COMPLEXITY: Physics of Life

Jennifer Dunne on Food Webs & ArchaeoEcology

Episode Notes

For as long as humans have erected walls around our cities, we’ve considered culture separate from the encircling wilderness. This difference came to be expressed in our “man vs. nature” narratives, beliefs in our dominion over the nonhuman world, and lately even the assertion that the Earth would be better off without us. Ecology research has strangely almost never included humans in the picture. And yet Homo sapiens is a phenomenon of nature, woven into food webs, demonstrating the same principles at work as any other creature on this planet. New research into trophic networks — who’s eating whom — has bridged ecology and archaeology to shed light on the many ways that human beings have participated as key members of ecosystems round the globe. The emerging portrait of our place in nature offers us the opportunity to tell new stories of the hairless ape and what we’re doing here — and just in time, perhaps, to help reshape our attitudes toward conservation and development, and what we dare to hope for in the years to come.

This week’s guest is Jennifer Dunne, SFI’s Vice President for Science and Fellow at the Ecological Society of America. Dunne got her PhD in Energy and Resources from UC Berkeley, joined SFI’s faculty in 2007, and sits on the advisory board for Nautilus Magazine.  In the first half of a two-part conversation, we discuss her work on food and use webs and the ArchaeoEcology Project working group at SFI, where she and her collaborators are transforming how we think of human history.

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Jennifer Dunne’s Website.
Quanta Magazine features Dunne on humans in food webs.

The New York Times features Dunne’s collaborator, SFI Postdoc Stefani Crabtree and her work on the Martu people of Australia.

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Episode Transcription

Michael: Jennifer, it is an honor and a pleasure to be here in your office discussing research that I find most interesting.

Jennifer: Great to have you here.

Michael: I'd like to anchor this in the human time scale, and then work our way out into bigger concerns. So, I guess the start is how did you become a scientist?

Jennifer: Ah, yes. I love origin stories. This is a question I often ask scientists myself. So, how did I become a scientist? I was a good student in science and math in high school, like many scientists were. I thought they were incredibly boring because I didn't really understand what math and science were at that point. I thought it was about memorizing a bunch of facts and a bunch of algorithms and kind of regurgitating them or applying them on tests, and so when I went to college I decided I wanted to get away from science and math and so I studied philosophy. And I studied philosophy because I was really interested in the progression of ideas through time, and I thought I was going to get that through philosophy and also it had the fewest requirements of any major at my university, so it gave me the most freedom to do a lot of other things.

 And I was interested in reading and writing and close reading of texts, and that thing. So philosophy kind of let me down in certain kind of ways too. Too much of it was sort of taking classes in dead old white men. But it was my sophomore year in college that I took a class on history of science, or philosophy of science actually, with Hilary Putnam, a very eminent philosopher of science, and that's when a light bulb for me went off. And so I ended up actually doing more work in history and philosophy of science because that's where I really got turned onto the progression of ideas through time; that's sort of where I was getting it. I wasn't getting it so much in the way I wanted it through philosophy itself in a lot of ways, but through understanding the history of ideas of scientific ideas and the philosophy of scientific ideas that really turned me on.

And so, by the time I finished college I was thinking to myself, "Well, maybe someday I'll go back and get a science degree, maybe I should check out this science thing for real." And I was out for a couple of years doing some environmental work and environmental activism until I was under stimulated and a little bored and I decided, well maybe now is the time for me to check out this science thing. And so, I dove back in, started doing a master's degree in ecology and systematic biology at San Francisco State University and then it kind of unfolded from there in a very still nonlinear fashion but that's a whole nother...that's the earliest part of the origin story.

Michael: Okay, so the meat of the conversation today is about your work in ecology and in trophic network reconstruction, so let's get into that and how you came to pursue that particular scientific passion.

Jennifer: Yeah, in terms of my interest in ecology, that sort of tied into just early childhood frankly, you know running around in the woods and catching tadpoles and raising them into frogs, and you know, budding little naturalist. I didn't express that until I kind of started decided to study ecology in my 20's. And I actually originally did my master's in PhD basically in plant ecology. I trained as what I call a conventional field experimental plant ecologist looking at the impacts of micro-climate and macro-climate on plant communities. Did my PhD research up at the Rocky Mount Biological Lab up near Crested Butte, Colorado. But towards the end of my PhD, I enjoyed it, I did original research, it was really exciting to become a scientist and to practice that.

