Science Friday - Four Lost Cities, Sourdough Microbiome, Queen Bees, Bison. Feb 5, 2021, Part 2

Episode Date: February 5, 2021

National Bison Range Returns To Indigenous Management Hundreds of years ago, tens of millions of bison roamed North America. They were an essential resource and cultural foundation for many Native American tribes. And by 1890, European colonists had hunted them nearly to extinction.  When President Theodore Roosevelt moved to conserve the remaining bison in 1908, he established the National Bison Range, an 18,800-acre reserve that the government took directly from the tribes of the Flathead Reservation—the Salish, Kootenai, and Pend d’Oreille. The tribes were not invited to help manage the recovery of a bison herd that they had helped save. At times, they were even excluded from the land entirely. For the past several decades, the tribes have been lobbying for the land—and management of its several hundred bison—to be returned. Then, in December 2020, Congress included in its COVID-19 relief package an unrelated bill with bipartisan approval: returning that land to the tribes.  Ira talks to Montana journalist Amy Martin, who has been covering the National Bison Range for Threshold, a podcast about environmental change, about why the return of the land is meaningful in the context of U.S. colonization, and the relationship between the environment and justice. Listen to the full report on the National Bison Range on Threshold.  A Reproductive Mystery In Honey Bee Decline As global honey bee decline continues through yet another decade, researchers have learned a lot about how complicated the problem actually is. Rather than one smoking gun, parasites like the varroa mite, combined with viruses, pesticides, and other factors are collectively undermining bee health to an alarming degree.   One part of the mystery is the increasing rate of ‘queen failure,’ when a reproducing queen is no longer able to produce enough fertilized eggs to maintain the hive. When this happens, beekeepers must replace the queen years before they ordinarily might.   Producer Christie Taylor talks to North Carolina State University researcher Alison McAfee about one possible reason this may occur—a failure to maintain the viability of the sperm they store in their bodies after a single mating event early in life. The condition may be caused by temperature stress, immune stress, or a combination of factors. McAfee explains this problem, plus the bigger mystery of how queens manage to keep sperm alive as long as they do. Mapping Sourdough Microbes From Around The World With more time at home over the last year, many people have experimented with baking sourdough bread. In new work published in the journal ELife, researchers are taking sourdough science to a new level. The team collected and genetically-sequenced 500 sourdough starters sent in by bakers on four different continents to try to draw a map of their microbial diversity. A sourdough starter culture contains a microbial community made up of both yeasts and bacteria. As the starter is fed and grows, those microbes ferment the carbohydrates in flour, producing the carbon dioxide gas that makes the bread dough rise. Over the years, a mythology has grown up around sourdough—that certain places have special types of wild yeasts that are particularly suited for breadmaking. However, the researchers found that on a global level, it was hard to tell the microbes in Parisian bread apart from those found in San Francisco or elsewhere. The differences in the starter culture seemed largely to be based on specific conditions within each bakery kitchen, and how the starter is grown and maintained.   Erin McKenney, one of the authors on the report and an assistant professor of applied ecology at North Carolina State University, joins SciFri director Charles Bergquist to slice into the bread study, and explain the team’s findings. Ancient Cities Provide A New Perspective On Urban Life There are certain skylines that come to mind when you think of big, urban cities. Maybe it’s New York City, dotted with skyscrapers and lit up by Times Square. Or it could be the central plaza of Mexico City, and its surrounding galleries and museums. But in Four Lost Cities: A Secret History of the Urban Age, author Annalee Newitz considers long-lost urbanity like Cahokia or Angkor.  These were huge, sprawling ancient metropolitan areas, constructed thousands of years ago. They had complicated infrastructure, and equally complex political systems that governed the tens of thousands of residents that lived there. But these cities were also eventually abandoned.  Newitz explains who built these places, and how their residents lived, providing a new perspective on how the ecosystem of a city works. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. Last December, Congress passed a bill to offer relief for people economically hurt by the COVID-19 pandemic. But that wasn't all that was in there. Among many things unrelated to the pandemic was a provision to return something called the National Bison Range. Return it to the surrounding indigenous community, the Confederate Salish and the Kootenai tribes of the Flathead Reservation in western Montana. Here's the background. After European settlers hunted the bison almost to extinction, President Teddy Roosevelt paved the way to set aside land

where one of the last remaining herds could recover in peace. That's the National Bison Range. And those bison are now part of what has become a resounding success story for conservation. And this provision returning the bison range to the indigenous people? Well, if you don't live in Montana, you may have no idea how big a deal that really is. Here to help is journalist Amy Martin. She's executive producer and founder of the podcast Threshold, which tells stories behind environmental change.

