Humans may have been in North America much earlier than previously thought. Here’s the evidence: chipped rocks, crushed mastodon bones, and reliable dates showing the remains are 130,000 years old. Is that enough to rewrite the history? SAPIENS co-hosts Chip Colwell and Jen Shannon talk to Steven and Kathleen Holen, archaeologists and co-authors of a controversial discovery. And they further evaluate the claims with the help of anthropologist Todd Braje.
- Steven Holen and Kathleen Holen are co-directors of the Center for American Paleolithic Research. Steven’s publications include series on Great Plains Paleoindian Archaeology and Ice Age Humans in the Americas. (He co-edited both series with Kathleen.) Steven and Kathleen were co-authors of the Nature article “A 130,000-Year-Old Archaeological Site in Southern California, USA,” published in April 2017.
- Todd Braje is a professor of anthropological archaeology. He has published two books and a co-edited volume. His most recent book is Shellfish for the Celestial Empire: The Rise and Fall of Commercial Abalone Fishing in California. Braje also serves as co-editor of The Journal of Island and Coastal Archaeology.
For SAPIENS’ original coverage of the mastodon site discovery, check out the news article “Broken Bones Could Rewrite Story of the First Americans.”
Matthew Simonson composed our theme song and all the other music in this episode.
Chip Colwell: [00:00:00] Hi, there. This is Chip, one of the cohosts with SAPIENS, the podcast that you’re tuning into right now. And if you’re enjoying what you’re hearing, I can’t tell you how much it helps if you rate us wherever you’re listening, if you share your comments, if you pass along the podcast to your friends and family. Make sure you go and read sapiens.org. Every week we have amazing, wonderful articles covering the whole breadth of the human experience, so keep listening and thank you. Alright, on to this week’s episode. [00:00:29][29.3]
Chip Colwell: [00:00:34] I love my job. [00:00:35][1.1]
Chip Colwell: [00:00:39] Every day, I get to come to the Denver Museum of Nature & Science. I walk through the doors and I pass this massive skeleton of a T. rex, and I keep going. There’s this blue whale hanging from the ceiling, and then I turn right, and I walk down this long white tunnel with these flashing fluorescent lights; I’m supposed to be walking toward a spaceship, and then I’m in my office. It’s an amazing place full of ideas and learning. And as a curator, I get to spend my time thinking about how people engage with science. How do they grapple with, like, the confounding questions of life that are still out there … “Hi, there, how are you doing?” … waiting to be answered? [00:01:23][44.8]
Chip Colwell: [00:01:24] Would you mind if I ask you a question? How long have humans been here in this continent? [00:01:29][4.6]
Museum Guest: [00:01:32] Well, [chuckles] 25 million years. [00:01:33][1.0]
Museum Guest: [00:01:33] 1492. I know that’s wrong, but that’s in my head. [00:01:37][3.4]
Museum Guest: [00:01:37] Longer than 10,000 years, is what I would assume. [00:01:38][1.1]
Museum Guest: [00:01:39] So 16 … 17,000 years ago? [00:01:42][2.6]
Museum Guest: [00:01:42] No idea. I don’t know. [00:01:44][2.3]
Museum Guest: [00:01:44] 100 years ago. [00:01:44]
Museum Guest: [00:01:45] America’s, I dunno, I dunno, Homo sapiens, seems like around 125,000 years ago, around there. [00:01:52][6.7]
Museum Guest: [00:01:53] Long time. [00:01:53]
Museum Guest: [00:01:53] 40 years. [00:01:53][0.4]
Museum Guest: [00:01:54] 40 million? 100 million? [00:01:55][0.4]
Museum Guest: [00:01:56] I say, a couple hundred thousand years. 500,000 and below. [00:01:58][1.8]
Museum Guest: [00:02:06] I don’t know, you guess, over 400 years ago? [00:02:07][3.8]
Museum Guest: [00:02:08] Yes, I think so, yeah. Because if anyone’s bones are there, how come human bones are not present? [00:02:13]
Museum Guest: [00:02:14] Seems like there’s a lot of evidence left behind and we’re still finding something new every day … [00:02:19][393.6]
Museum Guest: [00:02:20] I don’t know. What’s the answer? Oh, you don’t have the answer! [00:02:23][2.7]
