Science Friday - Protecting Sequoias From Wildfire Gets Tricky | Ancient Cave Art And Human Creativity

Episode Date: August 26, 2024

Sequoia National Park is largely designated as wilderness. That complicates efforts to protect its iconic trees from worsening wildfires. Also, archaeologists keep finding older and older cave art. Here’s what it could tell us about how humans evolved over time.Protecting Sequoias From Wildfire Raises Tricky QuestionsSequoia National Park in California is known for its towering, iconic sequoia trees, some of which are thought to be thousands of years old. Severe wildfires fueled by climate change and a long history of fire suppression have put these trees at risk. One solution to this problem is to plant new sequoias. But an interesting debate has sparked between those in favor of this and those against it.The vast majority of the park is officially considered “wilderness,” a federal designation that describes an area “untrammeled by man.” This concept of “untrammeled” has become more complicated in the age of climate change: Some people argue that it means humans shouldn’t intervene, even when the ecosystem is changing because of human-made climate change.Guest host Maggie Koerth speaks with Marissa Ortega-Welch, host and producer of the “How Wild” podcast from KALW and NPR. The first episode of this podcast, “Untrammeled,” highlights this debate.What Newly Discovered Cave Art Tells Us About Human CreativityIn July, researchers discovered the oldest known cave art. It was found in a cave on the Indonesian island of Sulawesi, and it shows three human-like figures and a wild pig. The painting was dated at 51,200 years old—5,000 years older than any other known cave art.The finding continues a trend of researchers unearthing older and older examples of human-made art, including those found outside of Spain and Southern France, where most cave art discoveries have been made.Guest host Maggie Koerth is joined by Dr. Isobel Wisher, a postdoctoral researcher with the Evolution of Early Symbolic Behavior project at Aarhus University in Denmark, to discuss how this field of archeology has changed over the years, how new technology is making these ancient cave paintings more accessible to the public, and what they can tell us about the human experience.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

What are archaeologists learning from cave art? It's something that really challenges some preconceived ideas about where rock art first emerged. It's Monday, August 26th, and you're listening to Science Friday. I'm Cyfry producer D. Peter Schmidt. Back in July, researchers discovered the world's oldest known cave art in Indonesia. It was dated at 51,200 years old, 500 years older than any other known cave art. Researchers keep finding older and older cave art, so we wanted to sit down with someone in the field to talk about what we're learning about early humans through this art and how scientists are using new technologies to bring more people into these caves. But first, here's guest host and science journalist Maggie Kerth, diving into a debate about whether or not national parks should plant new sequoias in the face of worsening wildfires.

Sequoia National Park in California is known for, yeah, sequoias, big, beautiful. trees, some thought to be thousands of years old. But severe wildfires fueled by climate change and fire suppression have destroyed some of those trees. One solution is to plant new sequoias. But this creates an interesting scientific debate. You see, most of Sequoia National Park is designated as wilderness. It's meant to be untouched by human hands. And some people argue that means humans shouldn't intervene, even when that land is changing because of human behavior. My next guest has a new podcast that explores this story and others in a quest to better understand the meaning of the word wilderness. Marissa Ortega Welch, host and producer of the

How Wild podcast from KALW and NPR in San Francisco, California. Welcome to Science Friday. Hi, thanks for having me. Okay, so before we dive into this controversy, around Sequoia National Park. Let's back up and talk a little about the importance of the word wilderness in this context. What is a capital W wilderness? Right. So you may have an image in your head when you think of the word wilderness, but the U.S. has these designated wilderness areas.

These are places within national parks or forests or other federal public lands that have this extra level of protection. So if you can picture Yosemite Valley, either you've been there or seen photos, The area is beautiful and iconic, and it is protected by the National Park, but that's not designated wilderness. You'd have to head out on a trail away from the roads of the valley, and after a couple miles, you'd enter into a designated wilderness zone. And these zones are governed by a law. It's the 1964 Wilderness Act that says these areas have to be managed for certain conditions. So they have to be undeveloped, roadless, but also they have to be natural and natural.