And she has done extensive podcasting on the history of bison in the U.S. Welcome, Amy. Thank you. Thanks for having me. So the tribes have been asking for control and return of the land for a long time. How do the members of the Flathead Reservation feel now that they have it back? Well, the people that I've had a chance to speak to are really, really excited about this. The Confederate Salish and Kootenie tribes have been pushing to get

control of the bison range back since the early 70s. This land was taken without their consent way back in 1908. This has been a long time coming. And one person I spoke to, Rich Jansen, he's the head of Natural Resources Department for the tribes. He grew up on the reservation, and he didn't even know that the bison range was there. He never went to it. It's this kind of strange island in the middle of the reservation where people who lived there, you know, didn't feel welcome. And I asked him how it felt to go back onto the bison range. And here's what he had to say. It felt really different. You know, to go onto the bison range and say, this is now tribal land once again. To be able to say to my friends and tribal members, this is yours again. And do not feel ashamed to come here.

do not feel threatened when you come here. This is yours. Take care of it. So they really are very excited, Amy, about getting their land back. Yeah, I mean, it's the land and it's the bison themselves because this bison herd, these are the descendants of animals that tribal people themselves helped preserve way back in the end of the 1800s, beginning of the 1900s.

The Salish and Coutini and Ponderry tribes who live there helped to preserve these animals. And then there was this strange irony when white conservationists realized that settlers had almost wiped out bison. They were like, wait, wait, wait, we need to save this animal. Here's a good herd. Here's some land where they like to be. And they just kind of took control of the whole process.

And native people were written out of the story at that point. So I think it just means so much to have control of the land back and to have the authority to manage this herd, which is so central to Salish Kootenie and Ponderry people, but also native people all over the country. That's interesting. Talk more a bit about why the tribes felt it so important for them to be part of that process. Why wasn't it enough that the bison were being protected? Yeah, that's a great question. I mean, I think, of course, it was important to have the bison protected at all to everybody who cares about these animals and their future. but I think maybe many Americans don't realize that there actually used to be bison from coast to coast and from the Canadian border to the Mexican border.

So tribes all over the country had different kinds of relationships with bison. Bison were a food source. Their hides provided shelter. And there's a special relationship there that goes into sustenance of the community and also the cultural heart of the community. I spoke with a woman several years ago. Her name is Jermaine White. And at that time, she was information and education specialist with the tribes.

She's a noted, wise person within the tribes. And she told me that it was really almost impossible to overstate the importance of bison to her community. Bison were at the very heart of our traditional way of life. For years, we hunted bison, lived in relationship with bison, and they provided for not just our material needs, our shelter, our clothing, our food. but also our spiritual needs as well. The elders never imagined that there would be a time that there were not bison here for us.

One of the things that was very clear as I talked to different tribal members in the area is that this conservation project, although they supported the goals of conserving the bison, it was undergone without any consultation or consent from the local people. That's what makes this story so interesting and important for us to think about

as Americans right now. sometimes in our pursuit of conservation goals and conservation justice, there has been a real lack of thinking about social justice. Teddy Roosevelt and people who came after him were very proud to have preserved the bison, as they should have been. But there was no acknowledgement that that preservation often came at the expense of completely writing native people out of the story and worse, you know, truly subjectating them and treating them as if they weren't fully human. And I think that that's what so many people are demanding right now in the United States and our world. around the world, that as we tackle environmental issues, we also need to be thinking about social justice issues, and there really is no solving one of those issues without the other. They are, in fact, the same thing.

Robert McDonald, who's the communications director for the tribes, he told me that the fact that the tribes were not consulted when the bison range was created has left a real wound and a scar among people who live on the reservation all of this time. Keep in mind at this point in time, we were not considered U.S. citizens. We had no voice politically. We did voice our concerns loudly. It's been documented and recorded, and there was no obligation for them to listen to us.

So they told us, you know, move, get out of the way. This is what this is going to be. And we had no choice but to follow along. So those members of the tribe still have intense feelings about this lack of power many years later. Absolutely. Absolutely. I mean, this is just one of the, the places, obviously, where that lack of power shows up. And it's also, I think, what makes the

fact that these lands and the herd itself has been returned to their authority feels so powerful. It's the land and the animals themselves, but it's also the symbolism behind it, the meaning behind it. Yeah. Of course, central to this issue is also a concern about the welfare of the bison. The tribes have a lot of experience managing wildlife in their environment, don't they? Yeah, absolutely. And in fact, the Confederate Salish and Kootenai tribes are really nationally recognized conservation leaders. They were the first tribe in the nation to designate their own wilderness area, for instance, the Mission Mountain Wilderness Area. They've done all kinds of innovative things for wildlife on the reservation. They've built highway overpasses that allow animals to migrate freely without risking being hit on the highways. And Rich Janssen, who we heard from earlier, the head of the Natural Resources Department, he has been a really big part of that story.