Museum Guests: [00:02:23] There’s no right or wrong answer because you can’t live to tell the story about, like, how far back their ancestors go … That’s right, we have to figure it out through science, right? … Yeah. [00:02:36][10.8]
Chip Colwell: [00:02:37] You know, the museum has a kind of answer to this too. I’m standing here at the end of an exhibit called prehistoric journey and it’s, it’s an exhibit about life on earth. It begins with the origins of the cosmos and ends in Folsom, New Mexico, represented by two bison ribs and in this glass case, you can see these ribs. They’re about three feet long and they’re sitting atop a big chunk of dirt and right between them is this gorgeous, pale, small carved stone, and it’s basically a spearpoint and it’s known today as the Folsom point. You wouldn’t know by looking at it, but this tiny object is actually one of the most important scientific discoveries of the 20th century. This point showed for the first time that humans lived in the Americas as early as the last Ice Age, around 12,000 years ago. [00:03:34][57.0]
Jen Shannon: [00:03:35] Chip. Wait a second. Twelve thousand years? I’m pretty sure I read an article in Nature that came out last year about how humans first lived in the Americas 130,000 years ago. [00:03:45][10.4]
Esteban Gómez: [00:03:46] Yeah, I remember that too, about crushed mastodon bones in Southern California. [00:03:49][2.8]
Chip Colwell: [00:03:50] Yeah. In fact, some of the scientists behind that discovery are my former work colleagues, Steve Holen and his wife Kathe. [00:03:56][6.2]
Esteban Gómez: [00:03:56] This stuff comes up all the time and there’s a lot of media attention and hype. And, honestly, I think I need to see more evidence. [00:04:02][5.3]
Jen Shannon: [00:04:02] Well, so, here’s another question. When these new discoveries come out, what do we do with them? [00:04:06][4.1]
Chip Colwell: [00:04:07] Yeah, and, I mean, how do we decide what really happened? [00:04:10][3.5]
Chip Colwell: [00:04:12] Well, I know some people we can ask. [00:04:14][2.0]
Esteban Gómez: [00:04:15] I’m Esteban Gómez. [00:04:16][0.4]
Chip Colwell: [00:04:16] I’m Chip Colwell. [00:04:16][0.1]
Jen Shannon: [00:04:17] And I’m Jen Shannon. [00:04:18][0.5]
Esteban Gómez: [00:04:18] We’re the hosts for SAPIENS. [00:04:19][0.8]
Together: [00:04:21] INTRO. [00:04:21][0.0]
Chip Colwell: [00:04:39] Steve and Kathe Holen are married to each other, and, in a way, to archaeology. [00:04:44][4.6]
Kathe Holen: [00:04:46] We married at an archaeological site and I got a mammoth’s tooth for a wedding gift. [00:04:49][3.7]
Chip Colwell: [00:04:51] Was it broken open? [00:04:52][0.5]
Steven Holen: [00:04:52] No, no. [00:04:52][0.3]
Kathe Holen: [00:04:54] No, no. It’s a whole one, and we still have it. [00:04:56][2.2]
Steven Holen: [00:04:56] My relatives ran gravel pits in the Platte River Valley in central Nebraska, and they would get mammoth teeth stuck on their pipe under water and they would have to bring up 30 feet of pipe and take the mammoth tooth off. They hated them, and they would give ’em away as souvenirs to relatives and customers. So I grew up with a mammoth tooth as a doorstop in my house. Once I got to excavate the first mammoth site, it was all over. I was hooked and kept doing this ever since. [00:05:22][25.2]
Steven Holen: [00:05:23] And then I had the good fortune of meeting Kathe in South Dakota. [00:05:26][3.2]
Chip Colwell: [00:05:26] Kathe and Steve met in 2000. Kathe actually started her career as a geriatric nurse practitioner, but she applied her experience to archaeology when she transitioned fields. [00:05:38][11.7]
Kathe Holen: [00:05:39] To me it was like a perfect fit. We’re studying as archaeologists. We’re basically trying to figure out human behavior. That’s what we’re all about. Well, that’s what nurses do. The big difference though is that the people that I originally worked with were alive and breathing and I could talk to ‘em. [00:05:56][17.1]
Chip Colwell: [00:05:57] They fell in love and soon they started working together excavating and analyzing mammoth sites across the Great Plains. Then enter … the mastodon. [00:06:07][10.4]
Chip Colwell: [00:06:11] For years, Steve and Kathe had been hearing stories about an interesting site in Southern California. [00:06:16][5.0]
