The Jordan Harbinger Show - 875: Jonathan Kennedy | How Pathogens Have Shaped Our World

Episode Date: August 8, 2023

Pathogenesis: A History of the World in Eight Plagues author Jonathan Kennedy joins us to discuss how microscopic pathogens have shaped our world. What We Discuss with Jonathan Kennedy: If we were to weigh all the bacteria on Earth, their mass would be about 1,000 times more than all humans. If all of the viruses on the planet were laid end to end, they would stretch for 100 million light years. About eight percent of the human genome's DNA comes from retroviral infections we've endured over our evolution. From them, we've inherited memory and the ability to give birth to live young. Our gut microbiota communicates with our brains and can directly affect our mood and influence our behavior. We modern humans have our ancestors' romantic soirees with Neanderthals to thank for genetic defenses against countless viral diseases. How the transition from hunting and gathering to agriculture was a double-edged sword that brought us innovative progress and population-decimating pandemics. And much more... Full show notes and resources can be found here: jordanharbinger.com/875 This Episode Is Brought To You By Our Fine Sponsors: jordanharbinger.com/deals Sign up for Six-Minute Networking — our free networking and relationship development mini course — at jordanharbinger.com/course! Like this show? Please leave us a review here — even one sentence helps! Consider including your Twitter handle so we can thank you personally!See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

This episode is sponsored in part by Conspiruality Podcast. You know how I'm always talking about critical thinking and spotting manipulation? Well, there's a podcast that's all about dismantling new age cults, wellness grifters, and conspiracy med yogis, basically the wild overlap of spirituality and misinformation. It's called the Conspiruality Podcast. The hosts, a journalist, cult researcher, and a philosophical skeptic, dive deep into how this stuff spreads, from Project 2025 and the Heritage Foundation's dystopian vision of the future to how former leftists get pulled into far-right conspiracies.

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Find Conspirality on Apple Podcasts, Spotify, and wherever you get your podcasts. Coming up next on the Jordan Harbinger Show. If we were to take all the bacteria on our planet and weigh them, their mass would be about 1,000 times more than all the humans. So despite the fact that these things are so small, they're invisible to the naked eye. There's so many of them that they weigh a thousand times all the humans.

Welcome to the show. I'm Jordan Harbinger. On the Jordan Harbinger show, we decode the stories, secrets, and skills of the world's most fascinating people and turn their wisdom into practical advice that you can use to impact your own life and those around you. Our mission here on the show is to help you become a better informed, more critical thinker

through long-form conversations with a variety of incredible people, from spies to CEOs, athletes, authors, thinkers, to performers, even the occasional former cult member rocket scientist. If you're new to the show or you want to tell your friends about the show, our episode starter packs are a great place to do it. These are collections of our favorite episodes

on persuasion, negotiation, disinformation, crime, cults, and more, and I'll hope new listeners get a taste of everything we do here on the show. Just visit jordanharbinger.com slash start or search for us in your Spotify app to get started. By the way, shout out to Farid for his feedback on the show intro recently. They were getting a bit long. I admit it, but we trimmed it all a little bit. How you like me now? Today on the show, the modern world has been shaped by microbes as much as it has been shaped by the men and women who inhabit it. My guest today, Jonathan Kennedy and I will discuss human history in terms of pathogens and diseases and the way that diseases and epidemics have shaped

society and civilization. Plagues, essentially, have made a lot of big moves in civilization and made us turn in some pretty stark directions. We're going to explore all that today. If you're a fan of books like Sapiens by Yuval Noah Harari or you love history and science or the combination of history and science, I think you're going to dig this episode. Here we go with Jonathan Kennedy. I got interested in this because while they're are tons of history books. I think few focus on how diseases, especially pandemics, have driven human history. And so that's a unique angle that I think you took with this. Yeah. And I think, you know, my background's in history and sociology. And I guess, you know, a couple of years ago,

I came to the realization that in many ways we're still very much stuck in the age of the Old Testament, you know, if you go back to your Genesis where God supposedly created humans in his own image and then gave us dominion over the land, the sea, and all the animals in it. And we still seem to think very much about the world in that way. We see the world as a stage on which humans, whether that's great men and women or classes that are struggling, play out our roles. And we see the natural world as just a blank canvas. But actually, you know, like the more I read about science and the science of diseases and pathogens and microbes, I realized that, you know, the world isn't a stage, the natural world isn't the stage with, you know, we live in a system, an ecosystem,

and we're a relatively small, small part of that. And, you know, you can measure the importance of microbes or pathogens in many, many different ways. And I can just throw out a few factoids that I think might blow your list as minds to start with, because they certainly did for me when I was researching the book. One is that if we were to take all the bacteria on our planet and weigh them, their mass would be about 1,000 times more than all the humans. So despite the fact that these things are so small, they're invisible to the naked eye, there's so many of them that they weigh a thousand times all the humans. And another crazy fact relates to viruses, which tend to be even smaller.

If we were to take all the viruses on the planet and put them end to end, according to an article in nature microbiology, they would reach for something like 100 million light years, which it's just kind of, it's just a mind-boggling figure. But I guess the research that really got me into this was not about the numbers. It was about the actual impact that these microbes have on our bodies. And we can look at the impact of viruses, say, on human evolution, which again is really, really, really surprising. I think your listeners might be shocked by it. So there are a particular type of virus called retroviruses,

and they reproduce by basically inserting a copy of their DNA into our DNA. When they infect the cells, our reproductive cells, so either our sperm cells or our egg cells, something really remarkable happens. Basically, the DNA from the virus gets passed down to our children and our children's children, and so on. That's kind of gross, actually. But go ahead, continue.

That gross, that skews me out a little bit, man. It gets grosser. Yeah, I bet. It does. So about 8% of all the DNA in our genome comes from these viral infections, which is surprising. But then we humans seem to have acquired functions

from these viruses that are really important to human existence. So one example is the ability to form members. So the way in which kind of information passes between brain cells is very similar to the way that viruses pass their DNA from one cell to another. And when scientists looked at the gene that codes for this in humans, they found that it was inherited from a viral infection that occurred maybe 400 million years ago. Wow. What?

So we have memory because an early ancestor of human, of homo sapiens, got a virus. Yeah, that seems to be the case. Wow. And scientists have managed to breed, I think mice, mice or rats without this particular gene. And these rodents aren't able to learn things and don't seem to be able to remember, remember things. So it's really kind of mind-boggling. But my favorite one is probably the ability to have children through kind of live birth also seems to have been, at least in part, made possible why one of these retrovirus infections that occurred, something like 180 million, million years ago. So the substance that binds the placenta to the uterus in the female body is very, very similar to the substance that viruses use when they're trying to enter a cell without being detected by the immune system.

And this might sound surprising, but actually it shouldn't be because the placenta is really a remarkable organ because it allows basically a genetically distinct object to form a bond with the host. And in most situations in nature, if something tried to do that, it would be destroyed by the immune system. Right, it's a parasitic relationship. Yeah, yeah, yeah. But because our bodies have copied or have borrowed this technology, I guess it's kind of prehistoric biohacking in a way from viruses, they're able to overcome that problem. And, you know, kind of being able to carry your young in your womb for nine months is a real evolutionary advantage, right? It's much safer than laying some eggs somewhere and then maybe running away when a lion comes and rules at you or something. thing. So, yeah, really, really, really mad. Let me get this straight. So basically, if humanity hadn't

been infected with this retrovirus, so in early ancestor of humanity, humans would reproduce by laying eggs as well? Yes. So if a shrew-like animal hadn't been infected by this virus about 180 billion years ago, we would be laying eggs or we would be born from eggs, which is, uh, wow, it's hard to get your mind around. It is. We're not talking about like a humanoid type of thing. We're talking about an early mammal. Yeah, it's a long time ago. Yeah. This is the beginning of mammals really, but we don't have to go back all this far.