We essentially manage the entire reservation for wildlife. We manage the black bear population, the white-tailed deer, the mule deer, the moose, the elk, grizzly bear conservation area, beautiful grizzly bears, and one of the largest populations in the lower 48. And that's right in our backyard. So we most definitely are qualified to manage the National Bison Range. You know, with all that experience and with everybody knowing how well that they manage the water, wildlife. Why did it take this long? You know, everything you're saying, everything he's saying so far makes a lot of sense that the people who know the most about an animal should be managing its well-being. Yeah. Well, you know, unfortunately, racism is a really strong force in our country,

and it's a strong force in Montana, and there are a lot of very toxic narratives about Native Americans and indigenous people and their capabilities and their rights and so far. It wasn't that long ago. It was, you know, in the 70s that you could walk in, I've heard this, that you could walk into a bar in Montana and see signs that said no dogs, no Indians. There's a real ongoing struggle there to have a multicultural society that is truly fair and just for everyone. So that's part of it. There's been pushback from people acknowledged on racial grounds or kind of woven into other stories that people have told themselves. I think maybe a less clear-cut opposition to it is a concern that if these lands were returned to the CSKT, would that mean that

other tribal land, or other lands that, well, basically all land was once tribal land. If that would open the floodgates that a whole bunch of other tribes would be able to say, like, we want our land back to. That's a complicated thing that's going to be playing out, I think, over the next several years or decades. I do think, though, that this case is special in many ways because this land was designated by the federal government as tribal land, and then this piece of it was carved out, and it's completely surrounded by the reservation on all sides. And there really aren't very many cases like that

that are so egregious, where the government said, okay, you can have this land, oh, except for this piece that we want back. The forces of inertia, the forces of racism and some complicated bureaucratic stuff, but they push through all of that, and now the land is back in tribal hands. Okay, so let's talk about one that transfer takes place, and how will this act? actually work? Well, you know what's amazing is that when the appropriations bill was signed on December 27th of 2020, the land was back in their hands. There is a two-year process for transferring the management over from the Fish and Wildlife Service. That is already underway. And there are tribal members who have been working for the U.S. Fish and Wildlife Service who are working at the Bison

Range. So I think it sounds like there's going to be a smooth transfer there between the two organizations and at this point they're in really great communication. Everybody's wanting the same thing. You know, the things that I've been hearing from people is we knew this is going to happen someday. It's been this long, long fight, and we just had to absolutely not give up. And Robert McDonald, the communications director, was one of the people who really communicated this long-term view of this fight. There was an effort to destroy the native, became an effort to destroy their lands came an effort to destroy any vestige of the language and culture, yet we're still here. It's pretty incredible the survival story you're looking at that somehow through all of this,

and we hear the stories of our parents, our grandparents, our great-grandparents, of frankly being right at the brink of not making it, but yet somehow we're here and we're growing. We're getting stronger. We're getting smarter. Well, I don't know if we're getting smarter, but we're learning new tools. Those are pretty powerful statements. And you know, for us listening to it, it's, I hate to say it, it's such a cliche, but it's sort of like a heartwarming story because it's something positive about inclusiveness that we haven't heard in a long time. This bill had bipartisan support from the Montana delegation. Republicans and Democrats supported the return of these lands to the Confederate Salish and Kootenie tribes. That's something else we don't hear of all that often these days. Good news. Thank you, Amy. We can use all of that we can get. Amy Martin, journalist and executive producer of Threshold, a podcast about environmental change.

And you can find a link to her full story about the national bison range up on our website, ScienceFriday.com slash bison. We're going to take a break. And when we come back, another clue in the mystery of declining honeybees, this time with a spotlight on the queen. This is Science Friday from WNYC Studios. This is Science Friday. I'm Ira Flato. We've talked for years about the crisis agricultural honeybees have been facing, whole colonies dying over the winter, and steep declines in population over the last decades. And as with lots of stuff in science, the closer scientists look at what's causing this disappearance,

the more complicated it gets. Sci-Fright producer Christy Taylor has more involving a key hive member, Honeybee Queens. Something I just learned this week is that Honeybee Queens only mate once in their entire lifetimes. Once she's done, she's storing all the sperm she'll ever need inside her body for up to as many as five years,

somehow keeping it alive. But what happens when she can't keep that sperm alive as long as usual? Here to talk about that process and new research on what factors may end a queen's reproductive life prematurely is Dr. Allison McAfee, a postdoctoral researcher at North Carolina State University and the University of British Columbia. Hey there, Alison. Hello, Christy. Like I said,

I just learned this thing about Queens this week, and I'm still kind of marveling that they can keep all this sperm that they need to create an entire colony alive for all those years. This feels like a pretty incredible feat. How do they do it? That is a big question. That is the reason why I'm doing the research I'm doing, because it's such a fascinating feat of biology. They have a very specialized storage organ called the spermathica, which actually looks something like a little pearl that's maybe half the size of a pinhead, and it is inside her abdomen. And when she mates, that becomes maybe half full of sperm, and the other half is full of this stuff called the spermathecal fluid, which is like a bath that keeps the sperm happy for years and years to come.

