How Past Extinctions At The La Brea Tar Pit Can Teach Us About Our Climate Future

12:11 minutes

Statues of ancient megafauna, one stuck in a tar pit recreation
The front entrance of the La Brea Tar Pits and Museum. Credit: Wikimedia Commons 4.0

If you drive through Los Angeles, you’ll pass by some of California’s most iconic sites—the Hollywood Walk of Fame, Universal Studios, the Santa Monica Pier.  But if you don’t look for it, you may miss the La Brea tar pits—a place where Ice Age life from around 50 thousand years ago got trapped and preserved in sticky black ooze. Visitors can see megafauna, including skeletons of saber tooth cats and dire wolves, along with a vast collection of specimens, including things as small as beetle wings and rodent dung. 

La Brea was recently named as one of the world’s most important geological heritage sites by the International Union of Geological Sciences. The museum is currently planning an extensive redesign that will seek to connect visitors to research, offering lessons about climate, extinction, and survival. Dr. Lori Bettison-Varga, president and director of the Los Angeles Museum of Natural History, joins Ira to explain the significance of the site, and how a trove of Ice Age specimens can serve as a modern-day climate laboratory. 

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Segment Guests

Lori Bettison-Varga

Dr. Lori Bettison-Varga is President and Director of the Los Angeles Museum of Natural History in Los Angeles, California.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow.

Later in the hour, how places around the country are dealing with the surge in RSV cases, and the importance of the connections between parts of the brain, yeah.

But first, if you drive through the heart of Los Angeles, you’re going to pass some of the most iconic sights, right? You’ve got the Hollywood Walk of Fame, Universal Studios, the Santa Monica Pier. But if you don’t look for it, you may miss one of my favorite places to visit when I’m in LA, the La Brea Tar Pits. It’s a place where life from around 50,000 years ago got trapped and preserved. It’s right there on Wilshire Boulevard. Look for the bubbling black ooze. You can’t miss it.

But La Brea is more than just a sticky time capsule. La Brea was recently named as one of the most important geological heritage sites by the International Union of Geological Sciences. And the black bubbly landscape has important lessons to teach about climate change.

Joining me now to talk about their plans to teach about climate change from the past is Lori Bettison-Varga, president and director of the LA Museum of Natural History, which includes the Tar Pits. Welcome to Science Friday.

LORI BETTISON-VARGA: Thank you. Thank you for having me.

IRA FLATOW: This is really one of my favorite places in LA. I’ve been going there for decades. And for those who haven’t been there, can you describe it for them?

LORI BETTISON-VARGA: So it’s about a 12 to 13-acre park and museum. But in the park are these incredible asphaltic deposits that have trapped the most amazing animals that used to be around Los Angeles. So 50,000 to 12,000 years ago. And it gives us a clue to what the landscape used to look like. We get anything from mammoths and mastodons and saber-tooth cats to microfossils, pollen, beetle wings, little bones from different mammals, small mammals. So it’s an incredible location.

IRA FLATOW: And you’re still digging up stuff there, right?

LORI BETTISON-VARGA: Absolutely. We are slowly working through 23 large boxes of material that were recovered from the excavation of the parking lot for the LA County Museum of Art. And their recent project also has revealed additional fossils for us to continue working on. So there’s lots of material and continued excavation going on.

IRA FLATOW: So as the song goes, they paved paradise, they put up a parking lot, but you’re digging it up.



IRA FLATOW: Just to be clear, there are no dinosaurs there, right? This doesn’t go back that far.

LORI BETTISON-VARGA: No dinosaurs. Or as my scientists over there like to remind me, no non-avian dinosaurs.

IRA FLATOW: Oh, yeah.

LORI BETTISON-VARGA: Not that old, right? So we’re really looking at material from the last major climate change event coming out of the Ice Age.

IRA FLATOW: You’re working on a redesign of the place. Tell me about that.

LORI BETTISON-VARGA: We are. We’re working on a redesign because, obviously, people come to the Tar Pits because they want to know about these incredible charismatic animals that used to roam LA. We like to say it was like the Serengeti, but with larger animals. So just to give you an image of that.

And there’s lots of skeletons to see at the current museum, which opened in the mid-’70s. But we’re not really telling the full story of the location that we think about today, and about that particular extinction event and how it can help us understand what’s happening right now. And so the new museum will continue to tell that story of extinction, but also of survival, and place it in the context of climate and ecological change in LA.

IRA FLATOW: Let’s talk about that link to climate and ecological change.

LORI BETTISON-VARGA: Yes. So we know worldwide that megafauna, about 60 species, went extinct around 13,000 to 12,000 years ago. The question, then, is this related to climate or is it related to humans coming into the scene, or is it a combination of both?

The wonderful thing about the targets is that you can see this event happening. We’ve got fossils– most of them go from about 45,000 years ago to about 12,000 years ago. And you can see the variation in the animals during the change of climate– the natural change, right? So we have a great backdrop to understand rate of change today and to think about what it takes for flora and fauna to survive a climate change like that.

IRA FLATOW: How soon do you think we might see that?

LORI BETTISON-VARGA: Well, it’s a big process. We’re just through the conceptual design, and we’re in an environmental impact review process– which is really important to all major development projects in Los Angeles– and then, of course, fundraising. So we hope that we will be able to do this in one tranche. It’s probably a four-year project. But if we need to phase it, it’ll take longer.

But we don’t have any start date yet, as we’re putting together the funding required to do this major intervention in the site, and make sure that it really highlights the indoor and outdoor connectivity of the space and the story.