But focusing just on plants wasn't doing it for me. Again, I was like, "What is it that I need? What is it I want?" And what I really was interested in was I wanted someway to grab onto the full set of species in an ecosystem. I didn't want to just know about one subset of species, and a lot of ecology tends to focus in on a particular ecosystem or a particular type of taxon or a particular interaction and I got exposed to food web research and that got me really excited because that was really excited because that was really trying to look at the full diversity of systems but then to understand the full set of complex interactions that are tying all these different kinds of organisms from bacteria up to top predators together.

And food web research, which in the 90s was kind of a small little disrespected backwater of ecological research at that time, but I saw the promise of it and also the promise of using networks and network theory and network approaches in general as a means for trying to quantify and dig into and understand the complexity of ecosystems in terms of how species interact. So it was at that point that I ended up switching from my PhD to postdoc, from being a plant ecologist to studying food webs and ecological networks, and taking these approaches from statistical physics and applying them to understanding the structure and the dynamics and the stability of ecosystems.

Michael: Some of the really least for me, some of the most interesting stuff that you've worked on in the last few years, to zoom out one layer, is in human history and to talk about an idea that has itself evolved over the history of human science and philosophy: our relationship to nature; do we belong in that category or out of it? And, your work on archaeoecological use web reconstruction so talk a little bit about that and where the different human communities and the different ecosystems in which you're doing this work. And also the way that this has brought you into affiliation with these indigenous communities and what that's like.

Jennifer: Okay.

Michael: Yeah.

Jennifer: There's a lot there.

Michael: There's quite a bit there.

Jennifer: But I'll try to unpack that a bit. So most of my work, I mean what has know, and this is another thing that ecologists do. So, ecologists tend to study, or pretend at least like they're studying ecosystems in the absence of humans or they may study ecosystems with human impacts, with humans as these external forcing factors and in fact my PhD research was about climate change impacts on plant communities. So, I was studying plant communities but trying to understand what climate change would be doing to them. So, in that case humans as this kind of negative external forcing factor. When I got into the food web research, I mostly at first was really doing work to try to understand the fundamentals. Does this food web from say a lake, is it structured similarly or differently from a food web in the ocean or from a food web in a forest or a food web in a desert.

So a lot of my early work was really about are food webs similar or different from each other in how they're organized? What are the implications of that for the robustness of those ecosystems to species loss and species change? But it was very much in this tradition of not thinking like humans are somewhere out there separate from the ecosystems I'm comparing and studying. And in fact I and others have found that there are very deep commonalities in how ecosystems are structured. But about a decade ago or maybe a little longer ago I got cold called by someone who's involved in a proposal to The National Science Foundation to fund what they were calling biocomplexity research in the Aleutian Islands of Alaska.

And so this was as group of environmental scientists, ecologists and archaeologists who were banding together to study this little piece of the Aleutian Islands, the Sanak Archipelago near the tip of the Alaskan Peninsula and to basically do an integrated study of the environment, the climate over time, of the ecology over time and of humans and how humans fit into and interact and impact those other elements so kind of looking at humans ecology environmental intertwined. So they contacted me because they had seen some of my food web work and said, "Huh, I wonder if we could...or if Jennifer, or Jennifer and her colleagues, could use those kinds of approaches as a means of thinking about the Aleut, the human hunter gatherers and how they kind of fit in to this ecological environmental system."

So they pitch this idea to me and I said, "Wow, that sounds really cool. That sounds really interesting, sign me up." So I became a part of the proposal, the proposal got funded and so that was how I first got pulled into thinking about humans. And in this case, a very important thing that we all agreed on from the very beginning and that is reflected in papers that have come out is this notion that we need to do more work both as archaeologists and as ecologists to not have these strong separations and to not think of humans as outside of the ecosystem or as just some negative forcing factor. And so we want think...I mean humans, in one sense are just another species, and they act in certain ways and their behavior, like with other species impacts other organisms and impacts the ecosystem. And so we were all committed to sort of this notion of pulling humans explicitly into ecological analysis and using ecological analysis to encompass species including humans.

