Disease as a Historical Force

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Dating back more than five thousand years ago proof that this disease was already devastating Eurasia in the late Neolithic, the late Stone Age period Nearly three thousand five hundred years earlier than the first recorded plague So where did it come from What was happening in Eurasia five thousand years ago? That sparked this outbreak Could this plague have triggered a neeolithic collapse, a stone Age collapse? and signaled the dawn of the Bronze Age in Europe. Welcome to The Ancients. I'm Tistan Hughes, your host And today we are telling the story of this prehistoric plane Our guest is the science journalist and author Laura Spinny Laura, it's a pleasure to have you on the podcast. I bet it's a pleasure to be here. And it is good to see you in person, we. two episodes in the past on Protondo European and the origins of mythology first time that we've done it face to face though, and for V historic plagues. I mean, what a topic is this This is a great another great topic where science is now revealing this hidden but incredibly important part of the pre history of humans. Yeah, it totally is. It's very, very exciting right now. because obviously from historical records, we know about epidemics and pandemics that have you know, devastated humanity and changed the course of history. but historical records only go back you know, five thousand years or so. So now we have the tools to look before that And so, you know, historians and prehistorians have long suspected that disease had a hand in shaping populations and shaping history. And there's the famous quote that I love from the anthropologist James C. Scott who says, you know Infectious disease has been the loudest silence in the archeological record. He was thinking particularly of the Neolithic period ten thousand years ago. That sort of goes across the board and that's now changing because we don't have to rely on written records anymore. So has there always been a hunch or for some time that wasas that prehistoric plague or prehistoric plagues that would have ravaged places like Europe. As you say, during the Neolithic period, the Stone Age period, several thousand years ago Yeah, so there was always this or there has long been this idea that M of the infectious diseases which were scourges of humanity for a long time. Some of them still are today But anyway from history, we know that they were, such as Plague being the most famous one. It's probably So the idea was that they probably became major problems around the invention of farming. So around twelve thousand, ten thousand years ago becausecause the idea is that with the invention of farming, new forms of producing food population started to grow And then people were living together in bigger sort of centers of population, not quite cities at the beginning, but later on, yes. And therefore they were living more densely and this was sort of the perfect breeding ground for contagious diseases, also known as crowd diseases for that reason And so that the idea was that they got their foothold then. And it was a good idea and it had a lot of, you know, it made sense And it's being challenged by now the evidence that is coming to light mainly with ancient DNA. So let's highlight this importance of of close connection with animals and how that might well have been a key part of the story Because when we talk about plague, what exactly do we mean? What disease are we talking about when we say the word plague? Yeah, it's a very good question because plague has become sort of generalised, hasn't it? And I think it's a kind of measure of how devastating and terrifying this particular disease was in history that sort of everything got ced by that one label. but When we talk about plague as a specific disease, we tend to mean bubonic plague. There are other varieties of the same disease that is caused by the same microbe, the same bacterium, that is yasinia pestis Y pestis? For short bubonic plague, you know this horrible disease where it starts out with fever and a headache and then you start to develop these Bubose swellings of the lymph nodes And before antibiotics, it was, you know almost certainly lethal And there two main varieties of that disease that we know about from history and also from you know places where we get cases today because we still get cases of plague today domemic form, so in the blood and the pneemonic forms, so that's the lungs that are affected and it's considered the sort of the most dangerous because it's transmitted on the air on the breath. coughs and droplets that come out when you cough and sneeze. And so very highly contagious form of the disease and just as lethal but spreads faster for that reason So that's the disease we're talking about. It's the one responsible we now know again, thanks to ADNA Definitely for the Black Death of the mid fourteenth century and the plague of London, the one that devastated London in the seventeen hundreds I was it sixteen sixty six near the G five was. Exactly a happy time for life But yes, so and it's only about fifteen years that we've been able to prove deffinitively that wh pestice caused the black death becausecause if you think about it, Most of the evidence we have for death in the past is cemeteries Also historical records, but again, historical records are not always available, but When you look in cemeteries of or very old cemeteries, what you're looking at is bone material. There's obviously no soft issue left And generally speaking, infectious diseases don't leave a mark. it's quite rare that they leave a mark on bones So, you know, you've got a you've got no evidence really unless, you know, that's why mummies have been such a valuable source of information about infectious disease in the Great past because you do have the soft tissue preserved in a mummy But obviously they're not that numerous