IRA FLATOW: Yeah. So how do you use your collections and research to be more than just a bunch of skeletons or specimens under glass?

LORI BETTISON-VARGA: Yeah. Well, the great thing about going to the Tar Pits is you can see, as a visitor, not only the excavation outside, but you can see the scientists and volunteers working in the museum. So we were one of the original, what we call, the fishbowl, where you can actually look in and see folks working on the fossils and separating particularly microfossils right now, or cleaning up some of the bones.

And so really telling that visitorship that this is an active place for science, from excavation to identification, to putting the story together and sharing it with not only disciplinary experts– over 400 scientific articles have come out of the Tar Pits’ fossils– but also with the public.

So there’s so many different ways to do that. We’ve been using AR and VR to showcase what these extinct animals would look like in the environment. We’ve also had scientists working, using new technologies, like CT scanning, which a recent study revealed that saber-tooth cats, we had one that suffered from hip dysplasia in our collection and–


LORI BETTISON-VARGA: Yeah, it’s really kind of shocking. Originally, we thought this was harm that had caused the individual to pass away, right? But now we know from the CT scan that it was hip dysplasia. And the age of the animal suggests that there was a supportive social structure that allowed this animal to live in community instead of getting killed.

So it’s amazing what kinds of things we’re able to continue to learn about these animals.

IRA FLATOW: What can you tell us, then, about the snapshot– let’s say a snapshot in time– about La Brea that tells us now about the present world?

LORI BETTISON-VARGA: Well, our scientists there are really working to understand how humans coming into Los Angeles might have impacted the animals, certainly, but also trying to see, from pollen and other aspects of the record and the material in the asphalt that is maybe not as exciting as what people think of with the megafauna, but gives us a lot of environmental information.

So they’re looking at what the timing was in relationship to extinction of the animals and when humans came in, and what was happening within the environment at the time.

IRA FLATOW: So if you build it, they will come, so to speak?

LORI BETTISON-VARGA: Well, they should, right?


The Geologic Heritage Site designation, I think it’s really important. obviously, it’s a statement to the world, but also to Angelinos. They drive by on Wilshire daily and may not really understand that this is such an important location in the world. People don’t think of LA that way, right?

IRA FLATOW: No, no. But when I was researching this and I went to Top Tourist Attractions in LA, you are rated by one of the rankers as number 8 in the city.

LORI BETTISON-VARGA: Right. We get a lot of tourism. It’s been interesting. During the pandemic, we had a lot of folks rediscovering LA. And because we’re indoor/outdoor, even though the museum itself is closed, a lot of folks were able to walk through the park and learn. Because we have didactic stuff in the park, so people can get a snapshot of what’s going on just walking around outside. Of course, it’s a better experience if you get the museum inside as well.

But that has been really interesting. I think a lot of Angelinos were rediscovering this incredible world gem. And we’ll see the tourism starting to come back. But we just hope that more and more Angelinos get familiar with what is in, literally, their own backyard.

IRA FLATOW: Yeah, I loved walking around the grounds because you’re actually still walking around active oozing.


IRA FLATOW: Coming up through the grass.

LORI BETTISON-VARGA: Yeah. It kind of brings out the kid in you, right?


LORI BETTISON-VARGA: People like to poke around in it.

IRA FLATOW: Well, don’t step in any– you have it marked off in little spots– don’t step on this thing.

LORI BETTISON-VARGA: Exactly. We have lots of cones around, orange cones– don’t put your foot in this. And I will say that one of the misconceptions, along with the thought that there are dinosaurs instead of these mastodons and other large animals that are more recent, is that that big kind of lake pit in the front, where you see the bubbling methane, that’s actually not an asphaltic deposit. That is an industrial excavation filled in with groundwater, but it’s very intriguing.

IRA FLATOW: Let me ask you, before we run out of time, do you have a favorite find from the collection?

LORI BETTISON-VARGA: That’s so hard. But in the museum I really love the Dire Wolf Wall. I think it’s just a representation of variation, subtle variation to the eye, but it tells us about the importance of collections. And we have a tremendous collection, the largest collection of Ice Age fossils in the world, in LA. And to me the Dire Wolves– and I’m a little bit of a Game of Thrones geek– so I think it’s pretty amazing that we have such a fantastic collection. So I love the Dire Wolf Wall. But I also think it’s pretty awesome that you can get beetle wings preserved in the asphalt.

IRA FLATOW: Yeah. I think you have your selling point there. You saw the movie. Now come see the real thing.

LORI BETTISON-VARGA: Winter is coming, yes.


IRA FLATOW: And one last question. I could talk about the Pits all day. Why should we care about them? Why should we care about the La Brea Tar Pits?

LORI BETTISON-VARGA: Well, we should care about them because they really are the backdrop for us understanding what’s happening in our world today and what we can learn from the Tar Pits about survival of our species and other species that we live with as the climate is changing very rapidly in comparison to the past. But we should also care just because, I mean, pretty awesome.

IRA FLATOW: Yeah. You know what I think? LA is so famous for human-made glitzy things, artificialness. Here you have something that is real.


IRA FLATOW: Right down there in downtown LA.


IRA FLATOW: Well, good luck to you. And good luck to your projects and your fundraising.

LORI BETTISON-VARGA: Well, thank you so much, Ira. Nice to speak with you.

IRA FLATOW: Nice to have you. Lori Bettison-Varga, president and director of the LA Museum of Natural History.

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