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How did syphilis get to Europe? · Daniel and Kelly’s Extraordinary Universe

• 0:00
  Speaker 1: Howdy, extraordinaries. Today, we're talking about the history of syphilis.
• 0:03
  Speaker 1: Where do we think it came from? How do we
• 0:05
  Speaker 1: study it, et cetera? I'm not gonna get into some
• 0:08
  Speaker 1: of the more difficult to hear about symptoms of the infection,
• 0:11
  Speaker 1: but we are talking about a sexually transmitted infection. So
• 0:15
  Speaker 1: if kids are around, well, you decide if that's a
• 0:18
  Speaker 1: good idea or not. In 1530, Giralamo Fracastruro, a physician
• 0:31
  Speaker 1: in Verona, publishes a poem in Latin called Syphilis Sive
• 0:35
  Speaker 1: Morbis Gallicus, or Syphilis or the French Disease. It begins
• 0:40
  Speaker 1: by discussing the symptoms of a deadly disease that was
• 0:43
  Speaker 1: totally new to Europe and then shared best practices on
• 0:46
  Speaker 1: how to treat it. The book ends with the story
• 0:48
  Speaker 1: of a shepherd who offended the god Apollo, who rained
• 0:51
  Speaker 1: the horrible new disease down upon humanity as punishment. The
• 0:54
  Speaker 1: shepherd was named Syphilis. And thankfully, Apollo eventually forgives him.
• 1:00
  Speaker 1: Upon receiving forgiveness, a tree appears, which can be used
• 1:03
  Speaker 1: to treat his affliction, and a helpful nymph appears to
• 1:06
  Speaker 1: tell him that mercury can be used as treatment as well.
• 1:09
  Speaker 1: Not so helpful, really. But anyway, nearly 200 years later,
• 1:13
  Speaker 1: a medical book gives the shepherd's name to the disease.
• 1:16
  Speaker 1: It doesn't become common usage until about the 19th century,
• 1:19
  Speaker 1: but syphilis is the name we use to refer to
• 1:21
  Speaker 1: this infection today. On today's show... We're going to be
• 1:25
  Speaker 1: talking about the arrival of syphilis on the European continent
• 1:28
  Speaker 1: in 1493 and what we know or what we don't
• 1:31
  Speaker 1: know about where it came from. Welcome to Daniel and
• 1:35
  Speaker 1: Kelly's Infectious Universe.
• 1:50
  Speaker 2: Hi, I'm Daniel. I'm a particle physicist who's really interested
• 1:52
  Speaker 2: in aliens, including alien diseases.
• 1:55
  Speaker 1: Hello, I'm Kelly Wienersmith. I study parasites in space and
• 1:58
  Speaker 1: I'm interested in all diseases, you know, alien or earthbound.
• 2:05
  Speaker 2: So my question for you today, this morning, Kelly, is
• 2:08
  Speaker 2: did you ever want to be a doctor? Lots of
• 2:10
  Speaker 2: my friends in biology started out as pre-meds. I was wondering,
• 2:14
  Speaker 2: were you on that track?
• 2:15
  Speaker 1: Yeah. When I was a kid, I used to love
• 2:17
  Speaker 1: watching the show ER. I was like obsessed. And so
• 2:20
  Speaker 1: I wanted to be an emergency room surgeon.
• 2:22
  Speaker 2: Who was your favorite?
• 2:24
  Speaker 1: I don't know. I really liked... You know, Dr. Green,
• 2:26
  Speaker 1: Noah Wiley. Like, I don't know. There were so many. Oh, Luca.
• 2:29
  Speaker 2: Oh, Luca.
• 2:30
  Speaker 1: Anyway, there were a lot of, let's say, good characters
• 2:35
  Speaker 1: in that show.
• 2:36
  Speaker 2: People to look up to.
• 2:38
  Speaker 1: Yeah. Nurse Abby. She was awesome. Anyway, lots of people
• 2:41
  Speaker 1: to look up to. And then I decided I wanted
• 2:42
  Speaker 1: to go to vet school. And then I decided I
• 2:44
  Speaker 1: wanted to be a scientist. So long journey. What about you?
• 2:47
  Speaker 1: You never wanted to be a doctor.
• 2:49
  Speaker 2: I never wanted to be a doctor because I didn't
• 2:51
  Speaker 2: want the responsibility. I thought it was crazy. That if
• 2:54
  Speaker 2: you didn't get enough sleep, like somebody's life was at risk,
• 2:57
  Speaker 2: you know, and, you know, these days, if I don't
• 3:00
  Speaker 2: get enough sleep, like a calculation happens more slowly or
• 3:02
  Speaker 2: a factor of two creeps in or something, you know,
• 3:06
  Speaker 2: bugs are harder to find. Nobody dies. So I like
• 3:10
  Speaker 2: the irrelevance of my research sometimes.
• 3:12
  Speaker 1: That's exactly why I decided I didn't want to be
• 3:14
  Speaker 1: an ER surgeon, because I didn't want to have to
• 3:16
  Speaker 1: be the one to say, like, hey, I'm sorry your
• 3:18
  Speaker 1: child died or like, heaven forbid, it was my fault.
• 3:22
  Speaker 1: I was like, that's I can't handle that. I mean,
• 3:24
  Speaker 1: thank goodness there are people who can handle that. And
• 3:27
  Speaker 1: I'm sure they save loads of lives. But too much
• 3:30
  Speaker 1: stress for me. Podcast hosting is the way to go.
• 3:32
  Speaker 1: Low stakes.
• 3:34
  Speaker 2: All right. And today we really are talking about saving
• 3:37
  Speaker 2: people's lives, right?
• 3:38
  Speaker 1: Yeah.
• 3:41
  Speaker 2: No. That was a.
• 3:42
  Speaker 1: Nice attempt at a segue. I mean, so we could
• 3:44
  Speaker 1: have a whole different episode about the development of salversan
• 3:48
  Speaker 1: and penicillin, which are antibiotics, which actually do save people's lives.
• 3:51
  Speaker 2: Yay, science.
• 3:53
  Speaker 1: But today we're talking about the fact that in like 1493,
• 3:57
  Speaker 1: syphilis showed up in Europe in a big way and
• 4:00
  Speaker 1: it had not been there before. And so we are
• 4:02
  Speaker 1: talking about sort of the history of How did it
• 4:04
  Speaker 1: get to Europe? How do we study this? Not really
• 4:07
  Speaker 1: how do we treat it, but I'd be happy to
• 4:08
  Speaker 1: come back on another episode about treatment if that's what
• 4:11
  Speaker 1: you want.
• 4:13
  Speaker 2: All right. So don't expect any upside, folks.
• 4:16
  Speaker 1: I don't think anybody who came to a Kelly episode
• 4:18
  Speaker 1: was expecting upsides.
• 4:19
  Speaker 2: All right. So then where does our story begin?
• 4:23
  Speaker 1: Our story begins in 1493. French King Charles VIII is
• 4:28
  Speaker 1: bringing a diverse blend of mercenaries from many different countries
• 4:32
  Speaker 1: over to Naples where he plans on laying siege. And
• 4:36
  Speaker 1: this group of mercenaries also has a group of prostitutes
• 4:41
  Speaker 1: trailing behind them. And so it's a big group of
• 4:43
  Speaker 1: people from lots of different places. They lay siege to Naples.
• 4:46
  Speaker 1: They win at first. They fraternize with the locals.
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  Speaker 2: Are we rooting for the French here or are we
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  Speaker 2: just telling their story?
• 4:53
  Speaker 1: We're just telling their story. Yeah, we don't have to
• 4:55
  Speaker 1: root for anybody here. We're definitely not rooting for syphilis.
• 4:58
  Speaker 2: You have to root for somebody. I mean, it's like
• 5:01
  Speaker 2: when you watch a sporting event, you got to pick
• 5:02
  Speaker 2: a side just so you have somebody to root for,
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  Speaker 2: you know, even if you don't actually care. Okay.
• 5:06
  Speaker 1: All right. Let's see. Let's root for King Charles VIII
• 5:10
  Speaker 1: because he doesn't have many years left ahead of him.
