Adrian Davies/NPL/Minden Pictures

Play
Pause

Go ten seconds backward

Go ten seconds forward

First on the show this week, Staff Writer Elizabeth Pennisi joins host Sarah Crespi to talk tongues: Who has them, who doesn’t, and all their amazing elaborations.

We also have the first in a new six-part series on books exploring the science of sex and gender. For this month’s installment, host Angela Saini talks with evolutionary biologist Malin Ah-King about her book The Female Turn: How Evolutionary Science Shifted Perceptions About Females.

Finally, detecting beer in early 19th century Danish paintings. Heritage scientist Fabiana Di Gianvincenzo of the Heritage Science Laboratory at the University of Ljubljana talks about her Science Advances paper on using proteomics to dig out clues to artistic practices of the day and how they fit in with the local beer-loving culture.

This week’s episode was produced with help from Podigy.

About the Science Podcast

TRANSCRIPT

[music]

0:00:05.6 Sarah Crespi: This is the Science Podcast for May 26th, 2023. I’m Sarah Crespi. First up this week, we have staff writer Liz Pennisi. She joins me to talk tongues; who has them, who doesn’t, and all their amazing elaboration. Today we also have the first in a new six part series on books exploring science, sex, and Gender. Host Angela Saini talks with evolutionary biologist Malin Ah-King about her book, The Female Turn: How Evolutionary Science Shifted Perceptions About Females. Finally, detecting beer in early 19th century Danish paintings. Heritage scientist, Fabiana Di Gianvincenzo talks about using proteomics to dig out clues to artistic practices of the day and how they fit in with the local beer loving culture.

0:00:57.6 SC: So once when I was having my teeth cleaned, my dental hygienist told me that some people have very active tongues. They’re very curious and they’re actually, they won’t leave the dental tools alone. Anytime a new thing comes in, the tongue has to go over and explore, and the dentist or the hygienist is constantly holding the tongue back with the mirror so that it doesn’t get hurt. And it’s just hard for people, certain people, to overcome how active and curious their tongues are, which I think is a really good segue into the fact that our tongues are a lot more complicated than we really think about it. They have all these jobs in our mouths and people are very curious about tongues. So this weekend, Science staff news writer Liz Pennisi wrote about the evolution of the tongue, when it came about and the many, many ways it has adapted to different lifestyles. Hi, Liz.

0:01:52.5 Liz Pennisi: Hi. How are you?

0:01:54.6 SC: Good. How active what do you feel a tongue is?

[laughter]

0:01:57.8 LP: My tongue or any tongue?

0:02:00.0 SC: Any tongue. [laughter]

0:02:02.5 LP: Well, I think it’s very, very active. I mean, it does everything. It talks, it swallows, it moves food around. It gets out of the way of our teeth. It does a lot. It helps us taste.

0:02:15.5 SC: Yeah. And it has microbes living on it too that help us with food or protect our teeth.

0:02:21.6 LP: Yeah, so they’re just beginning to understand, number one, what microbes are on the tongue, and then number two, what they do. The tongue is a very rich source of microbes and they live in these structured communities called biofilms. And apparently there’s some evidence that the tongue will take the nitrates that are in plants and turn it into nitrite, which is a substance the body can use to make nitric acid, which is something that helps control blood pressure. And so apparently people who take antibiotics or wash their mouth out with antiseptic mouthwash, fiddle with their blood pressure.

0:03:03.9 SC: That’s really interesting. This is, as you say, relatively new research and it turns out that it’s very difficult to study the tongue. Why has it been so difficult to get a handle on what it’s up to and how it works?

0:03:17.7 LP: Well, for one thing, you can’t see it. It’s not like you can stick a camera inside your mouth and video what’s going on.

0:03:25.0 SC: Not in a natural state. You’ll be very distracted by that, right?

0:03:30.7 LP: Yes, yes. It’s only recently that people who like to study how skeletal parts move have been able to come up with a technology where they label a tongue, not necessarily a human tongue, though they’re beginning to do those studies, but they surgically implant beads that show up in x-rays. And so they’ll put a whole bunch of beads in your mouth, in your tongue, take the x-rays, and then with computer animation, figure out how all those beads are moving with respect to each other, and therefore figure out what the tongue is doing.

