SPEAKER_1: Welcome to StarTalk, your place in the universe where science and pop culture collide.
SPEAKER_1: StarTalk begins right now.
SPEAKER_1: This is StarTalk.
SPEAKER_1: I'm your host, Neil deGrasse Tyson, your personal astrophysicist.
SPEAKER_1: And today we're gonna talk about ancient climate change.
SPEAKER_1: Ancient as in during the time we've been human, and maybe even a little bit of our pre-human ancestors.
SPEAKER_1: And what impact does climate change have on our diets?
SPEAKER_1: What did they eat?
SPEAKER_1: And was it good for them?
SPEAKER_1: Okay, I don't have any expertise in this at all, other than the fact that I eat food.
SPEAKER_1: So we brought in an expert for this.
SPEAKER_1: But before we introduce that expert, let me show you my cohost for today.
SPEAKER_1: Matt Kirshen, Matt, welcome back.
SPEAKER_1: Welcome back.
SPEAKER_3: Hey, thanks, Neil.
SPEAKER_1: Dude, dude, are you still doing that show, Most Likely Could Be Science?
SPEAKER_3: It's probably science.
SPEAKER_1: Probably, you know, I don't know why I cannot remember that.
SPEAKER_3: It's amazing.
SPEAKER_3: You're so good at remembering so many facts, that one seems to slip your mind every time.
SPEAKER_3: I don't know if you saw, by the way, my, you got a shout out from my cohost on Jeopardy last month.
SPEAKER_1: Oh, really?
SPEAKER_3: Andy, my, the other ProbablyScience host, had a, he did all right.
SPEAKER_3: He did us proud on Jeopardy.
SPEAKER_3: Oh, he was competing.
SPEAKER_3: He was a contestant.
SPEAKER_3: He was competing, yeah.
SPEAKER_3: And one of his anecdotes, one of his little bits of information was about the podcast and dropped the fact that you were at one point in his living room as a friend of the show.
SPEAKER_1: Well, excellent, excellent.
SPEAKER_1: So now I gotta remember it exactly.
SPEAKER_1: Okay, ProbablyScience, very good.
SPEAKER_1: Very good.
SPEAKER_1: So Matt and I will welcome today someone I met through someone else at the American Museum of Natural History, which it's an institution.
SPEAKER_1: Yes, we have astrophysicists there, but mostly they're like people who care about like cultures, anthropology, animal kingdom.
SPEAKER_1: And so there's a whole other place where I get some sort of osmotic thoughts about just what's going on in the rest of the scientific universe.
SPEAKER_1: And we have with us Tina Lüdecke.
SPEAKER_1: Did I say that right, Tina?
SPEAKER_4: Lüdecke, almost, but no American can, so don't be mad about that.
SPEAKER_1: Lüdecke, Lüdecke, Lüdecke.
SPEAKER_1: Excellent, excellent.
SPEAKER_1: We have you on this show today because you are a geochemist and you're dialing in from Germany.
SPEAKER_1: You're a geochemist and you focus on reconstructing paleo-ecosystems.
SPEAKER_4: Paleo-ecosystem, paleo-diets, paleo-everything basically, yep.
SPEAKER_1: So you're a Sherlock Holmes of their lives.
SPEAKER_4: Okay, yes, I take that.
SPEAKER_1: Okay.
SPEAKER_1: Okay, because they didn't have books for you to read about what they did, so you have to piece together the artifacts and reconstruct what was going on in everyday occurrences, right?
SPEAKER_1: That's what you do?
SPEAKER_1: Okay, so your current title is, I mean, read my notes here, you're a postdoc at the Schneckenberg Biodiversity and Climate Research Center in Frankfurt, Germany.
SPEAKER_1: Excellent, excellent.
SPEAKER_1: And you're also affiliated with the University of Oxford over in England and the Max Planck Institute for Chemistry.
SPEAKER_1: Exactly.
SPEAKER_1: In Mainz, Germany.
SPEAKER_1: How did I do?
SPEAKER_4: That is correct.
SPEAKER_1: Did I get a B plus?
SPEAKER_4: You do, yes.
SPEAKER_4: Well, it's difficult with all those things.
SPEAKER_4: I'm just about to switch jobs, so it's, yeah.
SPEAKER_4: It's not from...
SPEAKER_1: Don't switch jobs, we just worked on this.
SPEAKER_4: No, no, from Sankenberg, from my main affiliation, I would say, from Sankenberg to the Max Planck Institute.
SPEAKER_1: Oh gosh, it was shifting, okay.
SPEAKER_4: You have everything, I'm just switching.
SPEAKER_1: Don't change job titles, because then we worked hard on this one, for our sake.
SPEAKER_1: So tell me about your research, because we were at a gathering of museum colleagues, and that's when I learned more fully what you were into, and I said, whoa, we gotta get that on StarTalk.
SPEAKER_1: And so tell me what your research entails, and how do you piece together what ancient people ate?
SPEAKER_4: So basically my main research lies in the reconstruction of four to one million year old South African Palio landscapes.
SPEAKER_4: So a timeframe we can't even usually cope if you don't have an idea.
SPEAKER_1: Four million years old?
SPEAKER_4: Four million years old are my oldest samples, yes.
SPEAKER_4: My oldest samples are 12 million years, but I will not talk about these here.
SPEAKER_4: So human evolution, it's a really interesting time between four and one million years old, because a lot of things happened.
SPEAKER_4: We had a lot of different hominins in Texas and Texas that co-existed, so they lived in the same habitat.
SPEAKER_1: Okay, when we say hominid, Texas, okay, so you mean, so we are humans.
SPEAKER_1: Well, let me back up, just tell me if I got this right.
SPEAKER_1: When we think of rodents, we can think of rats and mice and dozens of other species within the rodent family, right?
SPEAKER_1: So are we in the hominid family, but we only have one species?
SPEAKER_1: Is that correct?
SPEAKER_4: In the hominid, we only have one species.