So my colleagues compiled a huge amount of data and that's a whole nother story but Spencer Wood, who's still a very close colleague of mine, he's up at University of Washington, he as doing a PhD in intertidal ecology, food web ecology at the time, and he did this big effort to put together this huge database of species feeding interactions or trophic interactions — that's just another word for feeding. And then also did local sampling of the intertidal and the near shore marine systems and was able to combine all this ecological information that we would normally use to pull food webs together and figuring out who eats whom and whose present and all that stuff. We combine that with archaeological data of various kinds, so for example, there’s 128 home sites on this small island, all of them were... And all of this work actually was done with the explicit approval and permission of the Sanak corporation which is the group of Aleut, the Sanak Aleut who used to live on the island, they moved off in the 50s. And they were actually very excited to support the archeological and ecological research that goes on and I'll come back to that in a minute

But, so the archaeologists excavated or took course from them middens by all the home sites, the middens are just the trash heaps, the human trash heaps, but they go down through time. So the deeper you go in the midden the deeper in time you are. And people have been on the island for 6000 years or longer. And out of that they were able to pluck out all these shells and bones and they can do zooarchaeology on them to figure out what fish species and what shell, you know, mollusks and birds and things they were feeding on. That's not a complete picture of what the Aleut were feeding on, so we were in that case, my colleagues were also able to include some anthropological data so they ethnographic studies and what they did was actually to go to the Sanak Aleut elders and actually who have lived on island and interviewed them and asked them like, "What did you eat?", you know? And "What did you eat in times of need? And what did you eat in times of plenty? And what were your preferences? And what was this? And what was that?"

So that really helped to fill out like they ate a lot of different species of algae and they ate a lot of different invertebrates and there was just a lot of things that they ate in addition to the little bones and shelly bits that we could recover. So you start...we used all that information in order to bring humans, in this case the Sanak Aleut explicitly into the food web as one of the nodes and connect them to all the different species that they were consuming. And so then again it was not the first time that humans have been included in a food web but the previous food webs that had included humans were very much kind of cartoonish. They were very small and poorly resolved and they weren't really good data for really doing anything scientific with. This was the first time that a really highly resolved food web with many hundreds of species resolved evenly at all levels of the food web explicitly included humans.

So, that then allowed us to start asking fairly simple questions, things like, “How do humans compare as predators or consumers to other consumers and the variety of things they eat?” You know, very simple question but unless you have the data you can't answer it. And so we knew first of all humans were feeding on about a quarter of the species in the marine system, in the near-shore marine system. And so is that a lot or is that a little? You don't know until you compare, so then we'd look at the other...we can do a histogram where we show basically how many of the predators or consumers in the system feed on x number of prey species. And so you get this distribution where most things are highly specialized and the feed on one to ten different things.

But then you have this long tail and humans are way out at the end of it along with cod…

Michael: And we're eating the cod, so, yeah.

Jennifer: Right exactly. And cod probably would've eaten humans if they had a chance, but I don't think they had a chance. And so those two species were eating many more different types of species and other species in that system. And not only that, humans were highly omnivorous. They were feeding at all trophic levels. So feeding on everything from the algae to the shrimp to the mollusks to the fishes and to the sea mammals, sea lions and things. So yeah, so we can start to use this kind of data to really start to understand how humans compare to other species in the context of an ecological network. And this is the reason actually why the Sanak Aleut were really…or, part of the reason they were interested in supporting this kind work, is because it actually gave them information about themselves.

I mean they obviously knew a lot of this already, they know what they eat and they even know what they eat historically; but to have it done in a very quantitative way and in a rigorous scientific way, it provides them with a lot of information that's actually quite useful to them as a people and as a culture. For example when things come up, I mean there can be law cases where they need to assert their rights to hunt and fish certain kinds of things and they need to demonstrate that they have a history of doing this. And so now this gives them some additional ways to actually kind of go, "Look, we have the charts and graphs to back us up." And it's also useful just for them in sort of maintaining ties through time of their current culture, which no longer lives on the island, to their past history as a people, and so it helps that continuity.

Michael: So in the abstract to the 2015 paper that came out of this research, you mention that potential extinctions in the simulation that you ran on this data decreased when an “invading omnivorous supergeneralist consumer,” that would be us, focused strong feeding on decreasing fractions of its possible resources. So, that seems to have some pretty broad implications and I'd like to dig in on that a little bit and then possibly also link that to the work that you and Stefani Crabtree did in Australia looking at the impact of human foraging technology and approaches to that particular ecosystem and...