I think another bit of research, another study that really encouraged me to look at the impact of infectious diseases on society was by some Belgian scientists. And basically what they did was they took the feces of 2,000 Belgian people rather than me. And they look through it. And they tried to sequence the DNA of all the bacteria in the feces. And they found some pretty remarkable things. First of all, they discovered basically that the bacteria in our gut or something like 90% of the bacteria in our gut is capable of producing neurotransmitters.

So chemical messengers like dopamine, serotonin that are capable of influencing human moods. And this kind of really raises the question why. And it seems like over millions of years, these bacteria have evolved to communicate with us because perhaps they realize that if we're more gregarious, if we're happier, we're going to go out, we're going to socialize, and we'll provide opportunities for these bacteria to colonize another body. I'm trying to think about how that might happen. Like, hey, let's make him happy so he goes to this party. Dot, dot, dot, dot.

Your poop gets into somebody else's body. It's like, what kind of parties were they having back then that allowed that? to happen. That was the days before germ theory, so people weren't washing their hands. Right, right. Now, that all makes, unfortunately, makes too much sense. Yeah, that's really, really gross. Imagine that research study, though, man. How did this Barbie doll head get in here? I don't know. There's a lot of, that's a lot of filtering through feces. That's an unfortunate position as a research student, as a PhD student, like, you're going to be spending the next three years digging through other people's poop. But it'll be interesting, we promise. Yeah, that's not for me. I guess, I guess they got there.

they got their rewards in the end. They got an article. I can't remember if it was nature or science, but yeah, it's a pretty shitty way to do it. I see what you did there. Excuse the pun. But what was really interesting as well with this study was that they basically found that people in the sample that had been diagnosed with clinical depression were lacking in a couple of types of bacteria. And these bacteria were capable of producing neurotransmitters like dopamine. So again, this is really, it's really fascinating. One, because it makes you wonder, perhaps in the future,

therapy or Prozac won't be the best way to treat clinical depression. Perhaps having some kind of fecal transplant will be even better. But it's, I mean, just this whole study, and there's loads of stuff. I mean, I'm sure you've had guests on talking about the microbiome

and the fact that there are more bacteria in our bodies than there are human cells. Yeah. I guess you're right. It's only a matter of time until you're not taking the pill orally, but you're putting it in your backside, and it's hopefully, hopefully that's all it is, and then it's colonizing your gut, you know, with something, because I'd wager most of the things

you take orally just never make it that far because of stomach acid and other digestive processes. Yeah, exactly. They just get kind of destroyed on the way, on the way through. And yeah, this got me thinking, you know, if bacteria and viruses have such a big impact on our bodies, on us as individuals, what kind of influence do they have on, you know, kind of aggregations of bodies, on society, on history, on economics, on politics. So all this research about pathogens and microbes, this really kind of got me thinking about history and society in a totally new way. And I guess it was also, you know, the fact that we were living through a pandemic at the time, which got me wondering about that as well. Is pathogenesis a real word or is it just a catchy

portmanteau of pathogen and genesis? I mean, my background isn't in medicine, but I found myself teaching in a medical school, teaching public policy and public health. And, you know, certainly people in the medical school study pathogenesis, so that's, you know, this is going to test my, test my Greek, but patho is kind of disease and genesis is the creation. So pathogenesis is basically kind of looking at the way in which diseases develop, usually in cells or in the body.

But I guess it's a play on words, the title of the book, in the sense that I look at the way in which diseases, you know, kind of create new societies or new opportunities for different exciting ideas to emerge out of the chaos that they create. The Black Plague and other pathogens have killed so many people. And you mentioned that those who survived had genes that gave them a stronger immune response or boost when faced with this pathogen. So it almost seems like this whole hubbub about like alpha males, natural selection, eat or be eaten or whatever, it seems like actually it comes down to immunity instead of being a tough guy, at least at the macro scale. Now that's a funny thing because, yeah, we think about this kind of Darwinian idea of survival of the fittest as being about, you know, kind of being able to fight other men or being able to fight off other alpha

or other apex predators, you know, your lions or your or, or, your tigers or whatever. But when you actually look at what have been the biggest causes of death, certainly over the last kind of 10,000 years since the transition to agriculture, it's been infectious diseases. And so the capacity to survive infectious diseases is kind of really a massive survival advantage. And I guess the kind of weird thing with that as well is that although often we can have genes that confer survival advantage on us in the face of infectious diseases, frequently these genes actually interfere with the normal functioning of the body. So the classic example here is with sickle cell anemia, which is really effective in places where malaria is endemic at

stopping the plasmodium kind of making you really sick. But the kind of downside of that is that it creates all sorts of complications in your body that kind of really create debilitating pain and really, really unfortunate. And this is just the kind of worst and most famous example. but this happens in multiple other cases with other infectious diseases that, you know, kind of a successful immune response also kind of leads to some other negative aspect in the human body. So although we're fit to fight diseases, in many ways we're less kind of well-functioning human beings. If the bacteria and viruses are able to transmit or transfer DNA to humans, were they able to do that with each other as well?

Can bacteria and viruses either interspecies or within their own species, can they transfer that DNA? Basically, how do they get it? Bacteria are really kind of remarkable because certainly they're able to engage in kind of the horizontal transfer of genes between species. So again, this is a kind of, I guess, a form of biohacking in nature. And again, something that really kind of shows you the limitations of the Darwinian model of evolution through natural selection. You know, one strain of bacteria can immediately acquire certain genes that provide it with, with advantages. And I think the interesting thing about this is that, you know, it helps us to understand why antimicrobial resistance is such a big problem, right? You know, we're kind of,

we're in this, or we have been for, ever since we've been on the planet in this battle with bacteria and they're inside us and all around us and many strains of bacteria are evolving in ways that harm us. But they have kind of a variety of advantages. One, they reproduce much quicker than us. And two, they're able to horizontally transfer genes between species, which makes it a pretty unfair, unfair fight in some respects. When you say horizontally transfer DNA,

do you mean that, let's make like a human analogy? If I'm a bacterium and I'm in the room with a bunch of other bacteria, can I say the equivalent of, wow, it's amazing. You're not killed by UV? I kind of want that special power. Can you give that to me? And then I get injected with that. And I'm like, thanks, bro.

Is that the dumb bro version of how this happens? Or is it more generational? I think that's pretty accurate. Ed Yong, who the brilliant science writer, he kind of describes it as being as easy as exchanging phone numbers. So I think your analogy is pretty spot on. I'm shocked that I got that even remotely close

because it sounded stupid before I said it and definitely sounded stupid after. That's incredible because they can almost sort of naturally select in real time, right? Oh, there's chemicals here that are not good for me. Oh, you don't seem to be affected by this. Give me that. It's like handing out gas masks in a room where there's a toxic gas or handing out sunshades because there's UV. It's just, but all almost in real time. Otherwise, because the bacteria, what do they live, a few hours or days or whatever, a lot of the time. So that's an amazing ability that is shockingly sophisticated for something that is

so tiny and so basic and millions or hundreds of millions of years old. That's incredible. Yeah, you know, it's totally incredible, as you say. What is the poison antidote model? I haven't know. First of all, I've got a note here and I don't know how to ask the question. I just wrote poison antidote model, but I have no idea how to lead into this. So yeah, it's a really interesting concept. So I guess the closest thing to the horizontal transfer of genes in humanity is kind of when we look back at the interrelation between homo sapiens and Neanderthals, 100,000, 50,000 years ago. And some of your listeners will will know that, you know, humans have certainly something like 2% of their genes comes from Neanderthals, at least if we're

of European or Asian origin. Native Americans as well, African, people of African origin have significantly less, but still some. And we've known this since. about 2010 when Svantapabo, who won the Nobel Prize for Medicine last year, managed to basically kind of work out the genome of Neanderthals and found that actually we were pretty closely related to Neanderthals. Surprise, surprise. We shared lots of genes with them. But the thing to remember is this 2% of genes, they're not randomly selected genes.

