Disease! Crash Course World History 203

Summary

In this Crash Course World History episode, John Green discusses the profound impact of disease on human history. From early human migrations to epidemics in civilizations, disease has shaped societies, economies, and even warfare. Notable examples include the Black Death, which ravaged Europe, and the diseases that devastated indigenous populations in the Americas during the Columbian Exchange. The episode also touches on the advancements in medicine, like inoculation and antibiotics, while reminding viewers that diseases, both old and emerging, continue to influence human history. The lesson concludes with a reflection on our interconnectedness with the biosphere.

Takeaways

• 🤒 Disease has profoundly shaped human history, even though it isn't often the focus in historical narratives.
• 🌍 Human migration from Africa to less disease-prone regions led to population growth, contributing to the development of civilizations.
• 💧 Early civilizations in river valleys faced new disease challenges, particularly due to population density and standing water from irrigation.
• 🐖 Many diseases originated from domesticated animals, such as swine flu from pigs.
• 🛡️ Disease sometimes protected populations from conquest, as it did in Africa until the 19th century.
• ⚔️ War and disease are closely linked, as armies and trade helped spread epidemics throughout history.
• ☠️ The Black Death, a 14th-century plague, caused massive devastation, killing about a third of Europe's population.
• 💸 The Black Death might have spurred economic opportunities by raising wages for surviving workers and contributing to social changes in Europe.
• 🌱 The arrival of Europeans in the Americas brought diseases that wiped out up to 90% of the indigenous population, profoundly reshaping global history.
• 💉 Advances like inoculation and antibiotics have dramatically improved humanity's fight against disease, but new threats such as drug-resistant bacteria and viruses continue to emerge.

Q & A

Why does John Green feel uncomfortable discussing disease in this Crash Course episode?

John Green feels uncomfortable discussing disease because he is a hypochondriac, and the idea of microscopic organisms potentially ending his life makes him anxious.

Why hasn’t disease been a major focus in traditional historical studies?

Disease hasn't been a major focus in traditional history because it is mysterious, often associated with divine will, and doesn’t fit neatly into the idea of history being driven by human actions. Additionally, historical records about diseases were often vague or poorly written.

How did migration out of Africa influence human population growth?

When humans migrated out of Africa into less disease-prone regions around 64,000 years ago, they escaped many tropical diseases, leading to population growth that enabled the development of civilizations.

How did the rise of river valley civilizations contribute to new disease problems?

The rise of river valley civilizations brought higher population densities and standing water from irrigation, which created breeding grounds for diseases and allowed for epidemics to spread more easily.

What role did domesticated animals play in the spread of diseases?

Domesticated animals, such as pigs, often carried diseases like swine flu, which could spread to humans. Living closely with animals increased the likelihood of zoonotic diseases.

What is the connection between trade and the spread of diseases?

Trade, especially transcontinental trade networks like the Silk Road, facilitated the spread of diseases as goods, animals, and people carried pathogens across long distances, such as the spread of the Black Death from China to Europe.

What were some effects of the Black Death on European society?

The Black Death led to labor shortages, higher wages, changes in construction techniques, and an increased receptiveness to ideas like the Protestant Reformation due to the perceived ineffectiveness of the Church during the crisis.

How did the Great Dying during the Columbian Exchange differ from the Black Death?

The Great Dying, which resulted from the introduction of European diseases to the Americas, was even more devastating than the Black Death, with up to 90% of the indigenous population perishing, compared to about a third of Europe during the Black Death.

How did medical advancements in the 18th and 20th centuries impact the control of diseases?

Inoculation became widely used in Europe in the 18th century to fight viral diseases, and antibiotics in the 20th century were highly effective against bacterial infections like tuberculosis and bubonic plague.

Why is disease still a significant factor in shaping human history today?

Despite medical advancements, diseases like HIV/AIDS, antibiotic-resistant bacteria, and modern epidemics such as various flu strains continue to affect human populations, reminding us that diseases still play a major role in shaping history.

Outlines

00:00

😷 The Role of Disease in Human History

John Green introduces the topic of disease in history, emphasizing his discomfort due to his hypochondria but acknowledging the rationality of such fears. He discusses the historical role of diseases, how they impacted human populations, and the shift from tropical regions where parasites kept populations low to the rise of civilizations in river valleys. The relationship between disease, human migration, population density, and domesticated animals is explored, along with how early humans dealt with the spread of disease through writing and trade. The interplay of disease and war, as well as its influence on the downfall of civilizations, is highlighted, laying the groundwork for further exploration.