Jennifer: Yeah, so I think there's often an assumption when people think about humans, and their impact on ecosystems that we always mess things up. We come into a system and things go extinct, and we mess up the environment, and we change the climate and just that we do bad things. And that, you know, certainly human, there's many examples of humans having negative impacts when they enter a system or if they are in a system for a long time and overdevelop or do too much agriculture or cause species to go extinct for whatever reason; but what we're finding with the food web research is we're actually, at least in historical and archaeological time, we're finding very interesting examples of humans coming into systems where humans hadn't existed and fitting into the system and sometimes being a very critical factor for stabilizing the biodiversity of the system.

So we have kind of two examples of this on, the Aleut one that I was involved with and led and then this other one that you mentioned that Stefani Crabtree was involved with. So in the case of the Aleut project up in Alaska, what we realized from looking at the structure of the food web and how humans fit into it is that humans were special in the roles that they played, in a sense; I mean they were these supergeneralists feeding on many different things and superomnivores feeding at all trophic levels and very closely connected to all the other species in the food web and just the fact of that, how they fit in, that alone suggest that they were poised when they came in 6000 or 7000 years ago, to have big impacts on the system. They potentially could have had big negative impacts given that they feed on so many different things and at different levels.

However, we have no evidence that there were any short or long term extinctions in that system, or severe environmental degradation, or other negative affects. They seems to kind of come in and fit in and this is in spite of the fact that they were these super generalist omnivores and in spite of the fact that they also used hunting technology, and they made kayaks, and they made all the tools that went along with kayaks, and their preferred food were sea lions and so they'd go out and hunt sea lions. But it was a big effort to try to get all that technology together, and also most of the time the weather didn't allow them to go out and hunt sea lions. So, what they would do and what they did was something that's very common to ecological generalists: they switched prey pretty much all the time. And so, if you can feed on many things, you may have a preference, in this case for the sea lions, but most of the time you can't go after that preferred thing for whatever reason; so you go, "Well, I'm going to go into the intertidal and I'm going to pick up sea urchins and eat sea urchins or big juicy mollusks, or whatever."

And then even within the intertidal you'll switch because you'll go after the big juicy things first, and then those get a little harder to find and so they just kind of naturally switch to a smaller-bodied thing. And then when the salmon run would arrive the salmon would come in and they would drop everything else and they would go focus on the salmon. And then if the weather was really bad and the salmon weren't around they might just harvest some bird eggs close to their home. So, but this kind of switching among your different prey items is what generalists do, and it makes a lot of sense if you think about it, it's kind of intuitive that you would switch under certain circumstances. The other thing it does, is it's very stabilizing for the ecosystem because it allows things whose local populations are decreasing because you're eating them or for whatever other reason, it allows them to recover. Your attention goes somewhere because it's easier to find this other thing and so, the population you were focusing on for food gets to recover.

So that's really good for the population, it's also good for the whole ecosystem and so what we did in that paper, in that piece of research was to run some toy models basically, some simulations of an idealized system that we invaded with a human-like species that's supergeneralist and omnivore. We also gave them kind of a stand in for using hunting technology. What hunting technology does for humans in effect is to allow them to feed at a rate that's much greater than their body size so typically predators you can sort of tag their success rate or their rate to hunt and acquire food, it's roughly a function of their body size, as many things are in biology. But if you start developing technology and using it, all of a sudden it's like you're a whole pack of people all smooshed together who can access many more calories all at once.

Michael: It's like that image of the big fish eating the smaller fish and then the entire school of fish…

Jennifer: Right, eating the big fish.

Michael: ...that's shaped like a giant fish, yeah.

Jennifer: And I mean and so, yeah, and group hunting behavior is a form of kind of feeding successfully at a higher rate than an individual be able to. So hunting tech does this for you. So, yes if human hunter-gathers had come into that system with a bunch of fancy hunting tech, and they had used hunting tech all the time on everything, that probably would have been really disruptive and caused some extinctions locally. However, most of the time the Sanak Aleut, they hunted some of the time, and they liked to go out and hunt, like I said sea lions, but a lot of the times they were just foraging, they weren't using technology or maybe they might have some kind of pail or bucket to put things in from the intertidal, but a lot of times they're just going out and foraging for stuff and not using fancy tech, so they're basically kind of tied to their body size.