They're ones that provided our distant ancestors with a survival advantage as we were pushing out of Africa between 150,000 years ago. So we would have evolved for hundreds of thousands of years in tropical Africa and would be used to that kind of climate and that disease environment. And as we were pushing up through the Middle East into northern Eurasia, it was cold, it was dark, but also we were coming across different infectious diseases and infectious diseases that were carried by other species of humans like Neanderthals, which had evolved in Europe and in other parts of Eurasia.

And I guess the thing to remember is when we first came into contact with Neanderthals after perhaps our ancestors being separated for half a million years, you know, it was probably really devastating. We were coming across new infectious diseases that we had no immunity to and the same for the Neanderthals. And so probably in the first interactions we would have met, we don't know what happened. We know that some of our ancestors had sex because we can still see the artifact of those trists in our DNA.

But it's also very likely that we got sick and a lot of people got very, very ill or died. And it doesn't seem like we kind of evolve through natural selection, better immunity. We just acquired wholesale these genes from Neanderthals. That's interesting. Oh, I see. So this is the poison antidotes model. The NAN-Stars give us the poison in the sense that they have these infectious diseases that are making us really ill. But they also provide us with the antidotes in the sense of the genes that they've evolved over hundreds of thousands of years. So again, it's like another prehistoric form of biohacking where we can kind of take wholesale these genes.

So somebody took one for the team in a big sort of immunity boosting way for the rest of humanity? Yeah, several people. in the... Several million possibly, yeah. Yeah. Doing this. So, okay, if humans and Neanderthals shared these immune defense plans, so to speak, along with the actual diseases, why did humans or Homo sapiens, I probably should use the actual term here, why did Homo sapiens prevail?

Is it because we're smarter? Is it because we had language? Is it because we had better social structures? Because it seems like they had better immunity, or did they just have different immunity? They had different immunity. So we were trying to push into a new disease environment, and they were suited to that, and we weren't. But yeah, it's a really interesting question. Why did Homo sapiens survive and Neanderthals disappear?

And the traditional argument is that we were smarter than them. And, you know, this argument is even inherent in the name that we give ourselves, right? We call ourselves Homo sapiens, wise man, wise humans. And in fact, there was a zoologist in the 19th century just after Neanderthals had been discovered, who suggested calling them homo-stupidus, so stupid humans to distinguish between the wise and the stupid species of humans. But the more that we learn about Neanderthals, the more that we realized that they weren't these kind of brutish cavemen. And there's been some really fascinating archaeological discoveries in the last few decades. So we know now that Neanderthals buried their dead.

They might have even buried their dead by putting flowers on top of the graves. There seems to be some evidence of that, although that's questionable. We know that they looked after they're sick because, you know, kind of, evidence of Neanderthals that were really badly injured in childhoods who survived for decades have been found. We know they were capable of traveling by boats in the eastern Mediterranean, that they used medicinal herbs to treat various maladies. We know that they talked, they used fire, they painted cave walls, not as, not as beautifully

as some of the cave paintings that occurred a bit later like Laskau, but still they were interested in these aesthetic concerns. I'm shocked they made boats. I hadn't heard that. I had no idea about that. That's really interesting. Incredible, actually. Yeah, so basically anthropologists, archaeologists have found evidence of Neanderthals in islands, certainly around Greece that were islands kind of 50,000, 100,000, 150,000 years ago. So there was no other way that the Leanderthals could have got from the kind of landmass of the old world to these islands without going by boats. So yeah, really amazing. And it kind of built up this picture of a species that isn't that different to us. So yeah, kind of the question is

why did we survive and they didn't? And the answer is pretty simple, really. We'd, we or homo sapiens, had been living in tropical Africa. And if we go back to our kind of basic physics biology, if you're closer to the equator, more sun hits the earth. So you tend to have more vegetation, more animals living on that vegetation and more microbes living on the vegetation and the and the animals. So homo sapiens, when they were pushing out of Africa, they carried more and more deadly infectious diseases. And so we overcame the disease burden of Neanderthals quicker than they overcame ours. And so we were able to kind of basically push through into Eurasia with immunity and spread throughout the world pretty quickly. Now, the agricultural revolution, we, humanity,

homo sapiens switch from, sorry, this is going to remain clunky folks, because I should probably use these technical terms here, these scientific terms, just to avoid confusion. But the homo sapiens switch from hunting and gathering to essentially agriculture and farming. What does this do for diseases? And why? You know, this is a really important development in the emergence of infectious diseases, because, you know, for the first time in history, humans are living in close proximity to one another, but also in really close proximity to animals, both farm animals and also the kind of parasites that live on those animals and the various kind of rodents and things that are attracted to grain. So all of a sudden you have kind of these Jim Scott, the Yale-based anthropologist refers to them

as multi-species resettlement sites. So basically all of a sudden humans are living cheek by jowl with animals of various sorts, which creates new opportunities for infectious diseases, zoonotic diseases, to jump from one species to the other. And we're also living close to one another. And we're trading with people in far-flung destinations. So this creates the ability for these diseases once they've jumped the species barrier to spread quickly through the village and then spread along trade routes. And this is when you get the emergence of infectious diseases as we now know them. So I think it's really interesting to think that, you know, we certainly wouldn't be here chatting on

Skype or Zoom if this kind of transition from hunter gathering to settled agriculture hadn't have happened. In some respects, we can argue that it's a good thing because it's brought us civilization or whatever we think of as civilization. But we should also remember there's a kind of dark side to this as well. And that's the emergence of infectious diseases, this kind of real golden age for microbes. And whether you look at the genetic data or you look at kind of art history. It's clear that many of the infectious diseases that have really devastated humanity for the last few thousand years emerged in the wake of this transition to agriculture. So things like the plague, smallpox, polio, they all seem to have emerged after the transition to agriculture.

I mean, it all makes sense, right? Instead of just walking around and setting up camp and picking berries and hunting the occasional animal with your small tribe, now you're living in a small, a small town or whatever a city was at that time, a few thousand people, and you're living with, I don't know, what do they domesticate early? Pigs and things like that. And then you've got rats and then you've got fecal matter on the ground from humans and animals that the rats are getting into and then they're biting you when you sleep. I mean, that all just seems like a giant cesspool, petri dish of new diseases that humans had never seen. No, no, exactly. And I guess like the scary thing is we can also make a comparison to today, right? I mean, sure. But yeah, I think we're,

We're living in a new, a new kind of golden age for infectious diseases now, right? You know, I think probably before COVID, a lot of us wanted to ignore this fact, but the unprecedented size of the world's population, the fact that we live so closely together, that we're encroaching on animal habitats, just the industrial scale of factory farming, not to mention the fact that we can travel so quickly between, you know, really distant parts of the world.

This creates the perfect conditions for new pandemics to emerge and to spread really quickly. So it's interesting to see that we're in almost kind of, yeah, the golden age for infectious diseases 2.0 and to look at the parallels between the kind of transition to agriculture and then, you know, whatever we're living in now, the industrial or the post-industrial age. You're listening to The Jordan Harbinger Show with our guest, Jonathan Kennedy. We'll be right back. If you're wondering how I managed to book all these amazing folks, it's all about my network. I don't like the word networking.

