 Yeah, I think so. So I know I don't look like Dan Shreg, and I definitely don't play him on TV. But thank you, everyone, for coming back from lunch to come learn a little bit about my research in the archeological past. So does anyone get the reference that I was giving with Kies Wiesje? No? The opening lines of the Entré Breton novel which I know has nothing to do with us. But I always think of it when I'm putting these together. So I have kind of a different background. So I just wanted to tell you a little bit about that. My background is both in anthropology and in environmental science. I do archeological excavation as well as anthropological fieldwork. You can see in that picture there. That's me learning how to process a Goan elizard with Nyalanka Taylor in the Western Desert of Australia. And I'm currently a professor, assistant professor of social environmental modeling at Utah State University and a fellow at the Santa Fe Institute. So what I really want to do is use the archeological record and archeological data as well as understandings of ecology to understand our human place in the world. The reason why is I think that archeology provides us so many examples of things that happened in the past that can help us understand things about human sustainability. I have a new paper coming out momentarily in trends in ecology and evolution that argues for this field that I'm calling archeoecology, kind of a bridge between paleoecology and modern ecology, which people have been doing this stuff in a grassroots way but coalescing this into using computational models. And please don't tweet this picture, just so you know. But using computational models and archeological data with paleoecological methods to try and really understand the trajectory of the human species. So I kind of encapsulate this in this figure here where we have the modern ecology with the goat and the tree and we can get pollen and tree rings which can also come from the archeological record but we can get this through time. This can tell us things about ecosystem change. So that's what I'll really be talking to you about today. Most of what I'm going to be talking to you about is my work with humans in food webs and I'm going to give you two different examples of that. I won't be going into the nitty gritty details of food web modeling, but I'm happy to answer any questions. And if there are clarifying questions that need to happen during my talk, please just go ahead and yell them out. So food web studies come back to Italy. The first food web was written by Lorenzo Camarano in 1880 in this beautiful paper that the translation of is on the equilibrium of living beings by means of reciprocal destruction. So Camarano noticed that organisms would eat each other and that these connections of consumption led to this overarching web. And so modern food web studies are really building on this 150 year science of things that Lorenzo Camarano started doing back in the 1880s. He ended up being a professor up in Turin. And so my work really honestly builds off of that. So from these very simple early models, we can move to these slightly more detailed models that you see on the right. This is a published food web from my work in 2017. So in a food web, we begin with the primary producers and just to orient you in this map, those are the red balls on the bottom, all of our plants, any other kind of primary production. As we move up in the food chain, we move up in the visual description of the food web where we have primary consumers on the bottom in the kind of orange and true predators at the very top for those who are going to ask who that rock star in the upper right is. It's actually an insectivorous bird that migrates through the area that has important implications for the insects in the area, but not very many things eat it. So and I think that these can be really interesting because if we start looking at what people do, that red arrow is actually pointing at people and that's what I'll be talking about, how people insert themselves into an ecological system. So at food webs, one of the things that they can tell us is the structure of an ecosystem. We can look at how many predators, how many prey there are. We can look at nutrient flows from that primary production all the way up to top predators. And that can tell us a lot. We can look at the redundancy of species. So are there eight different kinds of hummingbirds or plant pollinators or is there only one? We can look at what happens when we remove one organism, like on the right, that one that's kind of highlighted white. If I took that out, that would reorganize that entire model food web. So ecologists have been doing this for a long time, but highly resolved food webs have not really included humans until very recently for a number of reasons. And so I was drawn to using this kind of approach because archeologically we have preserved food remains. And so we should be able to build food webs of the past and look at how these change over time to tell us things about human resilience. So I build food webs of people. And just to ground you on how I do this is I begin first with the human aspect, whether that is coming from an archeological report or my actual archeological excavations. So what do we dig up? What do we identify zoarcheologically or archeobotanically? Or if I'm starting with ethnographic food webs like I did with Mardu, I begin with interviews with the elders, with follow studies of what