So the ability to extract DNA from skeletons, from teeth has really transformed our whole understanding of the role of infectious disease in the human past. And can you explain the role of animals in the spread of this disease? Why would we also call it a zoonotic pathogen? Yeah, so this goes back to the idea that farming was the point at which the invention of farming was the point at which many of these diseases cross the species barrier. And the idea is that they were Animal diseases originally. we know that because often many of these diseases including plague still have animal reservoirs So if there's no humans around, or even if there are, they may also infect animals populations And the idea is that when farming was being developed people started to live more closely with the animals that domesticated And therefore there was the perfect sort of petry dish, if you like to use a laboratory term for the microbe to experiment jumping into humans and probably most attempts would have failed because you've got to have the right mutations to be able to infect the cells of a different species. But you know, it's got this constant, it's got this long ity to keep experimenting and of course microbes reproduce very quick, so it doesn't really matter if one doesn't work, going to keep trying with different generations, different mutations Eventually one might take in the new host And you know, you might get a little justust one case, you might get a tiny little outbreak, might fizzle out. You know, this is natural selection in action in a microbe. If The virus or bacterium able to reproduce more of itself in the new host then it'll have an advantage and it willll become adapted to that new host and it will change genetically evolve. to acquire adaptations to that new host may even become specialized to that new host, although it may also keep the animal host. Anyway, this is evolution and how diseases adapt to new hosts and the idea is that farming created the perfect laboratory for these diseasase pens to do that. Perfect laboratory, and then that next stage which you mentioned, like the spreading via breath If we also think of the invention of farming you soon after you think of the inventions of the first cities or the lots of people close together in larger communities. So all of a sudden then you have that next stage right after where that disease could spread to other people. Yeah, and James C. Scott, the American Anthropologist I was referring to in his idea, I think he was writing certainly for this ADNA ancient DNA evidence became available But he was sort of saying, know when we see in the archaeological record, a sudden collapse of an early city or town You know, it might be civil, it might be that, but often it's very localized to the one settlement And he was speculating that maybe it would have been a local epidemic that we just simply don't have any evidence for. And now We at least have that capacity to go and look back and see what role it played I they've done a lot of work on more recent pandemics like the Spanish flu and the like How can studying more recent pandemics actually be useful when going back into prehistoric times and trying to learn more about what an epidemic might have looked like back then Yeah, so If you think back to COVID, not that long ago, although it seems a long time, doesn't it? It does, I no, yes, You remember that everybody well lots of people learned the word epidemiology for the first time and we learned about these people who whose job it was to basically track the evolution of the virus and even predict what might be the next strain that came out and try and get ahead of the game and you know, start testing for it and perhaps even, you know Once the vaccine came online and start to modify the vaccine to be able to cope with you strains. And so that was a lot of the scientific work that went into that pandemic Well that's essentially what is happening all the time in microbes. It' brranching, creating new strains, some of them don't work, so they fizzle out. some of them do, so they replace all the other ones that were there before and then they start again and branch and create a new tree. so We can watch that inaction in a pandemic that we live through with the tools that we have today And we can know that that was happening also in the past There are many more people alive today We travel much faster, we're much more connected. so perhaps the timings and the and the capacity for the virus to spread are greater today, but then we also have drugs. We also have, you know we understand how to stop it to some extent too they didn't have in the past. I mean, if you think about those very first epidemics in the earliest cities, they must have been absolutely terrifyied. the Plague of Athens, which is mentionedcal times Lucydides mentioned just how devastating it was. Bodies piling up in the temples. Yeah. And you know because of course there were no antibiotics, off course there were no There was no treatment of any kind. They may have had some sense of keeping the infected separate from the uninfected because quarantine is quite an old idea and even animals understand you know, about isolating sick ones from the healthy herd or some extent, But of course, they wouldn't have known what they were dealing with with and they would have had a completely different concept of disease as well, which is an interesting aspect of the story. You know it would have been an act of God, it would have been punishment for sins And so they would have been absolutely devastating and terrifying As you mentioned Trying to find evidence of this in prehistoric times has been notoriously hard for so long But you mentioned it earlier DNA. So how can DNA and how can The studying of bones What signs do they give that may indicate to a scientist today person died of the plague or something similar. Yeah So just to backpedal a tiny bit on