I think it's kind of gross. I've got a course on networking, for lack of a better word, over. at Jordan Harbinger.com slash course, but it's not cringy, it's not schmoozy, it's down to earth, it's not going to make you feel weird when you do it, it's not going to make you look bad, and many of the guests on the show already subscribe and contribute to the course.

Come join us, you'll be in smart company where you belong, and there's a happiness dividend with reaching out to people and creating new connections. Find the course again for free at Jordan Harbinger.com slash course. Now, back to Jonathan Kennedy. It is a vulnerable feeling, and you're right, I was going to mention

that you could go on a trip to the Amazon jungle for two weeks. I did that a few years ago and end up in the middle of absolutely nowhere sleeping at a far-flung science research station. In the longest part of the journey is the boat ride and the bus ride through the jungle. The plane ride is shorter, right? And that's kind of scary because that means you've gone really damn far into the middle of areas where there aren't even really humans other than uncontacted tribes that are staying well away from this.

and you're getting bit by sandflare. There was a guy on our trip. I've said this on the show before, I'll keep it short. There was a guy on our trip that got Leishmaniasis on his face, which is a flesh-eating bacteria. And it's gross. At least we knew what it was. But there's probably other stuff out there

that we are not quite sure what it is and some unlucky tour guide or tourist or whatever's going to end up with it at some point. Yeah, no, it's nasty to think about. But I guess kind of counterintuitively, or maybe not counterintuitive, but I think kind of the, you know, we have to worry about that, but also the size of farms and the people that kind of work in farms and the opportunities that that creates for diseases to jump

from one species to our own. It's pretty, pretty freaky too. But scientists have calculated something like there's a two to three percent chance of a COVID-strength pandemic happening every year, which, you know, it sounds okay if you take it year by year. But when you, when you kind of think cumulatively that in 25 years time, there's a kind of, 50-50 chance of another massive pandemic occurring. It's pretty sobering. Yeah, especially since a lot of people like my age are going to be the age that people died when they got COVID or slightly younger. And this could be a worse pandemic. So it's like, oh man, maybe we're going to end up with something way worse when I'm in a much more vulnerable position in terms of my immunity. Not super comforting

at all. Also looking at our reaction, it's a little scary because 25 years sounds like a long time, but are things really going to get that much better? I don't know. I'm not sure. I guess the thing to remember is we're in a better position than we ever have been. You know, kind of COVID was terrible when it killed millions of people and caused just almost unimaginable disruption. But it was really remarkable, almost miraculous how scientists got together, shared information about the disease, created several effective vaccines within, you know,

a year and rolled it out really, really, really quickly. And so, you know, certainly enormous amounts of money are being put. into medical research, some of the things that they will be capable of doing in 25 years are going to be, you know, beyond our imagination now. So we can perhaps be a little bit, if not confident. There's reasons to be hopeful as well. Yeah, indeed. I'm trying to be more of an optimist, but yeah, it's just scary that you can have a pandemic and then, oh, we're probably going to have another one because our parents didn't really have to deal with that at all, right? I mean, the last big one was, flu was what, 1918, Spanish flu? Yeah, well, I think the thing

is that, you know, antibiotics and vaccines, you know, they created a really exceptional period of time in the second half of the 20th century and the first couple of decades of the 21st. It kind of brought us this kind of really, really incredible reprieve in the age-old battle against infectious diseases that maybe lulled us into a full sense of security. I think so. But, yeah, certainly our parents were really incredibly lucky in many ways. Indeed. Medicine was another reason to be happy.

You mentioned in the book that many more child skeletons were found after humans settled, and that that tells us that there were more diseases that affected us in childhood. But, and I'm sure they've controlled for this, but I'm curious how, is that really because a disease or is that because we can simply find those skeletons because they're in ancient settlements? It seems like if your hunt are gathering and your child dies in the middle of the Eurasian step and you bury them in a shallow grave because you're moving along, like we're just never going to find those.

So is it kind of like a selection bias? bias in a way? That's a great question. And thinking back to the study, what the scientists show is that it seems like for about 500 to 1,000 years after the transition to agriculture, more or less anywhere in the world, you see a boom in population. The numbers of people living seem to expand massively. And then after about 500 to 1,000 years, you seem to have the emergence of infectious diseases. So they've measured this by showing that you have a kind of a really distinct increase in the number of children and adolescents in cemeteries after about 500 years from the transition to agriculture. So, you know, of course, when you're looking in the distant past, it's,

it's really hard to be certain and you're piecing together, you know, different bits of evidence, but you, you know, you obviously, there's an element of guesswork. But, you know, that study seems pretty robust to me and it kind of, we could just take an example. A couple of weeks ago in the UK, scientists managed to find the oldest evidence of plague ever. So this was in Somerset in the south of England and in Cumbria in the north. And this was basically kind of 4,000 years ago, so almost exactly 1,000 years after the transition to agriculture. So yeah, you seem to see this kind of more or less everywhere that you look, this kind of increase in mortality due to infectious diseases becoming basically,

infectious diseases becoming endemic, right? Because the adult population have either died in childhood or developed resistance. And so it's the young people who are dying. I'm just never going to assume that I thought of something after reading three lines in a book that the scientist who did the entire study that hadn't occurred to this world-renowned expert on this particular thing. I just always curious how they control for that sort of thing when it's it's almost like what's that fallacy post hoc, ergo proctor hoc, right? Like the correlation. versus causation. Or like sampling bias

just seems like a really low-hanging fruit. Like, oh, we're finding all these skeletons in ancient settlements that have cemeteries. And we're not finding them in places that, you know, checks notes, don't have cemeteries. Okay, well, duh, that makes sense. You're right to raise these questions. But, you know, I really must say,

having written this book that, you know, really tries to summarize and bring together a massive amount of information and a massive amount of evidence from all these different academic disciplines you know, kind of archaeology, genetics and things. You know, it's really incredible how much these researchers can tell from just a few clues and how they can kind of make these logical inferences.

It's really kind of really impressive. They're almost like alchemists. They can kind of turn a few fragments of bone into kind of this wonderful new knowledge. It's really incredible. It is. It's like Sherlock Holmes, right? Like, look at this fragment of bone. This is from a femur.

and you can tell that this person had some sort of neurodegenerative disease because this length would have been longer in a normal person of this age. Therefore, they must have had this type of disease and it looks like there were this age. So it must have been this particular. It's just really, it's like watching Sherlock Holmes, but with actual science. It's really incredible. That's why I love books like this and really love science like this. And in the book, you mention a lot about the Neolithic farmers bringing disease to hunter-gatherers. And there's really fascinating evidence for how these populations spread. One really cool example for the language nerd in me, which was that Farsi, so Persian, and European and other languages, all have

similar words for wagon and wheel and, I don't know, like other vehicle parts suggesting that the migration of those populations happened after wheeled vehicles were invented. And I don't know why that's so damn fascinating, but it really, really is. Because just to know that, these languages that you think probably have almost nothing in common. It's like, well, actually, they're all from the same ancestor language. And look, the word for wheel is so close. You can tell right away that this is the same popular, it was at one point, the same population of people.