SPEAKER_4: Terms are changing there quite often, but in the hominid taxa, we are the only remaining species.
SPEAKER_1: Okay, so you're going back to a time where there were more than what we call humans as hominids walking around.
SPEAKER_4: So we have homo and australopithecus, panthropos, adipithecus, for example.
SPEAKER_4: They all co-existed at some point in time and space possibly.
SPEAKER_1: Okay, so in the hominid family, or you said the word changed, just so I can be-
SPEAKER_4: Yeah, hominid is basically, that would nowadays also mean great apes, like orangutans or gorillas, chimps and everything, and all their ancestors.
SPEAKER_1: Matt, I knew an ape one time, and I thought he was a great ape.
SPEAKER_3: I thought he was a good ape, I thought.
SPEAKER_3: I'm still sort of coming to terms with the fact that there were so many of them living at the same time.
SPEAKER_3: Because I'm picturing the picture that we've all seen of the sort of the going from this to da, you know, a lot of people are listening to the audio version, so they won't see what I'm doing.
SPEAKER_3: But you can imagine what I'm doing.
SPEAKER_3: I'm hunched over, and then I'm standing more and more.
SPEAKER_3: There we go.
SPEAKER_1: Yeah, and then you start crouching back over again over your computer, yes, okay.
SPEAKER_3: Which is what I'm doing right now.
SPEAKER_1: A full evolution of it all.
SPEAKER_4: But it wasn't that linear, so basically that's why we don't even…
SPEAKER_3: And then we end up as just brains and jaws.
SPEAKER_4: Brains and jaws are very important.
SPEAKER_1: But yeah, it's very important, Tina.
SPEAKER_1: You're saying it was not linear, so there are times when multiple homo species were coexisting, and that's hard to picture because look how tribalized we are just as one species.
SPEAKER_1: Imagine if there were other hominids walking around.
SPEAKER_1: I mean, I can't even picture how we treat each other.
SPEAKER_4: And we call it even not a family tree really anymore, but many people like to call it a family bush, basically, because there are so many branches.
SPEAKER_4: And then of course, new species evolved, others went extinct.
SPEAKER_4: So you have the come and go of many species.
SPEAKER_3: Two of them became president, one tried and failed.
SPEAKER_1: So, this is before what we would consider today as anatomically accurate humans, is that correct?
SPEAKER_4: Modern humans, you would say, yes.
SPEAKER_4: Yes.
SPEAKER_1: Modern humans.
SPEAKER_1: Okay.
SPEAKER_1: Okay, so now, so this is the paleo era.
SPEAKER_1: Okay, that's cool.
SPEAKER_1: So now what did you find?
SPEAKER_4: So basically, I tried to reconstruct how paleoenvironment changed.
SPEAKER_4: So how did the landscape, the habitat and everything change over time?
SPEAKER_4: And with that, like how did the hominins change, especially their diet, which is the main driver for evolution, of course, like the energy you put in, you can use for something basically.
SPEAKER_4: So and as a geochemist, my favorite tools are stable isotope systems.
SPEAKER_4: So I work with isotopes, which means I basically different isotopes of different elements can like fingerprint different settings, different environmental proxies or what somebody ate.
SPEAKER_4: So I look at carbon, oxygen and nitrogen.
SPEAKER_4: And for example, carbon isotope systems can tell me what kind of plant was growing on a site or what kind of plant an animal ate, also early human, for example, ate.
SPEAKER_1: So I think I think Whole Foods now has an isotope section.
SPEAKER_5: I only buy the heavy stuff.
SPEAKER_3: It does sound very much like something that's represented by a glowing image in an advert.
SPEAKER_1: But that too, yeah, the glowing aisle.
SPEAKER_1: These are the isotopes if you want to totally mimic.
SPEAKER_4: I don't think that actually exists yet.
SPEAKER_4: That would be fun to just buy, for example, water.
SPEAKER_4: Water tells us about what kind of water is present.
SPEAKER_4: So oxygen in the water shows us, for example, is the water from a small puddle of leftover rain basically that evaporated and you only have a little bit of water remaining in a super arid environment, for example.
SPEAKER_4: Or is it from a river or a big lake that is present all year round in a music house?
SPEAKER_1: Okay, so this is deep.
SPEAKER_1: So what you're saying is, again, I'm only repeating so I make sure I understand.
SPEAKER_1: And so oxygen, as we know, it has sort of eight protons and eight neutrons in its nucleus.
SPEAKER_1: So we think of happy oxygen as oxygen 16, right?
SPEAKER_4: That is the one we learn in school, yes.
SPEAKER_1: That's the one we learn about in school.
SPEAKER_1: And then you can find versions of oxygen that have extra neutrons.
SPEAKER_1: One of them has eight neutrons and eight electrons and ten neutrons.
SPEAKER_1: This would be oxygen 18, right?
SPEAKER_1: So now if you make water, because hydrogen doesn't care, it just cares that it's oxygen, right?
SPEAKER_1: So hydrogen binds with the oxygen.
SPEAKER_1: Some of them will be bound with oxygen 18, others with oxygen 16.
SPEAKER_1: And now the water is just standing there, and you have slow evaporation.
SPEAKER_1: So is it correct to think that the lighter water molecule will evaporate preferentially relative to the heavier water molecule?
SPEAKER_1: So that standing water will ultimately have more oxygen 18 water molecules than fresh water that just came in.
SPEAKER_1: Did I get that right?
SPEAKER_4: And then if you, for example, drink from that water, and I pull your tooth out and measure it, and I can see on this...
SPEAKER_1: You just do this.
SPEAKER_4: I do that all the time.
SPEAKER_1: I'm not visiting your lab.
SPEAKER_4: Okay.
SPEAKER_4: Let's say, let's say, you might not be here anymore, and you get fossilized.
SPEAKER_1: I want to die first, and then you can pull my teeth out.
SPEAKER_4: And then in four million years, I will come, and I will find your tooth, and your tooth is so resistant to diagenesis, so to doing processes of fossilization, basically, that your isotopic fingerprint is still present in your tooth.