untrammeled. And untrammeled is kind of this old-timey word that means unrestrained or free. A lot of people hear untrampled, but it's a little different. This means that in this context, humans shouldn't control what happens in wilderness, and nature should just be allowed to take its course. Is anything really untouched in the wilderness, though, still? I mean, human-made climate change is affecting just about everything. Right. Every part of the planet is affected by climate change, sadly, even wilderness. So just like outside wilderness, inside wilderness, we're seeing longer periods of higher temperatures, we're seeing drought conditions, snow melting faster, extreme weather events. All of this is contributing to the more severe fires in wilderness areas that we're seeing in the west and across the country. So within that meaning of wilderness under the Wilderness Act, these areas are supposed to be quote unquote natural, but climate change and other human cause factors are making that challenge. So let's get into the story you've reported at Sequoia National Park specifically. What has happened there with the trees, with wildfires? Right. So since 2020, Sequoia National Park has had these really severe fires that are killing off Sequoia trees. And it is a combination of climate change and a phrase I've learned that's called fire exclusion. That means that fire has been kept off the land. And this has been happening for more than 100 years. First, by the displacement of indigenous people.

who actively burns the land as a management practice, and then through the suppression of fires by the Park Service. And what happens when you suppress fire is that the forest understory grows, the duff on the forest floor builds up, and then with climate change creating these hotter, drier conditions, all of that built up forest understory is just like dried, kindling, waiting for a match.

So the fires they've seen in Sequoia National Park for the last couple of years have been incredibly severe, and they're burning and killing these giant sequoias, which is saying something because these trees are actually built to withstand fire. They have this thick bark that makes them fire resilient, and they depend on the heat from the fire to help them reproduce. It triggers their cones to open and drop seeds. So this is saying a lot that we're losing these trees,

and some scientists are concerned that we could see a Sequoia National Park with no giant sequoias. Wow, that is sad. You talk to scientists, though, who want to intervene and they want to plant new sequoias. What did you hear from them? What's their plan like? Yeah, so the National Park and USGS scientists have been surveying the groves that burned. And so far they say there aren't enough living sequoia trees left to help reseed these groves and grow new trees. And the park managers are saying, look, this fire was started naturally, quote unquote, by lightning. But the conditions of the fire are unnatural.

they were fueled by human-caused climate change and fire exclusion. So the park managers decided that they needed to go in and replant the trees in some of these groves. And they see this as a necessary restoration to correct the damage done by humans. And they see it as their duty to restore those natural conditions required under the Wilderness Act. Here's Christy Brigham. She's Chief of Resource Management and Science for Sequoia and Kings Canyon National Parks. We made decisions that resulted in incineration of thousand-year-old trees, and rather than just let them disappear to plant seedlings and give those trees a chance to continue to adapt and grow and evolve in the face of climate changes that are going to occur in the next 100 to 1,000 years. So you talk to these park managers who want to plant trees, but there are other people that are against that idea. Who are they and what do they have to say?

Yes, there are groups like the nonprofit Wilderness Watch who make sure that the federal government is adhering to the law of the Wilderness Act. And in this case, Wilderness Watch believes that the replanting of giant sequoias goes against the Wilderness Act. They say this was a lightning cause, naturally started fire, and the park shouldn't be replanting after it. I spoke with Renee Voss. He's a natural resource attorney on the board of Wilderness Watch. And even though he agrees, the severity of this fire might be human caused because it's. of climate change and fire exclusion. He thinks if land managers use climate change as a reason to do restoration work that will open a door to a whole host of interventions in wilderness.

Where do we draw the line? I mean, climate change is affecting every ecosystem. We can't go down the line and try to fix the ecosystems that are caused by climate change because climate is going to continue changing unless we solve the climate crisis. So having reported the story now, what do you think is going to happen? Is there any indication of who's going to win this argument? Well, the park has already gone in and replanted in two of the Sequoia groves that they surveyed,

and they decided that those groves wouldn't come back on their own, and they're still finishing collecting data on the other ones. I think if their data shows something similar, they're going to go in and replant there too. The park is being sued by Wilderness Watch and three other environmental groups. I think this conversation is really interesting, and it's not just in Sequoia National Park. Land managers, environmental groups, are thinking about this question of how do we manage wilderness

in the era of climate change, given the legacy of 100 plus years of fire exclusion. There's this larger question in land management right now about how we correct for the mistakes of the past and prepare for what's coming in the future. Unfortunately, that's all the time we have for right now, but I'd really love to thank my guest, Marissa Ortega Welch, host and producer of the How Wild podcast

