely true that if man's caloric intake is sufficient, he will somehow stagger

to maturity, and he will reproduce."

And New World food was far more caloric than Old Word food, which is the central reason

that the world population doubled between 1650 and 1850.

Plants like corn and potatoes could grow in soils that were useless for Old World crops.

Potatoes were actually introduced to Europe as an aphrodisiac, but it turns out that you

have to distill those potatoes into vodka before they have the desired effect.

Anyway, if potatoes are an aphrodisiac, the Irish quickly became the hottest people on

Earth.

An acre and a half of potato cultivation could feed an Irish family for a year, and the average

Irish worker often ate 10 POUNDS of potatoes EVERY DAY.

Surviving primarily on potatoes, the Irish more than doubled their population between

1754 and 1845, when the potato famine showed up and ruined everything.

And it wasn't just Europe. Manioc, or cassava, is a New World plant with roots that provide

more calories than any other plant on earth, provided they are properly processed, otherwise

they're poisonous.

Manioc is so prevalent in Africa that many Africans swear the plant is native to the

continent. But it isn't.

Nor are sweet potatoes, and while New World grains never replaced rice in South East or

East Asia, the sweet potato is so common that it is known as the poor person's staple in

China.

Even in Japan the tomb of the farmer who is reputed to have first brought them to the

islands is known as the Temple of the Sweet Potato.

And it's also worth noting that corn, while it may not feature prominently in European

diets, has been the central source of food for animals in Europe for centuries.

And, in fact, that's still the case. In 2005, 58% of the corn grown in America went to animal

feed, is the kind of thing you learn when you live in Indiana.

Alright, so last but not least, the Columbian Exchange involved the transfer of lots of

people.

Again, in the early stages, this movement was mostly one way, with Europeans and Africans,

the Africans usually against their will, making their way to the Americas.

So, the Columbian Exchange led to the re-population of the New World following the disease devastation

of the initial encounter.

And better nutrition allowed the population of the Old World to grow, which in turn placed

population pressure on Eurasia, which led to to more people coming to the Americas.

In the process, the world's human inhabitants became more genetically and ethnically interconnected.

But it also led to the horrors of Atlantic slavery, which we'll be discussing next week.

What are we to make of the Columbian Exchange? It devastated the population of the Americas,

it led to the widespread slavery of Africans.

But, it also allowed for a worldwide population increase, and the lives of some natives, including

Plains tribes like the Lakota, became better and more secure—at least for a while.

Fewer people have starved since the Columbian Exchange began, but the diversity of life

on earth has diminished dramatically.

And planting crops where they don't belong has hurt the environment. So on the whole,

should we be grateful for the Columbian Exchange?

And should we work to continue and deepen its legacy of globalism and monoculture?

Crosby didn't think we were better off: "The Columbian exchange has included man, and he

has changed the Old and New Worlds sometimes inadvertently, sometimes intentionally, often

brutally. It is possible that he and the plants and animals he brings with him have caused

the extinction of more species of life forms in the last four hundred years than the usual

processes of evolution might kill off in a million.... The Columbian exchange has left

us with not a richer but a more impoverished genetic pool. We, all of the life on the planet,

are the less for Columbus, and the impoverishment will increase."

But let's give you the last word today. Do you agree with Crosby?