they're actually hunting, with ethnographies to get an idea of what people are eating. So this gives you this beautiful list of everything people ate. Then I can go from that and radiate out to create an entire network or as much of one as I can of the local ecology. And then I connect all of those taxa to each other and that gives this highly resolved food web. Excuse me. This is what it looks like. So for my archeological case study from Pueblo Southwest, beginning with very dusty reports, going to when you're compiling food data, going to expert knowledge, asking actual experts, does this bird actually eat this? Have you ever seen that? And documenting all of that data as well. Come on. So we'll be talking about the American Southwest, my food web published in 2017. And the food web published in 2019 from the Western Desert of Australia. We'll be beginning actually with the Western Desert of Australia. And Yaakov I think there might have been a question online and if it's a clarifying one, will you just yell out at me and ask? Thanks. So why the Mardu? So the Mardu Aboriginal people lived a traditional nomadic existence in the Western Desert of Australia from about 40,000 years ago. So the Western Desert we think remained relatively empty of people from the original founding of Sahul 70,000 years ago until about 40,000 years ago when it became a little more habitable. But they lived this traditional existence until 1964. They were nomadic foragers moving throughout the landscape. And in 1964, what changed is that the Australian government decided to remove them to cattle stations and missions on the periphery. Because they wanted to test the missiles in the empty Western Desert. So they actually shot a missile into the desert. They flew an airplane over, realized, oh dear, there are people down there. And they sent an anthropologist to contact them. There's a documentary called Contact, not the film, the Carl Sagan film, but it's a documentary that came out in 2009 that interviews a lot of the elders who came out. And so in the summer of 2017, I lived with the Mardu elders to ask questions of the ecosystem. So you see between the 60s when the people were removed to the periphery and when they were allowed back in in the late 1980s, there were cascading extinctions of small-bodied mammals, such as the Mala or Rufus Herdwalibi, Lagarchesta Cersutis that you can see on the right, which was ubiquitous in all of the arid zones of Australia and is now extinct on the mainland, but there are still relic populations on islands. So the question is, what happened? So when you remove people, and if this was a PowerPoint, you'd actually see a video shot by drone of fire, but Aboriginal people use fire throughout Australia for a lot of different reasons and the Mardu use it for hunting. In the winter time, so our summer there winter, they light these one to five hectare fires and what this does is it burns the spin effects. That's spin effects that you can see there and the spin effects grows really thick and shrubby and it requires different fire stages essentially. The Mardu, what they do is they create this patchy mosaic so they burn these little fires and then in their summer when the lightning strikes happen, the lightning fires don't spread and kill everything. So when you remove people and it's 40,000 year co-evolution between people and the environment, you're removing the ecosystem effects that people did as well. So paradoxically, it seems that people were actually keeping animals in this pretty vulnerable region alive. So I wanted to look at this long-term co-evolution between people and ecosystems and apply this food web model and work with Mardu elders to understand what could have been going on. Several of my colleagues, including my two co-authors on this study, have done work looking at how animals prefer certain fire stages. So you can see on the right, this kind of wheel where you have the burn where the dingo is and this kind of goes through the recent burn where the dingo is, the middle is the burning obviously. And they've looked at, used camera traps and various things to look at what animals are using which fire stages. This is work by Rebecca Blegie-Bird and Doug Bird. If you remove indigenous burning, you end up with less diverse ecosystems because the fires that happen in their summer can spread tens, hundreds of thousands of acres like we saw in 2019 to 2020. What that does is then instead of having this patchy mosaic where you have animals that live at the periphery, you end up with kind of a monoculture of spin effects throughout the area. So we wanted to model pre-1964 and modern food webs to see what the human effects were. So this is some of the Mardu food webs. So I started with Mardu, I lived with them, I followed them, I asked them what they ate. In the 60s, they'd talk about it, I'd ask them what some of the locally extinct animals ate and built this food web out. So on the left, we see this trophic level sorted, the white ball is Mardu. On the right, we have connectivity sorted. So this is everything that you're eating or that is eating you. So the reason that I'm showing the funny food web on the right is that shows you how very connected Mardu are. They're eating across the entire food web from tiny little seeds to very large birds like busters and the rock wallaby that we have, which is we don't actually have kangaroos in the western desert, it's too hot for them. But they're eating everything. So if