from KALW and NPR in San Francisco, California. Thank you for joining us. Thanks for having me. Back in July, researchers discovered the world's oldest known art. It was found in a cave on the Indonesian island of Sulawesi, and it shows three human-like figures and one wild pig. The painting was dated at 51,200 years old, 5,000 years older than the previous earliest known,

cave art. The finding continues a trend of researchers unearthing older and older examples of human made art, including those found outside of Spain and southern France, where most cave art discoveries have previously been made. So we wanted to take the time to check in on how this field of archaeology has changed over the years, how new technology is making these ancient cave paintings more accessible to the public, and what they can tell us about the human experience. And here to help us do that is my guest, Dr. Isabel Wisher, postdoctoral researcher with the evolution of early symbolic behavior project at Arhus University, based in Denmark. She studies rock art. Dr. Wisher, welcome to Science Friday. Thank you so much and thank you for having me. It's a pleasure to be here.

So let's first talk about that finding in Indonesia. What stood out to you about that? it's something that really challenges some preconceived ideas that we have about where rock art first emerged and it also is unusual in itself so for a long time in archaeology we kind of assumed that cave art and rock art was something that was restricted to europe that's where a lot of these sites are typically found and just now in the past decade or so we're starting to appreciate that that there's art that's as old and if not older in other areas of the world, particularly kind of Australia and Indonesia. And so what I love about this example, too, is the form of the art and what it depicts

is really interesting too. So a lot of the art that we have in Paleolithic rock art sites in Europe typically depicts individual animals and humans are very rarely depicted. But what we have in this example from Indonesia is what seems to be a kind of narrative scene playing out. So we have several human-like figures, which are extremely rare, but upper Paleolithic art in general. And then they seem to be interacting, possibly hunting this kind of pig-like animal in the center of the scene. So all of this is really remarkable and challenges some of these older ideas that we've had in the field. That sounds fantastic. And as we've been discovering this new art, as we've been, you know, dating it to this older time period, are there any theories about cave art and early humans that have also changed during that time? You know, like where it's coming from, how it was made, why people did it?

Yeah. I mean, that's a huge question, right? It's kind of the question that we tried to answer in archaeologies. Why did they do this? Why did they make this art? What I will say is, that maybe the origins of this behavior lie way further back in time, possibly before humans start dispersing out of Africa. So we know that nearly 100,000 years ago, that's when we get the very first sort of glimpses of humans doing something that's like art. So we have examples of them making some engraved patterns in ochre blocks. But perhaps what the Indonesia findings are showing us is this is spreading much earlier than we first assume. And then they're independently kind of in different regions of the world, experimenting with this and coming up with cave art and rock art that we see.

So one of the things I want to talk about with you is that we think of cave art, of this being a human project. But it might actually predate modern humans, right? Like it now looks as though Neanderthals were in on this as well. Yeah, exactly. So in 2018, a study was published that used new dating techniques in some of the more well-known cave art sites in Spain and sort of suggested that some of this art may predate the arrival of Homo sapiens in Europe. And this has been quite controversial in the discipline because it kind of completely changes our perspective of K-Bard in general, but also who the people were that were making this art. So we had this assumption that it was kind of exclusively homo sapiens behavior.

But yeah, now it might be that Neanderthals were engaging in this behavior too. Kind of moving forward, I guess, in time. You know, we are in this age now where we have technology, where we can go back, and we can use this new technology to study this old art in different ways than we've ever been able to before. And some of your research is focusing on peridolia in cave art. Parodolia is that phenomenon where we see faces or animals in things that are not faces or animals. Like when somebody sees a cloud in the shape of a rabbit or my favorite, which is the coat hook that looks like a drunk octopus that wants to fight you. So you have used new technologies to see how paradigms.