And so, as long as...I mean you could have the humans come into that system and give them a little bit of hunting technology, but as long as you limited it to a few things at a time, which is pretty much what the humans did in this system, then you basically don't see secondary extinctions. Now it's not the only reason you wouldn't see secondary extinctions in that system, because the human population was relatively small and also their kind of in an open system, so marine organisms are kind of flowing into the system from the outside and replenishing themselves also. But there certainly are scenarios where people have arrived on islands and wreaked havoc, they did not so that on the Sanak Island, and we think it's partly because they were prey switching and allowing things to recover, and they were only using hunting technology a fraction of the time.

So, that's the Aleut story. So the other story is this Australia story that Stefani Crabtree was involved with and did work building on a lot of work by Rebecca Bliege Bird, a professor at Penn State. And so Stephanie, she basically brought this food web kind of perspective to work that had been going on, looking at the Martu people, the hunter-gatherers of the western desert of Australia. Now this is a very different kind of system from what I'd looked at, at the Sanak islands, it's a terrestrial continental system basically, it's a desert system. Whereas the Sanak Aleut had been on their island for about seven thousand years, six or seven thousand years, the aborigines of Australia have been on their landscape for probably 80,000 years, maybe longer and in effect there is no ecosystem on Australia that is separate or prior to humans. Humans and the Australian ecosystems have co-evolved over many tens of thousands of years. So they put together, Stefani put together food web data for the Martu because what happened with the Martu is that the government of Australia, in their infinite wisdom, pulled the Martu people off of their lands, off the western desert of Australia in the mid 20th century, so just removed them from their ancestral lands. And so Stefani was able to put together kind of before and after pictures of the food webs including the humans, so with humans and then without humans. And, the impact within just a few years, frankly, was enormous.

When they pulled the Martu people off a bunch of small bodied mammals went extinct, there was a bunch of extinction cascades, the food web contracted greatly, it became much smaller and impoverished because what had happened basically is that the Martu people do small scale burning in order to access their main preferred food items, and their preferred food items are large bodied lizards. And so they would do this patchy burning on the landscape that would make it easier for them to hunt lizards and get them out of their holes in the ground. And so, they created...and over many tens of thousands of years they've been doing this and so they've created this beautiful mosaic of landscapes, of these sub landscapes on the desert that did several things; A, it created adversity of ecosystems, so it enhanced the bio diversity of the whole region because you have all these different patches at different levels of growth and development and so different kind of species can thrive in these. It also prevented massive wild fires because it was this kind of controlled burn thing that humans were doing but over many tens of thousands of years.

So when they pulled the humans out, all of a sudden they started also getting massive wildfires that would just burn everything to the ground and sterilize the soil for the top several inches and impede redevelopment of the ecosystem and reduce diversity. So Stefani was able to show the aspects of this through looking at these before and after snapshots of the food webs and what's happening now is that the Martu people are now moving back onto their ancestral lands in the western desert and are returning to their old practices, including this patchy burning of the landscape, and already the ecosystem is starting to rebound in terms of diversity and other impacts.

So those are two really cool examples where food web approaches were used to explicitly incorporate humans into ecological network studies, and for ecology to kind of encompass humans, in this case hunter-gatherers. And in both cases humans were important for the functioning of the ecosystem, even more so that's even more stark in the Australian case. But in both cases…I mean in the case of the Sanak Aleut, they came in 7,000 years ago or so and didn't wreak destruction and havoc and it's too early to tell now that humans have moved off those systems, how much of an impact that's going to have. In the case of the Martu people in Australia, there's very clearly a very negative ecological impact by pulling humans out of the system and an ecological benefit to having them come back onto the system.

Michael: This is know the way I've seen this portrayed in the news is, like you said at the beginning of this, a way to disabuse ourselves of this kind of self-destructive eco-guilt that humans are just ruinous wherever we appear.

Jennifer: Right and we're separate from nature and we're ruinous to nature, it's like, well we're a part of nature for better and for worse, as many other species are too.

Michael: Yeah I think we have in part films like The Matrix, you know Agent Smith, calling humans a virus…

Jennifer: A cancer, right. Yeah.

Michael: ...and that just seeded our imagination, yeah. So, I'm interested in, not just among hunter-gatherer communities, but I've heard seemingly related research into the areas around cities and how the built environment of human beings can actually provide zones of extraordinary biodiversity. And so like, we haven't even brought up the ArchaeoEcology Project…

Jennifer: Yeah, and we'll get there.

Michael: Yeah, which encompasses…

Jennifer: Much more than feeding, right?