you remove Mardu, you're actually removing one of the most generalist predators out there. We can look at this another way, which is by looking at, and this is both the 1964 food web, by the way, I didn't say that. And I also do have these in different seasons. So right now we're actually looking at the summer food web. There's not a huge difference, but there's enough of a difference and I'll tell you about that. So we can look at this another way and look at just what is that high generality and how does it change. So this is what the 1964 food web looks like and I have weights for the different organisms based on talking to Mardu and going through ethnographies and seeing how often they eat all of these things. So on the right you have plants and fungus. On the bottom we have mammals going across. On the left we have birds and then we go up to the herpetifona at the top. Mardu are eating a surprising amount of things. In the 60s we already do have some invasive species. I don't know if you can see it, but at the bottom here, let's see if this works. Ooh, that's a camel. I know you can only see it's hump. Camels are not native to Australia. They were introduced by some enterprising British person who thought that all deserts should have camels. But they were already there in the 60s as were cats and foxes in small amounts. Mardu would eat them because they are there. But you can see that there are certain organisms that are incredibly important to them. So then we can look at the modern food web. So what happens after they're gone for over 20 years and they come back? Because things do change. Well, we see a huge constriction and the flour and ham is just my illustrative representation of store-bought foods. They're not always eating flour and ham, though those are two of the main purchases that they make. But you can see that there's this huge constriction to some of the most important taxa that they ate before like Goanolizards at the top. A lot of the plants constrict down to bush tomato, selenium fruits, and some of the more important mammals at the bottom. But 80% of their diet in the summer is coming from store-bought foods. So I asked one of my informants, well, what happens? So there is a tiny little store in Bargore, the Aboriginal community that I worked in. What happens if the truck doesn't come in because that happens? And they say either you go hunting or you get really, really hungry. So they still have this representation or this connection to the ecosystem, but it's less strong than it was before. Okay, so we know that this changed, but there are several things that changed here. The human portion of what they're eating. So you can see that this is very different. There are also extinctions and there are also some invasions. So how am I going to compare food webs that have different sizes together? Is there an actual change that happens that we can detect? So I employed what's known as a niche model, which is an Erdos-Renyi randomization of the food web that maintains the hierarchical structure of the food web, ran those simulations a thousand times, looked at the difference between the 64 web, a web without people and a web with people. So what these niche models do is it simulates the food webs with similar number of links and looks at what random structure would be. The reason this is important is as ecologists, we know that extinctions just happen. It's one of the things. So we have to understand what the baseline rate might be before we compare to a modern food web and we can look at what affects humans and their ecological effects had within the food web. So these are essentially the results. What you're seeing here, the orange dot in the center, that is the 1964 web, the red bars around it, that's the niche model. The brown triangles are a web without humans and the yellow triangles are a web with humans. So we see some things where it's just within the natural variability. Vulnerability standard deviation, which is looking at vulnerability to predation, things like that are kind of within variability, but there are structural things that are very different between when people are there and when people aren't. And so what I determined from these analyses is that Mario tend to be these knitters of ecosystems, that their function within there, their grazing ability, their broadcast fire, all of these things are kind of holding that ecosystem together. One of the really, really, really critical features that they have is in the summertime. They're one of the only predators of large snakes and goanna. Large snakes and goanna love to eat the fluffy mammals that went extinct in sometime in the 70s. And Marty are also broadcasting fire, which creates these smaller spaces that these mammals can run to and hide. And so when seven years after Marty were gone, these huge fires started coming through, it transformed the landscape and Marty were not there to help perform these ecosystem services. So their presence essentially kept that food web together. And you can read about this in the paper that's in the lower left. Yeah, so the question was how common are Erdos-Renny's randomization simulations in food web studies? Yeah, so there's a paper by Williams in 2003, I think, that kind of establishes this as the baseline for looking at that. And so I was following his protocols for doing this. Good question. Okay, I'm gonna move on unless somebody else has something. And if people want to yell out the questions, I'm