05:02

💀 The Devastating Impact of the Black Death

John Green delves into the infamous Black Death, comparing it to iconic symbols like Liverpool Football Club and the Beatles to emphasize its significant impact. He explains how the plague, originating in China, spread via rats on trading ships, wiping out a third of Europe's population. The Black Death’s branding is explored humorously, followed by a vivid description from a Florentine chronicler on the plague's effects. Green also touches on the ongoing threat of Bubonic plague into the 20th century and its broader impacts on Europe's economy, Christianity, and lifestyle changes, such as the shift to brick houses.

10:03

🌍 Global Consequences of Epidemics and Colonization

The global consequences of epidemics are explored, with a particular focus on the Great Dying during the Columbian Exchange. Green emphasizes the devastating effects of diseases brought by Europeans to the Americas, wiping out up to 90% of indigenous populations. This demographic collapse led to European colonization pressures and was a key factor in shaping modern world history. He links the spread of diseases with European dominance, citing historian Jared Diamond, and discusses the role of scientific and medical advancements in combating diseases, such as the introduction of inoculation and antibiotics.

🦠 Modern Disease and Its Lasting Impact

In the final section, John Green shifts to modern diseases, acknowledging how despite medical advancements, infectious diseases remain a leading cause of death. He discusses the rise of antibiotic-resistant bacteria, the resurgence of diseases like tuberculosis, and the ongoing threat of modern epidemics such as HIV/AIDS and influenza. Green reflects on humanity’s interconnectedness with the larger biosphere, highlighting that human history is not solely shaped by human actions but also by our relationships with countless microorganisms. He ends with a note of thanks to viewers and supporters, encouraging them to 'stay awesome.'

Keywords

💡Disease

Disease refers to illnesses that can affect human populations, often causing widespread death and suffering. In the video, disease is central to the discussion as it highlights how infectious diseases have shaped human history, from smallpox to the Black Death. It emphasizes the uncomfortable reality that diseases, which are often beyond human control, have played a massive role in shaping civilizations and historical events.

💡Epidemic

An epidemic is an outbreak of a disease that spreads rapidly among a large number of people in a particular region or population. The video describes various historical epidemics, like the Black Death and the Great Dying in the Americas, which caused devastating effects on populations and economies, and also altered the course of history by weakening societies or enabling conquest.

💡Bubonic Plague

The Bubonic Plague, caused by fleas carried on rats, was one of the most devastating epidemics in human history, especially in medieval Europe during the Black Death. The video describes its symptoms, death rate, and historical significance, comparing its cultural and historical impact to a dominant soccer team or famous band, symbolizing its pervasive influence in Europe in the 14th century.

💡Columbian Exchange

The Columbian Exchange refers to the widespread transfer of plants, animals, culture, and diseases between the Americas and the Old World following the voyages of Christopher Columbus. In the video, it is noted that diseases brought by Europeans, such as smallpox, led to the Great Dying, which decimated native populations in the Americas, making disease a critical factor in European colonization efforts.

💡Black Death

The Black Death was a pandemic in the 14th century, often identified with the Bubonic Plague, that killed up to a third of Europe's population. It dramatically altered European society, influencing economic systems, labor practices, and religious attitudes. The video uses the Black Death as a prime example of how disease can change the course of history, affecting population numbers, economies, and religious beliefs.

💡Pandemic

A pandemic is a type of epidemic that spreads over multiple countries or continents, affecting a large number of people. The video discusses pandemics like the Black Death, which spread across Europe and Asia, and modern concerns like bird flu, HIV/AIDS, and antibiotic-resistant bacteria, emphasizing how pandemics have shaped and continue to shape human history.

💡Smallpox

Smallpox was a highly contagious and deadly viral disease that affected humans for centuries until it was eradicated through vaccination. In the video, smallpox is mentioned as part of the discussion on the Great Dying in the Americas and the success of inoculation as a medical advancement in combating viral diseases.

💡Great Dying

The Great Dying refers to the massive population decline among indigenous people in the Americas after the arrival of Europeans, mainly due to diseases like smallpox and measles. The video highlights this as one of the most significant impacts of disease in world history, contributing to European colonization by decimating native populations and leaving their societies vulnerable.