0:04:03.3 SC: That’s like motion capture for CGI, but with x-rays and implants. That’s pretty amazing.

0:04:09.6 LP: Yeah. See, the tongue is very unusual in our bodies because it moves in very complicated ways, but it’s a hundred percent muscle. It’s not like there are bones and joints and things to help it move. It’s all muscles and there’s all these muscle fibers going in all sorts of different directions that have to coordinate, roll your tongue, stick it out.

0:04:34.1 SC: You call the tongue, what is it, a hydrostat? What is that?

0:04:37.7 LP: It’s like a water balloon. It has a certain volume and that volume doesn’t change. So you can’t really squeeze it in one direction without it expanding in another direction.

0:04:49.5 SC: This was very surprising. There isn’t a standard definition of a tongue like the one that you described with all these muscle fibers going in different directions, it’s a hydrostat, it’s kind of filled with water, but it’s not like the tongue description from species to species.

0:05:03.6 LP: The tongue can be very different depending on the species and depending what it eats. Among birds, for example, the tongue is usually a very stiff, narrow thing, and among birds that feed on nectar, it can have tubes, it can have fringes, it can have all sorts of modifications that make it look nothing like our tongue.

0:05:28.8 SC: Yeah. So in some animals, it’s helping with sound, and some animals, it’s helping with sucking, and some animals, it’s helping with grinding. It really has gone a lot of different directions since it first of evolved, which, do we know who the first tongue holder was?

[laughter]

0:05:47.4 LP: Well, it depends how you define a tongue.

0:05:50.1 SC: Yeah, exactly. So if it’s perhaps hanging off the top of the mouth, is it still a tongue?

0:05:56.4 LP: That’s a good question, because many people who don’t study fish think fish don’t have tongues, and yet they can have things in their mouths that are like tongues. So for example, carp have these pads that are stuck to the top of their mouth that you could call a tongue. They’re called palatal organs.

0:06:18.2 SC: So it’s on the pallet and it’s a thing in the mouth that does something for food, I assume?

0:06:22.9 LP: That’s what they think. They think it might help move food around. But generally, fish don’t really need tongues because they use, they basically use water currents to move food into the mouth, around in the mouth, and down the throat.

0:06:37.7 SC: So when animals first left the sea and they didn’t have tongues, the way that we think of tongues today, like how did they swallow their food?

0:06:47.4 LP: They had to go back to the sea. So it might grab something on land and then waddle back to the water, and then get under water, and then use the water currents to suck the food down.

0:07:00.1 SC: Once animals hit the land and it became very tiresome to keep having to go back to a pool of water to eat food, they started to get these elaboration in their mouth that became tongues, and it just really completely changed the landscape of what they could eat.

0:07:18.2 LP: Once there was a tongue, it started to evolve in a lot of different directions to let its owner take advantage of different kinds of foods.

0:07:29.0 SC: We talked a little bit about nectar for birds, but then if you look at reptiles and amphibians, they have a completely different deal with their tongues, at least these ballistic feeders. Can you talk a little bit about that process?

0:07:42.5 LP: One of the things that happened in amphibians and some reptiles is they basically evolved a tongue that could get out of the mouth and catch the prey. Their tongues got really long and the muscles that control the tongue got changed around so that when the tongue is rolled up in the mouth or in the mouth, they store a lot of elastic energy. And then what happens is when they see an insect or a cricket or something like that, they flick the tongue out really, really fast and nab the insect and then pull it back in. And the tongue, in addition to being long, it can be almost as long as its body. And in addition to having these modified muscles, it has basically saliva that is really sticky. So once the insect is grabbed, it can’t get away.

0:08:39.6 SC: You even write about one that has protective mucus on the tongue.

0:08:43.8 LP: So horned lizards, these particular ones live in southwest Arizona, they eat ants and the ants they eat are particularly poisonous and nasty biters.

0:08:55.7 SC: Spicy ants.

[laughter]

0:08:57.4 LP: Yeah. And so what these lizards have evolved is both a tongue anatomy and a mucus that’s really, really thick. So when they grab the ants, the mucus surrounds it in these strings of mucus and they kind of get stuck in a mucus pocket. So when they’re being swallowed, they’re incapacitated and can’t bite anymore.

0:09:23.4 SC: And then it’s down into the acids that’ll take care of all that stuff.