Michael: Yes, the entire use web of all this stuff. Two of the questions raised by this project are, “How does space and dimension of territory influence the socio-ecological systems?” And then also, “A key role of humans may be bringing together other taxa that would not otherwise interact so, how variable is this integration? And how does this affect resource management and ecological stability?” So, there seems like a really important vital move toward understanding human settlements as areas where we can actually perform regenerative functions and that human created niches can lead to novel interactions; and I'd love to hear what kind of insights are actually being applied out of this? If you...I mean like.

Jennifer: I don't know.

Michael: Yeah.

Jennifer: I won't be able answer that.

Michael: Okay.

Jennifer: But I'll talk about sort of tangential related things. But I mean a couple of things, so in terms of...I mean I just mentioned two projects that are looking at humans in food webs and in these cases, cases where humans were a part of food webs, an important part of stabilizing food webs and so not ruinous to the webs. There's also, there is a socio of...I mean there are movements afoot, and The National Science Foundation has funded something so NSF and the United States have funded these things called long-term ecological research sites, so where they're actually supporting long term research over decades because too often research is kind of bounded by the length of a grant which is like three to five years. And so NSF invested in long-term ecological research, well as a part of that they actually funded a couple of urban rural gradient research sites, so basically they supported groups who were doing research in rural to urban gradients basically.

So where they go all the way from kind of a rural, more natural setting across space into the city and then they look at different aspects of ecological and human kind of involvement and environment along that gradient or along that transect and I think... and so, one of those was centered around Baltimore and one of those centered around Tempe/Phoenix, and I hopefully got that right. So, mean I think there's a lot of interesting work that people are starting to do along those lines. Now in terms of sort of the bigger agenda that we're looking at, me and my colleagues Stefani Crabtree and Spencer Wood and a variety of archqeologists and anthropologist shave gotten together and this kind of grew out...first off, all of it grew out of this humans and food webs work. It also grew out of conversation I had via a project I got involved with based in French Polynesia, so the islands of Moorea and some sister islands; so that's next to Tahiti.

So, I got involved in a similar kind of project in some ways in Moorea with some archaeologists, Pat Kirch and Jenny Khan, and we realized early on in the project a few years ago that we didn't really have the resources to compile a really complete full food web of all the species on multiple islands; we want to do that eventually. So we were kind of tossing around the idea of what could we do that we think is interesting and important that's shy of kind of doing this full food web thing that I did up in the Sanak Aleut project and so what we started around is like, well we have a lot of information on not just how humans were feeding on other species but how they were interacting with species in other ways and using them often in a variety of different ways.

And so, I brought this idea back to my colleagues, Stefani and Spencer and we started kind of brainstorming more deeply about this and this is sort of how the ArchaeoEcology Project was born and so what we decided to put together a working group to's not just about food, I mean food is important right? It's fundamental, everything has to eat one way or another. But in the case of humans, humans are also really good at using species in other kinds of ways and so we put together this working group to kind of hash out what are these primary ways? In terms of kind pre-industrial people. And in clothing, humans use other species for clothing and they use other species for shelter and they use them for fuel and they use them to make tools and they use them for transportation and they use them as pets and they use them a medicine and they use them for ritual purposes and they use them for cosmological purposes.

And so, we basically, what we realized, we had this whole potential rich new area that we had complied data in across many different kinds of systems and systematically gather data about all the different kinds of ways that in this case preindustrial humans were interacting with other species because as we start to compile that data, that opens up this whole world of interesting kind of questions that we can start asking including some of the ones that you've found in some of our materials. And it also, the way that I think about it is like so, you know, humans are interacting with species in these huge variety of ways; we can put numbers on those, we can create networks of those and we can use that to understand basically how humans are interacting with biodiversity and how are the patterns similar or different across systems all over the world and in different parts of time. And how does that relate to the ecological context?

So, what are the species as humans enter these systems, what are the species they have access to? What are the habits they have access to? What are the constraints and opportunities of the environment, of the climate? All the places have different kinds of climates, some are dry, some are wet, some are continental, some are marine. You know, and also, humans bring their own culture and their own stuff with them; their own taboos and their own tools and technology. I mean like when the ancient Polynesians, they came across and came into the Polynesian Islands. The Polynesian Islands in New Zealand where the last parts of the world to be occupied by humans and that happened 700 to 1,000 years ago.