💡Inoculation

Inoculation is the practice of introducing a small, controlled amount of a virus or bacteria into the body to create immunity. The video credits inoculation, likely invented in Asia, as a major medical advancement that helped humanity combat diseases like smallpox, marking a turning point in how society could fight viral epidemics.

💡Antibiotics

Antibiotics are medicines used to treat bacterial infections, introduced in the 20th century. The video discusses how antibiotics have been highly effective against diseases like Bubonic Plague and tuberculosis, but also warns of the rise of antibiotic-resistant bacteria, showing that while antibiotics have revolutionized medicine, new challenges remain.

Highlights

Disease has played a major role in human history, often overlooked by historians due to its mysterious and terrifying nature.

Human populations remained low for a long time due to tropical diseases in Africa, only growing after migration to less disease-prone regions.

The shift to agriculture in river valleys led to population density, which allowed for epidemics, contrasting with the relative safety of hunting and gathering societies.

Schistosomiasis, a parasitic flatworm disease, was recorded in Egypt as early as 1200 BCE, showing the early human interaction with diseases from water and animals.

Domesticated animals contributed to human diseases, such as swine flu from pigs and bird flu, reflecting the long-standing relationship between livestock and epidemics.

Pandemics like the plague recorded by Ancient Greek historians highlight the correlation between war, trade, and disease spread, seen in the plague during the Peloponnesian War.

The Black Death of the mid-fourteenth century, originating from fleas on rats, killed about one-third of Europe’s population and is one of the most famous epidemics in history.

The term 'Black Death' was coined in 1832 by German doctor J.F.K. Hecker, demonstrating the lasting impact of historians on disease narratives.

Economic impacts of the Black Death included labor shortages, higher wages, and the potential for guilds to admit new members, possibly accelerating the end of the Middle Ages.

The Great Dying caused by the Columbian Exchange may have wiped out up to 90% of the native population in the Americas, reshaping global power dynamics and colonial expansion.

Europe's immunological advantage, combined with diseases devastating indigenous populations, contributed to European dominance during the colonial era.

Inoculation, likely originating from Asia, and antibiotics in the 20th century have significantly reduced the threat of epidemics, though drug-resistant bacteria still pose a danger.

Despite medical advances, diseases like tuberculosis have made a resurgence, and new epidemics such as various strains of the flu continue to be threats.

The interconnectedness of humans with the larger biosphere means that disease has the potential to shape, and even end, human history.

The video concludes with a reflection on how humans cannot be separated from the environment and how the history of disease is also the history of humanity.

Transcripts

Hi, I'm John Green, this is Crash Course World History, and today we're going to talk about a subject that makes me profoundly uncomfortable: disease.

This is a tough subject for me personally because I'm a bit of a hypochondriac, but to be fair, my fears are kind of rational.

I am afraid that my existence will be ended by a soulless, microscopic organism, and to be fair, they have killed a lot of people.

You're not paranoid if germs are actually out to get you, and as we'll see today, they are.

Fortunately, we live in the twenty-first century, when communicable disease does not play such a massive role in human history,

unless of course you count bird flu, or SARS, or HIV/AIDS, or antibiotic-resistant bacteria--

alright Stan, let's just go to the intro!

[Theme Music]

Okay, so long-time viewers of Crash Course will remember the sixteenth-century Great Dying in the Americas, not only as an example of historians' total inability to name things,

but also as perhaps the most important and wide-ranging effect that disease has had on human cultures in millennia.

But traditionally, the study of history hasn't focused much on diseases, partly because they're mysterious and terrifying,

and partly because they don't fit in very well with our ideas about history being the result of human agency.

We like to imagine that things happen because we did good things, or because we did bad things, or at least because we did some kind of thing,

but, in fact, history often happens because lots of people got smallpox.

There's also the fact that diseases were often seen to be the result of divine will, or else divine wrath.

Plus, because people didn't know that much about disease, they didn't write about it very often,

and when they did write about it, they didn't always write about it particularly well.

So when you read primary sources, often they're like, "Why'd they die? Well, too much of that miasma."

That's not particularly helpful to us.

So given all that, we are going to have to engage in a bit of speculation here.

Mr. Green, Mr. Green! I love speculation; it's way more fun than history, like what would have happened if the South won the Civil War?

No, me from the past, not that kind of speculation, the kind of speculation where you guess what DID happen, not what would have happened.

So diseases have been with humans as long as there have been, like, humans.