ancient DNA because For a very long time, people thought it would be impossible to extract DNA from ancient human remains and analyze it in any meaningful way. mainly because of the problem of contamination. So if you or I are allowed, privileged enough to touch a bone in a museum, we immediately contaminate it with our DNA Now you won't be able to do that today probably. but in the past, it happened all the time. there's very few bones in our museums that haven't been handled by scientists of earlier times And so it was thought to be a dead loss that it wouldn't be possible. And then scientists ed out how to Basically Sift the ancient DNA from the modern DNA because ancient DNA has a generally a different profile because it's been around longer and it's more degraded. And that fact is helpful in separating it out And then they have all sorts of clever tricks where they can fill in the gaps and so on. So we can now read ancient DNA. It's never perfect, it's not perfect, but it does it is a huge new source of information Now. Since scientists started tracking humans using this new tool, because Now that you can extract DNA from ancient remains, you can Take it out of these people who are in this cemetery here. at this one end of Europe take it from people who are buried at the other end of Europe at roughly the same time and then you can learn all sorts of stuff about who moved, where, how they were related trade networks, they were part of what they're marrying marital customs we and so on The scientists also realized say about fifteen years ago probably now is that along with the eighteen NNA came the DNA of the microbes with which the people were infected. So that was a sort of serendipitous discovery, but now it's pretty much a routine thing. The people are going go looking for what microbes were infecting people, as well as the human DNA in those human remains and try and piece together the history of disease as well as the history of humans That kind of brings us nicely into this groundbreaking new study I'll also mention that other big historic case and I feel we should mention of pllague, isn't it? So you've The Black Death, you've got the London plague You've always got the pllague of Justinian, which is the earliest known Reorded evidence of what we think is Yenia pestis of what we think is historically, ye. So people talk now about three global three plague pandemics So the first one is the one that starts with the plague of Justinian in the sort of Mediterranean basasin in the near East mostostly it's thought to have started in Constantinople sixth century when Justinian was was the emperor. in Constantinople And that goes on til the Middle ages And then the second one is the one that starts with the Black Death in the fourteenth century and goes all the way up to the nineteenth century And then the third plague pandemic starts in the nineteenth century and goes on into the twentieth. Oh right. okay. So the London one in the seventeenth century is just well, it's an epidemic, isn't it rather than the pandemic? So that's part of the second plague pandemic. Because you can see plague is something that stays around for ages and sort of It can be endemic in an area and then it can, you know flare up from time to time. So that's the way people think about it now. and it's to do with incubation times, spread times, how long it can stay in an animal reservoir, go back into the animal reservoir, come back into humans. But yes, that's the way we categorize it now. Okay. Thank you for explaining. Now back into pre times then. but it was important because once again highlighting how long playue can stay around. And surely that would be the same in prehistoric times as well. Now you mentioned before we went into that tangent like the large area and how much you can learn from remains across a large Geographic context So How far back in time are we going with this groundbreaking research with this prehistoric plague? and how large an area are we talking about So If I go back to the plague of Justinian, right? the five forties AD, CE as we should say now That was a fascinating time in Europe because it was just after the fall of the Western Roman Empire and you've got people moving around, of course, it's your area, your territory. moving around Europe in large numbers and carrying whatever diseases they have with them. So it's a time when there are epidemics And it's not that surprising that there were these outbreaks. But what's happened in the last ten or so years is that people have realized that pllague has been around a lot longer going back prehistory And are now talking about what we has the catchy name, the late Neolithic Bronze Age plague because we have we have a naming problem, obviously. theP O Rice. LMBA plague I mean ye. So you know The Justinian plague is said to have started the first plague pandemic. So now if you discover one earlier, what are you going to call it?. You have a naming problem Essentially we have one that is ravaging Europe around five thousand years ago. It's not the first cases, but there is a surge around then Again, you know, it probably was quite drawn out in time But yeah, so they're calling it late Neolithic Bronze Age and that is also a hint to some of the questions that are being asked around it because it's basically the end of the neeolithic, the end of the period when farmers dominate in Europe and elsewhere And the Bronze Age comes in, you know, which Homer sings about a much different society, much more warlike, much more hierarchical initiated by the arrival of nomadic peoples from the Stees in Europe. And essentially the foundations of European civilization as we know it. Okay we're going to delve into all of that because you think of Bronze Age collapse, you don't think as much about a stone age neeolithic collapse, but we'll explore that as well But tell us about What study this was? What was this research