0:09:27.9 LP: Yes. Hopefully.

0:09:29.0 SC: That’s pretty great. Okay, so we’ve talked about birds, we’ve talked about amphibians and reptiles, and I think we gotta get over to mammals. So what are some of the interesting elaborations that have happened with mammalian tongues?

0:09:42.1 LP: One of the most critical things is suckling, and they use the tongue for that. And then some of the more unusual things is, so some bats, for example, click their tongues and use it for echolocation. While some animals, including whales and dogs, use their tongue to thermoregulate. So you think about a dog sticking out its tongue as it pants, and apparently whales do a similar thing.

0:10:09.2 SC: The other thing about mammals, obviously some of us, for example, humans can talk, and our tongue has become really important for that. And you write about how this relationship, how our brain and talking and the tongue all work together has a really interesting history.

0:10:25.3 LP: The interesting thing is obviously before there were hands, there were paws. That paws didn’t do much grabbing of food.

0:10:34.5 SC: They’re just kind of walkers, right?

0:10:35.8 LP: They’re just kind of walkers. And so some people think that the ability of the tongue to grab and manipulate food helped the early appendages that became our hands to grab and manipulate food, that some of the brain circuitry was co-opted to help the hands maneuver.

0:11:00.0 SC: So our tongue was our first hand?

0:11:01.1 LP: The tongue was our first hand, yeah.

0:11:03.6 SC: It’s our mouth hand, as you say in the story.

0:11:06.7 LP: The hand to the mouth.

[laughter]

0:11:07.8 SC: The hand of the mouth. Okay. So one thing I wanna touch on before we wrap up is you open your piece with how some athletes stick their tongue out when they’re doing something difficult. What’s going on there? Is it legitimately helping them or is it just evidence that they’re doing something difficult?

0:11:28.1 LP: Nobody’s really done a scientific study to evaluate whether sticking out your tongue before you dunk a ball, or sticking out your tongue before you throw a football helps you get that basket or help you make that accurate throw. But it is kind of funny how certain athletes do stick out their tongue right before they do these things. And it’s also pretty common, I guess, that dart players, as they’re taking aim at the bullseye, they also stick out their tongue.

0:12:01.4 SC: Oh, so there’s so many tongue mysteries to solve?

0:12:04.2 LP: There’s a lot of them.

0:12:05.0 SC: All right, Liz. Thank you so much. This has been great.

0:12:07.3 LP: Well, thank you.

0:12:09.7 SC: Liz Pennisi is a staff writer for Science. You can find a link to the story we discussed, and I’m assuming many pictures of tongues?

0:12:15.9 LP: Oh yeah.

0:12:16.7 SC: At science.org/podcast. Stay tuned for the first installment of our book series this year on the Science of Sex and Gender. This month host Angela Saini talks with Malin Ah-King. She’s an evolutionary biologist and her book is about the revolutionary shift towards studying the female of the species.

[music]

0:12:41.7 Angela Saini: Hello, I’m Angela Saini, science journalist, author, and the host of this special series of Books Podcasts. This is the first of six monthly interviews in which I’m speaking to the writers of thought-provoking books on sex and gender. This month I’m joined by Marlin Ah-King, an evolutionary biologist and associate professor in gender studies at Stockholm University in Sweden. She’s known for looking at sexual selection through a feminist lens. In her latest book, The Female Turn: How Evolutionary Science Shifted Perceptions About Females, Ah-King surveys what has become a noticeable change in the way that the researchers have started looking at female anatomy and behavior across a natural world. As she writes in her introduction, science has historically depicted female animals, including humans, as coy, passive, elusive, non-competitive, and sexually reserved. Not anymore. Marlin, thank you so much for being here. Can you start by just explaining the historical failures of scientists to notice or even properly understand the females of species?

0:13:49.9 Marlin Ah-King: So Darwin describes females as being passive and coy, and I think these ideas have continued within our field of evolutionary biology. So, many times, people have watched birds or other animals and didn’t record or didn’t notice the active strategies of females.

0:14:11.4 AS: One startling example you give in the book is a study of the clitoris. It is bizarre the way that you describe it in the book, the failures on that front.