• 5:12
  Speaker 1: So let's hope he has a victory before his early demise.
• 5:18
  Speaker 2: Apologies to the Neapolitans. All right.
• 5:20
  Speaker 1: That's right. But eventually the Italians rise up and Spain
• 5:24
  Speaker 1: has sent an army and it's landing and it's coming.
• 5:27
  Speaker 1: And so the French turntale begins. and run. And all
• 5:31
  Speaker 1: of the mercenaries from both sides, because there were mercenaries
• 5:34
  Speaker 1: on both sides of this, now spread out across Eurasia
• 5:38
  Speaker 1: as they go in search of new work or go
• 5:40
  Speaker 1: back to their homes. As they spread, they bring a
• 5:44
  Speaker 1: new disease with them. And that new disease is syphilis.
• 5:47
  Speaker 1: This was the first time syphilis had been reported on
• 5:51
  Speaker 1: the European continent. And through the mingling of all the
• 5:54
  Speaker 1: different mercenaries and the prostitutes and the Neapolitans and the French,
• 5:58
  Speaker 1: Lots of people end up with this disease and lots
• 6:01
  Speaker 1: of people bring it to new lands.
• 6:03
  Speaker 2: That sort of surprises me because I thought I remembered
• 6:05
  Speaker 2: hearing that syphilis is an ancient disease that like we
• 6:09
  Speaker 2: find evidence for it in like Egyptian mummies or something
• 6:12
  Speaker 2: like that. And that's just across the Mediterranean and like,
• 6:16
  Speaker 2: you know, Antony and Cleopatra and all that stuff. So
• 6:19
  Speaker 2: like there's definitely like Rome and Egyptian mingling. Why didn't
• 6:22
  Speaker 2: that happen earlier?
• 6:23
  Speaker 1: Well, so Roman-Egyptian mingling wouldn't have brought about syphilis if
• 6:27
  Speaker 1: syphilis was not present in Africa or Europe at that time,
• 6:32
  Speaker 1: which is important to keep track of. Also, another thing
• 6:34
  Speaker 1: to note is that so lots of people say, oh,
• 6:36
  Speaker 1: the papyrus ebers, this is this ancient Egyptian papyrus. mentions
• 6:41
  Speaker 1: all of these diseases. And so like, as I've been
• 6:43
  Speaker 1: studying a variety of diseases for this project that I'm
• 6:45
  Speaker 1: working on, you'll often hear about ancient Egyptian texts mentioning
• 6:50
  Speaker 1: these diseases. But once you dig in, the reference to
• 6:54
  Speaker 1: the disease is so vague, it almost could be any disease.
• 6:59
  Speaker 1: So like, you know, for example, we don't actually think
• 7:00
  Speaker 1: we have really solid evidence of gonorrhea until it's written
• 7:04
  Speaker 1: about by Arabic physicians around the Middle Ages.
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  Speaker 2: Right.
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  Speaker 1: Despite the fact that the name for gonorrhea comes from Galen,
• 7:11
  Speaker 1: who was way before that. He was describing gonorrhea means
• 7:15
  Speaker 1: something like seed flow. And he was describing a disease
• 7:18
  Speaker 1: where semen flows involuntarily at times when the penis is flaccid.
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  Speaker 1: And we think that actually that was not gonorrhea because
• 7:26
  Speaker 1: he doesn't describe the absolute excruciating feeling of that you
• 7:30
  Speaker 1: have when you try to urinate when you have a
• 7:32
  Speaker 1: really bad case of gonorrhea. So we think he probably was.
• 7:36
  Speaker 1: I won't ask why you said yes in exactly that way, but.
• 7:39
  Speaker 2: I said yikes.
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  Speaker 1: Oh, yikes, yikes. That makes more sense. But anyway, so
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  Speaker 1: we think he was actually describing some different disease, maybe
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  Speaker 1: a disease that's not even around anymore.
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  Speaker 2: Oh, all right. Cool. So this is our first record
• 7:53
  Speaker 2: of syphilis. It's 1493, the spread of the French losers.
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  Speaker 1: That's right. Well, our first record of syphilis in Europe.
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  Speaker 1: And as the mercenary spread, so does syphilis. In 1495,
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  Speaker 1: it makes it to France, Germany and Switzerland. And immediately
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  Speaker 1: people are afraid of this disease. So the Parliament of
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  Speaker 1: France says, hey, look, if you have syphilis, you have
• 8:15
  Speaker 1: to stay home until you're cured. And if you're not
• 8:17
  Speaker 1: from here, you need to leave immediately. And so people
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  Speaker 1: are starting to panic. It gets to England by 1497,
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  Speaker 1: India by 1498, and by 1505, it is plaguing people
• 8:29
  Speaker 1: in China. The naming is kind of funny. So people
• 8:34
  Speaker 1: have a tendency to, you know, blame things that they
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  Speaker 1: don't like on people they don't like. And so the
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  Speaker 1: French called it the Neapolitan sickness. The people from Naples
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  Speaker 1: called it the French sickness, as did the Germans and
• 8:49
  Speaker 1: the Italians. The... Japanese initially called it Chinese ulcer. Portuguese
• 8:55
  Speaker 1: called it Castilian sickness. Anyway, point is, it got named
• 8:59
  Speaker 1: after whatever group a country did not like at the time.
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  Speaker 2: I see.
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  Speaker 1: And immediately we knew that it was a sexually transmitted infection.
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  Speaker 1: That was pretty obvious from the start. We pretty early
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  Speaker 1: figured out that moms can pass it to babies and
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  Speaker 1: that wet nurses can give it to infants and that
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  Speaker 1: infants can give it to wet nurses. But we also
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  Speaker 1: knew that it was new. Like physicians at the time
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  Speaker 1: were saying, this is something we have not seen before.
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  Speaker 1: And so does the year 1493 make you wonder about
• 9:31
  Speaker 1: anything in particular? No.
• 9:35
  Speaker 2: Columbus sailing the ocean blue?
• 9:37
  Speaker 1: That's right. In 1492, right, Columbus sailed the ocean blue,
• 9:41
  Speaker 1: but he came back. Yeah. And he was back by
• 9:44
  Speaker 1: this time. And so very soon after this event, there
• 9:48
  Speaker 1: started to be speculation that this might be something that
• 9:52
  Speaker 1: Columbus had brought from the New World.
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  Speaker 2: Potatoes, tomatoes, and syphilis.
• 9:56
  Speaker 1: Spices, gold, syphilis, right.
• 9:58
  Speaker 2: Chocolate, yeah.
• 9:59
  Speaker 1: Yes. that's right. And, you know, it's worth noting that
• 10:03
  Speaker 1: the Europeans, between sending Europeans over to the New World
• 10:07
  Speaker 1: or sending people who were enslaved over to the New World,
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  Speaker 1: we ended up bringing smallpox, the flu, measles, cholera, chickenpox, malaria,
• 10:17
  Speaker 1: and plague. over to the New World. And so it
• 10:20
  Speaker 1: wouldn't be surprising if something traveled the opposite direction back.
• 10:25
  Speaker 1: Does that make sense?
• 10:26
  Speaker 2: Yeah, absolutely. Yeah, there should be some diseases in the
• 10:29
  Speaker 2: New World that are new to the Old World. Yeah.
• 10:31
  Speaker 1: Yeah, that's right. And so the question is, is syphilis
• 10:35
  Speaker 1: a disease that came from North America? And this has
• 10:38
  Speaker 1: literally been a debate for hundreds of years at this point.
• 10:43
  Speaker 1: And so today we're going to dig into what we
• 10:46
  Speaker 1: know so far. And you might think that shouldn't take
• 10:48
  Speaker 1: an hour. The answer should be yes or no. But
• 10:52
  Speaker 1: it's really complicated because it's, you know, humans and diseases.
• 10:57
  Speaker 2: All right. So we're trying to figure out who's to
• 10:59
  Speaker 2: blame for syphilis. Kelly, what are the clues?