Chip Colwell: [00:06:18] In 1992, Richard Cerutti was an employee at the San Diego Natural History Museum, and he was monitoring a construction crew on a stretch of Highway 54 outside San Diego. It was his job to look for any remains of extinct animals that the construction crew may unearth. [00:06:34][16.4]
Steven Holen: [00:06:35] He saw the backhoe hit the tusk with a rock and said, Oh … what’s going on here? We have to stop and look at this. So they stopped the backhoe, of course, right away and started excavating it. [00:06:48][12.4]
Chip Colwell: [00:06:48] This site was considered a paleontological site, meaning the focus was on fossilized animals and plants. As in—not human. [00:06:57][8.9]
Steven Holen: [00:06:57] Back in the ’90s, they had archaeologists come and visit the excavation and so forth, but everybody thought it was so old, of course, that there couldn’t be humans here then. [00:07:07][9.2]
Steven Holen: [00:07:07] Steve and Kathe made time to go see the artifacts for themselves. [00:07:10][3.0]
Steven Holen: [00:07:11] And I thought, well, I have a little travel money, I’ll just fly out there and so Kathe and I flew out to look at this collection. And that’s when this look of amazement and shock came over my face and Kathe would, I would be staring off into space with my mouth open, just: This is incomprehensible. This can’t be. I mean this goes against everything I’ve ever been taught and everything I thought I knew. But yet, here it is right in front of me, and it’s better than any of these sites that I’ve said are archeological, only it’s 10 times better. [00:07:40][21.6]
Chip Colwell: [00:07:41] To many, the site looked like a bunch of fragments of mastodon bone and rock. To Steve and Kathe, the rocks were actually a big hint that something else was going on. [00:07:50][9.6]
Steven Holen: [00:07:51] You would see pieces of rock, you know, large cobbles surrounded by fractured bone fragments and you have two concentrations: one, one with a lot of fractured bone right around it and other bone fragments and the heads of both femurs and another secondary one with not quite as much fractured bone around it and then, away from that, you would see larger rocks. [00:08:15][24.1]
Chip Colwell: [00:08:16] Steve and Kathe were so excited because they thought these little bone fragments might actually prove something really, really big: That humans lived in the Americas much, and I mean much, earlier than previously thought. But, that’s a pretty big claim. And Steve and Kathe were going to need to defend it. In archaeology, that meant three things. First, how did they know humans were even there? [00:08:41][25.6]
Steven Holen: [00:08:42] These mastodon bones were all broken to pieces and they’re in spirally fractured fragments, which means the fracture planes are very smooth. The bone was broken while it was very fresh. You can tell that by looking at the fracture patterns. So, so what you would see is two work areas and then off to the side, you’d see these complete bones with a large piece of femur with a big impact notch on it. And that was one of the key pieces of evidence. [00:09:07][24.3]
Jen Shannon: [00:09:08] So if the bones were fresh when they were broken, it means that they weren’t crushed later on by like a backhoe or a tractor. [00:09:15][6.9]
Chip Colwell: [00:09:15] Right. And that’s key to the argument that bone fragments were also found near large rocks … [00:09:23][7.8]
Steven Holen: [00:09:24] … weighing in the range of 20–30, over 30 pounds. And based on experimentation and a lot, we’ve done a lot of experimentation: two elephant bone breakage experiments and dozens of cow bone breakage experiments. You have to set a bone up on an anvil to give it a solid surface to be able to break it open. [00:09:39][15.1]
Steven Holen: [00:09:40] If you just set the bone on the ground and hit it with a rock, it’s, the bone is a little bit flexible and the ground’s a little bit flexible. It’s almost impossible to break it, so you have to have that solid base, a rock anvil to set the bone on and then come down on it with another big rock, and it, and it gives it compression from both sides. [00:09:57][17.3]