0:14:20.5 MA: Yeah, it’s very interesting how the interest in the clitoris has waxed and waned across science. So at the time when the clitoris or the orgasm was thought to be important for the fertilization of an egg, the female orgasm and the clitoris was important and was studied by medical researchers. But as this perception of the importance of the orgasm for the fertilization declined, then the interest of the clitoris also declined. And then in the 1970s, when the women’s health organizations took an interest in women’s pleasure than the interest in studying and exploring the role, the clitoris was priested again.

0:15:07.3 AS: Right. So you can see how the politics in the background of the science then really does influence the kind of science that’s done.

0:15:14.1 MA: Exactly.

0:15:14.6 AS: You have so many examples in which objective studies of female behavior have challenged these earlier preconceptions, not just in humans and primates, but also in snakes and frogs and spiders and birds. So can you give a few examples that stood out for you?

0:15:31.3 MA: It’s interesting when the technical, the innovation of DNA fingerprinting actually showed the range of birds in which females were actually mating with several males in many, many species in which these females were thought to be monogamous. But in the beginning, this was explained in terms of a male strategy imposed onto the females. However, over time, feminist biologists were really important to challenging this perception of females as passive, and that females had active strategies. There’s one interesting example in snake research. So Jesus Rivas, he studied green anacondas, and he found the first example of a species in which the females are mating with several males. Because at the time, in the 1990s, snakes were assumed to be males mating with several females. All the different snakes were described as having different kind of mating systems, in which the males mate with several females. He was the first one to describe a species in which females were mating with several males. But as he went back into the literature, he found that there are many different examples described in which females actually do mate with several males. So he and a colleague of his described and revisited this knowledge to describe many species in which female multiple matting had been ignored.

0:17:10.3 AS: So there really is a great deal of agency involved here, and sometimes, as you document, females being quite aggressive.

0:17:19.1 MA: Absolutely. And this was also against the perceptions of females as being peaceful. And the early studies of female aggression were also criticized, and people were challenging those new results about female being aggressive.

0:17:35.8 AS: Why was there such a reluctance then? What have you seen that can explain that reluctance to accept that females in other species might be behaving aggressively?

0:17:46.6 MA: One thing I’ve been trying to figure out is how ignorance have been produced about several different features of females. So our preconceptions about what females can do and our theories about females have enabled us to see certain things and made us ignore certain other behaviors.

0:18:10.5 AS: What examples do we have of species in which we can see aggressive female behavior?

0:18:14.7 MA: In the 1980s, when Patricia Gowaty was studying the eastern bluebird, she did experiments. So she put out text dummy display birds around their territories, and she could see that the females were aggressive toward these. And she took photographs of them. And when she presented this work, somebody senior said to her that they wouldn’t have believed it if it hadn’t been for the photographs of these aggressive encounters.

0:18:48.0 AS: So one interesting observation you make is that outside the west, different cultures can have very different ways of interpreting animal behavior. And you mentioned Japan in particular, where even though primatology has been a male-dominated profession, there hasn’t always been the same way of looking at females. And for this reason, you write, there hasn’t been the need for a female turn in research because females were already well studied. Why is that? Can you explain that?

0:19:16.6 MA: So in Japanese primatology, which developed independently from western primatology, they had another approach towards studying animals. So there is not this great divide between perceptions about humans and animals. So they see this as a continuum and therefore they also approach the animals with a way of anthropomorphic or sociological method of studying these animals in which they tried to understand the whole species society and all the relationship in the society. So they started out really early on to document all the individuals and the relationships between those individuals, and they realized much earlier than the western scientists that the females had a large role in power relationships in these Japanese macaques that they were studying. They really tried to understand all the relationships and they didn’t have this same preconceptions of passive females. It’s also in their culture that they have female goddesses that have a lot of power and that might also be influencing their perceptions of females.

0:20:30.4 AS: That’s so fascinating because in my experience at least, scientists don’t often think of their work as being cultural. Many might say that they sit outside culture because they’re making universal empirical observations about the world, but you are very insistent in your book that we need to understand our cultural context when we’re observing other animals.

0:20:53.7 MA: I think that these kind of detailed histories of how certain scientists come to know certain things and placing those knowledges in their context, in the lived experience of the scientists, explaining why these were the persons who realized that females were active. I think that might change the way that scientists are viewing their own knowledges. I think that feminist science philosophers work are important to understand how we can see science as a cultural process. Even if we do make a discovery, it doesn’t become knowledge until the scientific community in which we belong to have received this as knowledge. We have to persuade others that the discovery we made is important to this field, and in that way, all science is cultural.