This seems a lot more complicated than all of the processes that male bees or mammals even would go through to produce sperm. Yeah, it's very challenging because of the extreme length of time that she has to keep them alive for. So ants actually do the same thing and they are even more extreme than honeybees. They'll keep sperm alive for decades even. But it means that the queen then has a pretty big responsibility to somehow keep, the sperm from being damaged, keep the effects of environmental stressors at a minimum. It's a very challenging thing to do. They've been under very strong selective pressure to kind of optimize these systems. But as I was saying, they don't always keep the sperm alive and happy that whole time.

Sometimes it goes wrong. And that's what you're researching. Yeah, I think of my research as like I'm playing queen detective these days, sampling all the honeybee queens that I can from beekeepers who are willing to give them to me, and measuring all the things I can about them to try to figure out why they're actually failing. So one of the results we've found is that queens that are rated as failing by beekeepers have significantly lower sperm viability or more dead sperm stored inside them than healthy queens. And so I'm really interested in all the kinds of factors that can lead to that sperm death. And there appear to be quite a few. Such as. Temperature stress is the first thing that I looked at. And that's maybe not all that surprising because actually hot temperatures

at least are known to kill sperm in all kinds of different animals, including humans. So it's not a big deal for a mammal because you can produce more sperm, but a honeybee queen is stuck with all the sperm that she got early in life and she can't go acquire more if it starts to die. So hot temperatures is one of them, cold temperatures also, which is worrying because queens are very vulnerable to temperature changes when they are shipped all around the world. So there's actually a worldwide queen distribution system that beekeepers in many places, including Canada, where I am right now, rely on. So when they're shipped, they're exposed to, or they're vulnerable to essentially whatever the ambient environment is. And pesticides, you might guess,

are another factor affecting sperm viability. Some people have shown that when you actually apply a pesticide to a queen, that the sperm you start to die then as well. And so your most recent research was looking specifically at some of the biochemistry of molecules that queens have in their systems when their sperm is either in good shape or in bad shape. What are those clues too for you? Yeah, so our most recent research has started looking at the impacts of pathogen infections, specifically viruses. The failed queens, they're essentially more sick.

they have higher levels of a couple different viruses in them. And in those same queens, we also find that they have, as you might expect, an elevated immune response. So they are producing more of these proteins that help them normally fight infections. And what it's looking like is happening, or at least the data are very consistent with these other well-known ideas in reproductive biology that, there's essentially a trade-off between how fertile you are and how well you can fight off infections. So if you launch an immune response against some pathogen, you know, you may have to do that in order to stay alive, essentially.

But that is an energetically costly activity. And so by launching that response, you have to take resources away from something else, assuming that there's a finite amount of resources, which there usually is. And in the case of the queen, that something else would be reproduction, because that's what she is normally spending the vast majority of her resources on. She actually lays her own body weights equivalent of eggs every day. So you can imagine the energetic cost involved in reproduction for her. Do you think that this knowledge about sort of the effect on sperm viability is something we can use to save honeybees from possible experience? I mean, it's clearly one piece of a very large puzzle, but it is something that we can actually do something about, thankfully. So I mentioned that queens are vulnerable to temperature stress

during shipping. And, you know, it could be something as simple as just changing the kind of containers or cages that we ship queens in. Something that I'm also worried about, though, is that climate scientists are predicting more heat waves in the future. So that worries me because we have done some work where we place temperature loggers inside colonies during heat waves. And we find that it actually gets surprisingly hot inside there. So that's worrying. But thankfully, that's also something we can do something about.

We can change the materials that we actually have the bees in. You know, anytime we talk about honey, decline, it can get to be feeling kind of depressing just in terms of what it says about ecosystems that we're dependent on. But I just want to go back to how amazing it is that under normal conditions, queen bees are able to put a living sperm cell into deep storage for five years. That's a technology that human beings only kind of figured out in the last, you know, 50 or 60 years. So can we learn from honeybee queens things that might assist our understanding of reproductive science in the wider animal kingdom? I think so.