Yeah, I love reading about that stuff as well. And I guess kind of there's been a mystery ever since people realized the connection between English and Greek and Russian and languages like Hindi or Sanskrit. They're from the same language group, you know, kind of why is this? and what's the origin of this? And there's this assumption that what we call proto-Indo-European started off being spoken by a small group of people somewhere in the world or somewhere in Eurasia. And then at some point in history, they spread to Europe and they spread to Central Asia

and even to South Asia and brought their languages, their language with them. And then gradually over time, these languages became more and more different and basically evolved into the tongues that people speak today. it's only the last few years that scientists have really understood what the actual source of Indo-European languages is. It seems to have happened about kind of 5,000 years ago when you have this massive movement of people from the steppe, so the kind of the vast grasslands of beyond kind of Europe in southern Russia above the Black Sea, going all the way to China, basically. There was this big movement of people out of the grasslands and they swept across Europe.

And we can map this kind of by looking at the DNA of skeletons, how they moved across Europe. And this movement of people happens as wagons and horses were also introduced into Europe. And so we can infer from this that this population movement was responsible for the spread of Indo-European languages. But interestingly, there's kind of a few language isolates in Europe. So languages that aren't related to any... Basque in Hungarian. Basque seems to be the language that was spoken by the people that lived in Europe. before this big movement of so-called step-herders.

Yeah, this is another kind of interesting artifact. You know, I didn't really think about that. I just thought a specific population had either evolved their own language or moved to that area, but actually it's the equivalent of having a state in the United States that speaks whatever Apache, Native American language entirely,

and it's because they just somehow managed to not get overtaken by the Neolithic farmers who had wagons. Do they live in mountains or something? How come they survived and nobody else seems to have preserved their language and culture? Yeah, the vast country is pretty mountainous. It's kind of the border of Spain and Spain and France. And so, yeah, they seem to have managed to avoid the pressures to speak this new language.

There's a massive historical advantages to being a really big pain in the ass to either invade, conquer, or travel through, right? It's just if you live on the edge of something and you're really high up or really far down, it's like, I'm not going all the way up there. just to oppress people. I've got enough slaves or labor or animals or resources down here. I'm not climbing all the way up there. The book has a lot of different sort of historical plagues and as almost landmarks in history, Greece, Sparta, Athens, ancient Greece between the power balance between Sparta and Athens. I'd love to skip ahead, though, to the Roman Empire because you've got the Antonine plague. And you described the Roman baths and sewage system, which is just a marvel of the entire world, right? The aqueducts and the fact that they had this massive sewage system and

the bathhouses and the water coming in. So it's simultaneously one of the coolest inventions in history, but also super revolting. I mean, it's just absolutely a miracle that any of those people survived having that kind of system in place because as disgusting as it is, it is really, it does show you how resilient humans can be, but man, is it gross? Can you speak to that a little bit? Like I said, It's a miracle anybody made it out of there alive. I mean, I guess when you travel to Rome or former Roman cities today, you know, you see the infrastructure that they built. You know, if you go to Rome, you can still see evidence of the baths and the aqueducts that brought kind of this enormous amount of fresh water flowing into the city. And it seems like, yeah, it must have been a pretty clean place.

But actually, when you think about it, when you look at the evidence, it was pretty gross. So people would go to these communal baths. Sometimes they had the capacity for several thousand people. It's not clear how often the water was changed. And the bayers certainly didn't use soap. They maybe used a bit of olive oil. The baths would have a fair amount of fecal matter and other stuff. Can you imagine how they smelled too?

I mean, all the BO from all the people. And yeah, no soap. Didn't they rub olive oil on and then basically scrape it off right into the water too? There's just this, I don't even want to. Yeah, no, no, exactly. And something even grosser, perhaps, is the communal toilets. So, again, you can still see these communal toilets in various places. Some of them are even made of marble.

So it's just these big rows of marble with holes in over the sewers. And it seems pretty civilized, but then you remember that there's no kind of barriers. So everyone's just sat there doing their business. And there was no toilet paper either. So the Romans had these sponges on sticks that seemed to be shaped. Oh my gosh. communal bathrooms, which is... Oh, sorry for anybody who's listening to this over there, lunch hour.

I was not expecting that. That's so disgusting. Oh, don't worry. I'll just wash it off in the bathwater. I'll be right back. The sewers weren't great either, so apparently you had kind of regular exposions would kind of thrust fire and human waste out of the...

Fire. Oh, because of the gas lighting. Yeah, yeah, the gas. The gas, the methane, whatever, and the heat would build up, and then there'd be these kind of periodic explosions that would fire poo out of the toilets. Into the air for everyone to enjoy.

That's really, really, really gross. That's even worse. I thought the shared bathwater thing was gross. That is next level disgusting. Wow. So, shockingly, they had plagues in the Roman Empire. Can we talk about that? Because you mentioned coin production

is kind of almost a barometer of how well the population was doing, thought that was also quite fascinating. Yeah, so I think, you know, maybe we should start with the Pax Romana. So this was this period for about 150, 200 years at the beginning of the first millennium. And it was a time of unprecedented peace, obviously, but also prosperity. Rome was a city of a million people. So perhaps London in the 19th century was the next city to reach this size.

It's really remarkable that 2,000 years ago, there was a city that was this big, even if we kind of could be discussed by the states of the public health. It's still remarkable that you had a city of that size. And you had enormous amount of trade within the empire, but also, you know, you had trade links with sub-Saharan Africa, with India, and you even had kind of people traveling as far as China in the middle of the second century AD. I guess kind of so often in the story of this book,

progress, technological developments, improves lives for people, but it also creates the perfect conditions for pandemics. So again, kind of this increased interaction with the wider world and basically kind of created opportunities for infectious diseases to kind of travel into the empire from outside the citizens had no, no immunity to. And then, of course, because it was such a heavily populated, urbanized, well-connected polity, basically this created really the perfect conditions for infectious diseases to spread. And so you have a couple of really devastating pandemics in, well, the middle of the second century, in the middle of the third century. And, you know, we can look at eyewitness accounts

to understand what was going on. But as you say, one of the really interesting ways that scientists have discovered, you can understand what was going on is by looking at ice cores dug in the Arctic or drilled in the Arctic. And this allows you to go back and look at ice laid down 2,000 years ago. and see what the quality of the water and the air was like. And so basically, scientists really ingeniously have looked at the lead pollution through ancient times. And lead pollution is important because it would be a byproduct of processing silver ore. So when lots of silver ore was being mined and processed and used for creating Roman coinage, then there'd be lots of lead pollution in the ice for those years.

but you see kind of an absolute collapse in the middle of the second century AD, and it gets even worse in the mid-third century when you have what's called the Plague of Cyprian, which seems to cause kind of absolute chaos in the empire. And it does manage to recover, but it's never quite the same again. And this is certainly the kind of the beginning of the end for the Roman Empire as we know it. in big part because the Romans in their urbanized, populous, well-connected empire are really badly affected, but then you have these so-called barbarians, as the Romans called them, who were living beyond the borders in conditions that were much less conducive for the spread of infectious diseases.

So Rome wasn't just weakened in absolute terms by these pandemics. It was also weakened relative to its neighbours, and this created opportunities for the barbarians to breach the kind of rivers of the north, the Rhine and the Danube, and also to kind of attack from other directions too. What was the big one, hemorrhagic flu? It's like Ebola, right? You're bleeding from your eyes, ears, and it knows. I mean, it's just, it's really bad.

I mean, I think Ebola still kills like half the people it infects, even with modern medicine. Maybe I'm exaggerating a little bit, I'm not sure. No, no, that's about right. So, yeah, Carl Harper, certainly the historian, He looks at the eyewitness accounts and cross-references that with modern medicine, and he reckons that the plague of Cyprian was, yeah, some kind of hemorrhagic fever, something like Ebola, and, you know, that's a really, really deadly disease.