And humans first appeared in tropical regions in Africa, which are home to a wide variety of microparasites,

so it's probably a good bet that those parasites played a role in keeping human populations really low for a long, long time.

It's only after we see migration out of Africa and into regions less amenable to diseases, about 64,000 years ago,

that we start to see the growth of human populations necessary to create what we, problematically, call civilizations.

So humans migrated into river valleys that became the cradles of civilization, with agriculture, and surpluses, etc.

This allowed us to escape those population-limiting tropical diseases, but it created all kinds of new disease problems.

The communities in river valleys had more people and more population density, which allowed for epidemics.

I mean, one of the great things about hunting and gathering is that diseases cannot wipe out a city if you don't have cities.

Also, river valleys could be breeding grounds for disease, especially where cultures developed irrigation, which often relied on slow-moving or standing water,

and if you've ever had to clean a bird bath, you'll know that standing water is the perfect environment for disease-carriers and nasty microorganisms.

For example, schistosomiasis was recorded in Egypt as early as 1200 BCE. What is, what is that Stan?

Oh, apparently, it's a parasitic flatworm, do we still have that?

I think we do, we do. Awesome.

Anyway, lots of diseases come from domesticated animals, but you can't have bacon without swine flu.

So, you know, it's comme ci, comme ça.

That's going to be a hilarious joke when we all die of swine flu. Just kidding! We're all going to die of bird flu.

But from like a macrohistorical perspective, it's not like disease is all downside,

I mean, sometimes it's helped populations shield themselves from conquest; that was the case in Africa until the nineteenth century.

Okay, so we like to say that one of the hallmarks of civilization is writing,

and pandemic diseases were the type of events that people tended to write about in early civilizations, because they were a big deal.

Like pestilence appears in the epic of Gilgamesh; early Chinese historians described the increase in disease as populations spread from the northern Yellow River region to the more tropical Yangtze River region;

Ancient Greece was relatively disease-free because of its climate and also the isolated nature of city-states,

but the more the cities became involved in trade, the more susceptible to epidemics they were.

The best example of this was the plague that struck Athens in 430 and 429 BCE during the Peloponnesian War,

and that leads us to a very important point, which is, there is a decent correlation between war and disease.

Armies tended to carry it along with them, and food shortages and displacements made civilians more likely to get sick.

That is still very much the case, and the weird, symbiotic relationship between war and disease is something that we're going to look a lot at in the next several weeks.

But nothing spreads disease quite like trade.

Trade is so good for economies and so bad at keeping individual human beings not dead.

Like Ancient Rome's integration into transcontinental trade networks, like the Silk Road, may explain why the historian Livy recorded at least eleven pestilential disasters,

and it is very likely that disease, and the accompanying decline in population, contributed to the fall of the Roman Empire.

But of course, you can't talk about the history of disease without mentioning the most famous epidemic of all time: the Black Death.

I mean, if the Black Death were a soccer team, it would be Liverpool Football Club.

If the Black Death were a band, it would be the Beatles.

If the Black Death were an industry, it would be eighteenth-century textile processing in Liverpool.

The plague, which struck Europe in the mid-fourteenth century, originated in fleas that came from rats, and Bubonic plague can be found throughout the world, even in the western US today.

It's more treatable now, thankfully, but anyway, the Black Death started in China and spread westward over the caravan routes,

really picking up steam when plague-carrying rats jumped onto Mediterranean trading ships.

So the death rate from this plague was incredibly high; perhaps a third of people living in Europe died.

Oh, it must be time for the open letter!

Oh look, it's the Grim Reaper. Stay away from me.

An open letter to the Black Death:

Dear Black Death, I don't want to compliment you, but that term, "Black Death," is just some fantastic branding.

Such a scary term; it's a shame that people in the actual fourteenth century didn't use it.

It was first coined in 1832 by a German doctor and professor of the history of medicine, J.F.K. Hecker.

And the term became popular in English after it was used in A History of England by Elizabeth Cartwright Penrose.

So, great job, J.F.K. Hecker!

It took a historian who was also a doctor to come up with a name as catchy as the "Black Death," but for once, historians, you did it!

A terrifying thing got the terrifying name it deserved. Best wishes, John Green.

So we're not 100% sure that the Black Death was Bubonic plague; its virulence suggests that in some places, it might have been pneumonic,

but we have descriptions of it that match Bubonic plague, like this one from Florentine chronicler, Matteo Villani:

"It was a plague that touched people of every condition, age, and sex.