• 11:03
  Speaker 1: Well, first of all, I don't want to say that
• 11:05
  Speaker 1: this is a blame game, you know, like I certainly
• 11:07
  Speaker 1: wouldn't blame anyone in the new world if they, you know,
• 11:11
  Speaker 1: were colonized and then those colonizers happen to like, you know,
• 11:14
  Speaker 1: go back with the disease.
• 11:15
  Speaker 2: I'm not blaming individuals, you know, it's not like, you know,
• 11:17
  Speaker 2: it's the fault of Pablo or Sam or something, but,
• 11:21
  Speaker 2: you know, it could be the fault of a whole continent.
• 11:23
  Speaker 2: The way you can, like, blame Virginia for its Virginian-ness,
• 11:26
  Speaker 2: even if, you know, all the people in Virginia are lovely.
• 11:29
  Speaker 1: You can thank Virginia for its Virginian-ness is what you
• 11:32
  Speaker 1: can do, my friend. That's what I'm doing. It's fall
• 11:34
  Speaker 1: in Virginia right now, and it is absolutely stinking perfect.
• 11:38
  Speaker 2: The few weeks when Virginia resembles California.
• 11:41
  Speaker 1: Except we have leaves that are changing color, and it's gorgeous. Okay,
• 11:45
  Speaker 1: so here's the thing. There were theories at the time
• 11:48
  Speaker 1: other than the Columbian hypothesis, which I just want to
• 11:50
  Speaker 1: mention because they're sort of funny from our more privileged
• 11:53
  Speaker 1: position today. So one of the theories was that it
• 11:56
  Speaker 1: came because of the conjunction of Mars and Saturn. One
• 12:00
  Speaker 1: of the ideas was that this was a God-given punishment
• 12:02
  Speaker 1: for blasphemy. And I found this really amazing woodcut where Mary,
• 12:06
  Speaker 1: the Virgin Mary, is sitting with Jesus on her lap.
• 12:09
  Speaker 1: And on one side, she's crowning Maximilian of the Habsburg dynasty.
• 12:13
  Speaker 1: And on the other hand, there's a little infant Jesus
• 12:16
  Speaker 1: who's like throwing shade at a bunch of people who
• 12:18
  Speaker 1: have syphilis below. And it's not... It's like he's raining
• 12:23
  Speaker 1: arrows of syphilis down on them. Maybe he's raining the cure,
• 12:27
  Speaker 1: but he definitely has this like smug face, which suggests
• 12:29
  Speaker 1: he's not raining the cure on them. So anyway, this
• 12:32
  Speaker 1: was stigmatized even then. There were other crazy ideas like
• 12:36
  Speaker 1: this happened because women had sex with monkeys or women
• 12:39
  Speaker 1: who had their period had sex with lepers. But pretty
• 12:42
  Speaker 1: soon after some of these more crazy ideas were, you know,
• 12:46
  Speaker 1: waved away, we ended up with the Columbian hypothesis and
• 12:49
  Speaker 1: the pre-Columbian hypothesis. So the Columbian hypothesis we've sort of
• 12:54
  Speaker 1: hinted at already. The idea here is that Europeans brought
• 12:57
  Speaker 1: a ton of diseases to the New World. Maybe when
• 13:00
  Speaker 1: Columbus was in Hispaniola or the landmass that he would
• 13:03
  Speaker 1: call Hispaniola, he His crew fraternized with the locals, let's say,
• 13:08
  Speaker 1: and brought back syphilis. There are some reports of people
• 13:12
  Speaker 1: on the ships returning back to Spain having some sort
• 13:15
  Speaker 1: of skin diseases. There were some reports written by people saying, oh, yeah,
• 13:20
  Speaker 1: this came from the locals. The locals had syphilis. It
• 13:23
  Speaker 1: was called something different at the time. But we now
• 13:25
  Speaker 1: think that a lot of those reports are a bit suspect,
• 13:28
  Speaker 1: not super reliable. And so it's not like a slam
• 13:31
  Speaker 1: dunk based on these reports that it definitely came from
• 13:34
  Speaker 1: the Americas.
• 13:35
  Speaker 2: So, you know, we are not blaming individuals, but you're
• 13:38
  Speaker 2: calling this the Columbian hypothesis, which, you know, sounds a
• 13:42
  Speaker 2: lot like it would be Columbus's fault. But all right,
• 13:45
  Speaker 2: let's keep going.
• 13:46
  Speaker 1: That's a fair point. But the important time point is
• 13:50
  Speaker 1: had Columbus gone to America or not, what would you
• 13:53
  Speaker 1: call it?
• 13:54
  Speaker 2: Yeah, no, I'm happy to blame Columbus. That dude deserves blame, yeah.
• 13:57
  Speaker 1: Yeah, okay, good, good. Let's go ahead and lean into
• 14:00
  Speaker 1: that then. And so then the pre-Columbian hypothesis is this
• 14:03
  Speaker 1: idea that actually the bacteria that causes syphilis had been
• 14:08
  Speaker 1: floating around Europe for a while, but either it had
• 14:12
  Speaker 1: been causing syphilis and nobody had sort of noticed. Maybe,
• 14:15
  Speaker 1: for example, we were confusing it with leprosy.
• 14:17
  Speaker 2: Hmm.
• 14:18
  Speaker 1: Or it was already there and it like mutated and
• 14:20
  Speaker 1: this mutated version got super quote unquote lucky and ended
• 14:24
  Speaker 1: up in the middle of a war with thousands of
• 14:26
  Speaker 1: people who got bored and were having sex with each
• 14:29
  Speaker 1: other and then spread out and brought it all over
• 14:32
  Speaker 1: Europe and Asia. So those are the two hypotheses. How
• 14:36
  Speaker 1: do we study them? Well, the main way we study
• 14:39
  Speaker 1: it now is archaeology and genomics. And so let's start
• 14:44
  Speaker 1: by talking about archaeology.
• 14:45
  Speaker 2: Okay.
• 14:46
  Speaker 1: All right. So if you are unfortunate enough to get
• 14:50
  Speaker 1: syphilis in the era before you can get treatment, syphilis
• 14:53
  Speaker 1: ends up with this stage where sometimes it will grow
• 14:57
  Speaker 1: like in your bones. And when it grows in your bones,
• 15:01
  Speaker 1: it causes this chronic inflammation that forms a hard lump.
• 15:05
  Speaker 1: And this hard lump starts to eat away at the
• 15:07
  Speaker 1: bony tissue. Oh, no. And in the skeletons, it leaves lesions.
• 15:11
  Speaker 2: Yikes.
• 15:12
  Speaker 1: Or sometimes it will, like, leave lesions that are noticeable
• 15:15
  Speaker 1: on the skull as well.
• 15:16
  Speaker 2: This sounds painful.
• 15:17
  Speaker 1: Yeah, incredibly painful. And actually, right when syphilis ended up
• 15:21
  Speaker 1: in a new area, we have, you know, historical evidence
• 15:24
  Speaker 1: that it was much worse than it ended up being.
• 15:26
  Speaker 1: It seems like over time it became a little bit
• 15:28
  Speaker 1: less intense, which kind of makes sense because if you
• 15:31
  Speaker 1: imagine yourself as a syphilis bacteria... And you cause.
• 15:35
  Speaker 2: I'm going to try to be sympathetic here. All right.
• 15:37
  Speaker 1: That's right. That's right. And you cause super intense symptoms
• 15:42
  Speaker 1: that are visible. Then the people who have those super
• 15:44
  Speaker 1: intense symptoms are probably not going to be in the
• 15:47
  Speaker 1: position where they can pass it to someone else. Right.
• 15:49
  Speaker 1: You know what I mean?
• 15:50
  Speaker 2: Right. They're getting overlooked at the club.
• 15:52
  Speaker 1: Yeah. That's right. That's right. Whereas if you produce slightly
• 15:56
  Speaker 1: less intense symptoms, the chances of being transmitted go up.
• 15:59
  Speaker 1: And so my guess is that less virulent strains had
• 16:02
  Speaker 1: an easier time passing. And that's what happens. But we
• 16:05
  Speaker 1: don't actually know the mechanism. But we do know that
• 16:07
  Speaker 1: over time, the symptoms became less severe and fewer people
• 16:10
  Speaker 1: died from the disease.