It's also interesting, you know, kind of certainly these plagues had a devastating effect on the empire, but they also created opportunities for other ideas to emerge. And it's interesting to think about the impact that the plague of Cyprian seems to have had on religion. Yes, I'd love to talk about that because it basically, yet of a tiny sect of Judaism, Christianity, that's now over 2 billion people. How did the plague influence this? And I'd like to really break this down so Christians listening can learn about this. I'm not religious, but I would wager that most Christians don't know about this and would find it really interesting because I'd never heard this in my life. Yeah, so I think the thing to remember is that Christianity didn't immediately emerge as a empire-wide religion during the life of. Christ or even immediately afterwards. So in the beginning of the third century AD, Christianity was, as you say, still a really small sect of Judaism. It maybe had 100,000 followers out of a population

of 70 or 80 million in the empire. So something like Sikhism in the US today, I think, if my calculations are correct. And then all of a sudden, in the second half of the third century, you see the popularity of Christianity absolutely explode. We know this by looking at. at the numbers of Christian burials in the catacombs of Rome, or by looking at the increased percentage of people who have Christian names in papyrus documents that have survived in the arid Egyptian desert. And then, yeah, in 312, Constantine, the Roman Empire, converts to Christianity, and then a decade later, Christianity becomes the official religion of the Roman Empire. You know, that's the beginning of Christianity becoming a world religion. It's a really, really important

step in the development of Christianity towards something like what we see today. And there's a big mystery. Why did this happen? Why was Christianity not that popular for a couple hundred years? And then very, very popular from the middle of the third century onwards. And I think the most convincing explanation, and this is one that's put forward by a variety of people, certainly Rodney Stark, sociologist argues this, that basically Christianity provided a much more assuring,

guidance to life and death during an age of pandemics than paganism did. So paganism had been the great religion of the Greco-Roman world, and they believed that pandemics were caused by angry gods, that it was the arrows of Apollo that kind of made people ill. And pagans also didn't really have a very well-developed idea of the afterlife. They thought that the here and now was basically the main show. And, you know, there were some vague ideas of what happened afterwards, but it wasn't very, very nice. And then, you know, the message of Jesus is really different, right? It's this idea that, you know, pain and suffering in this life can help us by or help us kind of enter this kind of eternal paradise in the next life. So all of a sudden provides meaning

to what was going on, this kind of horrific sickness that people were experiencing. It was no longer some kind of meaningless anger of God that we couldn't understand. We were suffering for a reason. And I think the other thing is that Christianity really emphasizes the importance of good deeds as a way of gaining favor with God. And so you have these eyewitness accounts of Christian bishops saying how the pagans abandon their dead and try and run away from the plague, whereas the Christians take them in and they care for them. And although, as we said, kind of Ebola or another hemorrhagic fevers, they're really deadly. If Christians were, you know, even giving these sick people water and some food and some shelter, this would have decreased the mortality rate by maybe something like

two-thirds, I think Karl Harper estimates. So this basically gives Christians the best commercial that any religion could ever have, which is miracles or miracles in inverted commas. And so this seems to help explain why you have this explosion of interest in Christianity in the second half of the third. Not only does it look like it works, but you're like, oh, these people have my back. I should probably join them because my entire family just ran away from me. My eyes start bleeding and everybody just leaves me behind. It's totally unfair. Yeah, I kind of get it. And you start seeing the plague is a good thing. It's kind of, it's testing me. It's testing my faith. I don't need to worry. If I die, I'll end up in a better place. That's right. You really find out

who your friends are when you start emmerging blood from every orifice. Exactly. This is the Jordan Harbinger show with our guest, Jonathan Kennedy. We'll be right back. If you like this episode of the show, I invite you to do what others smart and considerate and, and frankly, good-looking listeners do, which is take a moment and support our amazing sponsors. All the deals, discount codes, and ways to support the show are at Jordanharbinger.com slash deals. You can also search for any sponsor using the AI chatbot on the website as well, Jordanharbinger.

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Thank you for supporting those who support the show. Now for the rest of my conversation with Jonathan Kennedy. And another cheerful topic, how about the Black Death? This started and essentially leads to what we now know is modern capitalism. It really changed the entire world and the economics of Europe at the time. Yeah, so I think it's important to think what the world was. like at the beginning of the 1300s, you know, in certainly Western Europe, you had a feudal system where basically you had the king at the top and you had these big aristocratic clans that were

sometimes warring with one another that hopefully provided support for the king at various times and the king would give them the right to kind of control some land. And then those aristocratic clans would give lesser lords the right to control that land. And you had this kind of basically pyramid of obligation. It was very much like the game of Thrones. And this kind of worked reasonably well in a society where politics was very unstable because basically it allowed people to raise armies. But it was not conducive at all to any kind of innovation. Basically, if you're a lord, you want to spend any surplus that you have on either kind of building up an army or building your castle to defend yourself. And if you don't do that,

another lord who spent all his money on his army and his castles will come along and will take your little kind of area of land off you. Your fiefdom. Your fiefdom, yeah. And it's pretty similar if you're a peasant, if you're a serf at the very bottom of the pyramid as well. If you're a surf, you know, you want to take a really risk-averse approach because, you know, if you grow too much, the lord might take all that stuff off you.

And you just want to make sure that you have enough to live. So you plant different crops in different places on the estate. and you hope that some of it survives wild animals and bad weather and maybe marauding armies, so you have enough to live throughout the year. So basically kind of the economy more or less stagnates. You've had no real increase in the majority of population. Things haven't really got better since Roman times. But then all of a sudden you have this massive, exogenous shock. You have the black death. It comes from Central Asia. It spreads throughout Europe. Some estimates, suggests that it kills up to 60% of the population in about eight years.

Oh my God, can you imagine living through that? Holy cow. That's terrible, but the thing is that, you know, the plague returned again and again, you had the second plague in 1361 that killed maybe 30% of the population, and it just keeps returning every few decades for hundreds of years. For example, the population of Britain doesn't recover to pre-black death levels until about the early 18th century. There's this kind of massive demographic scar and really, really horrific, but the interesting thing is that this provides the impetus to basically revolutionise European society. So certainly you see in England there's all of a sudden a big struggle

between the serfs and the lords because the serfs all of a sudden realize that lands plentiful and labor is scarce and so they want better conditions. And the lord fights back. They use their domination of Parliament to pass various laws, laws that basically ban serves from moving from one manner to another. When that fails, they pass other laws that say that if you move from one manner to another, you can have your forehead branded with the letter F for falsity. I never quite got that. But yeah, and then another interesting law that was passed the kind of sumptuary law. So basically, they try to regulate the clothes that people at various, in various classes could wear, and even the foods that they could eat. And this basically suggests

a period of great kind of social upheaval where the upper classes were really concerned with what was going on and they wanted to keep the lower orders in their place. But eventually the Lord's efforts to stop change to kind of keep back the demographic tides failed. And about 100 years after the Black Death, basically every serf had won their freedom. And, you still continued with this struggle. And basically the situation that you ended up with maybe 200 years after the Black Death was one in which the Lords still owned the land, but they rented it out at market rates to the most entrepreneurial peasants who basically had big plots. And because it was at market rates, they had to use the latest technology. They had to grow crops

that were particularly suited to the climate and to the soil. And so you have this massive boom in agricultural productivity that, you know, basically kind of enables the growth of cities because an increasing proportion of population are able to live in in cities. And even the food prices begin to fall, which means that workers have more, more money to spend. And this really kind of kickstarts industrialization because they want to spend this money on manufactured goods, so things like textiles. But it also has an impact on colonization because people get a taste for sugar and they increasingly want to spend their money on sugar. So you see the kind of colonization of Caribbean islands and in order to grow sugar cane. So interesting that a disease kind of kickstart its capitalism.