led at the University of Copenhagen, if I'm not mistaken? Yeah, well, it's a huge collaboration. Many many groups across the world have been collaborating to this work. The University of Copenhagen in a way has taken the lead because it was The first one to really realize, as I said earlier that, you know It's worth extracting the microbial DNA as well as the human DNA because you can learn, you it's a whole other source of information. So they've been doing that on a routine basis So they tend to take the petrus bone is a good source of DNA which is a bit bone in the skull near the ear. It's very very dense Another good source, a very good source is teeth Because in life, teeth have their own blood supply And so the microbes get caught in the blood that goes through the teeth and get preserved there. So you can drill into the teeth into the cementum and you can if you're lucky and if the person was infected at the time of death extract the DNA of the microbes that were infecting them, assuming those microbes entered their blood which is not always the case that also it highlights that The remains that were used in this project would have largely been skeletons, it would have been like the mandible, it would have been the Pctrosperone in the ear because those are the best ones for preserving DNA, not just of themselves, but also of the microbes and just so I can get my head around it as well. How can we distinguish between microbe DNA and the humans' personal DNA. So I guess that they will be pulling it all out together, but then they can distinguish it with their clever techniques because you the genomes of the human and of the microbe will be very different sizes and have very different profiles. so it's quite easy to distinguish. Thank you for the science. So You've got the evidence of plagues from five thousand years ago, which we'll get to, but I'd also like to ask because it seems like a big project where they also analyze remains older than five thousand years ago So in those ones, did they find any examples of microbes at all? Yeah So just to say also that because you've got the human evidence as well You can say things, for example, you've got radiocarbon dating. so you can say, for example, how old a cemetery is, you know when people were buried there You can also say whether they're related to each other. and then you can look at the diseases that affected them. So you can see how those diseases were spreading in the group across social networks and how they might be linked to you trade networks or other activities that those people were involved in, including, for example, religious activities But yes, you're absolutely right. So this study, which was huge went back tens of thousands of years. and what they see is that until about four thousand five hundred BC So let me get my dates re. Let's say six thousand five hundred years ago microbes present in the teeth are essentially what you would find in the oral microbiome. So as you know, our mouths are full of bacteria, most of them neutral, some of them beneficial And they just live there, you know with us symbiotically and they help us digest our food and it's normal. So no deadly microbes before that time? No no deadly microbes. At that date, they start to detect deadly and dangerous microbes causing causative agents of infectious disease but at low levels. And what happens is that about five thousand years ago, so about three thousand BC Those search So you get a massive peak So already from this study and other studies which have shown similar things evidence that is throwing doubt on the idea that all these Diseeases were present from the time of the fararming Revolution because that was much earlier. So what is this surge at five thousand years all about? Well, we know from archaeology And is when these people come in from the East from the ste, the first arrivals Before we get into the details of that, I would just like to say up frront that the timing is not precise enough for us to be able to say yet whether they brought it, whether they walked into it, whether they came for other reasons, picked up strains en route from people who they engaged with and then As having superior immunity for other reasons, we were able to survive at least some of them those infections and then they carried them further on So it's not necessarily that they were bringing them, although it could be, that's all to be determined I'd like to ask about the between the six thousand five hundred years and the five thousand years ago where you see that big spike But does that indicate that that the origins of That leap between animals and humans like for the like the plague that the origins of the plague could have been some six thousand five hundred years ago And in those fifteen hundred years, it starts to get more deadly Deadly is a very difficult and interesting question. What nature the disease actually took back then and how similar it was to the diseases we know it today, for example, or as we know it from historical records is a good question And there's no guarantee that it would have been the same Okay, so Diseeases evolve, their genetic makeup evolves, and that also changes the way that they manifest So one idea is that these diseases got a foothold in lararge dense settlements, the first ones to form about four thousand five hundred BC before the nomads come in no towns yet, of course But in these great big mega settlements, I think we might have mentioned them before by this culture called Tripillia that is centered on Ukraine and these very mysterious, troubling T troubling because we can't explain them because we have no burials from them. so we have very little information But we know that there were these great big settlements, thousands and thousands of people bigger than any settlement that existed before. centered on Ukraine and If people were living densely there and we don't know that for