SPEAKER_4: So four million years later, or even 20 million years later, if preservation is well, I can see what kind of water you drank.
SPEAKER_4: So did you live in New York and you drank from the Hudson River, or did you live in the Savannah and you have a tiny puddle of just a little bit of standing water full of mosquitoes and bugs?
SPEAKER_1: Wait a minute, so you had, so you already, you can identify Hudson water.
SPEAKER_1: Which isotope is that?
SPEAKER_4: Okay.
SPEAKER_3: You don't want to know.
SPEAKER_4: Now we get really deep.
SPEAKER_4: So it's, I mean, you can, with isotopes, you can actually see where a product came from in soil and in something.
SPEAKER_4: I was, I would not be able to right now have 10 samples and pick out which one is Hudson River and which one is the East River or anything.
SPEAKER_4: But all I'm saying is I can see what kind of water it has.
SPEAKER_4: Like if it's evaporative water or if it's in a lush bean landscape, basically water that is available all over the place, which is of course for our human evolution quite interesting if those early hominins had a lot of water stress and they had to migrate long distances or they, I don't know, they couldn't find any water and would maybe.
SPEAKER_4: I am a geologist actually.
SPEAKER_4: I am a geosciences by training as my undergrad and then I focus on geochemistry a long time ago, like a long time in my time frame, not in geological time frame.
SPEAKER_1: She was there when I'm the last 10 years in the last 10 years.
SPEAKER_1: So so when we hear the paleo diet, which is showing, it rears its head every now and then.
SPEAKER_1: And my first thought is, you know, paleo people didn't really live much past 30.
SPEAKER_1: Do I want to eat the way they do?
SPEAKER_1: Why is that something we should?
SPEAKER_1: So tell me, what is the what is the I don't want to ask a health food person.
SPEAKER_1: I want to ask you, what the hell is a paleo diet?
SPEAKER_4: And that is a question that we there is no paleo diet, I think.
SPEAKER_4: So if you think about I just talked about three to four million years time span and early hominins that evolve, that lived in different areas and different continents, basically, in younger times, they expanded to Europe and everything.
SPEAKER_4: So they had really different resources available and everything.
SPEAKER_4: So if somebody talks about the paleo diet, I always think, how paleo do you want to go?
SPEAKER_4: Like how far back do you want to go?
SPEAKER_4: Do you want to eat like an oestrolopithecus three million years ago?
SPEAKER_4: Or, I don't know, Neanderthal, which is not that long ago, but lived in a very different, very different environment, nevertheless.
SPEAKER_4: So for me, it's always really difficult to understand the paleo diet.
SPEAKER_4: And if I then read up on it, which of course I should, because I get this question sometimes, then I was thinking, another point is you can't get a paleolithic diet.
SPEAKER_4: So we modified our food so widely, like plants, but also animals were manipulated, basically.
SPEAKER_4: If you think about a banana, for example, it used to look very, very different.
SPEAKER_4: Now we have those beautiful bananas, but they can't even reproduce.
SPEAKER_4: They don't have seeds anymore.
SPEAKER_4: And while a meal that for our ancestors was healthy because they were running around in the savanna, they were hunter and gatherers, they were outside all day long, they didn't necessarily became that old, but they were really healthy.
SPEAKER_4: They had a good nutrition.
SPEAKER_1: They were vital.
SPEAKER_4: They were vital, exactly.
SPEAKER_4: They thrive usually and everything.
SPEAKER_4: And then we started this agricultural lifestyle, basically, which was in a way awesome for us because it was possible to, it made our population explode, basically.
SPEAKER_4: Suddenly you had crops, you could maintain food, you could store it often if you're at one place and everything.
SPEAKER_4: But of course, then people were also getting more obese, they had cavities, they got sickness by living together in close proximity with animals, for example, and all of this.
SPEAKER_1: We even had to invent a word to describe when everybody gets sick from having getting a disease from animal.
SPEAKER_1: Pandemic.
SPEAKER_4: Very present this year, yes.
SPEAKER_1: We got to take a quick break, but when we come back, more of Tina Lüdecke.
SPEAKER_4: Not bad.
SPEAKER_1: Who's our paleo expert in the house and we'll see you guys in just a moment.
SPEAKER_5: Hey, I'm Roy Hill Percival, and I support StarTalk on Patreon.
SPEAKER_5: Bringing the universe down to earth, this is StarTalk with Neil deGrasse Tyson.
SPEAKER_1: Thanks for listening.
SPEAKER_1: We're back, StarTalk.
SPEAKER_1: We're talking about the paleo diet and paleoclinic, with Tina Lüdecke.
SPEAKER_1: Did I get that right, Tina?
SPEAKER_4: Almost, Lüdecke.
SPEAKER_1: Almost, okay, we'll keep working on it.
SPEAKER_1: And of course, Matt Kirshen as my cohost.
SPEAKER_1: Always good to have you back, Matt.
SPEAKER_3: Lovely to be here.
SPEAKER_1: We're thinking about the paleo, paleo, Tina, what do I call that period of time?
SPEAKER_1: Paleo-
SPEAKER_4: Paleolithic, or neo gene.
SPEAKER_1: Neo gene, paleolithic, okay.
SPEAKER_4: Neo-paleolithic, we have lots of different terms, a lot of different spans.
SPEAKER_1: Okay, all right, I'll go with it.
SPEAKER_1: I'll take them all.
SPEAKER_1: And so in there, you're thinking about not only climate, but environment in which our ancestors lived.
SPEAKER_1: I'm intrigued because when people say, I wanna go on a paleo diet, and you're telling us that different places had different diets, so there is no one paleo diet.
SPEAKER_1: And so you are figuring this out from your scientific investigations.
SPEAKER_1: You told us about the oxygen and isotope of oxygen.
SPEAKER_1: Carbon, also we all know carbon-14, right?
SPEAKER_1: That's a famous carbon isotope.