It just killed enough of the labor force that they were like, wait a minute, I have more value than subsistence. You have to pay me now. Now I'm going to brand your forehead, which by the way, we should almost edit that out. I don't want to give Amazon any ideas. But the idea that they could try to enforce that was just like a losing battle. You look at capitalism now. It was a losing battle from the beginning. I know I'm going to take flack for this. I'm going to get a zillion emails. It really does look like the authoritarian communism that you'd see in like the Soviet Union. No, you just have to work and you just have to take miserable wages and we're just going to do this. And it's like, well, actually, I'm just going to sell things on the black market. I'm going to

walk out the back of the factory and it's going to breed corruption. And it just capitalism, it just sort of finds a way. It's like water in a container with cracks. it's really, really interesting. The diseases also seem to have played a role in wars. We didn't touch on the Greek stuff, but at least in the Spanish takeover of South America, I didn't know this, but the Spanish were relatively small number of troops, which makes sense, right, they came over on boats, but that civilization that they took over was absolutely huge, rivaled those of Europe in many ways, especially in terms of the numbers and population. And history kind of tells you it was horses, or depending on what history you're reading,

it might be miracles and horses. Good old fashioned racism plays a part too. The white man was sophisticated and the locals weren't. They were just naked running around eating berries or whatever. It's just not true. It really turns out to be germs, germs, germs, from the sound of it.

Yeah, yeah, I think, you know, that's a really good way of putting it. So, I mean, one point to make is, as you say, you know, there's this idea that the Americas was populated by a really kind of backward kind of population, but actually the evidence suggests that there were certainly some really quite advanced civilizations. If we look at the Mexico, the Aztecs, you know, they had this vast island city, Tenochtatlan, which is now the site of Mexico City that had maybe a population of 100, 200,000 people.

So it was perhaps about four times the size of the biggest city in Spain at the time, Seville. And eventually Hernan Cortez managed to conquer this great Mexico empire. with a thousand troops. And even accounting for the fact that he had some horses and he had some pretty unreliable guns, it's really hard to explain without resorting to miracles. But, you know, actually the key factor here seems to be infectious diseases and smallpox in particular, which devastated the Mexico and then actually raced ahead of the Spanish and ended up kind of causing massive disruption in South America and devastating the Inca Empire, another great. really sophisticated, advanced empire before the Europeans even arrived. And so you get Francisco

Pizarro turning up with 168 men and managing to conquer this vast empire of maybe 7, 8 million people. And yeah, no, I think if you look at what happened in the Americas in the 1500s, it's really shocking. You have first smallpox than pandemic after pandemic that doesn't affect the Europeans at all and literally decimates the indigenous population. The population of the Americas at the beginning of the century is something like 60 million and at the end of the century at 6 million. And again, going back to ice core data, scientists have noticed a dip in the amount of carbon dioxide in the air in the 16th century because so many American people died, so many Native American people died. They were no longer engaging in this slash and burn agriculture.

You can actually see this in kind of ice cores. And, you know, scientists have even suggested that this led to a fall in the world temperature and contributed to the coldest period of the little ice age, you know, kind of when the Thames in London froze over for several months every winter and entrepreneurial Londoners built bars and cafes and ice rinks on the river. So, again, it's kind of, yeah, it's a fascinating story that reminds us of our interconnectedness. and the vulnerability of certain populations to infectious diseases. So we hear about how cold, smallpox, stomach bugs, whatever,

killed all these indigenous people who were not used to these germs and had no immunity. But how come it didn't work the other way around? How come the Spanish didn't roll into South America immediately just get wrecked by some disease that the indigenous people have had endemic for thousands of years already? How come they didn't have a common cold that just decimated the Spanish? Is that just really bad luck for the environment? indigenous people and really good luck for the Spanish? Or does it have to do with the animal hurting and things like that? Yeah, that's a good question because there were certainly kind of

urbanized societies in the Americas and societies that engaged in settled agriculture. So, you know, there's a question why, why did infectious diseases emerge in the wake of the agricultural revolution in Europe, but not so much in the Americas. And the answer is pretty simple. And actually kind of this is one point where Jared Diamond is pretty spot on. He points out, He wrote guns, germs, and steel, right? Guns, germs and steel, yeah, yeah. And he points out that there aren't that many domesticatable animals in the Americas. You have muscovy ducks, turkeys, a few others, llamas, alpacas.

And the only ones of these that are herd animals are alpacas and llamas. And herd animals are particularly interesting because if animals live in big herds, then it provides opportunities for infectious diseases to kind of emerge. and be maintained in the community. But alpacas and lamas, they didn't live in really big herds. And so you don't see the emergence of these kind of neolithic infectious diseases

in the Americas that you see in Europe. But there is maybe one infectious disease that has its origins in the Americas, and that's syphilis, which caused much pain, much embarrassment to medieval Europeans or late medieval, early modern Europeans, but didn't cause,

the kind of devastation that smallpox or measles or flu caused. So there were infectious diseases that would have ravaged parts of the population, but it was more like it burns one IP as opposed to my entire village is wiped out kind of consequences. Yeah, yeah, got it. You can put it that way. Okay, yeah, I'm just an irreverent brick, I think. So your book really does underline the idea that Cortez was losing horribly against the locals, but then smallpox killed something like half the population.

inside of a few months or was it a few years, that level of devastation is really something. It's hard to imagine that level of devastation. How many debt are we talking about? Do you know numbers off top of your head? They estimate a third of the population in a few months, but then you have other diseases that cause similar levels of devastation. I think the real important thing to remember

is the fact that the Europeans weren't affected. And you can kind of start to imagine the impact that that must have on the indigenous population, right? We must have seemed like we had some kind of super power, or I guess, kind of our gods were just better than theirs. And this maybe helps to explain why, you know, kind of much of Central and South America today are still so religious. You know, the indigenous populations of the America seem to really kind of adopt Christianity in such a kind of enthusiastic way. And that enthusiasm endures to this day. By the way, if you're not eating right now, you can go ahead and Google smallpox and click on images and you will not like what you see.

Because smallpox is a really bad. It's a really disgusting way to go. And to watch like half your population die of this, you would be running to the nearest person who could tell you that it was the fault of having weak God. I mean, you really would. Actually, it wasn't even just the Spanish who defeated the local empire, right? They fought aside rebellious tributaries who later also got killed by smallpox. So it almost sounds like the Spanish were there. as is sort of typical of colonizers, to loot, steal, stir the pot, and kind of just pick up the pieces for the surviving, from the survivors. Yeah, the last men standing. And then they built this, they built the colony on the, I guess, on the ruins of the empires that they took over. Quite literally. Where are you seeing modern examples of diseases altering the course of history? Or is it too early to tell? Can you only see these things 500 years later? Yeah, I think, kind of, if we look at the book, you know, a lot of these examples,

examples play out over decades and centuries. But I guess the thing is history has speeded up quite a lot in the last few hundred years. If we think that it took a good 18 months for the Black Death to get from Constantinople all the way to Northern Europe in the middle of the 14th century, whereas, you know, COVID, it was discovered in the autumn of 2019. And a couple of months later, it was, it was, you know, kind of a real course for concern. And yeah, it's, it's a fourth. It's a fourth. It's a all's errand to predict the future, but I think we are starting to see the long-term impacts of COVID, but also our response to COVID play outright. I'm certainly not so sure how it is in the US, but in the UK we have really sky-high inflation at the moment, and this is a kind of large

consequence of the government response and the increase in borrowing and the impact that that has had on the economy. But there's also some quite positive impacts of the pandemic. If we look, example, at the increasing possibilities to work from home, it's been absolutely transformative for so many people as someone with a young child. It's really made my life so much better that, you know, working from home is much more, much more accepted now. Yeah. It sounds silly when you say it like that, right? It's like millions dead, sky high inflation, crumbling economy. On the other hand, I can do this interview with no pants on. So that's, I got that going for me. But yeah, you're right. It really does increase the quality of life.

general. Yeah, for those of us that have survived and are lucky to have kind of, you know, middle-class jobs. But yeah, there's all sorts of things playing out. And I think we have to wait and wait and see. But I think there's a bigger, you know, it's also played a big role in the kind of ideological struggle that we see in the world, right? If we think of the response of the UK and the US, where it was just a liberal, let the virus rip, see what happens. You know, it was pretty devastating. And, you know, I wouldn't advocate the Chinese response. That was pretty terrifying as well. It was a really effective way of stopping the disease spread to have these really strict lockdowns, but, you know, it has a massive consequence on all our, all our social lives and on the economy.