They began to spit blood and then they died -- some immediately, some in two or three days, and some in a longer time..."

"...most had swellings in the groin, and many had them in the left and right armpits and in other places;

one could almost always find an unusual swelling somewhere on the victim's body."

Stan, I appreciate you doing that in text and not pictures because it sounds truly horrible. Thank goodness that was the last we saw of outbreaks of Bubonic Plague.

What's that? There was an outbreak in 1904 in San Francisco? Oh boy.

And India in 1994?!

Obviously, the plague affected a lot of individuals' lives, but it also affected world history.

Like, plague probably contributed to the fall of the Yuan Dynasty in China in the fourteenth century, but its greatest effects were felt in western Europe.

Okay, let's go to the Thought Bubble.

There's some debate about whether the Black Death kickstarted Europe's economy and ended the Middle Ages.

It probably did create some opportunity, like guilds were forced to admit new members to replace the many workers who had died,

and persistent European inflation until the end of the fourteenth century suggests both a shortage of products and higher wages.

Again, Matteo Villani provides us with some evidence of the effect of the plague on Italy's economy:

"Nurses and minor artisans working with their hands want three times or nearly the usual pay,

and laborers on the land all want oxen and all seed, and want to work the best lands, and to abandon all others."

So the plague may have actually been good for workers, at least those who survived.

The plague also probably changed European Christianity. When faced with seemingly random and widespread deaths, some people abandoned piety for hedonism,

and ineffectiveness of priests in dealing with the crisis may have led to an increase in anticlericalism and a greater receptiveness to the ideas of the Protestant Reformation.

And attempts to combat the plague changed the way that Europeans lived, too.

For example, there were new construction techniques, such as building out of brick instead of wood,

and in many places, tile roofing replaced thatched roofs, where rats liked to live.

These new shelters created more barriers between humans and disease-carrying rodents, and plus, there were fewer plague-infested rats falling out of the ceiling, so that's nice.

Thanks, Thought Bubble.

So the Black Death looms larger in our Eurocentric imaginations, but in terms of devastation and human suffering, it pales in comparison to the Great Dying that accompanied the Columbian Exchange.

The pre-Columbian Americas were certainly no paradise, but the records we have suggest that Amerindian cultures were largely free of disease until the arrival of Europeans.

They did have syphilis, but that's preventable.

Not to be redundant, but the most obvious and often most overlooked aspect of the Great Dying is the dying.

I mean, perhaps 90% of native populations of the Americas may have perished, destroying communities, and families, and entire cultures.

And at the same time that diseases were destroying indigenous social orders, Europe's population was growing, thus creating more pressure to colonize the Americas, Asia, Africa, and eventually Australia,

and so it's fair to say, as historian Jared Diamond has, that disease was, if not the decisive factor, a crucial determinant of Europe's dominance in the modern era.

So while not exactly the last hurrah of epidemics, the world has not seen anything remotely like the devastation brought by the Columbian Exchange, since.

Some of that is due to our new shared immunological profiles, but much of it can be chalked up to massive improvements in science and medicine.

The most significant medical advance in the battle against viral epidemic diseases like smallpox was inoculation,

which was probably actually invented in Asia, but came into wide use in England after 1721 and in continental Europe about a century later.

And then, the development of antibiotics in the twentieth century proved extremely effective against bacterial diseases, like bubonic plague and tuberculosis.

Some of these advances have had tremendous results, like smallpox has been eliminated from the human population,

but infectious disease continues to be a leading killer of humans, and we still see deadly epidemics of diseases like cholera around the world.

And, even though antibiotics have been in wide use for less than one hundred years, many drug-resistant bacteria have already emerged, and terrifying diseases like tuberculosis have started to make a bit of a comeback.

Then you have modern endemic diseases like HIV/AIDS along with the working threat of new and terrifying epidemics like the various flus we often hear about.

All of that reminds us that disease is still shaping human history and has the potential to be the most powerful force in human history, like the one that ends it.

We like to think that the human story is both told by and made by humans, but in fact, it's a lot more complicated than that because we share this planet with countless creatures.

I know we all like to think of ourselves as individuals, but we cannot separate ourselves, not only from other people, but also from the larger biosphere.

That whole story is the story of history.

Thanks for watching, I'll see you next week.

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