happy to just repeat them instead of waiting for the microphone or we can wait for the microphone, whatever works. Happy to do it. I'm happy to repeat questions. So one of the best things just happened about this. Three days ago, I was emailed by a colleague of mine, Sean Olm, that my paper made it into the Australia State of the Environment, which is the report that the government of Australia will be using to help with biodiversity and biodiversity loss in Australia. So this was just published or published, it says 2021, but I think just came out online. And it's very exciting for me because I think that this shows how important this kind of deep time work is for understanding our present and future of our species. We can't understand our modern ecosystems without understanding what we did in the past. Otherwise, we're kind of walking blindly. And so this is, I think, the most exciting thing for me. And I hope you think so too. So let's move to the American Southwest. This one will be a little more brief. I'm working with this data again and moving forward with some other analyses, but I'm gonna give you a little story. So here is where, if you've been to the Southwest, Santa Fe is somewhere. Well, shoot. It's south and east of Chaco Canyon, National Historic Park, but this gives you an idea of where I'm working. So all my sites come from within that square on the Colorado, Utah, Arizona, New Mexico border, okay? So this area is where the ancestral Pueblo are from. In the late 1800s, these two cowboys were riding up the canyons, driving their cattle, and they looked up and saw these cliff palaces like you see on the right. And they scrambled up the side and found entire jars sitting on the ground, stuff that looked like people had just stopped and left, and they were coming right back. They took pictures, or they invited a newspaper columnist out who took pictures and pretty much people became obsessed with the ancestral Pueblo. People wanted to know where they went and why they left. People hypothesized a huge drought that happened, but we now know that they lived through a lot of very bad droughts. They hypothesized hostile invaders, but we now know that the Athabaskan speaking people from the north came hundreds of years after this was abandoned. So I figured I should look at the 700 year occupation of the area to understand how people lived, to understand why they left. So people entered this area fully fledged as farmers in around 8,600, and they left by about 8,300. So they had this 700 year occupation where they thrived, they had families, they interacted with the environment, and then everyone essentially went away. So I built a food web because how are you going to understand people if you don't understand what they eat? Since we're in Italy, we all know that's true, okay? So this is the ancestral Pueblo food web. I think it looks kind of like a layer cake since we're talking about our graphs in terms of food. It's not a chapati, this is a layer cake. So that arrow is pointing at people, and this is the meta food web for all of the Southwest, but then I can pull this out for the many different sites that I have. The original publication, I had three sites, I now have over 30, and so I'm able to look at what changes happen over time. Excuse me. One of the things that you can do is look at some very simple statistics and look at key species for people. So people liked eating deer and they liked eating maize. Connectivity is one of these statistics where we can look at what you eat and what eats you. So we can see that when humans come in and bring maize with them, so this is not native to the area, they, when they migrated in, they brought it. Oh, I'll take your fancy water. We can see that people inserted themselves into the ecosystem, but deer are native to there, and so you can see where they are within this, but if we remove one side of that and just look at predation, we can look at vulnerability to predation. One of the things that humans did when they brought maize is they unintentionally brought candy with them. So in going through the reports of all of the species in the area and reading about every single species in the area, every single animal that eats plants will eat maize. And we do know that farmers in the area occasionally have to, when corn is castling, chase off organisms to protect it. We know that ancestral Pueblo people had a lot of storage to deal with kind of insurance, if you will. They would have about three years of storage with them at all times. We know that that was raided from time to time. So we can look at this and see that over time, people brought this candy with them and increasingly had more vulnerability over time, and I'll show you that. So most archaeologists, when they look at the ecological things, they just look at one or two taxa that they care about, such as the deer and the maize. But in compiling a food web, you read about the entire ecosystem and you get this natural bio-history, essentially. One thing I noticed is that in the sites that I gathered and my newer sites, we have these two taxa here, elk and snowshoe hare, as well as many others, that depend on forested corridors for breeding and for feeding. We see this, we see them up until sometime around AD 800, and then they start disappearing from the archaeological record. By the time AD 1180 shows up, we start seeing these two bird species that do not exist in the area anymore. Scaled quail on the left, they're from