Steven Holen: [00:09:59] And everyone here in the Great Plains accepts this kind of evidence when you see these notches on bison bones as evidence of marrow extraction and nobody ever questions it. But for some reason they seem to question it when you see it on much larger bones that are much harder to break. [00:10:15][16.0]
Chip Colwell: [00:10:16] Steve and Kathe sent the rocks to a rock expert specializing in early human use without context to see what they could find. [00:10:23][7.2]
Steven Holen: [00:10:24] We sent him three of these rocks over to Australia. We didn’t tell him how old we thought they were. We said, These rocks were found with a mastodon. Do you think these are artifacts? That’s all he knew. And he, after a few months, emailed back, and he said, Um, well these aren’t grinding stones. He must’ve thought we thought they were grinding stones for some reason. Well, these aren’t grinding stones; these are pounding stones. They’ve been used to pound something fairly hard. Maybe the bones they were found with, you know. So that was, that was, that was a blind test, and that’s what we like to do in science. [00:10:58][33.4]
Chip Colwell: [00:10:58] That’s not the only way they tried to prove the presence of humans. They also used experimental archaeology, which is a method to recreate events at the site as they were 130,000 years ago. This means spending romantic holidays breaking apart bones in an experiment and even flying to Tanzania to try to extract bone marrow using heavy rocks on dead elephants. [00:11:21][22.6]
Steven Holen: [00:11:22] We went because we thought maybe we would accidentally get some elephant bone to do an experiment. Kathe and I both got malaria and we were pretty sick, and we decided to leave the project early and so we got in this car, they were going to drive us four hours back to the airport. We went up across the rim of Ngorongoro Crater National Park and our driver and good friend by then, Shibu, looked over and went tembo, which means elephant in Swahili, and there was a dead elephant laying right along the road. One of about 25 elephants in the whole area died conveniently a couple of days before this, and so we turned around and went back and stayed and were able to get one bone to do this experiment. [00:12:02][40.1]
Jen Shannon: [00:12:02] I’m just imagining you sick with malaria and, like, hands deep in elephant femur. [00:12:08][5.8]
Kathe Holen: [00:12:11] It was, it was pretty bad. [00:12:11][0.1]
Steven Holen: [00:12:11] They wouldn’t let us cut the femur out for about a week and it was covered with flies and maggots at that time, and you really have to love experimental archaeology, and it stunk terribly. [00:12:21][10.0]
Jen Shannon: [00:12:23] Alright, back to Southern California. To sum up, they think someone long ago used big rocks to extract meaty bone marrow from a freshly dead mastodon. [00:12:33][10.2]
Chip Colwell: [00:12:34] Yep, and that brings us to the second thing that they needed: Secure the context. Like if you agree that humans smash these bones, then how do you know these bone fragments weren’t later relocated somehow by a flood or a gopher or something. [00:12:51][17.0]
Steven Holen: [00:12:51] To have a good archaeological site, you have to have a good geological situation, and all of the geologists who’ve studied this, it is very fine-grained, low-energy flood deposits. [00:13:01][9.5]
Jen Shannon: [00:13:02] What does low energy mean? You’ve said that a couple times. [00:13:02][0.1]
Steven Holen: [00:13:03] Very, the water comes up over the bank. It’s a very gentle flow; it deposits a little bit of sand or silt. Over years, it builds up and builds up. There is absolutely no evidence of floods and it’s very easy to see when you get a big flood and you deposit. The other evidence against flooding is that these tiny little spirally fractured piece of bone fragments are there right around the animals. If there had been a big flood those little fragments would be miles downstream, probably out in the Pacific Ocean. [00:13:33][29.8]
Chip Colwell: [00:13:34] OK, so they got their context. Now, the third thing they needed to do was date it, and this is where things got a little hairy. [00:13:43]
Steven Holen: [00:13:43] We dated three fragments of the mastodon bone and the dates from all three bones were consistent and gave it an age of 130,700 when averaged. [00:13:53][19.0]