SPEAKER_4: So maybe you noticed that so far, I only talked about the plant-based diet, right?
SPEAKER_4: So with carbon, I can look at what kind of plants we're eating.
SPEAKER_4: And nitrogen is actually a great tool to reconstruct the meat-based part of the diet.
SPEAKER_4: So it was meat consumed by the individualized sample.
SPEAKER_4: And we see with each trophic level, basically, the delta-15N values would increase.
SPEAKER_1: So this would be nitrogen-15, which is the isotope of the happy nitrogen at 14, which is seven protons, seven neutrons.
SPEAKER_1: Okay, so you look at the ratio of those two, and what does that tell you?
SPEAKER_4: Exactly, so this usually tells me trophic level.
SPEAKER_4: So was meat consumed or not?
SPEAKER_4: And here, it's interesting.
SPEAKER_4: So this system is well-established.
SPEAKER_4: I mean, there is always loose ends about it, but it's well-established, but it was only possible to measure, actually, on samples that were up to 150,000 years old, basically.
SPEAKER_4: So some of the underthals were measured, for example.
SPEAKER_4: But 150,000 years, and I just said, I wanna look at millions of years.
SPEAKER_4: So I was always bothered by the fact that I could reconstruct, and since, like, in really early hominins, I could reconstruct the plant-based diet, but I could not look at the meat part of the diet.
SPEAKER_4: And we have stone tools, we have cut marks, which are, like, three and a half million years old or something, so cut marks on fossilized bones.
SPEAKER_4: So we have indicators that meat consumers started quite early in hominins, but no, it was not possible to actually look into this.
SPEAKER_1: All right, so you're inferring, correctly, no doubt, that you see bones of animals that have, fossilized bones of animals that have markings on them, indicating that someone was hacking at them, cutting, perhaps cutting away meat.
SPEAKER_3: Yeah, with some kind of tool.
SPEAKER_1: With a tool, and why would you do that unless you were gonna eat the animal?
SPEAKER_4: But that's the question, who exactly did it?
SPEAKER_4: Who, I mean, we don't find an australopithecus with a stone tool and a cut mark bone in his hand, basically.
SPEAKER_4: So we don't have direct evidence who actually did it.
SPEAKER_4: So I was really frustrated about the fact that I was not able to reconstruct the meat part of the diet.
SPEAKER_4: And then finally, this year only, actually, basically, I was able to establish a method to measure nitrogen on fossil teeth and with colleagues from the MPIC and especially Jennifer Liglietters.
SPEAKER_4: So I was able to now-
SPEAKER_1: MPIC, Max Planck Institute.
SPEAKER_4: Exactly.
SPEAKER_4: And now finally, for the first time ever, we are able to have direct evidence of meat consumption, or we can have it if we measure different hominins, of which hominins started when to include meat in the diet and what that possibly means, like for the success of our species, for example, or the extinction of other species.
SPEAKER_1: So this would have been the beginning.
SPEAKER_1: Once they figured out how to eat meat.
SPEAKER_1: Matt, do you think I'm right here?
SPEAKER_1: This is the birth of vegetarians because they don't want to eat meat.
SPEAKER_3: Yeah, I mean, I don't eat meat and I would have been very unspecial in the before carnival time.
SPEAKER_3: So what would you even talk about?
SPEAKER_3: How would you distinguish yourself at a party?
SPEAKER_4: You must become vegan then.
SPEAKER_3: How would you make yourself a nuisance?
SPEAKER_1: Yeah, they're vegans.
SPEAKER_1: Where are the vegans?
SPEAKER_1: Right, we haven't invented vegans yet.
SPEAKER_4: We basically have if you take away breast milk.
SPEAKER_4: So of course, early hominins were also not yet eating or drinking milk once they were older.
SPEAKER_4: So after weaning, after taking away the breast milk, they would also be vegan.
SPEAKER_4: You would basically have a diet like a typical have before.
SPEAKER_1: Right, so what you're saying is some paleo diets in your range of food consumption that you found would be classified as vegan.
SPEAKER_4: Mm-hmm, correct.
SPEAKER_1: Right, so this idea that paleo diet is just meat and no potatoes, that's just a misnomer.
SPEAKER_4: Yes, in a way, yes, yeah.
SPEAKER_4: You don't, there is, our stomachs and our guts, for example, are not adapted to just eat meat.
SPEAKER_4: We can't have a diet like a lion has nowadays.
SPEAKER_4: We just can't.
SPEAKER_4: So we are omnivores, we have to eat plant parts.
SPEAKER_4: And as we know, as Matt just said, he's vegetarian, and I used to be a vegetarian for 10 years, and I'm fine.
SPEAKER_1: How do you know you're fine?
SPEAKER_4: I feel okay, I didn't die.
SPEAKER_1: You could be completely different now, had you not.
SPEAKER_1: You don't know, you are just new in any moment.
SPEAKER_1: Now, actually, Matt's collected questions for us from our fan base, so this is sort of a hybrid cosmic queries, but we still have so much more we want to learn from you directly.
SPEAKER_1: But Matt, why don't we throw in a question?
SPEAKER_3: Yeah, so I've got a bunch of questions from Patreon.
SPEAKER_1: Good.
SPEAKER_3: First of all, Josh V asks, what kind of evidence is considered when determining what an ancient tribe of people regularly consumed?
SPEAKER_3: Are there remains of food from tens of thousands of years ago?
SPEAKER_1: Interesting.
SPEAKER_1: Yeah, can food get fossilized the way other things can?
SPEAKER_1: Like, can you see a whole table setting fossilized in place?
SPEAKER_4: First of all, I have to say, I really like the word regular in there.
SPEAKER_4: Oh, I hate it.
SPEAKER_4: I like it.
SPEAKER_4: I'm not sure.
SPEAKER_4: But if I think about my, like if my study to look at stable isotopes, I have one point in time from one individual, but it's actually really interesting to see what an whole tribe would eat and what it would regularly eat.