• 16:12
  Speaker 2: That's good, I guess. That is. No, that is.
• 16:14
  Speaker 1: That's great.
• 16:14
  Speaker 2: I'm looking for a silver lining here. Yeah. Yeah.
• 16:16
  Speaker 1: I mean, that's better than the alternative, I guess. OK.
• 16:20
  Speaker 2: Yeah, okay.
• 16:20
  Speaker 1: So if you find ancient skeletons, they leave these lesions
• 16:24
  Speaker 1: that could be indicative of syphilis. Right. And so what
• 16:27
  Speaker 1: you need to do are three things. First, you need
• 16:30
  Speaker 1: to find a skeleton. You need to figure out if
• 16:33
  Speaker 1: that skeleton is showing any indication of an advanced syphilitic disease.
• 16:38
  Speaker 1: And this is already kind of difficult because just because
• 16:40
  Speaker 1: someone had syphilis doesn't necessarily mean that it advanced to
• 16:43
  Speaker 1: the stage where it was causing problems with the bones.
• 16:47
  Speaker 1: So you need to find a skeleton that stuck around
• 16:49
  Speaker 1: and happened to have symptoms. Those are probably pretty low
• 16:51
  Speaker 1: probability events. And then you need to use radiocarbon dating
• 16:55
  Speaker 1: to figure out how old the skeleton is so you
• 16:57
  Speaker 1: can decide if it's pre- or post-Columbian.
• 17:00
  Speaker 2: Mm-hmm. Okay.
• 17:01
  Speaker 1: And you agreed to explain radiocarbon dating, so go.
• 17:09
  Speaker 2: Radiocarbon dating, super clever way to figure out when something
• 17:13
  Speaker 2: that used to be alive stopped being alive. And it
• 17:16
  Speaker 2: relies on measuring how much carbon-14 and carbon-13 are in
• 17:21
  Speaker 2: your body or in the object. These are different isotopes
• 17:24
  Speaker 2: of carbon. Remember, elements are defined by the number of
• 17:27
  Speaker 2: protons they have, but they can have different numbers of neutrons.
• 17:31
  Speaker 2: So carbon 12 is stable, six protons, six neutrons, but
• 17:34
  Speaker 2: you can have carbon 13 and you can have carbon
• 17:36
  Speaker 2: 14 with two extra neutrons. Carbon 14 is radioactive and
• 17:41
  Speaker 2: not stable. It only lasts for around 5,700 years, which
• 17:45
  Speaker 2: means if you have a bunch of it, then after
• 17:47
  Speaker 2: 5,700 years, half of it's gone. Now, the cool thing
• 17:51
  Speaker 2: about carbon 14 is is that it acts in your
• 17:53
  Speaker 2: body the same way carbon does. So if it's in
• 17:55
  Speaker 2: the environment, you breathe it, you eat it, you do everything,
• 17:59
  Speaker 2: and you have some carbon-14 inside you. And it's not
• 18:01
  Speaker 2: a big deal. It's a tiny bit of radiation. But
• 18:04
  Speaker 2: once you die, you stop eating and you stop breathing.
• 18:08
  Speaker 2: And so the carbon-14 that was in the environment no
• 18:11
  Speaker 2: longer is coming into your body. So the moment you
• 18:14
  Speaker 2: stop eating and breathing, the carbon-14 in your body becomes
• 18:17
  Speaker 2: a clock because it decays. And over time, you have
• 18:20
  Speaker 2: less and less of it. So somebody who has just
• 18:23
  Speaker 2: died has the same amount of carbon 14 as the environment.
• 18:26
  Speaker 2: Somebody who died 5,700 years ago is half the carbon 14.
• 18:30
  Speaker 2: Somebody who died a long time ago has much, much
• 18:33
  Speaker 2: less carbon 14. So just by measuring the carbon 14
• 18:36
  Speaker 2: to carbon 12 or 13 ratios, you can figure out
• 18:40
  Speaker 2: when this body stopped interacting with the environment. And you
• 18:44
  Speaker 2: might wonder like, well, where does carbon-14 come from? If
• 18:47
  Speaker 2: it decays, why doesn't it just decay in the environment?
• 18:50
  Speaker 2: And it does, but the environment is also making new
• 18:52
  Speaker 2: carbon-14 because their cosmic rays, particles from space are hitting
• 18:56
  Speaker 2: the upper atmosphere and creating carbon-14. Yay, cosmic rays. And
• 19:02
  Speaker 2: so constantly replenishing it. And there's an amazing science of this,
• 19:06
  Speaker 2: like figuring out how much carbon-14 is in the environment.
• 19:09
  Speaker 2: How does that vary with time? Because if carbon-14 goes
• 19:13
  Speaker 2: up or down through history, then that can throw off
• 19:16
  Speaker 2: your measurements. And it turns out that global warming, burning
• 19:19
  Speaker 2: fossil fuels, reduces the carbon-14 because it emits a bunch
• 19:23
  Speaker 2: of non-14 carbon, which dilutes it. And setting off nuclear
• 19:27
  Speaker 2: weapons enhances the carbon-14. And all sorts of events through
• 19:31
  Speaker 2: history affect this. And they actually use the Egyptian records
• 19:36
  Speaker 2: of the kings to calibrate this scale because they knew
• 19:40
  Speaker 2: from other sources that when did this king die? And
• 19:43
  Speaker 2: then they could carbon 14 date it and they get like, okay,
• 19:45
  Speaker 2: this is off by a little bit. Let's figure it out.
• 19:48
  Speaker 2: And they're able to trace it back to explain, like, oh,
• 19:50
  Speaker 2: there was more carbon 14 in the atmosphere here or
• 19:52
  Speaker 2: less there. And you can use tree rings also because
• 19:55
  Speaker 2: trees record this carbon essentially. You can see how much
• 19:58
  Speaker 2: is in each ring. So it's an amazing bit of
• 20:01
  Speaker 2: science discovered accidentally in like the 40s and completely changed archeology.
• 20:06
  Speaker 2: It allows you to carbon date so many things and
• 20:09
  Speaker 2: give you really clear understanding of what actually happened. And
• 20:13
  Speaker 2: it really changed like people's understanding of, you know, the
• 20:16
  Speaker 2: history of humanity. We were able to like date the
• 20:19
  Speaker 2: Dead Sea Scrolls to see that like they were really
• 20:22
  Speaker 2: 1900 years old and date the Shroud of Turin and
• 20:25
  Speaker 2: see like actually it seems like it was made from
• 20:27
  Speaker 2: stuff that died in the 14th century. And more generally,
• 20:31
  Speaker 2: it just changed like our understanding of how technology spread
• 20:34
  Speaker 2: in prehistory. We used to think that it was created
• 20:38
  Speaker 2: in one place and then spread around, but now it
• 20:40
  Speaker 2: looks more like things are made independently, locally, from independent innovations.
• 20:46
  Speaker 2: So it's an incredible tool into the past.
• 20:48
  Speaker 1: That's an incredible description. Thank you. And no surprise here.
• 20:53
  Speaker 1: Sometimes it gets a little bit more complicated. So that
• 20:55
  Speaker 1: carbon-14 dating is based on the amount of carbon-14 in
• 20:57
  Speaker 1: the atmosphere.
• 20:58
  Speaker 2: Yeah.
• 20:59
  Speaker 1: But if you happen to be a people who eat
• 21:01
  Speaker 1: a lot of food from the ocean.
• 21:03
  Speaker 2: Yes.
• 21:03
  Speaker 1: The relationship between carbon-14 and carbon-13 in the ocean isn't
• 21:07
  Speaker 1: necessarily the same as what's happening in the atmosphere. And
• 21:10
  Speaker 1: so if people eat a lot of fish, then that
• 21:12
  Speaker 1: can make them look older. Yeah. than if they ate
• 21:16
  Speaker 1: entirely land-based things. And so there's a lot of calibration
• 21:18
  Speaker 1: that needs to happen. And a little bit more calibration
• 21:21
  Speaker 1: will sometimes happen if, for example, you have a gravestone
• 21:24
  Speaker 1: with a date on it and you know that that
• 21:26
  Speaker 1: person ate fish, you can say, okay, this group probably
• 21:30
  Speaker 1: ate some fish because the date we're getting doesn't match
• 21:32
  Speaker 1: with this gravestone. And so now we know these people
• 21:34
  Speaker 1: in this area maybe ate fish. And so there's a
• 21:36
  Speaker 1: lot of calibrations.