0:21:56.2 AS: And certainly, throughout your book, one of the strands that you have is that you interview very many scientists, including very famous feminist scientists like evolutionary biologist, Patricia Gowaty and Sarah Blaffer Hrdy, who is very famous for overturning preconceptions about primates, female primates and things like motherhood and sexuality. How does that feminist science approach then differ from the approach of traditional science as we might call it?

0:22:27.9 MA: I think feminist scientists are often reflective about the biases in the field they’re working, but also the possible biases that they may well themselves carry and therefore they may make extra controls in their experiments, and they also have a relationship to this feminist philosophy of science.

0:22:53.2 AS: And in that sense, they’re really bringing in the social sciences into the science then?

0:22:56.9 MA: Absolutely. But I also found that there are many different ways to come to the knowledge about active females. It’s not only… I mean these feminist scientists have been really important for shifting these perceptions, but there are also other ways in which scientists have come to the same conclusion. One example is Randy Thornhill, which I thought was interesting because he has both presented this female centered hypothesis, the cryptic female choice that females may influence which sperm fertilizes their eggs, and at the same time, he has also published this book, the Natural History of Rape, which was very much criticized both from feminists and from social scientists and also evolutionary biologists. So this was a bit of a conundrum to me, but when I interviewed him, it turns out that he has watched these hanging flies and he watched the males coercing the females into mating, but he also noticed how the females were having their strategies of disrupting these matings and influencing in different ways which sperm came to fertilize their eggs.

0:24:10.4 AS: That example is interesting because it does kind of highlight that depending on the species that you as a researcher are is focusing on, it’s very easy then to make generalizations, which once they’re out in the public, can have huge repercussions for how the public think about themselves, how we as humans think about ourselves. So you have to be quite careful there then I would think?

0:24:34.4 MA: Absolutely. There is a tendency for biologists to think that their language doesn’t matter so much, that how we use language within our science is something that we share between other scientists. But it’s absolutely very important what kind of language we use for describing behaviors.

0:24:56.6 AS: Your book seems to start with the assumption that there is something of a sexual binary in nature. You’re showing how studies have extended from males to females, but not beyond that. Later in this podcast series, we’ll be looking at sex and gender in a more expansive way. Do you see this as another frontier for evolutionary biology, to think beyond that sexual binary of male and female, or is that unlikely in your view?

0:25:23.7 MA: I’ve been working with trying to kind of expand the notion of biological sex towards a dynamic view of sex in which all this knowledge about variability and sex, sex changing fishes and temperature dependent sex determination, and for example, some turtles in which the egg is not sexed from the beginning, but they develop their sex due to the ambient temperature, and how we can kind of include all of this in our notion of what biological sex is and that that is dynamic to begin with. I do see new models in which either sex is not the starting point or the stereotypical notions of of sex and sexuality are challenged. For example, there’s a paper on a new way of thinking about how sexuality has changed over time. Traditional models take heterosexuality as the starting point and then they try to explain how same sex sexuality has developed in different lineages. But this new model has this idea that perhaps the starting point is that individuals are bisexual and then this same sex sexuality has been part of the evolution from the beginning, and then we need to explain how this has been lost.

0:26:53.2 AS: That’s amazing. Marlin Ah-King, thank you so much for your time.

0:26:58.0 MA: Thank you.

0:26:58.7 AS: And thank you where you are for listening. I’m Angela Saini, and in the next interview of this series I’ll be speaking to Dorothy Roberts, author of Killing the Black Body.

0:27:07.7 SC: Don’t touch that button or dial, real or virtual. We’ve got beer and paintings and proteomics up next.

[music]

0:27:22.0 SC: In Science Advances this week, Fabiana Di Gianvincenzo and colleagues write about using proteomics to detect proteins from yeast and cereal grains in paintings from the Danish Golden Age. The combination of proteins actually suggest beer was used to prepare the canvases. Fabiana is here to tell us about this technique and about the relationship between beer and painting in early 19th century Denmark. Hi Fabiana. Welcome to the Science Podcast.

0:27:50.0 Fabiana Di Gianvincenzo: Hi Sarah. Thank you for having me.