around Farmington, New Mexico, which is a couple hundred kilometers away. Since 1909, there have been three sightings of scaled quail in this area. And on the right, we have sandhill crane, which since 1909, we now have 11 sightings because there were two last year. But we see these in abundance. There's a diagnostic hyoid bone for a scaled quail as opposed to a California quail. And so we can actually identify them in the archaeological record. What this is telling me is that there is some kind of an ecological shift. We've known about deforestation in the area for a while, but this is showing us other effects of that. Humans are creating a niche for other species. So people had to clear trees for building their fields. When we talk to descendant communities, they talk about how you can figure out essentially the acidity of the soil based on what plants are growing there. And they like to plant maize where juniper used to be. So they clear juniper from the fields. They also use juniper for building their houses and things like that. Over time, they're going to be clearing the landscape, which we've known about from pollen cores. And we know that people have to go farther and farther afield for their wild resources. So even though people are farmers, they're still engaging with the wild ecosystem as well. Other people have estimated the population in the area. Dylan Schwint estimated the population to be about 27,000 in the 1200s, right before depopulation. This is a very, very high amount of people. It's about the amount of people that live there now. And there's a Walmart there. So these people are farming and fielding or gathering wild resources. And they're only going to be able to do that, really, when there are smaller densities of people. Otherwise, there's so many people packed on the landscape that it becomes problematic. So I talk about this obviously a lot more in this paper. I have follow-on papers that should be coming out in the next year. But I really want to go to what could uses beyond food tell us? Because we're people and we do things other than eat. We make clothes, we build buildings. And so with some collaborators, I've started looking at the various ways that humans interact with the biotic environment. So categorizing things, not just in food, but looking at clothing, housing, fuel. These are categories I debated with other archaeologists for a long time. And we've started cataloging this for not just the ancestral Pueblo, also the Mardu, Miriam Islanders, Pacific Northwest. I have a published paper with the transition from the Mesolithic to the Neolithic in Central Europe. But this is a way for us to start looking at the ways that people interact with ecology. Here's one thing that will be forthcoming in this paper that I think really takes the discussion away from just the importance of maize as a food, the importance of rabbit and turkey and deer as foods, but looking at all of the uses for all of these. And for this, I'm relying on, if you see something archaeologically like a by-face, an arrowhead, hafted to a piece of juniper. We can say that that's an artifact, right? The juniper is used as an artifact. But also working with descendant communities to identify how they use things. So one thing that I want you to see here is that maize is really important, but so is juniper, the primary tree species, as well as pinion. And these are used as well in food and in ritual and all of these things. So you're making a choice between eating and building things, and these would be hard choices over time. Choices that we are making today too. How do we decide how to use our biodiversity and how do we provision our children when we know that there is a slow unfolding catastrophe before us? So this is from the Swifterbond study where we looked at these kinds of connections in an overall network. And what this tells us, using network analysis, it can kind of tell us the importance of a taxa to the connectivity of everything. How many things is it used in? What happens if you remove those taxa from the landscape? So in Swifterbond, it's interesting because we have the Neolithic population coming in and replacing the hunting and gathering way of life, whether it's people changing or switching of the population is still debated. But one of the things that we can see is we can actually look at this and what this kind of structure does to the ecosystem. And I apologize for not putting the citation on there, but I'm happy to share it with anyone. It's open source, so you can find it, open access. Another thing that we can look at is how people bring things together. So remember I said people are eating maize, but they're also actually eating juniper. So a lot of the time for niche normalization to make sure that your corn has protein in it, you end up boiling it with a little bit of ash from a tree. And so when they make peaky bread, the Descendant Communities do, they follow this recipe where they add chinapodium, which is essentially a quinoa type species. It's goose foot in this area, as a dye. They're adding juniper ash. They're using Helionthus, a sunflower hood to put over it to help the bread kind of rise. And this is coming together on this little stone there. You can see the picture that I took to make the bread. And so this is really important. So imagine you're a person who has inherited a landscape where deforestation has happened over time and across space. So you're having to make these choices and decide what