SPEAKER_4: So the actual study of food material, as you said, it's super difficult because most of the food decay.
SPEAKER_4: We know that.
SPEAKER_4: But however, if you have burned a meal, so by accidental cooking accident in your little cave or something, then material like seeds and pollen and grains can preserve super long timescales, basically indefinitely, if you have the right environment for them.
SPEAKER_4: And these plant remains, you can actually see, for example, if a crop was wild or cultivated already by the structure they have.
SPEAKER_4: That, for example, dated like the earliest domestication of rice to like 11,500 years ago in China, for example.
SPEAKER_4: But of course, that is still not the long timescale we look at because you have to find those ashes basically with the food in it.
SPEAKER_4: But then there are lots of different fun things.
SPEAKER_4: For example, coprolites are really interesting.
SPEAKER_1: What is that?
SPEAKER_4: Coprolites.
SPEAKER_4: What is that?
SPEAKER_4: That is fossilized feces.
SPEAKER_1: Keep the other name for it.
SPEAKER_4: Coprolite sounds much nicer.
SPEAKER_1: Sorry, I asked.
SPEAKER_4: So you have fossilized feces.
SPEAKER_4: And you do have wonderfully preserved coprolites, where you can, of course, do different chemical or other analyses with them to see what the animal ate, digested and then left behind, basically.
SPEAKER_1: Yeah, I think there's a good scene in the original Jurassic Park film, where one of the scientists was an expert in studying the feces.
SPEAKER_1: And so the animal keeps moving, and it's still kind of steaming, right?
SPEAKER_1: And then it would reach in, and we're all just kind of looking at that.
SPEAKER_1: But I'd forgotten that, yeah.
SPEAKER_4: It doesn't stink anymore 42 million years later.
SPEAKER_4: That's a good part.
SPEAKER_1: I don't believe you.
SPEAKER_4: But then we also have, of course, if you think about human, like the oldest food, and there you have, for example, the oldest bread is like 14,400 years old in Jordan.
SPEAKER_4: So that is even older than the start of archaeology.
SPEAKER_4: So you made it with vile cereals.
SPEAKER_4: And one of the oldest things I can think about right now is wine.
SPEAKER_4: So in Georgia, wine was produced 8,000 years ago.
SPEAKER_1: Just outside of Atlanta, I think, in Georgia.
SPEAKER_1: That's where they did that.
SPEAKER_4: The other one.
SPEAKER_1: The other one.
SPEAKER_4: There's a Merker.
SPEAKER_3: I heard 5,801 BC was a particularly good vintage.
SPEAKER_4: Really sunny, really nice, but it's quite expensive.
SPEAKER_1: So you have a lot of access points into what we did.
SPEAKER_4: Into, for me, which is the really young past, basically.
SPEAKER_4: Again, if I think about million of years ago, it becomes, I mean, calculates, as I said, or you can have the dental calculus, which can have like pollen or even DNA structures of whatever you ate.
SPEAKER_4: But of course, something like the wine or the bread or some super old cheese from Egypt, for example, that is, of course, something what I consider just yesterday, from yesterday, basically.
SPEAKER_1: Right.
SPEAKER_1: And in another 100,000 years or so, your descendants will look at the North America and what was once the United States, and they'll find perfectly intact Twinkies.
SPEAKER_4: Don't like burgers also stay, like McDonald's burger, like forever.
SPEAKER_3: I believe so.
SPEAKER_1: So whether it can be preserved is a whole other thing because that changes, whether it was preserved is another sort of effort to make that happen.
SPEAKER_1: Matt, give me another question.
SPEAKER_3: This comes from Leslie Goodwill, but actually from Leslie's daughter, Trinity, who asks, how does the change in diet, parentheses cooked food, impact upon human development?
SPEAKER_3: Can this be applied to other animals?
SPEAKER_3: Thank you.
SPEAKER_1: So Tina, that question reminds me that today, among the many sort of paths of diets that people take, one of them is the raw food diet.
SPEAKER_1: And so I never really understood that because I think the food tastes better if you cook it.
SPEAKER_1: But I think this is a brilliant question from Trinity, I guess, ask that.
SPEAKER_4: Yeah, I agree.
SPEAKER_4: It's very interesting.
SPEAKER_4: So if you cook food, you break up, for example, the starches in potatoes or something, into easily available energy-rich sugars.
SPEAKER_4: So you still have the same stuff in your potato, but it's easily accessible for your body, and you can actually use it.
SPEAKER_4: And so when cooked, you have a higher energy output of the same food product, basically.
SPEAKER_4: So if you think about early hominins, which are like, they have these brains that grew over time and they developed, they have lots of babies and fetuses and everything.
SPEAKER_4: So you would think about you have access to food that has higher energy, basically.
SPEAKER_4: So you spend much less time of actually eating, collecting.
SPEAKER_4: I mean, you spend time on preparing food and pounding and cutting and cooking, of course, but you would then have more of it.
SPEAKER_4: So you have more time for social behavior, for grooming.
SPEAKER_4: I just think about...
SPEAKER_4: I was with primatologists in Mozambique in the Gorongongo National Park, and they look, they study baboons, and they took me a day on a field trip, basically, and I was giving a chart with the checklist, and you would see what an animal and baboon does all day long.
SPEAKER_4: And I had this checklist, and it ate and ate and ate.
SPEAKER_4: It just sits there and eats.
SPEAKER_4: It has not that much time for anything else.
SPEAKER_4: So for us, we then had, we had lots of energy to actually change our morphology, basically, to grow bigger brains, to have more kids.
SPEAKER_1: Did I hear Tina correctly, Matt?
SPEAKER_1: Didn't she just say that had the baboon been given higher energy food, it would have time to build spaceships and construct and create a whole civilization?
SPEAKER_1: I think that's what she just said.
SPEAKER_3: I think so, and that also worries me, because I'm still in lockdown and I'm just eating and eating and eating, so I'm pretty worried about being overtaken by the baboons.