• 21:37
  Speaker 2: You're saying the dates were fishy.
• 21:38
  Speaker 1: No, yes, I was saying the dates were fishy.
• 21:42
  Speaker 2: And that's just because cosmic rays are creating the atmosphere.
• 21:45
  Speaker 2: So the carbon-14 that's made doesn't mix into the ocean
• 21:47
  Speaker 2: evenly always. But yes, there's real science there.
• 21:50
  Speaker 1: Yes, absolutely real science here. And these these dates, it
• 21:53
  Speaker 1: can give you like really amazingly accurate dates. But if
• 21:58
  Speaker 1: you're talking about something like skeletons, one of the papers
• 22:00
  Speaker 1: that I read said it usually can't resolve the order
• 22:04
  Speaker 1: of events if they're separated by something like less than
• 22:06
  Speaker 1: 50 years. So it can do like, you know, amazing accuracy,
• 22:10
  Speaker 1: but it can't tell you like 1912 or something. You know,
• 22:14
  Speaker 1: there's like an error of at least a couple of years,
• 22:16
  Speaker 1: sometimes a couple of decades. Okay, let's take a break.
• 22:18
  Speaker 1: And when we get back, we will discuss what we
• 22:21
  Speaker 1: have learned with this technique. Or will we? We're back,
• 22:44
  Speaker 1: and I promised that I was going to tell you
• 22:46
  Speaker 1: what we've learned from Carbon 14 dating, but it's me,
• 22:49
  Speaker 1: so first we're going to talk a little bit more
• 22:51
  Speaker 1: about how things are complicated. And so here's the deal.
• 22:56
  Speaker 1: The bacteria that causes syphilis, whose name I won't say
• 22:59
  Speaker 1: so that Daniel doesn't roll his eyes.
• 23:01
  Speaker 2: Because it adds nothing to the conversation.
• 23:03
  Speaker 1: Sure. Okay.
• 23:05
  Speaker 2: Has.
• 23:05
  Speaker 1: Very closely related strains, like where there's an argument about
• 23:09
  Speaker 1: whether or not we should call these strains or subspecies
• 23:12
  Speaker 1: or like what we should call them exactly. But they
• 23:14
  Speaker 1: are very closely related to syphilis, but they cause different diseases. So,
• 23:19
  Speaker 1: for example, they cause diseases called yaws. And Bejel. Bejel.
• 23:26
  Speaker 1: I'm so sorry. I'm probably getting that wrong. It's B-E-J-E-L.
• 23:29
  Speaker 2: Bejel.
• 23:30
  Speaker 1: Matt can go. But these are diseases that tend to
• 23:34
  Speaker 1: be acquired in childhood and are not sexually transmitted. They're
• 23:39
  Speaker 1: also diseases that cause sores that have the bacteria in it.
• 23:43
  Speaker 1: And encountering that bacteria can transmit, you know, this bacteria
• 23:47
  Speaker 1: between person to person. So there's a lot of similarities
• 23:50
  Speaker 1: between these diseases. But in some parts of the world,
• 23:54
  Speaker 1: instead of getting syphilis, you're more likely to get yaws
• 23:57
  Speaker 1: or a bagel.
• 23:58
  Speaker 2: Bagel. Those sound better than syphilis, actually. I prefer those.
• 24:02
  Speaker 1: I think that's probably because you have like a bit
• 24:05
  Speaker 1: of a stigma associated with like, like almost everybody. Syphilis
• 24:08
  Speaker 1: is a word you've associated with something that you don't
• 24:11
  Speaker 1: necessarily want to get. But yaws and are both disfiguring
• 24:15
  Speaker 1: diseases as well, which can have impacts on the bones,
• 24:19
  Speaker 1: which is to say massive impacts that are, you know,
• 24:22
  Speaker 1: felt all the way down to the bones. And so
• 24:25
  Speaker 1: if you pull out a bone and that bone happens
• 24:28
  Speaker 1: to have a lesion on it, You can't be 100
• 24:31
  Speaker 1: percent sure that it was caused by syphilis instead of
• 24:35
  Speaker 1: being caused by yaws or bedule. And so scientists have
• 24:39
  Speaker 1: been trying to figure out, like, all right, well, what
• 24:40
  Speaker 1: do we do about this? And so for a while there,
• 24:43
  Speaker 1: we thought that syphilis was the only one of those
• 24:46
  Speaker 1: diseases that could transmit from mothers to babies. And so
• 24:50
  Speaker 1: trigger warning, we're going to be talking about, you know.
• 24:53
  Speaker 1: fetus bones, which is sad. But when it transmits from
• 24:57
  Speaker 1: mothers to babies, it tends to have very particular impacts
• 25:00
  Speaker 1: on the teeth. It causes what's called Hutchinson incisors. And
• 25:06
  Speaker 1: there's some pictures in the outline I sent you. But basically,
• 25:09
  Speaker 1: they've got teeth where the top of the tooth has
• 25:11
  Speaker 1: a bit of an indentation and it looks like there's
• 25:13
  Speaker 1: points on the far side of either tooth. And then
• 25:16
  Speaker 1: there's another thing called mulberry molars, where like, you know
• 25:19
  Speaker 1: how your molars have like ridges on them? These molars
• 25:23
  Speaker 1: have a lot more ridges and they go all the
• 25:25
  Speaker 1: way around in like a circle. And so these are
• 25:28
  Speaker 1: like pretty distinctive features of congenital syphilis.
• 25:33
  Speaker 2: Okay.
• 25:33
  Speaker 1: Which until recently we thought was the only version of
• 25:36
  Speaker 1: this bacteria that was transmitted from mothers to babies.
• 25:39
  Speaker 2: And so that would help us understand when syphilis arose
• 25:42
  Speaker 2: because we were seeing this in babies that we, what,
• 25:45
  Speaker 2: dug up?
• 25:46
  Speaker 1: Yes.
• 25:47
  Speaker 2: Yeah.
• 25:48
  Speaker 1: Well, you know, yeah, skeletons that we dug up and
• 25:50
  Speaker 1: they happened to be babies. Super sad. Okay, and so.
• 25:55
  Speaker 2: Is it cool that we're digging up skeletons? Like, what's
• 25:57
  Speaker 2: going on here? This is like cemeteries we're just rifling
• 25:59
  Speaker 2: through because of our curiosity?
• 26:01
  Speaker 1: Oh, yeah, that is a great question. Actually, archaeology has
• 26:04
  Speaker 1: a long history of digging up bones in unethical ways.
• 26:08
  Speaker 1: That field is much more sensitive to that issue now.
• 26:12
  Speaker 1: And there's a lot of rules in place about what
• 26:14
  Speaker 1: you're allowed to dig up and examine, what you're allowed
• 26:16
  Speaker 1: to do, what information you're allowed to share. I am
• 26:19
  Speaker 1: not an expert on that. We're not going to be
• 26:21
  Speaker 1: digging into that today. We could maybe have an archaeologist
• 26:23
  Speaker 1: on the show if you want to talk about that more.
• 26:26
  Speaker 1: But I am going to be talking about what we
• 26:28
  Speaker 1: have discovered.
• 26:29
  Speaker 2: Yeah, OK.
• 26:30
  Speaker 1: Yeah. Not whether we should or not.
• 26:33
  Speaker 2: We're not placing blame. We're working so hard to not
• 26:36
  Speaker 2: place blame.
• 26:38
  Speaker 1: I mean, you know, sometimes I think you got to
• 26:39
  Speaker 1: place blame, but, you know, maybe not always. So there
• 26:44
  Speaker 1: is a skeleton that we found in what's modern day
• 26:47
  Speaker 1: Turkey now. That appears to have signs of congenital syphilis.