That's one of my main goals in my research is to get to a place where I can actually try to somehow recapitulate this complicated system that the queens have come up with in their sperm and thica to be able to store sperm of hopefully any animal on the bench quite easily and for a long period of time so that we can study more things about what keeps them alive. It took humans a while to figure it out as you mentioned, but queens, don't even rely on cryopreservation. They do this all just at regular temperatures. So that makes it even more remarkable. Amazing. Well, I think that's all the time we have. I'm so sorry. Thank you so much for joining me, Allison. Yeah, thank you very much for having me. Dr. Allison McAfee, postdoctoral researcher

at North Carolina State University and the University of British Columbia. She joined me from Vancouver. For Science Friday, I'm Christy Taylor. What new hobby or interest have you taken up while spending so much time at home? Well, for me, it was sourdough breadmaking. I wanted that bread with that San Francisco sourdough taste. You know, it involves making a starter in the place of that store-bought yeast. So when SciFrize Charles Berkwist mentioned some new research looking at the yeast and the bacteria and the start is microbiome, I needed to hear about it.

Hey, Charles. Hey, Ira. How's the breadmaking going? You know, I love it. No two loaves are ever the same, and they're very tasty. So I'm sure you're familiar with the legend of San Francisco sourdough. Yes, who is not and who has not tried to make the sourdough taste just like the San Francisco bread? The starter, some people say, was started back in the Gold Rush days.

That's 1849, something like that. And people claim that they have kept their starter going for over 100 years. And yes, there's this thing about the sourdough from San Francisco having a distinct flavor due to the legacy of its starter microbiome. And I have always wondered about that. Is it true? Well, researchers decided to map out what around the world was making people's bread rise to try and get a sense of the sourdough microbiome around the world. And I asked one of them, Dr. Aaron McKinney, an assistant professor of applied ecology at NC State University, about how different sourdough was from place to place. There's a tremendous amount of variability.

In a nutshell, we collected some 500 starters from folks living on four different continents. Everybody thinks that their location matters. And what we found is at least at a global scale, where you live doesn't really make a significant difference to the microbiology of your sourdough starter. So you collected stuff from all over the world. how did you get a hold of 500 different bread samples? We sent out a survey, you know, tell us about your sourdough starter. We had a thousand people return that survey.

And what we thought initially might be a sentence or two responses, you know, why do you bake? Why do you keep a starter? Actually, with paragraphs of these really intimate narratives of the emotional importance and the long-term investment in these starters, which really gave us a window to these communities of practice and the motivation and the experience of these bakers. And, you know, fine print at the bottom, we said, and if you want to share some of your starter, send us a sample in the mail. And usually, you know, if you ask from survey respondents or something, the return rate on a community science project with public engagement, if you get 10% response, you're really lucky. over 50% of the people who completed the survey sent us samples. So that's how we got 500 starters.

Were there ones that had just amazing legacy stories? This was my great, great, great aunts or something like that? Yeah. So the majority of the starters that we collected were quote unquote young, like under 50, but we did have a number that were over 100 years old. And we had a few that were over 200 years old. So not just your great, great, great aunt, but this was originally from Russia and was brought over by ancestors. These are the heirloam pets that outlive you.

And then you took all of these pets and sequenced the genomes of the mix of things that was in them? Yes. We sequenced the bacterial genes and the yeasts. Across that global data set, we found, say, 70 types of yeasts that show up in sourdough starters from across the entire world or from across the entire poor continents were we sampled. But any one given sourdough starter tends to be dominated by one type of yeast. So it's a tremendous amount of variability from starter to starter, and it's not predicted by geography. So I couldn't hand you a sample of starter, and you would say, oh, this is clearly from St. Louis.

I don't know that I could, yeah, give you the forensic. This was the origin. So in my personal starter, there's just one kind of yeast hanging out in there? Or I always thought it was a wild mix of things? Yeah, there's generally one, maybe two that dominate, like 90% of what's in there. Huh. Yeah. You might have some other types, but they would be very rare. Interesting. So I have a starter that's supposed to. the child of my mother-in-law's starter. And we live maybe 30 miles apart, general, same climate and everything. But her bread always has just much more sour-doughiness than mine. What's going on there?

The way that you keep and maintain your starter could contribute to some differences in the way that it behaves and in the aromas that it produces compared to another maybe a sister or a mother starter. It could also depend if you kept your house at a very different temperature. You could have starters that originated from the same jar, but if one is kept on the counter or one is in the fridge, again, these are human controlled factors that in the global data set that we analyzed really didn't account for a lot of variation, but they added a little bit of difference between these different starters. So at a smaller scale, if you're comparing just two starters, then it could have something to do with the way you keep your house or the flower that you feed it or even the differences in the microbes that are on your body versus her body.