Steven Holen: [00:13:54] Three of the leading experts on uranium series dating in the world have confirmed that these are state-of-the-art, best uranium series dates you can get. [00:14:02][7.7]
Jen Shannon: [00:14:02] So the issue was not the dating process; it was that the dates themselves are so far out of the current accepted range. [00:14:08][6.5]
Chip Colwell: [00:14:09] They wrote all this up over 10 years with nine other scientists. They named the site the Cerutti Mastodon Site in honor of Richard Cerutti, and then they submitted their findings to Nature, one of the most prestigious academic journals there is. What was your memory then of that moment? [00:14:25][16.0]
Kathe Holen: [00:14:26] It was exciting; it was like, this evidence has to be put out there. People, other people have looked at this before and nobody wrote about it, nobody; everybody said, Well, yeah, that looks like somethin’, but nobody wrote it down and that’s what I kept feeling: It’s like, Yes, we’re gonna write this down and put it out there and what comes, comes. No guts, no glory. [00:14:49][22.6]
Steven Holen: [00:14:50] That’s right. [00:14:50][0.2]
Jen Shannon: [00:14:51] I can only imagine how it must have felt. I mean submitting a paper like that, challenging years and years of research from, geez, probably hundreds of other scientists. It’s like walking into a room full of your colleagues and looking each of them in the eyes and telling them: You’re wrong. [00:15:06][15.3]
Steven Holen: [00:15:08] I should add that the Nature editor warned us of the storm that was coming and that it could affect our careers. Of course, Kathe and I are retired, so I keep saying, Who’s going to fire me? My wife is a co-author and she’s the only one that can fire me. [00:15:24][16.2]
Chip Colwell: [00:15:26] April 26, 2017, the article goes live and the storm rolls in. [00:15:31][5.3]
Simulated Reporters: [00:15:32] Debate heats up over whether 130,000-year- old bones were broken by humans. [00:15:35][3.4]
Simulated Reporters: [00:15:35] Archeology as blood sport: How an ancient mastodon ignited debate over humans’ arrival in North America. [00:15:41][6.1]
Simulated Reporters: [00:15:41] A new study has dropped a bombshell in archaeology claiming signs of human activity in the Americas far earlier [than thought]. [00:15:47][5.4]
Simulated Reporters: [00:15:47] Critics attacked study that rewrote human arrival in Americas. [00:15:50][2.9]
Simulated Reporters: [00:15:51] Ancient bones sparked fresh debate over first humans in the Americas. [00:15:53][2.2]
Simulated Reporters: [00:15:54] A year later, the skeptics are still not convinced. [00:15:56][1.7]
Simulated Reporters: [00:15:57] Don’t believe the base story about humans roaming America 130,000 years ago. [00:16:02][4.8]
Steven Holen: [00:16:03] It was the most intense week of my life, I think, in terms of … I mean, Kathe and I were in bed one evening at 10:30 in the evening and BBC called up and said, Can you do an interview with us in about 20 minutes? I guess, I’m lying here in bed. I guess I can do it. [00:16:19][16.6]
Esteban Gómez: [00:16:19] See all that buzz and clickbait headlines. It kind of got frustrating. [00:16:22][2.6]
Jen Shannon: [00:16:23] I totally see what you mean: blood sport, bombshell. The media definitely frames this almost as some kind of personal battle. On the other hand, the discovery does challenge everything. Can we go back to those three important things you mentioned at the beginning? What was the first one again? [00:16:39][16.2]
Chip Colwell: [00:16:39] Yeah. So, first, we need evidence that humans were actually there. [00:16:44][5.0]
Jen Shannon: [00:16:45] OK, so we know that it seems like there were freshly broken bones and there were some rocks that could be a hammer and an anvil. [00:16:53][8.1]
Chip Colwell: [00:16:54] Yep. [00:16:54][0.0]
Esteban Gómez: [00:16:54] Hold on, I don’t want to be that guy, but it seems like there’s a number of possible explanations going on here. We don’t have human remains and we don’t see a spearpoint in a mastodon’s ribs. [00:17:03][9.0]
Chip Colwell: [00:17:04] Yah, like, I mean if you had an actual human body there, that would be pretty definitive evidence, right? Yeah. What about the second point: context. [00:17:11][6.9]