0:27:52.8 SC: Oh, sure. So before we get into the specifics of beer and painting and proteomics, well, let’s talk a little bit about what you do. You’re a heritage scientist. Can you tell me a little bit about this field and and how it’s different from say, historical preservation or just archeology?

0:28:07.8 FG: It’s very hard to draw a line somewhere, and heritage scientists themselves sometimes have trouble doing this. But in general, heritage science is an interdisciplinary field which merges the use of natural sciences and in my case in particular, analytical chemistry, with the study of cultural heritage, and in particular, what materials were used to produce cultural heritage, how they age, how they are preserved in times and how to improve their presentation in time for the next generations basically.

0:28:39.0 SC: Proteomics, like most things that have omics at the end, is basically looking at across an entire sample, an entire cell, and it just tells you every single protein that can be identified, that can be detected. In this study you did proteomics, it’s very open-ended, looking across any protein that might be present in a sample from a painting. How is that different from how people might have analyzed materials like this in the past?

0:29:06.1 FG: Proteomics is not a routine analysis for this type of materials. It has been applied to cultural heritage and archeological materials and paintings only in about the last 20 years. It’s still a lot more usual to use techniques that are, let’s say, more targeted. There are techniques that are very common in heritage science that basically look for protein materials in a selected range. So for example, you select the three materials that are more conventional and then you look for those three specifically. Instead, using proteomics, we can look at all the proteins that are in a sample. This means that we are not limited to what we expect, but we can see anything that is there.

0:29:48.7 SC: For example, you mentioned in the paper that the more limited method might say we’re gonna look for collagen or we’re gonna look for egg, ’cause those are materials that you know are already in books and paintings. But if you use proteomics the way that you did, you can say, show me everything you have and then try to find what those proteins identities are in various databases?

0:30:10.9 FG: Yes, exactly.

0:30:12.6 SC: Why did you pick the paintings that you looked at?

0:30:16.6 FG: One of the questions that we had during this study was also to try and look at what materials were used specifically at the Royal Danish Academy of Fine Arts. The two painters that we studied, Eckersberg and Købke, were both associated with the academy in different ways. Eckersberg was professor and Købke was a student, and we know that the academy would provide some materials for the professor, students that worked there. So we selected some paintings that they produced while they were affiliated at the academy and after they were not affiliated with it anymore so that we could compare the recipes used inside the academy and outside the academy.

0:30:53.7 SC: And did you find a difference?

0:30:55.4 FG: We did see a pattern of use of this brewing material. We only found this proteins associated with the brewing material in the paintings from the academy.

0:31:05.8 SC: Okay. Onto the beer. Why did you think that there might be beer proteins in the paintings that you looked into?

0:31:13.5 FG: We didn’t expect this at all at the beginning. It was quite a surprise actually. But we found proteins from cereal and baker’s yeast. And after going through the range of possible materials that could have been used in this case, we thought that the most likely one was something coming from brewing.

0:31:33.2 SC: From beer brewing, yeah.

0:31:35.4 FG: Yes. So it might be beer or we think even more likely a byproduct of brewing like, residual yeast. This was also present in some of the recipes from the time as we found thanks to the great team of also conservators and curators and historians that was working with us.

0:31:53.4 SC: You said it was unexpected that there was beer in this painting, but beer was actually really important at this time in Denmark.

0:32:00.4 FG: Beer was absolutely fundamental in 19th century Denmark. It was such an important part of the society and the economy and the culture also. It was so important that beer itself was used in some cases to pay salaries, and residual yeast was also used as a commercial product sometimes. It could be commercialized.

0:32:20.2 SC: So you made these mockups to kind of allow you to further experiment on what’s happening in these paintings that are a little bit too precious to keep touching and and extracting from. So how exactly does the beer layer fit in with preparation of these canvases or making these paintings?

0:32:38.2 FG: What we think is that, and this is very heavily based also on the results that we got from the mockups, is that this material was added to make it a more uniform layer. In the ground layer, we have results both from our study and from some other previous studies which looked at other types of materials. So instead of proteins, for example, they looked at lipids. And what we saw when we were making the mockups is that these materials do not necessarily mix well together. Having something like beer or even better, in our experiments, the residual yeast, helped keep this material together and made it very very uniform, very smooth, and it remained in a very good condition also after drying, whereas other materials that we tested, once they were dry, they were all cracky, more fragile.