you are going to do. So when people left the ancestral Pueblo area, one of the things that my paper from 2017 talks about is they were experiencing a landscape of shortage over time. But they had come to a kind of sustainable way of doing things if they came to a new area. And so my argument is that it was time for people to go, which is what Descendant Communities will tell you, to bring these sustainable strategies, to migrate to a new place where there weren't people living there yet, and have these sustainable strategies that when Europeans came to the US, we saw the Descendant Communities using. I think this can link to some of the discussions we're going to be having tomorrow about migration, because people had a place to go then, but we don't really have a place to go. So with these studies, one things that my colleagues and I have talked about is ways to understand how people process information about the landscapes that they lived in. And so this is a representation of that, showing it with an ocean habitat, so up in Iceland, essentially. But we're looking at these information flows, so how much of the local landscape do you understand? And what happens if you aren't quite sure what's happening? So for an example, because this is basically a description of Iceland. In Iceland, there's a, when the medieval north showed up, they started harvesting duck eggs, and they realized after a while that the populations of the Eider ducks were declining. So they put together laws to protect the Eider harvest, which means that today we actually have very strong Eider colonies there. They recognize that there's about a three-year leg between what you harvest now and what will happen later. And so having that information, that ability to understand and transcribe that information pass it on is really important, but what happens when that doesn't happen? So you can have these kinds of, this flow chart here shows you this idea of when you modify the ecosystem, and there's an instability. Do you identify the problem? Do you not identify the problem? Are you able to change things and have remedial action, and so you have a good outcome? Or are you not able to change things, either because you don't care, or because it's too difficult, or all of these? So these are the ideas that we came together. For this upcoming paper, and I developed a very simple conceptual model, which is here, that is looking at how there's total information within an environment that we can't access. We cannot know everything about an environment no matter how good of scientists we are. So there's going to be some kind of costs of processing the information, which leads to available information and usable information. There's going to be costs of actioning the usable information, which can lead to that wielded information, and there will be losses of information due to your perceptual limitations. This was just accepted in Global Environmental Change, where we use this very, very simple conceptual model to then look at three different case studies around the world, the Pueblo, the South Pacific, and Iceland as well. And so this is new work that I have coming forward that should be out in the next couple months. So to sum up, humans do impact ecosystems, but we are a part of the environment. We have evolved, and at least around 300,000 years ago, we started moving out of Africa, and we started impacting ecosystems around the world. These impacts are not uniformly good, and they're also not uniformly bad. But the archeological record can help us understand when they're good and when they're bad. And we can look to these experiments with the past to understand what has worked and what has failed. And I think one thing our modern society is really bad at doing is learning from our ancestors. But I think that we can, and I think that's why we all are here. And so what I do, archeo-ecology, and modeling methods, I think can be useful for understanding this human place and ecosystems and helping us to move forward in a just way. So thanks to my funders, and thanks to all of you as well. Thank you. Questions? Yes, Sandra. Thank you for the fascinating talk. Do you think that your method, your approach could be applicable to our present food web? And do you think the best way to proceed could be to build hundreds of very specific kind of local food webs? Or alternative you think is better trying to build, if possible, the food web of the whole humanity. Only one big layer cake. I don't think we can build a gigantic layer cake at this point, but I'd love a slice if we could. No, but so with the Australian work, one thing that I'm, I have this project that I'm working on right now is that I have that 80% connection to the store. Well, I have receipt data from what people were buying at the store. And we know where those products come from. And so something I'm working toward is being able to decompose that global position of the food web, the flour that they have. A lot of it is Bob's Red Mill. And so it comes from Oregon. Their beef comes from Sydney, or Sydney processing plants. But these kinds of things I think can be useful with probably some other tools like agent-based modeling, for example, where we can look at those trade-offs between buying from the store and hunting and how hunting actually gives back to the ecosystem. Vulnerabilities in the supply chain make local people vulnerable as well. And so I think that those approaches can be useful. I think as a lot of