Dolia might have influenced how these cave paintings were made. Can you tell us a little more about that? Yeah. So it's been long observed that a lot of this art kind of integrates the natural features of the cave wall. So they might be using a crack to represent the back of a horse or undulating features to kind of evoke the muscular dimensions of a bison or something like that. And people have suggested maybe this is paradolia, this phenomenon of seeing, things that aren't really there that's playing a role in the making of art, but no one had tested it before. So what I wanted to do was find a way to test it using a kind of psychological experiment where we immersed participants in virtual reality caves. So these VR cave environments took real cables, 3D models of real cables, took away the art, and then used eye-tracking to see whether modern participants are kind of visually drawn to the same features that we know Paleolithic people used in their paintings. And also whether they saw these features as looking

like certain things or certain animals. So we found that sometimes that's absolutely the case. And there are some very clear examples from this research where it seems that where a bison was depicted using a crack for the back, for example, modern participants will look at this and see it looking like a bison, which pretty kind of demonstrates that paradolia may have had a very active role in determining this sort of form and the placement of some of this art. But equally, and what I find interesting too, is sometimes this really wasn't the case. And sometimes maybe it's just that the artist has an idea of what they want to depict, and the effects of paradolia are not influencing or having an impact on what they

decide to draw. So it's really exciting using these new technologies, like 3D, modeling and virtual reality to start to test some of the theories that we've had for some time in archaeology. Yeah, this sounds so cool. And you've had to do this with VR, right? Because you can't actually bring an open flame into these caves. That's part of the protection. Yeah, exactly. I think I would probably not be allowed in a cave ever again if I tried to bring an open fire into some of these very protected cave art sites. So yeah, virtual reality allows us to do a lot of things that we just can't do in the actual archaeological sites. I also want to ask you a question about preservation of these caves because there's kind of

an irony to the fact that these places where humans first made representational art are now places that we can't go back to look at that art because being there would destroy it. Yeah, this is a shame about a lot of these cave art sites. We're no longer able to, to go in and research them in person. Oh, not even that? Oh, wow. Yeah, so for Lasca, for example, this is a very famous cave art site, probably the most famous cave art site in southwest France. It's completely sealed now.

So, yeah, not even researchers can really go in. And that's because the mere presence of human bodies, the heat that we generate, and also what we're sort of bringing into the cave, or we're accidentally traipsing in on our feet and breathing. out. All of that kind of bacterial and fungal growth started to degrade some of the art. So there was a decision made that, you know, this cave should just completely be closed with the idea that maybe if we preserve this now, at some point in the future, we might have better technologies that allow us to go back into these caves. And this happens a lot in archaeology. And it's a real shame,

but it's also something that's necessary for the preservation of this art for the future. Have you learned anything about how you view people or what it means to be a person? Like, has this shaped the way you think about the human experience? Yeah, it's a really interesting question. And I think it absolutely has something that really strikes me in researching this stuff is humans are innately creative. We love to kind of experiment with materials and make stuff. And that's very uniquely human. No other species kind of has this urge to just create for the sake of creating. So that's something that I've appreciated in my research is seeing humans that were existing in really harsh climatic conditions.

You know, they're trying to hunt animals and sort of surviving in these landscapes. They still have time to, you know, explore a cave and enter this cave and produce amazing works of art on the surface. It's actually quite a deeply emotional experience seeing some of this art. And I find this especially when I see traces of hands or fingers that really is resonant and evocative for me because it's literally the hand of someone who stood where I stood maybe 20,000 years ago and placed their hand right in front of where I'm looking and produced some art there. There were people here and they're standing where I'm now standing. It's a very powerful experience.

And I think if you're looking at this behavior in any other species, we'd be like, why are you doing that? But for us, it's something innately human, right, about this desire to kind of create and explore and build new connections to each other and our environment in doing so. So making art with other people build social connections. Making art that's about animals allows us to think about these animals and relate to them in a new way. So, yeah, I think that's the thing that's really stuck with me is just how creative we are as a species. I love that. Thank you so much for taking the time to explain this all to us. Yeah, of course.

Thank you for having me. Dr. Isabel Wisher, postdoctoral researcher at Arhus University, based in Denmark. You can see images from Dr. Wisher's research, as well as that video of her VR cave experience at Science Friday.com slash cave art. And that's all the time we have for today. Lots of folks help make the show possible, including Kathleen Davis, Diana Plasker, Beth Ramney, Shoshana Booksbound. On the next episode, astronaut Katie Coleman talks about her new memoir,

and the challenges she faced getting into space. But for now, I'm SciFri producer Dee Petershmit. See you then.