SPEAKER_1: So, Tina, what you're saying is, what percentage of your life do you spend tracking down food to eat?
SPEAKER_1: Then that's all you do for your survival.
SPEAKER_1: There's no free time, there's no leisure time, you can't think up algebra, there's no luxury of thought that doesn't contribute to your own survival.
SPEAKER_4: And of course, the own survival is also given by having kids, and we still benefit from this cooking of meat.
SPEAKER_4: If you think about, we only breastfeed for a year on average or something like this, and modern humans can have kids easily a year and a half apart.
SPEAKER_4: So my older sister is only one and a half years older than I am, and that is quite okay and normal.
SPEAKER_4: If you look at chimps, they're usually five years apart.
SPEAKER_4: But we have the advantage, we cook our food, we can mush it, we have all this energy in it.
SPEAKER_4: And then you would, you are able to feed your kid much earlier food, like mashed up potatoes and carrots and not just give it a potato or a carrot in the hand and let it munch on it.
SPEAKER_4: So this actually helped our species to evolve and to be successful as well.
SPEAKER_1: I think what you're really saying is it helped our species to get fat much earlier than others.
SPEAKER_4: That as well.
SPEAKER_2: As well.
SPEAKER_1: We're gonna take another quick break when we come back more of this installment of StarTalk, The Paleo Diet.
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SPEAKER_1: We're back, StarTalk.
SPEAKER_1: We're talking about paleolithic peoples, and what they ate, and how that mattered in their lives, and then how did it help the birth of civilization.
SPEAKER_1: I wanna go get back to Trinity's question about eating raw versus cooked foods.
SPEAKER_1: I think I read a book, or knew of a book, that said that cooking food meant you didn't have to chew your meat as long.
SPEAKER_4: That is also very true, you break the proteins in a meat are getting broken up already during cooking.
SPEAKER_4: So you get more out of your steak if you don't eat it raw, but if you eat it well done.
SPEAKER_1: If you break the proteins, does that change their nutritional value to you?
SPEAKER_4: It just, I think it just makes it easier, accessible for your body.
SPEAKER_4: So you can use more of the energy.
SPEAKER_1: You can use more of the energy, and you get the energy in your body faster, so that you can spend less time chewing and more time chewing and more time inventing calculus.
SPEAKER_4: For example.
SPEAKER_3: For, okay, that's it.
SPEAKER_3: That also does cover Cody Kloboski's question to an extent, which is what changed the addition of cooked meat making the diets of early hominids?
SPEAKER_3: So specifically the meat aspect.
SPEAKER_4: The meat, yeah.
SPEAKER_4: Yes, there we go.
SPEAKER_4: So I think meat, as I said earlier, I tried to really pinpoint down which taxa would eat meat and when they would start and what effect that has on evolution basically.
SPEAKER_4: Right now we think about two and a half million years ago, that's without the ability of controlled fire, meat was already part of the diet.
SPEAKER_4: But then roughly 1.9 million years ago, a dramatic change began to occur in early hominid bodies.
SPEAKER_4: So they grew larger, the brains increased a lot in size and complexity and they had adaptation for long distance running.
SPEAKER_4: And a long time it was thought that just because they had more access to meat, they had the resources basically, the energy to do all this.
SPEAKER_4: But new studies suggest actually that they had control of fire during that time.
SPEAKER_4: So they were able to cook this meat.
SPEAKER_4: So it doesn't mean they wouldn't eat more meat, but it also means they would cook the meat and get more out of it basically.
SPEAKER_1: So here's an interesting thought I think.
SPEAKER_1: All right, so right, you can't cook meat until you harness fire.
SPEAKER_1: So who had the idea when they see a burning bush and say, let me put my meat in that and then eat it?
SPEAKER_1: This is a brave person.
SPEAKER_4: But I think, I would think it would happen more like you have a wildfire and a day later you go back through it and you find a burned antelope or something.
SPEAKER_4: And then you would be like, huh, that smells tasty.
SPEAKER_4: That's what I could imagine.
SPEAKER_4: That's not my expertise.
SPEAKER_1: That's sure, that's gotta be how it happened because otherwise you can't get close enough to the fire to think that anything good is gonna happen by you interacting with it.
SPEAKER_1: But you're right, I'm hungry and there's a bang and the antelope is there and I'm hungry and it's like yum, yum.
SPEAKER_1: Let's do this again.
SPEAKER_1: Very cool.
SPEAKER_1: Matt, give me another question.
SPEAKER_3: All right, and this one, I'm guessing is a parent who's trying to get kids to eat because it's from Abhinav Abraham.
SPEAKER_3: And the question is, hey, Neil and Tina, is there any evidence of condiments being used by our early ancestors?
SPEAKER_3: Can't imagine the fuss created by the young ones to eat raw veggies and meat.
SPEAKER_2: Wow, I love that.
SPEAKER_3: That's definitely a parent.
SPEAKER_1: What's the invention of sauce and ketchup?
SPEAKER_1: Yeah, give it to me.
SPEAKER_1: What do you have?
SPEAKER_3: Salt, pepper, what have you.
SPEAKER_4: As far as I know, condiments are not really known in our early ancestors.
SPEAKER_4: I can't imagine that happened like anytime super early.
SPEAKER_4: One early condiment I can think of is garum.
SPEAKER_4: So it's produced by crushing the innards of fish and then you ferment them with salt and that enhances your flavor.
SPEAKER_4: Like you have glutamic acid basically and it enhances the flavor of your given food.
SPEAKER_4: And that was already used by like the Romans, but I think only the elites.
SPEAKER_4: So if you're super rich, you could afford this and you would pack your food with it.
SPEAKER_1: Okay, so Romans are like yesterday on your time scale.
SPEAKER_1: So it's easy to extrapolate backwards and say, no, nobody had ketchup or anything like it.
SPEAKER_4: I can't imagine, but then again, there might be just the evidence might be not there.
SPEAKER_4: It doesn't mean it's not present.
SPEAKER_4: We just haven't found it.