So it might not be so much the land around your kitchen as the land on the cook's bodies. Yeah, if you think about similar climate, but we all live in glorified caves, right? We're keeping our starters inside for the most part. So those environmental similarities outside of your house really might not have as big a role in your sourdough's life in ecology as the conditions specific to your house. This is Science Friday from WNYC Studios. In case you're just joining us, I'm talking with Aaron McKinney of NC State University

about building a global map of microbial diversity in sourdough starters. Where do you go from here? What do you want to know next? Seeing the full community is great. I always want to know how the community is formed. So I've been asking a lot of questions about the first 14 days of a starter's life. I also keep imagining, you know, where's like one of the wildest applications or largest scale? You know, what could happen with this? I think about brewers, how you can essentially, you can walk into a brewing supply store and say, I want to make a clone of this beer.

And they'll say, here's a recipe. You know, you use these types of malt and barley and this variety of hops and this strain of yeast. I don't know. Part of me kind of dreams about, you know, if you can't guarantee that there's a sourdough terois, then maybe we have a baking supply store in the future where you say, I want to make this type of bread. and at some point maybe we understand enough, either to say, okay, inoculate, we won't just have packets of baker's yeast, but, you know, maybe specific blends of microbes, you know, bacteria as well, or a diversity of yeast.

For now, I would hope that this would empower us short term to trust the microbes and to really lean into learning about what makes our individual starter happiest and figuring out, you know, feeling empowered to, experiment in our own kitchens. Interesting. Dr. Aaron McKenney is an assistant professor in the Department of Applied Ecology at NC State in Raleigh, North Carolina. Thanks so much for taking time to talk with me today. Absolutely. Thanks for having me. For Science Friday, I'm Charles Bergquist. Well, when she's got that bread flavoring starter, I'm waiting in line for it. Thank you, Charles. We're going to take a break. And when we come back, author Annalie Newitz takes us on a tour of ancient cities and the people who built them and why these sprawling urban centers were abandoned, including an ancient city in St. Louis.

This is Science Friday from WNYC Studios. This is Science Friday. I'm Iroflato. When you think big urban cities, what places come to mind? Maybe it's New York, right, with its skyscraper-dotted skyline and Times Square all lit up, or maybe it's the central plaza of Mexico City and all the surrounding galleries and museums. But have you ever considered Cahokia or Anchor? These were huge, sprawling ancient cities that existed thousands of years ago.

They had complicated infrastructure and political systems that governed the tens of thousands of residents that lived there. And these cities were also eventually abandoned. One of them was a major part of what we now call St. Louis. We may have missed these cities in their heyday, but my next guest is here to take us on a tour of a couple of ancient civilizations, and to talk about who built these places, how the residents lived, and how the ecosystem of a city works, and eventually what became of them. Hennelly Newitz is a science journalist, an author.

Their latest book is called Four Lost Cities, a secret history of the urban age. Welcome back. Hey, thanks for having me back to talk about this. What got you interested in this? Well, I love cities. I've lived in San Francisco, which is a city, for a long time. And I think, like a lot of writers, I always want to ruin things that I love by studying them really, really intensely and finding out everything that goes into making them. Although this, as you point out, this idea of a city being lost is a bit of a bit of, of a myth, isn't it? It's really a myth. And in this book, the four cities that I talk about,

which are all sort of famously lost, none of them were ever actually missing. The people who lived near them knew about them. In the case of Anchor, which is in today's Cambodia, when Europeans arrived there, there were monks living there. In the case of Cahokia, which is near St. Louis, when white settlers arrived there, there was a tribe living there called the Cahokia. And so the people who found it said, oh, it must be Cahokia. But of course, the Cahokia tribe had not actually built the city. They were living in the ruins of the city. Are the Cahogia tribes still around? No, they're not. We think that the people who lived in Cahokia, the city, the original city, which was kind of a going concern about a thousand years ago, probably joined Siouxan tribes. And the Cahokia have also

moved on because, of course, white settlers moved into the area. Well, I want to talk about Kohokia because, I mean, I've lived in this country my whole life. I've never heard of it, but it's right in our backyard near St. Louis. Do they know in St. Louis? The people in St. Louis know what the history of that city is? A lot of them do. And a lot of them don't at the same time. When I've written about Kohokia in the past, I get a lot of emails from people saying, wow, they forced me to go there when I was in elementary school, but I never realized it was a huge city. I just thought it was a boring old place. And in fact, of course, it was a thriving metropolis.

It was at the heart of a massive civilization called the Mississippian civilization that was thriving about a thousand years ago all along the Mississippi River. And Cahokia was kind of a spiritual center where people came and had big pageants and parties. And about 30,000 people were there, which rivals the size of European cities like Paris at the time.