sure, we don't know even if they were inhabited all year round, for example, they might have been religious gathering areas for seasonal annual gatherings or something like that They could have been inhabited it all the time. And the idea is that you know, the disease may have got a foothold there spread through trade networks And then somehow when other people came in, they spread them around or there was some other reason why it spread and took on a peak reached a peak later on but that the initiation of it was in those settlements. And the remains that have those microbes from six thousand five hundred years ago, which might be as a cause of that, no speculation at the moment Were they found in areas around Eastern Europe? You mentioned that there no burials from Chapillia that survive. but But the ones with those earliest cases of the plague Were they stood in that rough area of central Eastern Europe? this is what's troubling. So we know even before the Yamnaya head west and by the way, they also headed east. that there were a couple of cases, for example, in Orkney. Okay, interesting. So that's really far away from It's really far away. And we know that there were some cases in a multig generational family of farmers in Sweden round about the time that the Aamnai arrived, but probably before they had any contact with them or Sadly before they started interbeding with them and the population started mixing. So that's a bit off as well if the Yamniire is supposed to have brought it. And then another piece of evidence is that We know that pllague was killing antig gatherers in Siberia so way east pointoint of departure of the Yamai who left from sort of close to the northern shore of the Black Sea before the Yamnaya emerge or spread So I suppose the converging consensus now is that plague was pretty much ubiquitous, It was all over, but It may not have been highly contagious yet The strains that were around then might have been just like causing very localized outbreaks, late lethal outbreaks probably, but localized that didn't spread through populations. That's another possibility. So it seems to be there at the time, but there's no big wave. Until until Who are these people known as the Yamnaya and what were they doing five thousand years ago? So Yamaya is is the name that Russian archaeologists gave to this Culture this Ididentity, I suppose, package, archaeological package of behaviours, material remains. They think of former unity. and it means pit grave because that's the way that those people buried their dead in a pit grave under a burial mound in the stepp. You still see them today They're pretty much the only landmarks and They were the first people to perfect the lifestyle of nomadic pastoralism in the steppe, which meant that they could stay in the steppe an extremely hostile environment all year round, moving around in a sort of circle with the seasons, with their herds, to new pastures trying to find water sources and they perfected that. They were highly mobile, they moved around in wagons And they had big herds and importantly They lived in extremely close proximity to those herdts. They were them all day long. they practically slept with them You know, so they would have been in a particularly intense relationship with these microbes doing their laboratory bit, making that experimental leap across species would have happened much more intensely in those people than it would have done in the farmers who lived differently and kept the animals at a bit more of a distance and had smaller herds, we think So in the Amnaya It would have been brutal to begin with, but perhaps you know, small outbreaks. And then over time, their immune systems would have adapted. Right So tempered. Like so that is a thing that the bacteria even though it probably makes that leapis mention the laboratory setting But over several generations, our human bodies can develop a natural immunity to that bacteria. Right Eactly. And many of the adaptations we have today in our genomes, to infectious diseases were honed from that time on and even now have become damaging in a very different hygienic context. So for example, multiple sclerosis is caused by a sort of overactive genetic variant of something that would initially evolved to protect us against those infectious diseases So one of the ideas is that when the Yamnnai come into Europe They have at least partial immunity to diseases that the farmers don't have immunity, will have less immunity. So there's this immune advantage. And in fact, part of this huge new collaboration of research, different groups are doing different parts of it But people are also looking at how the human immune system, how the genes that control the human immune system have adapted over time in a parallel course to the infectious agents and try to understand You know, how does the human adapting to the bug? How how is the bug adapting to the human? and cross references in time. The immunity that the Yamnai, we believe they have a partial immunity is to a particular As of yet, we still don't know much about it, but a particular strand of Yesinia pestes of what we would call play. I don't think we have that detail yet. but we know that they had Plague Bake has been found in Yamnaya teeth. Right, okay. And as I say, from that time on, It is a problem in Europe It looks probably like fairly sizable and lethal outbreaks Very hard to say though, for example, how it spread at that time So Unethical to revive those very dangerous pathogens. So even if you've got the whole genome sequence in theory, you could revive that Jum It's unethical to it. It's very dangerous as well, isn't it? it maybe if you don't actually have the immunity today for it. Yes. So the WHO says no, the World Health Organization says we don't do that unethical And in fact, anyway, even if with some of these diseases, you were to revive it and to say infect an animal, it might