0:33:26.3 SC: So you have canvas, you stretch it, then you apply something to it to kind of make it interact with the layers that are above it, that are of the painting to make them behave and not just soak right into the canvas and disappear?

0:33:37.8 FG: Yes, that’s basically the principle. You use it to improve the interaction between the paint and the support, in this case, the canvas.

0:33:45.5 SC: I know that proteomics requires you to destroy a small bit of sample, but do you think that something like this should be applied to other artworks to look for more surprise ingredients?

0:33:56.6 FG: I definitely think that this should be applied to other paintings. Just like we were not expecting to find this material, there might have been other paintings that either contain a material like this or contain a different materials that we don’t know or we don’t expect, or there might even be paintings that have been studied in the past with other techniques that couldn’t have found anything like this. I definitely think that it’s worth looking further, studying more paintings as much as possible. Given that, as we mentioned before, this is a destructive technique, but this could give us so many answers and it could be so helpful and it could then evolve into then maybe using non-destructive technique.

0:34:34.8 SC: So what could you do to make this technique less destructive, make it a little bit less invasive for paintings?

0:34:42.8 FG: There are definitely improvements that can happen on the instrumental level. Luckily, progress on the instrumental level and on the hardware in general for these types of analysis as going so so fast. The machines are getting better and better every year, which is already a big progress for us because it allows us to see much smaller amounts of material and therefore using much smaller samples. But there’s also a lot of study being done on ways to get proteins from objects without actually removing a sample. We also tried to study, in this work, the results from a different point of view. So instead of just using the proteomics approach, we used the data that we had already produced to also look for smaller molecules using a metabolomics data analysis approach, and we did manage to find something. We cannot be 100% sure about this because, as I said, it’s not what we were targeting, but it’s still an interesting starting point and it’s something that should also be studied further also related to the minimizing the impact, the physical impact of sampling, for example. If we could get more information from using one sample and doing, for example, one chromatographic and mass spectrometric run, but we can still get double information from it, we are learning so much more.

0:36:00.0 SC: It’s like a duplex. So you take your sample, you run it through specific machines, you get your readings and you apply one type of analysis to those readings and you get your proteomics. And then you apply a different type of analysis to that reading and you get these small molecules. And then you can take those and look at different databases and know a lot more about not just the proteins, but also any metabolites or small molecules that are picked up by these techniques?

0:36:26.7 FG: Potentially, yes, that’s exactly it. And this needs to be optimized, but what we did was a starting point and hopefully it will be developed further in the future.

0:36:38.7 SC: This application of beer to these paintings doesn’t just tell us something about these master painters. It also tells us something about the town and how important this particular resource was, how much beer stuff was going on. It kind of connects the painting, the practice of painting and as well the context of the society around it. Is that something that you’re hoping to do more of as you expand this approach?

0:37:05.3 FG: Absolutely, yes. This is one of the things that we loved the most about finding this results. If we based our knowledge of artistic production on manuals or on just studying the most important literature resources, it seems like artistic production is something not standard, but let’s say they do rely heavily on a limited range of materials. When instead we start to look more into the details into local traditions, in particular into the connections with culture, we see that art production was very much bound to this and very closely connected to this clearly. And this is an example of the use of a beer brewing material, and it could be an example for other types of materials elsewhere and in other places, in other context.

0:37:49.4 SC: Thank you so much, Fabiana.

0:37:52.3 FG: Thank you so much to you, Sarah. This was great.

0:37:55.8 SC: Fabiana Di Gianvincenzo is a postdoc in Heritage Science at the University of Ljubljana, Slovenia. The work we talked about was actually conducted at the Globe Institute, University of Copenhagen. You can find a link to the Science Advances paper we discussed at science.org/podcast.

[music]

0:38:14.2 SC: And that concludes this edition of the Science Podcast. If you have any comments or suggestions, write to us at [email protected] You can listen to the show on our website, science.org/podcast, or search for Science Magazine on any podcasting app. This show is edited by me, Sarah Crespi and Kevin McClain with production help from Podigy. Jeffrey Cook composed the music on behalf of Science and its publisher, AAAS. Thanks for joining us.

doi:10.1126/science.adi8761