• 26:52
  Speaker 1: And it was dated in this case, not using radiocarbon dating,
• 26:55
  Speaker 1: but a technique called stratigraphy. And it was dated to
• 26:58
  Speaker 1: the 13th century, which is pre-Columbian. So stratigraphy. is when
• 27:03
  Speaker 1: you essentially look at the other things that are buried
• 27:06
  Speaker 1: in the stratified layers above and below the skeleton. And so,
• 27:10
  Speaker 1: for example, if you find a coin that like, I
• 27:12
  Speaker 1: don't know, has a year printed on it or has
• 27:14
  Speaker 1: like the face of a particular emperor on it, then
• 27:17
  Speaker 1: you can say, OK, this body almost certainly came from
• 27:20
  Speaker 1: the time period when this person was emperor and we
• 27:22
  Speaker 1: can date it, you know, to around that time. Does
• 27:25
  Speaker 1: that make sense?
• 27:26
  Speaker 2: Yeah, I thought stratigraphy was going to be about handwriting analysis,
• 27:29
  Speaker 2: but now it makes more sense. It's a little bit layers. Yeah, yeah, yeah.
• 27:32
  Speaker 2: See how like weird Latin names are not so helpful.
• 27:36
  Speaker 1: Ah, interesting. All right, all right. You have been heard, Daniel.
• 27:38
  Speaker 2: All right, but we're still trying to figure out, like,
• 27:41
  Speaker 2: when did this person die, right? And that's the goal here,
• 27:44
  Speaker 2: so we can put together a story of, like, how
• 27:46
  Speaker 2: this disease spread.
• 27:47
  Speaker 1: Yes.
• 27:47
  Speaker 2: So we can figure out who's to blame, but we're
• 27:49
  Speaker 2: not going to blame them.
• 27:50
  Speaker 1: That's right. Exactly, exactly. Okay, and so they have this
• 27:53
  Speaker 1: skeleton that appears to have signs of syphilis that was
• 27:56
  Speaker 1: transmitted from mom to baby in an era before Columbus
• 28:02
  Speaker 1: had gone to the New World. Okay. But because it's biology,
• 28:09
  Speaker 1: we have more recently discovered that actually yaws and can
• 28:14
  Speaker 1: sometimes pass from mother to fetus. We thought that it
• 28:17
  Speaker 1: wasn't transmitted in that way. Oh. But now that we
• 28:21
  Speaker 1: have genetic tools, we've been able to identify some strains
• 28:24
  Speaker 1: and some strains that we thought were syphilis actually appear
• 28:27
  Speaker 1: to be the strains that we had associated with yaws
• 28:31
  Speaker 1: and like vice versa. And so now we're like, oh, well,
• 28:35
  Speaker 1: this definitely tells us that a disease caused by that
• 28:39
  Speaker 1: bacteria was present in Turkey. But was it what we
• 28:44
  Speaker 1: would think of as syphilis?
• 28:46
  Speaker 2: So we used to have what we thought was a
• 28:47
  Speaker 2: very clear marker of syphilis that we saw in Turkey pre-Columbian.
• 28:52
  Speaker 2: But now, because it's biology, we discovered it's actually muddled
• 28:55
  Speaker 2: and we don't really know anything.
• 28:57
  Speaker 1: Exactly.
• 28:57
  Speaker 2: All right.
• 28:58
  Speaker 1: But, you know, that's like kind of a more exciting challenge,
• 29:01
  Speaker 1: you know, to figure it out. I mean, yes, this
• 29:03
  Speaker 1: is like, this is a dark... topic to be thinking about.
• 29:06
  Speaker 1: But but, you know, like maybe we'll be up to it.
• 29:09
  Speaker 1: Maybe we won't. And so then there was another study
• 29:11
  Speaker 1: that found some ancient Greek skeletons that also possibly showed
• 29:16
  Speaker 1: signs of infection with this bacteria. But again, we don't
• 29:20
  Speaker 1: know if that was syphilis or if that was like
• 29:23
  Speaker 1: yaws or bedule. Like we can't tell if it was
• 29:26
  Speaker 1: sexually transmitted just by having these skeletons. But so the
• 29:29
  Speaker 1: point is, that you want to note here is that
• 29:32
  Speaker 1: there are skeletons that we have found in Eurasia that
• 29:37
  Speaker 1: show evidence of being infected by this bacteria during their
• 29:42
  Speaker 1: lifetime and this disease reaching advanced stages, but we can't
• 29:45
  Speaker 1: tell from those skeletons if it was syphilis or not.
• 29:48
  Speaker 1: Does that make sense?
• 29:49
  Speaker 2: Mm-hmm.
• 29:50
  Speaker 1: It's worth noting that we've also found a bunch of
• 29:52
  Speaker 1: skeletons in the Americas that show evidence of treponemal diseases
• 29:57
  Speaker 1: as well. And so now we're essentially in this situation where,
• 30:00
  Speaker 1: based on archaeology, we've been able to find skeletons on
• 30:04
  Speaker 1: both sides of the Atlantic that have evidence of having
• 30:08
  Speaker 1: been infected with this bacteria, but we are still kind
• 30:11
  Speaker 1: of trying to figure out when this became a sexually
• 30:13
  Speaker 1: transmitted disease.
• 30:15
  Speaker 2: Hmm. All right, well, I need a break from all
• 30:18
  Speaker 2: these skeletons. It makes me sad. So let's take a break.
• 30:22
  Speaker 2: And when we come back, we're ready to hear Kelly's
• 30:25
  Speaker 2: definitive answer on whether syphilis came from the New World.
• 30:30
  Speaker 2: Is it Columbus's fault or not? All right, we're back
• 30:52
  Speaker 2: and we are digging into whether Christopher Columbus brought syphilis
• 30:56
  Speaker 2: back with him from the New World. So, Kelly, take
• 30:59
  Speaker 2: us on the path to understanding.
• 31:01
  Speaker 1: Okay, so we've learned a lot from the bones that
• 31:04
  Speaker 1: we found, but it would be really great if we
• 31:07
  Speaker 1: could also extract DNA from those bones. And by using
• 31:11
  Speaker 1: that DNA, maybe we could get a better handle on
• 31:13
  Speaker 1: whether or not a skeleton had syphilis, yaws, or... Bejel.
• 31:17
  Speaker 2: Mm-hmm.
• 31:18
  Speaker 1: But what's really difficult about trying to do this is
• 31:20
  Speaker 1: that these strains are so closely related that most of
• 31:25
  Speaker 1: their genome is exactly the same. And so you kind
• 31:28
  Speaker 1: of can't use like, you know, in the early era
• 31:31
  Speaker 1: of genetics, you would like pick a couple genes and
• 31:33
  Speaker 1: then you'd use those genes to try to identify like
• 31:36
  Speaker 1: different species, for example. But when you've got strains that
• 31:38
  Speaker 1: are so closely related, a couple of genes won't do
• 31:41
  Speaker 1: the trick. They're probably similar at those genes. So you
• 31:44
  Speaker 1: need like the entire genome. so that you can make
• 31:47
  Speaker 1: enough comparisons between these different strains to feel pretty confident
• 31:50
  Speaker 1: that you've got a yaws-type strain versus a syphilis-type strain,
• 31:55
  Speaker 1: for example. In 2018, we had the first genomic evidence
• 32:00
  Speaker 1: in an archaeological site that we were able to use,
• 32:03
  Speaker 1: and this was from Mexico City. It was dated to
• 32:05
  Speaker 1: the 17th century, so too late to be helpful for
• 32:08
  Speaker 1: our pre-Columbian versus Colombian debate, but still interesting from the
• 32:12
  Speaker 1: perspective of, like, can we do this? And they found
• 32:16
  Speaker 1: skeletons from babies that had evidence of treponemal disease. And
• 32:21
  Speaker 1: they were able to pull enough genomic data and they
• 32:25
  Speaker 1: were able to say that two of the samples appeared
• 32:28
  Speaker 1: to have the genome that's associated with syphilis. And one
• 32:32
  Speaker 1: of the babies had the genome associated with yaws. And
• 32:36
  Speaker 1: so this was one of the first times we were like, oh, man,
• 32:40
  Speaker 1: yaws is transmitting congenitally. And in the same area, you
• 32:44
  Speaker 1: can have symptoms that were caused by the syphilis strain
• 32:46
  Speaker 1: and the yaws strain. Oh, no.