Jen Shannon: [00:17:12] Oh, right. So that’s more about the site and the discovery and whether everything was intact back then is still intact now? [00:17:20][8.0]
Chip Colwell: [00:17:21] Exactly. And so, for me, that is pretty good evidence, you know, that we’re dealing with good context. I mean, there’s no evidence, for example, of a big flood because of the sediments and also you finding big rocks there mixed in with big bones and also small bones, I mean, things weren’t just washed in, you know, like in one big flood event. So, I think we got pretty good context. [00:17:40][19.7]
Jen Shannon: [00:17:42] OK, and then the third thing? [00:17:42][0.5]
Esteban Gómez: [00:17:43] Dates. [00:17:43][0.0]
Chip Colwell: [00:17:44] Oh, yeah, dates. [00:17:44][0.2]
Jen Shannon: [00:17:44] OK. This one really struck me because I think they’re pretty solid. You have these really high-level, top scientists in their field and they’re staking their reputation on these dates. [00:17:54][9.5]
Esteban Gómez: [00:17:54] Yeah, I think some of that work was fantastic. I think the mastodon bones themselves were solid in terms of the dates, it’s just 130,000 years ago. It just seems so long ago. It’s really bonkers. [00:18:05][11.0]
Chip Colwell: [00:18:07] Hard for you to buy, huh? [00:18:07][0.5]
Esteban Gómez: [00:18:08] Right. [00:18:08][0.0]
Chip Colwell: [00:18:08] It sounds like we should probably talk to another expert, then. [00:18:10][2.2]
Todd Braje: [00:18:19] Hi, Jen, this is Todd. [00:18:19][0.1]
Jen Shannon: [00:18:20] Hi, Todd. [00:18:21][0.3]
Jen Shannon: [00:18:21] I called Todd Braje, Chair of the Anthropology department at the California Academy of Sciences in San Francisco. He’s a specialist on coastal migrations, and he’s spent a lot of time thinking about the earliest peoples in the Americas. [00:18:35][14.0]
Jen Shannon: [00:18:36] So, when do you think people first populated the Americas and why? [00:18:39][3.7][00:18:40]
Todd Braje: [00:18:40] Well, I think to both of those questions, the big answer right now is that we don’t know, and I don’t know. My best guess, based on the archeological evidence and other lines of evidence like linguistic evidence and genetic evidence, suggests that people came sometime in the last 20,000 years, likely between 20 [thousand] and 15,000 years ago. [00:19:06][25.4]
Todd Braje: [00:19:07] Why they came? It’s a big question and sort of the human odyssey, right? [00:19:14][7.3]
Todd Braje: [00:19:15] Why do people migrate? Why do people travel? Discovery? Following resources? It’s probably one in a number of things, right? Twenty years ago, I think most archaeologists would tell you that and most of the archaeological evidence suggested that people walked across the Bering land bridge, this exposed land bridge that connected Northeast Eurasia with Alaska. In the last 20 years, a number of sites have been discovered in the New World that predate that story. And I think most people think the strongest evidence suggests that people were coming in boats, sort of hopping along the Pacific coast lines down, you know, following the, the Pacific coast down North America, Central America, and into South America. [00:20:07][52.7]
Jen Shannon: [00:20:08] So this really sounds very interesting because this new data on the coast actually caused people to rethink what was possible. And I’m wondering if you could talk about what is the scientific process for measuring and evaluating new data. [00:20:24][15.7]
Todd Braje: [00:20:26] Archaeology is a, is a fairly conservative science, right, that when we, we start thinking about sort of the, the initial peopling of the New World, this idea of “firstness,” our standards of evidence are really rigorous, right. So, the problem with that is, in archaeology, we have to think about not only, OK, what kinds of sites are we finding and how do they help us interpret this story of the human past, but also what potentially aren’t we finding and what aren’t we looking for? [00:21:03][37.0]