SPEAKER_4: So as I say, the farther you go back in time, so much difficult it will be to find like this one mustard seed that's older than 3000 years or something.
SPEAKER_1: Yeah, it might have just started out where they just put different, you know, foods have different flavors.
SPEAKER_1: And then you realize if you use one to help change the flavor of another one, that can make a whole new kind of dish.
SPEAKER_1: It could just be the food ended up touching itself on the plate, you say, hey, that's better together.
SPEAKER_1: Yeah, yeah, because, you know, kids hate that.
SPEAKER_3: Would salt be, would you be able to detect any salt in someone's diet?
SPEAKER_3: Would there be more sodium or chlorine in their bones or would, because we naturally have salt in us anyway, right?
SPEAKER_4: We would, yes.
SPEAKER_4: We have quite a lot of salt.
SPEAKER_4: And of course we know salt has been used like for fermentation and for preservation.
SPEAKER_4: There's the word, thank you.
SPEAKER_4: I wouldn't know if you would find it in your bones, basically.
SPEAKER_4: And as I said, bones are difficult because they're so porous.
SPEAKER_4: So they change during the time of fossilization.
SPEAKER_4: So it's always difficult to find anything like this out of really old fossils, basically.
SPEAKER_1: So what about vitamins?
SPEAKER_1: Obviously vitamins are a modern understanding of the needs in our foods, but paleo people obviously knew nothing of vitamins, yet so back to the previous question, if we know certain vitamins come to us from vegetables and little children hate vegetables, no reason why those children would love it and ours hate it.
SPEAKER_1: I'm guessing they hated vegetables too, but they needed it for their own health.
SPEAKER_1: Do you have any insights into the role of vitamins back then?
SPEAKER_4: I'm not sure about this.
SPEAKER_4: So I think, so I picture the kids of early hominins like chimps or something today, or as you said, they want the tasty fruit that has lots of sugar and not the boring plant with the vitamins or something.
SPEAKER_4: But I think what we lost over time a little bit is like the, sometimes you have a craving and then you really want, I don't know, a red pepper or something like this.
SPEAKER_4: So I think your body instinctly often feels what it's lacking.
SPEAKER_4: And so you have it in the wild too with animals of, yeah, some birds, some be eating salt or something because they really need it.
SPEAKER_4: So I think this natural instinct might have been more present in early hominins and then possibly they would not hate it that much.
SPEAKER_1: There's a YouTube video of goats, mountain goats, ascending the side of a dam because the minerals in the rocks are high in salt.
SPEAKER_1: And this ascending, and it's really, really steep.
SPEAKER_1: And they go up there and they start licking it.
SPEAKER_1: It was like, dude, just go to the local store.
SPEAKER_1: I'm glad we have civilization because we'd be some dead humans attempting that.
SPEAKER_3: But it's about the challenge.
SPEAKER_3: It's about the joy of getting up there.
SPEAKER_1: Oh, that's what they're telling each other.
SPEAKER_1: That's what you're sure about that, man.
SPEAKER_4: Come on, Tim, let's go up there and lick some salt.
SPEAKER_1: So Matt, give me another one.
SPEAKER_3: Okay, so this one comes from Dave Armstrong and says, let's say we have a close shave on changing our planet and we actually live through it.
SPEAKER_3: It's a relatively pessimistic view, but plausible.
SPEAKER_3: What diet changes should we be making to prepare for climate change, including agricultural processes and systems?
SPEAKER_3: What diets sustained our ancestors through tough times and what could we do to systemize them that for possible climate shift?
SPEAKER_1: Yeah, so Tina, you could be the number one source of insight that we can get when our world becomes so bad that either the animals go away or the crops go away and you'll say, well, back, you know, Lucy, the Australopithecus, she did this, so why don't we do that?
SPEAKER_4: Well, but she didn't make it, so let's do it different than Lucy.
SPEAKER_4: Yeah, I really like this question.
SPEAKER_4: It's a tough one, but it's cool.
SPEAKER_4: It's interesting because people usually think that we are such a successful species, so nothing can really happen in us.
SPEAKER_4: But if you think about it, Lucy and her whole taxa and her species and all of our other ancestors sooner or later went extinct, so they did not make it.
SPEAKER_4: So it's interesting if we think about the current climate change and what that brings with us, it's much faster than what usually happened in the paleorecord.
SPEAKER_4: So it will happen, or it already starts to happen super quick for different reasons, of course, mostly from us and dews.
SPEAKER_4: And it will be soon, it might be hotter on our planet than it has ever been during early hominin times, basically.
SPEAKER_4: So it will be new challenges.
SPEAKER_4: But so far, I think what brought us through it is flexibility.
SPEAKER_1: I only just figured out what you meant when you said, Lucy, the Australopithecus didn't make it.
SPEAKER_1: What you meant was that that entire hominin line didn't make it.
SPEAKER_1: Because if they did, they'd still be, we'd have Australopithecus living next door, right?
SPEAKER_1: If they made it.
SPEAKER_1: So whatever it was they were doing with their environment, they went extinct.
SPEAKER_4: Yes, and they just adapted in a different way.
SPEAKER_4: And one of the most keys of success for our species is thought to be the high flexibility.
SPEAKER_4: So we were able to survive ice ages, for example, and cold climate and warm climate and wet and dry climates and everything.
SPEAKER_4: Because also due to our big brains, we were able to adapt to different environmental pressures basically.
SPEAKER_4: And I think we take this now to a totally different level.
SPEAKER_4: So if you think about adaptation, or if I think about adaptation, I think about a different size of a jaw and longer legs, or something like this.
SPEAKER_4: But if you think about it today, we build greenhouses.
SPEAKER_4: We ship water, like we transfer water from A to B to water some crops.
SPEAKER_4: We, I don't know, even shoot particles in the sky to introduce rain, for example, and stuff like this.
SPEAKER_4: So we alter our environment.
SPEAKER_1: To fit us.
SPEAKER_4: To fit us basically.