not it probably wouldn't work because many of these diseases became human specialized diseases But I'm saying is that you can't make the disease work again in a living host and ask how it manifests. Can't do that But what you can do is you can look at its genetic code and compare it to the genetic code of Germs whose effects we do know because either they're still present today or they have only been eradicated for a short period And you can say, well, that gene variant is there. It's not there. So we can say things about how it's spread by comparing with the modern diseases. and in play that's interesting because As you may know plague These days often spreads by a bite from a rat fl So the fee carries the Terium. And when the flea bites a human, the bacterium is transferred to the human. But the ancient form of plague from the LNBA play the one're talking about the the prehistoric place.ic It lacked a genetic variant which allowed it to survive in the flea stomach whichich means It probablyably didn't spread by flea bites. The fleas are innocent. The fleas are innocent and probably not innocent anyway. The fleas are never innocent There are other ideas could it perhaps have been transferred breath from human to human, but we can't assume that there was human to human transfer was posossibly, for example, might have been spread at that time through undercooked meat because we know that plague inffects other animals and you know, maybe their cooking hygiene wasn't you know, what what we require a today in our restaurants If it was undercut meat probably It was just the people who ate that meat, who would have been affected and then you would have a very, very localized outbreak which would have fizzled out quite quickly. So these are questions we don't have answers to yet, but obviously they change our understanding of how far emics might have had an impact. doing some research for this, I also found interesting that one of the Yamnaa One of their livestock, it's cheap and Is it correct at the Un other ones that really develop wool clothing and bring wool clothing where so could actually be that you were wearing something if they were trading woolen goods that actually The farmers who bought these goods bartered or whatever They actually were wearing something that could have given them this historic form of plague. So this is another story that's evolving. My understanding at this point in time is that the Yamni did not have sheep of the long haired variety that produced the wool that we are familiar with and that we knit into our jumpers and into my earrings Their descendants did have. So within them a few hundred years, perhaps five hundred years of their arrival wool clothing was being worn in Europe for the first time. and There is an idea that certain diseases One in particular being relapsing fever, which is pretty rare today But it's a relative of Lyme disease and it's As its name might suggest, it causes fever and headaches, intense headaches in repeating bouts And that's caused by borelia recurntis The idea is that at some point around about the arrival of these nomads from the east or a little bit later. That bug adapted to this change in the human landscape, if you like, because it leapt from ticks which infected animals previously into the louse, the wool louse, the one that lives on the sorry, the body laouse, human body louse that lives on the human body and likes to nestle in nice, warm wool After that findinding a nice new niche. in this Laus and in the human post for the disease, it became a human specialist Right So that's a really nice example, I think of how human behaviours and human Cultural changes and diseases can interact and shape each other. Yes, because we've been focusing on plague. Yeah, but actually not the only one. It's not the only one. So you have also this one Borelo, I've got it on my notes here Borerelio recurntis as well. Yes, it's almost just you've got this wave with the Yan Naya probably. and then a little bit later you've also got this other pathogen arising to the fore, which the difficulties they must have faced is Yeah, we're only just seeing the beginnings of it. Yeah, totally. But I think you know, infectious disease was the main killer of humanity right up to the early twentieth century, don't true. So yes, they would have been deadly and awful outbreaks. Nobody would have been able to help anyone else. nobody would have had any immunity. The definition in a way of an epidemic or a pandemic is something where you get this explosive incendiary outbreak because the people have no immune system to it. So that might mean that it's a new variant that they haven't been exposed to before. or that it's an old variant that's come back many generations so the human immune memory for it is lost Now we did mention that the AMNI might have some partial immunity. So we could be looking at a situation, could be, mean We don't know y where The Aamni bring a strain into you a place where there are many farming settlements those farmers have no immunity to the particular strains that the AMni bring And so they die and much larger numbers And then what happened, perhaps the Yamni just took their lands and took over their herds, who knows or perhaps that Yan Maya saw an advantage becausecause violence wasn't absent from that world and knocked off the last of the farmers and then proceeded to impose their own culture you know there are many permutations possible and this is all the kinds of questions that are being asked now. Because that's interesting because I think when someone says the Aamnaya, The natural idea is that they come from the east, they go westwards and they start killing a lot of people and it's quite violent their takeover. couldould a reason actually seek a reason behind that seeming violence of the Yamnaya is maybe that other part It's a really really, really important point because when When the geneticists