• 32:49
  Speaker 2: So it's going to be like impossible to figure this out.
• 32:51
  Speaker 1: That is perhaps actually the point. We can wrap it up.
• 32:56
  Speaker 1: I was going to give a little bit more information,
• 32:58
  Speaker 1: but that's kind of where we're getting is that it
• 32:59
  Speaker 1: might be impossible to figure this out because this bacteria
• 33:03
  Speaker 1: does very different things. And we don't yet understand why
• 33:08
  Speaker 1: in some cases it causes a disease like yaws and
• 33:11
  Speaker 1: why in other cases it causes a disease like syphilis.
• 33:14
  Speaker 1: And it's really hard to do experiments on this kind
• 33:17
  Speaker 1: of stuff. So it does turn out that rabbits are
• 33:20
  Speaker 1: infected by a syphilis-like disease. So you could– sorry, trigger warning.
• 33:26
  Speaker 1: We're talking about animal research. You could do some research
• 33:29
  Speaker 1: there and try to figure out like what– makes the
• 33:33
  Speaker 1: bacteria act differently? Like, are there environmental conditions? Does this
• 33:36
  Speaker 1: depend on how the host immune system responds to it? But,
• 33:40
  Speaker 1: you know, like, it would not be ethical to do
• 33:42
  Speaker 1: experiments on humans to try to figure this out. So
• 33:44
  Speaker 1: at the moment, we're just sort of stuck, not really
• 33:46
  Speaker 1: sure what to do.
• 33:48
  Speaker 2: But I have a kind of basic question.
• 33:49
  Speaker 1: Yeah.
• 33:49
  Speaker 2: So we're trying to figure out if syphilis came to
• 33:51
  Speaker 2: the New World with Columbus, but the confounding factor is
• 33:55
  Speaker 2: that there was already a syphilis-like disease in Europe. And
• 34:00
  Speaker 2: does this syphilis-like disease exist we think have a common
• 34:03
  Speaker 2: origin with syphilis? Is this like there's some original disease
• 34:07
  Speaker 2: and then it's split off and the new world version
• 34:10
  Speaker 2: separated from the old world version and now they're coming
• 34:12
  Speaker 2: back together? Is that the story?
• 34:14
  Speaker 1: Well, that's a great question. That's what we're trying to
• 34:16
  Speaker 1: figure out now. So the question is, like, did a
• 34:19
  Speaker 1: strain from the Americas make it to Europe and then
• 34:23
  Speaker 1: in this new population do something totally different?
• 34:26
  Speaker 2: Yeah.
• 34:26
  Speaker 1: Or was it a strain that was already present in
• 34:29
  Speaker 1: Europe that for whatever reason, you know, maybe like social
• 34:33
  Speaker 1: changes changed the way it could get transmitted, plus some mutations? Like,
• 34:37
  Speaker 1: is that where syphilis came from? Was it already waiting
• 34:40
  Speaker 1: in Europe just for its perfect moment?
• 34:42
  Speaker 2: But even if it wasn't waiting in Europe for its
• 34:45
  Speaker 2: perfect moment, there's a related disease already in Europe, right?
• 34:50
  Speaker 1: Right.
• 34:50
  Speaker 2: Doesn't that suggest that either way there's some common origin
• 34:53
  Speaker 2: of the two diseases?
• 34:54
  Speaker 1: Yeah, right. And so some scientists were trying to figure
• 34:57
  Speaker 1: out where do they think this bacteria arose initially?
• 35:01
  Speaker 2: Yeah, exactly. And is it aliens?
• 35:03
  Speaker 1: Yes. Well, I should have guessed we were getting there,
• 35:07
  Speaker 1: but that's not what I had on mind.
• 35:10
  Speaker 2: Was it cannibalism?
• 35:11
  Speaker 1: It was cannibalism. Yeah. And white chocolate and smoking banana peels.
• 35:15
  Speaker 1: So anyone who's got their DKU bingo card, you're welcome.
• 35:19
  Speaker 2: That's right.
• 35:20
  Speaker 1: So there was this 2024 paper that looked at ancient
• 35:24
  Speaker 1: genomes to try to figure out where did this bacteria
• 35:27
  Speaker 1: come from?
• 35:27
  Speaker 2: Yeah.
• 35:28
  Speaker 1: And they think that this bacteria originated in the Americas.
• 35:33
  Speaker 1: And it looks like the upper bound for a common
• 35:37
  Speaker 1: ancestor for this bacteria, so like when this bacteria split
• 35:39
  Speaker 1: from another bacteria, is like 9,000 years before Common Era.
• 35:44
  Speaker 1: So really, really long ago. It's possible that it jumped
• 35:48
  Speaker 1: from another animal into people. We really don't know. But
• 35:52
  Speaker 1: it's been around long enough that like, you know, could
• 35:54
  Speaker 1: it have gotten across the Bering Land Bridge? Like when
• 35:57
  Speaker 1: people came from... Europe over to the Americas, could it
• 36:01
  Speaker 1: have gone the other way as well? There was also
• 36:04
  Speaker 1: some evidence of Vikings coming over this way at some
• 36:07
  Speaker 1: point in the past. Maybe the Vikings picked it up
• 36:09
  Speaker 1: and brought it back over and it's been there since
• 36:12
  Speaker 1: the Vikings visited. And so we don't know the answer.
• 36:16
  Speaker 2: Are you saying Scandinavians are syphilitic people?
• 36:18
  Speaker 1: I am. Why are you doing this? No, I'm not
• 36:21
  Speaker 1: saying that. Absolutely not.
• 36:23
  Speaker 2: Because those are my people. You know, I'm married to
• 36:25
  Speaker 2: a Danish lady, so be careful.
• 36:27
  Speaker 1: I can tell that you're very defensive. Yes. I mean,
• 36:31
  Speaker 1: we do think that we've seen the yaw strain in
• 36:33
  Speaker 1: bones from Finland from the 15th and 16th century. But 15th,
• 36:38
  Speaker 1: 16th century is like, you know, it overlaps the Colombian
• 36:42
  Speaker 1: date that we're all interested in.
• 36:44
  Speaker 2: So.
• 36:45
  Speaker 1: It looks like this is ancient. We don't know when
• 36:47
  Speaker 1: it made it over to, like, Europe for the very
• 36:50
  Speaker 1: first time. But it's pretty old and appears to have
• 36:52
  Speaker 1: started in the Americas.
• 36:54
  Speaker 2: And tell us why scholars are interested in this. Like,
• 36:57
  Speaker 2: I think it's interesting just because history is fascinating. And
• 36:59
  Speaker 2: I like to know, like, how did we get here
• 37:01
  Speaker 2: and what happened and, you know, how small things can
• 37:04
  Speaker 2: snowball into big effects. But, like, why are the archaeologists
• 37:08
  Speaker 2: and the historians excited about this?
• 37:11
  Speaker 1: Yeah, that is a great question. So I think part
• 37:13
  Speaker 1: of it is because this is a debate that was
• 37:16
  Speaker 1: like written down in historical records like hundreds of years ago.
• 37:20
  Speaker 1: And so I think to some extent, like, you know,
• 37:22
  Speaker 1: historians and people who are interested in history like want
• 37:24
  Speaker 1: to know the answer.
• 37:25
  Speaker 2: It's like the Navier-Stokes equation, but for history. It's like
• 37:28
  Speaker 2: a longstanding open problem.
• 37:30
  Speaker 1: That's right. How old is the Navier-Stokes equation?
• 37:33
  Speaker 2: Not as old as this one, no.
• 37:34
  Speaker 1: Okay, yeah, yeah. But I'll note that when I was
• 37:38
  Speaker 1: reading a lot of the recent papers written in the
• 37:40
  Speaker 1: last couple years, the authors are clearly exasperated with the
• 37:44
  Speaker 1: fact that when they say that they study treponemal diseases
• 37:49
  Speaker 1: and their history, people are like, Did Columbus bring it
• 37:52
  Speaker 1: from the new world to the old? And they're like, look,
• 37:55
  Speaker 1: that's not what's important. What's important is the impact this
• 37:59
  Speaker 1: disease had, whether it was yaws or syphilis, like whatever
• 38:02
  Speaker 1: it was, the impact it has on the communities that
• 38:05
  Speaker 1: you find it in over time.