And, they came across from Southeast Asia and they came across open water, thousands of miles of open ocean water in canoes that they brought whole little ecosystems with them because they were agriculturalist so they brought a bunch of agricultural plants like bananas and taro and coconuts. They brought pigs and they brought chickens and they brought hitch hikers, rats and other things. And so they bring all these things into the ecosystem and it's like, how does the ecosystem respond to that? They've got these crazy new species coming in, humans plus all these associated species. You know, humans started alternating the ecosystem, they had cut down trees in order to create agricultural land but then they started taking advantage of what's there too; they become fisher people or continue to be fisher people and take advantage of the reef system. So basically this a new thing, no one's tried to compile this kind of data systematically before there.

There's a ton of information out there about uses of different species but it's usually very piecemeal. Like in the Pacific Northwest, there's whole monographs and careers have been on like a thousand and one uses for red cedar. So what we got was a group of archaeologists and anthropologists to basically commit to compiling the same kinds of data for their systems so that we could then go back and start comparing them and being like, "Well, does the Pacific Northwest coast people...what's common and what's different with how they interact with species versus what goes on with the Martu people of Australia?" And there's a zillion different interesting questions you can start to ask with data like that if you can compile that data — which we think we can, we're getting there.

One thing that I'm interested in that's a kind of perennial topic of discussion at the Santa Fe Institute is innovation: technology use, technology development and innovation across cultures. And I mean the way that, that's been looked at by archaeologists for example and past systems has often been to look at pot sherds or you know, but they've been very limited in kind of the way...or for modern systems we look at the patents, you can look at patents and sort of unpack and look at patterns in patents. But what we're doing now for these preindustrial systems at latest is we're providing a way to start to understand the complexities of technology use and technology's use by different people, and this goes back to sort of different examples of hunting and gathering.

So, certain kinds of interactions with species are very simple, you know, if you want to eat a berry you wait until it ripens, you go out into the forest, you find a berry and you eat it. Or if you want to eat a mussel you got out to the intertidal, you crack a mussel on a rock and you slurp its insides out. But if you want to go hunt a whale, which the Pacific Northwest people do, all of a sudden you have to do this crazily complex set of interactions with a variety of species in order to create the technology that you need in order to hunt whale. So you have to cut a tree down to make a canoe, you to have use all kinds of tools that are made out of other species in order to make the canoe, you have to make all these associated technologies, a sphere and floats and other things and you have to do rituals of a certain kind that require interaction with a different set of species.

I mean just making a cane alone requires humans using about a dozen different plant species and about a dozen different animal species in a variety of different ways. So it's its own complex little network just to create the canoe itself and that's just one piece of the puzzle, for the technology to go out and successfully hunt and eat a whale. So the data as we start to dive into it and get into some of the complexities of how we sort of understand the variety of different ways humans are interacting with species all of a sudden like you get this really rich network data that allows you to start to kind of make comparisons. Is there a trade off? For example, the Martu people have a really rich cosmology, is that partly because they’re fairly resource poor in other ways and so they have a richer cosmology.

Although that may not be true because the Pacific Northwest people both have a rich cosmology but they also have access to many more different types of species. So there's lots of hypothesis that people have put out there about different things, but this is going to give us new ways to kind of get at some of those comparisons and questions but using this new kind of quantitative data.

Michael: It's really interesting in light of this, you know, Brian Arthur type question about the evolution of technology and the idea that technology as an evolutionary system is path-dependent so, like the question about, what happens if we have a civilizational collapse and then we have to reboot with all the metals…

Jennifer: You lose the knowledge, yeah.

Michael: ...mined out already and all of the oils and natural gases mined out already, so can we actually rebuild the civilization that we have from a different starting place?

Jennifer: Right, and actually that's in a smaller sense, that's sort of one of the things we'll be asking of our different systems. What kinds of technologies do people develop given particular kinds of opportunities they had or lack of opportunities they had? And in some cases we're looking at people who brought technologies with them from other places. In other cases, we're just looking at people who basically co-evolved with the ecosystem over many tens of thousands of years and just developed their own approaches and technologies. So I think we can start to kind of play some of these games in a sense but not games, you know, it's like this is what humans actually did on a variety of different landscapes.

But by looking at it through the lens of biodiversity and our interactions with different species, it gives us a hook an ecological hook into trying to quantify and understand some of those things. And it just gives us a new lens and a new kind of framework for trying to answer some of these interesting questions or old questions in new ways, and ask new kinds of questions, so.