first saw in the ancient DNA this massive turnover in the European gene pool about five thousand years ago, which was their first clue that there had been big migrations from the east first genetic clues, if you like, because we had archaeological evidence A lot of people jump to the conclusion that it must have been violent. You can't get that kind of rapid turnover in the gene pool unless people are being slaughtered or you know women are being raped and you're imposing your genes on the next generation The explanation has been changed utterly in the last ten years. and there may have been some violence, but nobody thinks I would say it's fair to say that violence was the main. mechanis Pandemics might have been one contributing factor if they cleared you know whole swathes of European land and then the people came in and resettled There are all sorts of fascinating social explanations. So these nomads had very different Social networks, you know they were used to being spread apart, separated for large periods of time over large periods of space because that's what their life. ered them into. that's what they had to put up with in the step. And so they were very good at reinforcing their social networks over huge areas of space and time, reinforcing their identity. They did that through pality through taking each other in, wining and dining, bards who told fabulous stories that everyone could remember because they were so fabulous And all of this was part of their way of living that they brought to Europe at that time There an Indo European language? or they European languages? they have a lasting impact on Ancient Europe down to the present a completely transformative impact. And to think that actually maybe disease was a key part of that in their life. There you go. It may have been a key part of the story that ushered in the Indo European languages, languages that the most Europeans speak today. And the remains that we have who have evidence of plague from five thousand years ago, the prehistoric plague I'm presuming they are not just Yem Naya remains to we find the evidence like maybe as far west as France and Spain and Britain, you know, which seems to be evidence showing just how far and wide it spread. Yeah. You remember I said that we can't necessarily detect all cases of infectious disease because Some diseases don't enter the blood. So for example, that's the case with TB Generally speaking, it doesn't enter the blood and doesn't leave a mark on bones. So you're not going to be able to detect TB from ancient DNA So and that's true for other diseases And, you know, maybe a A disease is going to kill somebody without leaving any trace that we can detect. That's generally the case. So this sort of assumption of the genetesis is that we're only seeing the peak of the iceberg there would have been a lot more infectious disease around and probably earlier than they can detect it. Obviously that's a fast moving field and it's getting pushed back a lot. So You can see this is a very sort of dynamic landscape at the moment. People are finding new cases I mean, this finding of the surge at five thousand years is very solid because it comes from studies that look across huge tens of thousands of years. and large swathes of space, you know, large parts of Eurasia So they're kind of constructing a timeline of those infectious diseases. That's a fairly reliable finding. But say we were to find a individual case or a cluster of cases plague in Western France that were of the same strain that the Yamnai brought Th then you'd have to revise your thinking about how it got there and who brought it in initially So it's very important to pay attention to the divergence of the genetic divergence between the strains that are affecting these different cases. because we may have had plague, for example, in Orkney. you mentioned that beforefore the Yamnai arrived, but was it the same strain and so on. That's the story that's being reconstructed at the moment. and You know, that's why it's very difficult to say which is caus and which is effect, you know, we did Possibly, I'd say the most convincing story at the moment is that pllague was a major problem in Europe before the Yamnai arrived, but they may have brought new strains, new changes of life that made it much bigger, a much bigger problem much more present than with their huge herds, you know. So whereas it may have not had a major impact on population numbers before Perhaps it does now, and perhaps now it becomes a major sculpting force in history or prehistory. There go I must ask about the end of the Stone Age then, the end of the Neolithic and the potential impact there of of this pake So we think then some We have three thousand BC or two thousand five hundred around there. so That's Almost five thousand years ago, so kind of similar time You get the arrivals of these so called Beaker people and Association with the early Bronze Age, as you mentioned earlier, with new people coming in to certain areas and taking over from the from the local populations Could it be that disease that the prehistoric plague or other diseases we simply don't know about right now, but may have been even more deadly. are actually one of, if not the main factor as to why these new populations come in at that time Beuse what maybe you could say is a neolithic collapse So Long before all of this work We knew about a neeolithic collapse, right from archaeology Starting about seven thousand years ago So a little bit earlier than what we're talking about, you're already seeing signs of Cooling climate, signs of an agricultural crisis, crop returns not being so good A thinning of the footprint of humans in the landscape in general and more violence and that violence ammong the farmers, right? This is Before the Amnai arrived reaches quite a devastating peak. I mean, you have settlements in central Europe been excavated relatively