Jen Shannon: [00:21:03] Yeah, it sounds like the system kind of supports existing ways of thinking and it makes it a little bit harder to go out and seek something that’s unconventional to the standard, accepted theories. So, yeah, I mean, it’s been really interesting because there, there is quite a bit of critical feedback in the scientific process going on for the Cerutti site, and we tried to speak with nine other people about their critiques of this theory, and no one would go on the record. Why do you think that is? [00:21:37][33.8]
Todd Braje: [00:21:39] I think people become exhausted. Right. I mean some of the press that’s come out and some of the criticism that’s come out on the Cerutti site, I feel like it’s been a little heated, right? That it claims that this is bad science, right, or bad archaeology. And I’m not saying that, I’m not saying it’s bad archaeology, I’m just, I’m suggesting that it doesn’t meet the standard of evidence for challenging, you know, all these alternative lines of evidence that suggest a very different scenario and that nature can be quite tricky and create what looks like archeological sites. Nature can bang rocks together in ways that are consistent with human-produced percussion tools and create what looks to be archeological sites. And so, they can fool even very good scientists, very good archaeologists and geologists into thinking something that is geologically made, naturally made, was human made. And this has happened time and again in archaeology in issues of the peopling of the New World. The Cerutti site hinges on pretty nondescript broken stones and broken bones, mastodon bones, and they’re clustering in one area, right. And the argument is made that this extends back human colonization of the New World, California in particular, a 110,000 years, over 110,000 years older than any accepted archaeological site in the New World. So … [00:23:40]
Jen Shannon: [00:23:41] That’s a big leap. [00:23:42]
Todd Braje: [00:23:43] It is a huge leap, and what it does is, it not only defies sort of traditional archeological thinking, widely accepted archeological thinking about peopling in the New World, but it goes against linguistic evidence, it goes against genetic evidence, it goes against what we know about hominid migrations out of Africa and around the Old World. [00:24:01][141.9]
Jen Shannon: [00:24:02] You know, I’m wondering what you think about how and why skepticism is essential to the scientific process? [00:24:08][6.2]
Todd Braje: [00:24:09] Right, yeah, I mean, we need good skepticism. Right? Skepticism is not easy. You know, and I love to read Carl, work by Carl Sagan, who talks a lot about this and you know, these are, get to issues of epistemology, how we know what we know and the philosophy of science, and we need positive skepticism, not skepticism that sort of hinders archaeo-, hinders scientific, good scientific research. But skepticism that challenges what we think we know, right, and how we know it and what the standards of evidence are. So, skepticism done in the right way is healthy, and it’s good for science. [00:24:54][44.4]
Chip Colwell: [00:25:08] At its heart, science is the process of revealing great truths about our world, about ourselves. Skepticism, just as much as wonder, is a part of this continued quest for greater understanding, which takes us back right here to the Folsom point. [00:25:28][20.0]
Chip Colwell: [00:25:37] So how do you feel when you’re standing before these ancient spear points that were so important in the history of knowledge of coming to understand when the Americas were first occupied? [00:25:48][10.4]
Steven Holen: [00:25:49] I guess my first feeling is, I’m still proud because I designed this exhibit. It kind of feels good to see it again after all these years. Yeah, but I think the thing we have to learn is that we never have all of the answers. You know, it’s an open question. Humans may have come into North America and become extinct. Actually, we don’t know that. They may have come in several different times, which I suspect is right, you know, several different migrations, but we just have to keep an open mind and keep looking and maybe there’s a site out there older than 130. I don’t know. [00:26:21][32.6]
Chip Colwell: [00:26:22] So, what will it take for the Cerutti site to become like the Folsom site in New Mexico? [00:26:30][6.1]
Steven Holen: [00:26:31] We need to find one or more, one or two more sites of the same age with even better evidence, I would say. [00:26:38]