• 38:07
  Speaker 2: You can sense their frustration in their writing and their
• 38:09
  Speaker 2: like dry academic prose.
• 38:11
  Speaker 1: I mean, there was a 2025 paper where they were
• 38:13
  Speaker 1: not pulling any punches. They were like, look, we are
• 38:16
  Speaker 1: going to review the literature on the Colombian pre-Columbian debate,
• 38:20
  Speaker 1: but we do not think it's interesting. And I was like, oh, wow.
• 38:23
  Speaker 2: That's like Katrina saying like, our virus is alive. She
• 38:26
  Speaker 2: doesn't care. Like, it's not an interesting question. And I
• 38:30
  Speaker 2: think like, is Pluto a planet? Like, whatever. It's just
• 38:33
  Speaker 2: an arbitrary dotted line.
• 38:34
  Speaker 1: Yes. I mean, I think like evolutionary biologists and epidemiologists
• 38:38
  Speaker 1: do think that this question of what causes this bacteria
• 38:43
  Speaker 1: to take different forms, that's an important question. And like
• 38:47
  Speaker 1: that might even help us understand... You know, the worst
• 38:50
  Speaker 1: impacts of this bacteria and maybe even how to control
• 38:52
  Speaker 1: it or how to treat it. Those are important questions.
• 38:56
  Speaker 1: But like at the end of the day, I think
• 38:58
  Speaker 1: most of the scholars are like not super interested in
• 39:01
  Speaker 1: this Columbus. And part of their lack of interest might
• 39:03
  Speaker 1: be exhaustion. Like we've been talking about this for so long.
• 39:07
  Speaker 1: We'll probably never get a slam dunk yes or no answer.
• 39:11
  Speaker 1: But what we do know is that it was in
• 39:13
  Speaker 1: both places and it's complicated. So let's wrap it up.
• 39:16
  Speaker 1: What are the take home messages here? One of the
• 39:18
  Speaker 1: papers that I looked at that was looking at like
• 39:20
  Speaker 1: ancient DNA, trying to figure out where this disease came from,
• 39:23
  Speaker 1: ended up saying that like, look, DNA might never be
• 39:26
  Speaker 1: able to answer this question. I know. And if DNA
• 39:30
  Speaker 1: can never answer the question, then we probably can't really
• 39:33
  Speaker 1: get an answer.
• 39:34
  Speaker 2: Oh, wow.
• 39:34
  Speaker 1: That's frustrating. I know. And then that review paper that
• 39:37
  Speaker 1: I was reading that was, like, clearly exasperated with the
• 39:40
  Speaker 1: Columbian question, they were pretty much like, look, the Columbian
• 39:44
  Speaker 1: hypothesis doesn't have a lot of evidence now that we
• 39:47
  Speaker 1: know that this bacteria was in Europe before Columbus got here.
• 39:52
  Speaker 1: And so... Maybe it didn't come from the Americas. We
• 39:55
  Speaker 1: already had the strains here. And like we're probably not
• 39:57
  Speaker 1: going to be able to slam dunk this one way
• 39:59
  Speaker 1: or another. And again, they don't think that's an interesting question.
• 40:02
  Speaker 1: And so thank you for spending 45 minutes with me
• 40:04
  Speaker 1: on this question that they don't think is interesting anymore.
• 40:07
  Speaker 1: But but I think that like what's interesting here is
• 40:10
  Speaker 1: that every time we dug in. there was another layer
• 40:14
  Speaker 1: that we had to understand. Like there was another set
• 40:17
  Speaker 1: of interesting questions that help us understand like evolution and
• 40:20
  Speaker 1: the lives of people and like what, how different people
• 40:24
  Speaker 1: suffered at different times and like, you know, like windows
• 40:27
  Speaker 1: into what their lives were like. And, you know, often
• 40:29
  Speaker 1: when we look at the things that are around these skeletons,
• 40:32
  Speaker 1: we also get a sense for like how people cared
• 40:35
  Speaker 1: for people who had syphilis. We get a lot of
• 40:37
  Speaker 1: sociological information as well, which I think is really interesting.
• 40:41
  Speaker 2: Super fascinating. And I'm pretty sure Tony Soprano would be
• 40:43
  Speaker 2: happy to hear that you can't blame Christopher Columbus for syphilis.
• 40:47
  Speaker 1: We can blame him for lots of other things. You know,
• 40:50
  Speaker 1: I think the diseases that got brought from the old
• 40:51
  Speaker 1: world to the new, I read an estimate that it
• 40:53
  Speaker 1: killed something like 85 to 90 percent of the people
• 40:57
  Speaker 1: who had lived in the new world already. So absolutely devastating.
• 41:01
  Speaker 1: We can blame him for that. And anybody who wants
• 41:03
  Speaker 1: to learn more about syphilis or this question should check
• 41:06
  Speaker 1: out Alice Roberts' book Crypt, Claude Quetel's book History of Syphilis,
• 41:12
  Speaker 1: or Oriol's book The Scars of Venus. These are all
• 41:14
  Speaker 1: like really interesting histories, in some cases about syphilis. And
• 41:18
  Speaker 1: I can tell you from experience that if you read
• 41:21
  Speaker 1: the history of syphilis on a train, you won't have
• 41:23
  Speaker 1: to sit next to anyone. One person got up when
• 41:28
  Speaker 1: they saw what book I was reading and moved away.
• 41:31
  Speaker 1: And then the person who sat next to me next said,
• 41:34
  Speaker 1: what are you reading? And then I said, the history
• 41:36
  Speaker 1: of syphilis. And he backed away a little bit and said,
• 41:40
  Speaker 1: for personal reasons? I said, no, not for personal reasons.
• 41:46
  Speaker 1: And then we had a lovely conversation about the Colombian
• 41:49
  Speaker 1: and the pre-Columbian hypothesis.
• 41:51
  Speaker 2: I would have said, I'm reading How to Get Rid
• 41:53
  Speaker 2: of Nosy Train Neighbors.
• 41:54
  Speaker 1: He was very nice, actually. We had a really nice conversation. Actually,
• 41:58
  Speaker 1: his interest in the conversation that we had is what
• 42:01
  Speaker 1: made me think this might be a good podcast episode.
• 42:04
  Speaker 1: So glad he asked.
• 42:05
  Speaker 2: Well, thank you for taking us on this historical journey.
• 42:07
  Speaker 2: I'm always interested in what happened, how we got here.
• 42:11
  Speaker 2: And I'm impressed by the archaeology and the detective work
• 42:15
  Speaker 2: involved in trying to unravel the history of our existence.
• 42:19
  Speaker 2: So even though it hasn't been solved, I think we
• 42:21
  Speaker 2: learned a lot along the way. Like, don't get syphilis
• 42:24
  Speaker 2: and don't be Christopher Columbus.
• 42:26
  Speaker 1: Yes, right. Also, but, you know, I just want to
• 42:28
  Speaker 1: say real quick, we do have treatments for syphilis now.
• 42:31
  Speaker 1: It doesn't have to have a stigma in general anymore.
• 42:34
  Speaker 1: Sexually transmitted infections can happen to any of us.
• 42:40
  Speaker 2: So talk to your doctor, folks.
• 42:42
  Speaker 1: That's right.
• 42:49
  Speaker 2: Thanks, everybody, for listening. Please go and do us a
• 42:52
  Speaker 2: favor and rate the show on whatever podcast app you're using.
• 42:55
  Speaker 2: It really helps people find us.
• 42:57
  Speaker 1: Daniel and Kelly's Extraordinary Universe is edited by the amazing
• 43:01
  Speaker 1: Matt Kesselman.
• 43:02
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• 43:05
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• 43:11
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• 43:12
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• 43:16
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• 43:17
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• 43:23
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• 43:29
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