recently where you have a sort of central gathering of of dwellings And then you have defences, which get higher and higher over time you have signs of Human sacrifice. Massacres. Mass graves One archeologist I spoke to a German archaeologist called Det Lef G Ronenborn told me that he images in his mind of apocalypse now, you know people with painted faces and limbs hanging in trees. I mean, it was really There was a real peak of violence there at least in parts of Europe So Yes, the question is You know, how do these things fit together in time Now There are Some of these archeologists and geneticists who've been working on this prehistoric plague who are fairly convinced that they don't yet have the evidence, but they say they will have very soon that the plague was the cause of the neeolithic decline And of course there's this gray area because we don't think we've got the earliest cases of it. So we don't think we've got the full picture. But there's another school of thought that know it was already happening beforehand and the real the genuine underlying cause was the climate change, the agricultural crisis. And maybe it was just exacerbated by the play that came in or maybe the The Amnia brought the plague in, all the very lethal contagious strains of the plague, which basically just finished off these communities that were already in dire straits and some of them had even abandoned their settlements or vanish We would potentially have been suffering from as of year an invisible disease that we don't know about. Yes. Eactly. R it's so fast and it sounds like from you saying from Just then that this is just the beginning that with more research into the DNA, microbe DNA and more samples taken from across. Eurasia from across Europe that we are now going to start learning more and more. about just how important Plague was in our historic human story. Yeah, totally And even, you know, making major new findings about historical period. so we were talking about the migration period of the Barbarian invasions after the fall of the Roman Empire and You know, fairly recently The geneticists have found smallpox in Viking populations who were moving about all over Europe at that time, spreading it around And that's way before we thought it was a major problem. smallmallpox is one of the most lethal diseases known to man, it's thought to have killed was the three hundred thousand three hundred million people, sorry, in the twentieth century alone Of course, it was eradicated or declared eradicated in nineteen eighty But it's absolutely lethal and And so knowing when it began would be interesting. There's the famous case of Ramses five, the young phharaoh, who is thought to have died of it because A mummy again and there's evidence of the blisters, the smallpox. Ms poook marks on his body. But I don't think his DNA has been tested yet, so that's remains to be determined with certainty that he had smallpox and he died more than three thousand years ago So this is a story in progress The dates are changing and again with smallpox We don't know what kind of disease it was back then because what it looks like is that the form that the Vikings had was very different genetically from the form that we knew in later history. So one idea is that it was actually quite mild back then common and quite mild So you know we always have to take into account that the diseases were not necessarily what we think of them you know when we hear the name. The difference today I said, donon't blame the fleas for theistic place. are innocent. you know, because I wrote my book about the Indo European languages and these two stories have become so entwined.. I think we need to get our heads around how disease has shaped history I mean, in modern times because we have the tools to control them, although of course, we are not immune to pandemics, as we've just seen proportion of the population that is lost to a pandemic each time is now relatively small. So you know you're not going to wipe out a whole civilization or a culture or a way of life with a pandemic probably anymore besides which we've got historical records to tell us what we were doing and so on Nevertheless, They remain a powerful force and in pre history probably in those shapes, ideas that people had the languages they had, that they had the survival of whole populations and cultures, we need to start to think about diseases as a major historical force. It could destroy an entire farming community if their way of life was you know gathering around a fire or sharing secrets in a hut or something like that, it could eradicate an entire community, which to us today, feels Unrelatable, quite frankly. And if you think say this hypothetical community had its own religion had some very advanced technologies, why not? And those were all wiped out with it and there was no written record because we're talking about pre history. pererhaps there have been massive losses that we didn't even know, you know what was there beforehand and disease is the culprit. And we touched it briefly to think about like psychologically when they see this coming or you hear about the village over that suffered likeike how will they respond? What kind of offerings would they make? How were they trying and to appease the plague before modern medicine and the like That's another podcast in its own right, but that kind of human element behind how they tried to How scared they must have been as well, trying to appease what must have been, in their eyes, a divine punishment almost. Yeah ye, yeah, yeah, absolutely Laura, this has been absolutely fantastic as always, always fun to go back and do Science and prehistory together with you, it just goes to me to say thank you so much for taking the time to come back on the show great pleasure to be here Well there you go, there was Laura Sinney returning to the show. Walk through the story of the prehistoric place