SPEAKER_4: But that of course will only go to one extent.
SPEAKER_4: At some point, I think it will all be too bad.
SPEAKER_1: Is it true that you find humans in more diverse, other than some small bacteria perhaps, you find humans in more diverse environments than any other animal?
SPEAKER_4: Yes, I think so.
SPEAKER_4: I think so.
SPEAKER_4: I mean, we have, we be, and we are all like, we all look quite still alike, right?
SPEAKER_4: We should all be adapted to one ecosystem, but we make clothes and we eat different diets, possibly if we live in different regions to like, for example, to get more vitamin D if there's no sun around and stuff like this.
SPEAKER_4: So we inhabit every corner of this earth basically and no other species really is able to do that.
SPEAKER_3: Well, this also dovetails quite neatly into the final question, which is from Agastaya Suresh, says, I've seen homo sapiens referred to as the childs of the ice age.
SPEAKER_3: If we were shaped in that extreme climate, what kind of evolutionary adaptations could we expect in the future given extreme climate change?
SPEAKER_4: So actually thinking about the ice age, the climate is not even that extreme.
SPEAKER_4: So what happens during a cold phase there is so much water gets bound on the northern hemisphere.
SPEAKER_4: Basically, you have that kilometer thick ice decks, but it binds so much water that yes, it is colder, but it's also very dry.
SPEAKER_4: So you don't have this horrible icy rain that I would hate so much that even with the modern clothing, you can't really shelter from.
SPEAKER_4: So you have dry, cold environments.
SPEAKER_1: You're telling me that the famous joke about...
SPEAKER_1: Yeah, I visited hell.
SPEAKER_1: It was hot, but it was a dry heat.
SPEAKER_1: So now you're telling me, I say it was cold, but it was a dry cold.
SPEAKER_4: Which is much better.
SPEAKER_4: Did you ever wait for the bus or something for 10 minutes standing there?
SPEAKER_3: That's true.
SPEAKER_3: I've definitely been warmer coming off a ski slope and just sitting in the sun having a beer than I have back in England in the sleet and rain.
SPEAKER_1: Okay.
SPEAKER_1: So when cavemen were waiting for a bus, they would have preferred dry...
SPEAKER_4: They would have.
SPEAKER_1: That's what you're saying.
SPEAKER_1: Okay.
SPEAKER_4: And what's really interesting there during that time, you have actually a similar...
SPEAKER_4: In Europe, you had mammoths, you had woolly rhinos and lions and hyenas.
SPEAKER_4: So you have a different fauna than you would have in Africa, in the savannas.
SPEAKER_4: So people actually, early humans migrating, found a setting that they could actually work with and slowly adapt to, basically.
SPEAKER_1: Okay, so you're talking about adaption because we're smart and we can figure out how to shape an environment.
SPEAKER_1: You're not talking about an evolutionarily adaptive aspect of us, correct?
SPEAKER_1: I mean, we can adapt because we can put on a coat.
SPEAKER_1: But I think part of that question might have been, is there something in our evolutionary future?
SPEAKER_1: I think what would have to happen is, climate change would kill half the population and whoever survives, their bodies are just fine with it.
SPEAKER_1: Right?
SPEAKER_1: I mean, that's how evolution works.
SPEAKER_4: But over millions of years.
SPEAKER_4: So I think what we're thinking right now would be really, is really quick, basically.
SPEAKER_4: And I think there, the expansion of our brain and our intelligence is what hopefully will save us from this.
SPEAKER_4: So I, of course, the humans are also morphology still evolving.
SPEAKER_4: We do change.
SPEAKER_4: Our gut system changed to different.
SPEAKER_4: Yeah, this lactose intolerance, for example, is a super new trait, basically.
SPEAKER_4: And so we do evolve, we do change.
SPEAKER_4: I don't think that if the climate gets hotter by two degrees Celsius very quick, that suddenly we will all adapt to that in a way of having sales we can, I don't know, evaporate our sweat better or something.
SPEAKER_4: I don't really see that happen in the timeframes we are looking at.
SPEAKER_1: Except if we have control over the genome, then we play God, right?
SPEAKER_1: And we make whatever change we want.
SPEAKER_4: Ah, that's going to be thought out.
SPEAKER_1: I want six fingers so I can play the piano with, you know, play more keys on the piano.
SPEAKER_3: More complex chords.
SPEAKER_1: Yeah, exactly, exactly.
SPEAKER_1: See, that's in the, possibly, we'll have to bring you back and comment on that when that happens, okay.
SPEAKER_3: Yeah, can you extract nitrogen isotopes from pianos?
SPEAKER_1: That's right, the carnivorous piano.
SPEAKER_1: The famous carnivorous piano way back from the year 2050.
SPEAKER_1: Anyway, Tina, we have to call it quits there, but Tina Lüdecke, I think that's a little better than I began.
SPEAKER_1: Great to have you on.
SPEAKER_1: This is a path of expertise.
SPEAKER_1: Who even thought that we have experts running around who think about this sort of thing?
SPEAKER_1: And it's great to have you and get a little slice of what your world is.
SPEAKER_1: And so, Matt, always good to have you, man.
SPEAKER_3: Oh, it's lovely to be here.
SPEAKER_1: Okay.
SPEAKER_3: And it's science sometimes.
SPEAKER_3: Probably science.
SPEAKER_1: Probably science.
SPEAKER_3: That's the podcast.
SPEAKER_1: Probably science podcast.
SPEAKER_1: And I was delighted to have been a guest on your show.
SPEAKER_3: It was a treat.
SPEAKER_1: And invite me again.
SPEAKER_1: We'll do it again.
SPEAKER_3: Oh, that's fantastic.
SPEAKER_3: I'd love that.
SPEAKER_1: Okay.
SPEAKER_1: Excellent.
SPEAKER_1: So, we got to call it quits there.
SPEAKER_1: I'm Neil deGrasse Tyson, your personal astrophysicist.
SPEAKER_1: And always, I bid you goodbye.