scientists, what we do is we learn a technique and we just start applying it everywhere. And that's something that I would like to not do with my work, but I do think that I've found some compelling stories for this. I'm not sure if building tens of thousands of food webs would answer all the questions, but I think that for specific questions, it can be one tool that can be really useful. I think there are a lot of other tools that can be really useful, like systems dynamic models or agent-based models or just working with local communities and trying to help with local foods movements and things like that. We're gonna need to be flexible, I think, as we deal with challenges and understand the local constraints to be able to deal with them. Yeah. Can you hear me? Yes. Yes, please. Who is this? My name is Joe. This is Joe Carlin. And I'm speaking to you from New York. Great. Thank you very much for your very creative and original work and for this presentation of it. I have two questions. One is, could you say more about the possible importance of the taxa that eat people? Not only what they eat, but the taxa that eat them and whether those taxa played any role in the departure from Mesa Verde, if I'm remembering the name correctly. And second question, so that's basically infectious diseases and parasites. Secondly, I believe you used the niche model of Neo Martinez and Williams Yes. in your analysis of the impacts in the Western Australia. Yes. And I think it would be important to do a sensitivity analysis to compare the conclusions from that model with conclusions from a number of other random food web models to see whether your conclusion is an artifact of the model or is a robust conclusion or at least on what assumptions your conclusion depends because the assumptions differ between the different models. So have you considered doing a sensitivity analysis with another model to cast your conclusion? Yeah. Those are my two questions. All right, I'm going to answer your second question first and then your first question. So yes, it's Neo and Rich's work. I erroneously put Rich as the first author that I used for the niche model. And you're absolutely right. I think that I can draw conclusions based on comparing my model and running the simulation, but I didn't run a comparison against a lot of other webs as has been done in ecology. And this work is going forward. And so I do think that that is a very valid thing to do, especially if the Australian government or anyone else is going to be paying more attention to this work. I think that there are valid results that came out of this modeling exercise, but I think that if we want to look at the strength of those in comparison to other places that we absolutely do need to do a sensitivity analysis and compare this against some of the other model webs. As to your first, did you have something to add, Joel? I'd like to hear your answer to the first question. Okay, so your answer to the first, my answer to your first question, what eats people? Generally speaking, I did not include parasites within this web and Jennifer Dunn has done work looking at the importance of parasites within food webs. And the reason that I did not include parasites in this web is the data was not available. And so this is a terrestrial food web of looking at mostly macroscopic organisms. And so the predators of people are generally things that will eat the young. So cougars will sometimes prey on young people. Packs of coyotes have been known to do that. We do have evidence of cannibalism in the American Southwest. It's not something that people had to deal with all the time. But there are some papers on the violence in the Southwest. One was published in 2014 called The Better Angels of Their Nature by Tim Kohler et al and Christian Cucklerman. And so there are predators of people, but they are in lower levels and generally sub-adults who would probably be picked off in certain circumstances. I don't think that people had to deal with regular predation by other organisms quite regularly, but it's still important to include those links. Thanks very much, Stefan. Thank you so much for your questions. Thank you, very nice talk. Could you expand a bit more on your conceptual model? Where you had the information, I don't think I understood it. So are these numbers that you can measure or...? We do have, so within the paper, we do have some numbers that we measured from Iceland, where we looked at, because in Iceland they actually had written documents and so we can look at when they had enough information that came in about the environment, how they had remedial change and when they didn't have enough information and how they did not. And so we used numbers-ish, looking at they had very high information flow, so between 70 and 90% and things like that and looking at how this can change the outcome in the end. So at what point does it matter that you have these compounding variables, that you don't have great information, you don't have people wanting to make change, so they're not wielding the information well? What does that do to the ecosystem in the end? It's really a very conceptual model, but I think that it can be helpful for looking at how people gathered information in the past and places where we can look at what the outcome was and look at this potentially for some things, some situations going forward. Okay, so if we don't have other questions, then we thank you again, Stephanie, for this great talk.