Chip Colwell: [00:26:40] Big picture, you know, 30,000 feet looking down, does this discovery have the potential to transform our view of humanity, of human history, of, of what we call home here in North America? I mean, what, what really matters with this discovery? [00:26:58][27.4]
Kathe Holen: [00:26:59] To me, it matters because it shows that probably we were more of a global village than we previously believed, that people were all over the globe. [00:27:11][11.3]
Steven Holen: [00:27:12] I think that’s one of the take-home messages that we keep seeing over and over again: People seem to want to separate North America off from the rest of the world and have our own little story. I think we need to become part of that global story more than just kind of saying, We’re from the United States or we’re from North America. We know what happened in North America, and I think we need to listen to paleolithic archaeologists from other countries that have different kinds of understandings than we do. [00:27:41][28.5]
Kathe Holen: [00:27:41] The benefit of our critics, even if they’re outlandish, sometimes, is they push us to keep digging. And what could be better? Because that’s what we’re gonna to do. We, we saw what we saw. And it motivates us to keep seeking. [00:27:56][14.7]
Steven Holen: [00:27:59] And I think, we really would like someone else to make the next discovery. [00:28:03][3.5]
Kathe Holen: [00:28:03] Absolutely. [00:28:03][0.0]
Steven Holen: [00:28:04] Because. [00:28:04][0.0]
Chip Colwell: [00:28:05] It’s too suspicious? [00:28:05][0.5]
Steven Holen: [00:28:05] You know, I don’t know if I want to go through another 30, 35 drafts of Nature. [00:28:08][2.7]
Kathe Holen: [00:28:10] I’m not writin’ another word about this. [00:28:12][1.5]
All: [00:28:13] Laughter. [00:28:13][0.0]
Kathe Holen: [00:28:13] I won’t bring up the word divorce, but my hand was on the doorknob a couple times. [00:28:17][4.1]
Kathe Holen: [00:28:20] It was rough because we had to critique each other, and we were being critiqued by our co-authors, which, of course, was important, that’s what it was all about. It was rough. [00:28:30][10.5]
Steven Holen: [00:28:31] I think it was stressful for our marriage, but I think it speaks to the strength of our marriage that we made it through, because … [00:28:36][4.9]
Kathe Holen: [00:28:36] Amen. I agree. [00:28:36][0.0]
Steven Holen: [00:28:36] It was very stressful going through all of these drafts and waiting for people who would lag behind. You know, they should have been getting us comments and, you know, because other people are busy and have their own, other agendas and so forth. So, you know, it was very stressful, but I think we’re stronger because of it. [00:28:54][18.3]
Kathe Holen: [00:28:55] I do too. [00:28:55][0.3]
Steven Holen: [00:28:55] And we have a better marriage probably because of it. [00:28:56][0.7]
Kathe Holen: [00:28:56] I do too, and I think we’re better at archaeology because of it. [00:28:58][2.2]
Chip Colwell: [00:29:01] This episode of SAPIENS was produced by Cat Jaffee, edited and sound-designed by Matthew Simonson, and hosted by myself, Chip Colwell, Jen Shannon, and Esteban Gómez. SAPIENS producers Paul Karolyi, Arielle Milkman, and House of Pod intern Lucy Soucek also provided additional support. Christine Weeber is our fact-checker. Our cover art was created by David Williams. Music for this episode is by Matthew Simonson. [00:29:25][24.0]
Chip Colwell: [00:29:30] Thanks this time to our guests Steve and Kathe Holen, Todd Braje, and the many visitors at the Denver Museum of Nature & Science, who let me ask them the tough questions that even anthropologists can’t totally answer. Thanks also to Danilyn Rutherford; Maugha Kenny; and the entire staff, board, and advisory council of the Wenner-Gren Foundation. Amanda Mascarelli, Daniel Salas, Aaron Brooks, Christine Weeber, Cay Leytham-Powell, and everyone at SAPIENS.org. SAPIENS is part of the American Anthropological Association Podcast Library. This is an editorially independent podcast funded by the Wenner-Gren Foundation and produced by House of Pod. [00:30:07][36.2]
Chip Colwell: [00:30:08] If you find any mastodon bones, please do let me know. See you around, fellow sapiens! [00:30:16][2.3]