So it was really quite large and impressive. Something that's different than other civilizations you point out in your book is even though they had this huge plaza, this huge square. In other civilizations, this would be a common marketplace where people bought and traded goods and services. But that wasn't what they used it for in Cahokia, was it? That's right. At the base of Monks Mound, this huge mound at the center of Cahokia, there was this massive grand plaza that would have been quite a feat of civil engineering. People, building it would have had to grade the land to get it very, very flat and then would have covered it in a nice layer of sand. And its footprint is about the size of the pyramid at Giza,

just to give you a sense of how big it is. And it has two terraces and a flat top where archaeologists have found remains of large structures. So we know that there was some kind of temple complex up there or maybe even housing for very important people. They had a game called Chunky, which is still played today, the Cherokee play it. And there's no evidence of a marketplace here at all. It seems like the area was used for chunky games, which makes sense. It's a big sports arena. But it was also probably used for public gatherings. When people spoke from the top of Monk's Mound, their voices could be easily heard kind of booming across this plaza. So it could have been a place for political rallies or spiritual gatherings. And we know that there was feasting there.

We know that people partied. There's huge trash pits just full of barbecue, half eaten meat and things like that, all around that area. So it was clearly a party zone. But we don't see evidence of commerce. And when I was visiting there, I kept asking archaeologists like, well, obviously, people came here to trade. Like, why did people come to Kohokia? And they all kind of shook their heads and looked sort of sad and said, no, no, everyone thinks that. But it wasn't that kind of city.

It was a city for spirituality and pageantry. And, you know, people had their own farms. And so it seems as if family groups were feeding themselves through farming and didn't need to do large-scale trade and large-scale economic engagements with other groups. And you're right that eventually Cahokia was abandoned. But it seems like the households planned for this. And that runs counter to what we. you point out, think in Western cultures that cities normally, they start out, they rise in a peak,

and then they collapse. But that's not true here. It's not true here. And, I mean, really, it's not true anywhere. I mean, we don't really see this neat little pattern of collapse in any area. But in Cahokia, it's especially notable because we know that there was a cultural ritual that archaeologists call closing up house. and any time that someone left their home for whatever reason, maybe someone died and they weren't using their home anymore, the next group that was going to come in and build a house on that spot, all the houses were made of wood. They would burn a lot of items on the floor of that house.

So you have to imagine the sort of clay floor. And these items would be things like precious plates or mica, which was a really treasured sort of sparkly, mineral and, you know, other kinds of offerings, baskets or maybe some grain, they would burn it and then they would smooth a new layer of clay over top of the burning, as if they were kind of saying, all right, this house is sealed up, the old house is gone, here comes a new house. And they seem to take that same approach to the entire city, that there's this notion that any house, any structure that's built has a lifespan. And it does go against our Western idea of

cities where when we think of cities, we think of building something that will last forever. And, you know, we think of a city being successful if it never is abandoned, you know, that if a city is abandoned, that it must have failed in some way. But it seems like the framers of Cahokia and the people who lived there didn't have that same attachment to the idea of a city lasting forever or house lasting forever that somehow abandonment or leaving behind was built into the city from the beginning. And when we see people starting to leave the city, sort of in the 1400s, they're leaving in dribs and drabs. They're not kind of all leaving at once. But it seems like kind of a natural progression. There's no kind of big horrible thing that happens.

There's no pandemic. There's no fire. People just start saying, you know, I think I'm going to go somewhere else now. They just migrate someplace else. That's right. And that's exactly what they did. A lot of them just got on the Mississippi and found new places to live, smaller communities, different kinds of tribes. It doesn't seem to have been a struggle. We know that the city went through a lot of changes. Cahokia had definite social movements that changed the way the city was laid out and changed people's relationships to some of the monuments in the city. But it doesn't seem like any of those big changes were part of what made people leave. It seems like leaving was just something that they did. Fascinating, fascinating. Another city that you looked at is Anchor, known for all of its Watts.

How was this city planned and laid out? And you seem to point out that it was planned with sort of a fatal flaw built in. That's right. So Anchor was at the heart of the Khmer Empire, which stretched across many nations in Southeast Asia. And Ankur is now located in Cambodia, but you have to remember that that would have been a city that had tentacles out into Thailand and Laos and other places in the area. And it was built near rivers. And it's also a city that is at the nexus of two monsoon systems. So this is a city that's just battered by water. And so every iteration of this city, which at its height about a thousand years ago, had almost a million people living there.