But certainly I think it, you know, it kind of made liberal democracies like the US and the UK look a little weak and a little vulnerable. And I think we're seeing that play out in in world politics at the moment with, you know, kind of increasing numbers of countries in, you know, certainly Africa and other parts of the world, looking to China and Russia as their example of what to follow. That will be interesting. And I think from a disease or health perspective, we're likely to see, and this is my sort of uninformed dude bro opinion, I'm wondering what you think. The connection between wealth, poverty, and healthy eating, affecting things like life expectancy and frankly also probably immunity at some level because you and I are sitting here

on Zoom or the equivalent thereof squadcast.fm rep that company but we're sitting here doing our work as knowledge workers sitting on our butts at home there's plenty of people listening to this right now who are like yeah easy for you too schmucks to say i'm in the amazon warehouse listening to you idiots while i pack your crap or i'm serving food for people like you i can't just sit at home so you know that what you're, I can't relate. And I understand that. And those people are far more vulnerable to the next pandemic than we will be with the option to just never leave. Those people are the people that have to go pick up my stuff from DoorDash and bring it to my door and leave it there, right? Like they're just completely left out of this. And I, I feel like that could really play a part

in the next one if we're still doing that kind of thing. Yeah. And I think that's another important lesson in the book that, you know, of course, the COVID pandemic was about the virus. but it was also about the way that we or our societies created, you know, conditions for the virus to affect some people much worse than others. So, you know, people in the poorest parts of the country, people with particular jobs, as you, as you point out, people from particular ethnic groups suffered much more than others. And these pandemics are a social phenomenon as well as a, as well as a kind of biomedical phenomenon. We need to remember that. And that's another reason to be hope for, right? Because, you know, social problems, you know, should be easier to sort out. I mean,

I talk about this a bit in the book going back to the 19th century and the way in which kind of urban slums created the perfect conditions for cholera and TB, but eventually politicians got together and they invested in better housing, in better sanitation, in fresh water, and they resolved the problem. And I think, you know, kind of bearing in mind we're living in a new golden age for infectious diseases, a golden age 2.0, then I think, you know, there's an argument that politicians, society, businesses have to get together again and kind of understand how the best way to make ourselves resilient to the next pandemic is in part to invest in new medical technology, but also to create a healthier society anyway, a society in which people are going to be able to kind of survive the next pandemic when it comes. And that's, you know, a social and economic, a political issue as much as a, as much as a medical one. Thank you so much, pathogenesis. Really interesting history of the world in, in several diseases. We didn't even talk about, again, ancient Greece, we skipped through Rome quite quickly, but you even get into slavery in the U.S., which I am sort of grateful we didn't have time

to touch on, because that's one where I'm like, oh, let's make this not horribly offensive. And you do well in the book, but I'll leave people to it. And thank you once again for coming on the show. Really appreciate it. Fascinating conversation. Thank you so much, Jordan. Really enjoyed it. It was great to talk to someone who clearly has read or listened to the book, and yeah, it's really humbling. You know, you spend all this time in your spare room working on this, and it's lovely to have a conversation. So thanks for that. You got it. I hope it spreads like the plague. Thank you so much. Well, have a great rest of the day. You too. Take care. Take care. Bye-bye. You're about to hear a preview of the Jordan Harbinger show about the warning signs for Civil War.

There were times when I was writing that I myself started to get terrified. Is this right? Am I getting this right? Because what I'm saying is going to hit people hard. There have been hundreds of studies of civil wars. The group that tends to start these wars are the once dominant groups that are in decline. The group that has been politically, socially, economically, dominant since the very beginning of this country, white Christian males for the most part. America is going through this radical demographic transition. From a white majority country

to a white minority country, white working class men have declined on most social and economic measures that hasn't happened with any other demographic group. And there's a subset of this population that's deeply resentful of that, that's deeply threatened by that, and truly, truly believe that it's their patriotic duty to do something about this. January 6th was so public, it was so obvious. This is part of a far-right white supremacist anti-federal government movement here in the United States. We know that some of the far-right militias, the oathkeepers, the proud boys, and the three

percenters actively encouraged members to join the military, to join the military, to join enforcement. If you continuously portray this as these are just crazy individuals, then you remain blind to what's actually the cancer that's growing slowly from within. To hear whether we're on the cusp of a civil war here in the United States, check out episode 718 of the Jordan Harbinger Show. We didn't get to this on the show, but even more scary is how diseases can be essentially stored in certain species for thousands of years. I'm not talking about the stuff they're digging up in the permafrost.

That's a whole different thing. But Central Asian tribes, they have rules for dealing with certain animals that might carry diseases that predate human knowledge of pathogens. The Old Testament has a bunch of this stuff too, right?

When you look at religious or pseudo-religious rules about trapping and touching certain animals, Central Asia, they have rules with like marmits. And in the Old Testament, you know, the whole don't eat pork thing, that was probably because pigs are really, really gross, right? They roll around in their own crap

all the time. They carry all kinds of trachinosis and whatnot. There's a lot of clove and hoof and this and that and the other thing in the Old Testament. There's reasons for that that have to do with pathogens before germ theory was even a thing. I do wonder if there will be a future edition of this book in a hundred years where we talk about how climate change forced animals with diseases towards the human population, the permafrost thing that killed half the planet. Who knows? I mean, I think we're kind of the beginning of some of the pandemics we're going to see just due to modern science and climate change. And fun fact, I thought was interesting. The word quarantine actually just is kind of a play off the word 40, because when ships,

merchant ships would come to Italy way back in the day, 40 days was about as long or longer than it took for people on that ship to develop symptoms of whatever crazy disease they brought with them on that boat. So they put the ship in quarantine, meaning nobody gets on, nobody gets off for 40 days. And then they can see if, I don't know, if anyone's left after that, then they can unload the ship. Interesting idea. but it just shows you how cognizant people were and are of pathogens,

and that is not going to change anytime soon. Hope you all enjoyed this episode. All things Jonathan Kennedy will be in the show notes at Jordan Harbinger.com or ask the AI chatbot on the website, transcripts in the show notes as well, advertisers, deals, discount codes, ways to support the show, all at Jordan Harbinger.com slash deals. Please consider supporting those who support the show. We've also got the newsletter every week.

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You can connect with me on LinkedIn as well. This show is created an association with Podcast 1. My team is Jen Harbinger, Jace Sanderson, Robert Fogarty, Millie O'Kampo, Ian Baird, and Gabriel Mizrahi. Remember, we rise by Lise by Lerbush. lifting others. The fee for this show is you share it with friends when you find something useful or interesting. And the greatest compliment you can give us is to share the show with those you care about. If you know somebody who's interested in history, science, diseases, or the history of

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