So it's huge. And the centralized planning came from the royal family and all of their retinue of engineers and spiritual advisors. And they really wanted a way to have lots of water stored up from those monsoon seasons for all the dry seasons because this is a city that's vacillating between basically drought and floods. So when you go to Anchor, as I know that you did, one of the things that you'll immediately see is that there are these huge reservoirs downtown, enormous, like eight kilometers long, these big rectangular, they're called Burryes, where people held water. And those are just the

biggest ones. The city is full of smaller reservoirs. It's got an incredibly, a lot of, elaborate canal system. And the canal system would have been for bringing water in, but also for transit, for boats, for bringing in supplies from all of the different satellite cities, places where they, you know, hewed the rock that helped build Ancor Wat, for example. And the problem is all of that water infrastructure requires a lot of human labor to maintain. And so the city catastrophically flooded a number of times. One of the big problems that they had was things like silt getting into the canals and just not having enough labor power to shovel all of that silt out of the canals. And so you'd get an inability to bring water down from the mountains because these

canals were getting silty. So they'd build more canals. And then when they had a wet season, suddenly that silt would get washed out and you'd have water coming in from a huge number of canals, which again would overwhelm the city's water system. And so it really looks like this was a big part of what led to people abandoning the city was that it was just being mismanaged. You know, things were falling apart. The water system wasn't working the way it used to. And it was just hard to live there. You know, it would be like if you were living in a city now and your water didn't work part of the time.

Or, you know, the city was flooded half the time and nobody was doing anything about it. And the government would say, well, too bad. you know, we're over here in Anchor Watt, and we don't care. Well, if I remember correctly reading your book, is that the emperor did not listen to the engineers who told them, you know, you're building, you're asking us to build these canals in the wrong direction for flooding purposes. Yeah, that's right. So at the time that the West Burai was being built, which is this eight-kilometer long reservoir

are right next to Ankhore Wat, the famous temple, the king really wanted everything to be built on an east-west grid because that's basically what his sort of spiritual advisors were saying would be the most promising way to build it, the luckiest way to build it, the most in harmony with the cosmos. And so the king was like, great, that's the way that you build is you build in harmony with your spiritual beliefs. And the engineers said, well, if we do that, this reservoir is going to, it's on a slope. So, you know, it's going to be, you know, it's never really going to fill because it's, it's, it's on a slanted hillside. And the king didn't care and just said, nope, go with the ideology. Don't go with the engineering. This is Science Friday. I'm Irafledo. In case you just joining us,

we're talking with Annalie Newitz about their latest book. called Four Lost Cities, a secret history of the urban age. You know, I want to bring up a topic that I have asked many people about since I was at Angerwat, and when I was there, I saw a very interesting relief. It was an engraved image to me what looked like a stegosaurus dinosaur, engraved right into the wall. Did you see that? I did see that. It's so famous that now it's in all the guidebooks. That's right. So when you visit the temple complex at Anchor Wat, which is huge, and there's a number of

different temples in it, and it's surrounded by this beautiful moat, you know, you'll be directed to the Stegosaurus because I guess Westerners have become so excited by the idea that there were dinosaurs a thousand years ago in Angkor that they want tourists to know. Could they not have dug up the bones of a stegosaurus? You know, I mean, anything's possible. It's really hard to say. This is the thing that I love about archaeology is that there's always these wonderful ambiguities where, yeah, could have been that they dug something up and imagined it, or it could have been that it was just a representation of, you know, one of the mini serpents or monsters in the mythology of the area. But I will add that

one of the things that's really wonderful about visiting Angkor Watt is that there actually are a lot of Easter eggs in the carvings. There's tons of carvings everywhere, all these ball reliefs on the walls and tons of artisans would have been employed by the royal court to do these. And there's a famous part of one of the temples that's called the Hall of Dancers. And it's, as advertised, it's a hall full of ball relief of dancers. But often one of the temples, one of the temples, that's called the hall of corner behind like a kind of a niche in the wall, one of the artisans carved a dancer with no pants. So just a little Easter egg for anyone who was in the hall who kind of snuck off into the corner to kind of be alone. And there you'll see the one dancer. Now you have two things

to go look for when you go visit. Exactly. Look for the dancer with no pants. Annalie Newitt, science journalist and author, their latest book is called For Lost Cities, A Secret History of the Urban Age. It's a terrific read because you'll learn stuff you never knew about civilizations there. Thank you, Annalee, buzz saws and all in the background for taking time to be with us today. Yeah, thank you. They're working on the tree in my backyard.

And that's about all the time we have. If you missed any part of this program or you'd like to hear it again, subscribe to our podcasts or ask your smart speaker to play Science Front. And yes, we want to hear from you. We're working on creating more inclusive, diverse stories, and of course, your feedback is important. So we're putting together a focus group. If you're between the ages of 18 and 24, we want to hear your thoughts. You can find details up on our website, ScienceFriday.com slash focus groups. And of course, we're active all week on social media, Facebook, Twitter, Instagram. You can email us, of course, SciFri at Science Friday.

com. Have a great weekend. We'll see you next week. I'm Ira Flato.