The Power of Adaptability with Herman Pontzer

0:00Wow. I feel like I more deeply understand who I am in this world. It's the way it goes. As a biological entity. I feel like I more deeply understand Neanderthal sex.

0:16Some perspectives on the origin of who and what we are coming up on Special Edition. Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk Special Edition. Today, we're going to be talking about the human condition that is centerline to what StarTalk Special Edition is all about. And of course, if it's Special Edition, it means we've got Gary O 'Reilly. Hey, Neil. All right, Gary. Yep. Former soccer pro. Yes. And of course, Chuck Nice. Chuck your baby. Hey, what's happening? So, Gary, tell me about the human condition and what's going to happen today.

1:06All right. I suppose in many ways this is the specialist edition because we are talking about the science behind the things that make us different, that make us special. And that, as a species, makes us adaptable. So what makes us special you mean which makes our species special? Yeah. Among all species of life on Earth. I mean, humans have survived and thrived in just about every location, every climate on Earth. Well, so far, that is. Things are changing. This adaptability has seen the human form take many different body shapes, sizes, blood types, and skin colors. Yet, with all this uniqueness, we are 99.9 % similar in our DNA.

1:52999. 9, yes. Yes, it's even more than 99.9, but go ahead. Okay, now seems like a good time to understand a little more about the diversity and our diversity and adaptability through the lens of evolution and biology. So if you would introduce our guest. I will. This is an old friend of mine. Oh, who left town some years ago before COVID and we hadn't heard back from him. Well, maybe he was as good a friend as you thought. I'm thinking it, you're saying it. Professor Herman Ponser, welcome back to StarTalk, dude. Hey, thanks for having me back. So the last time you were here was like early COVID.

2:31EC. EC. EC, early COVID. And all I remember is that you talked about zebra testicles. That's all I remember. It left an impression. That's good. You'll have to dig that one up out of the archives. So right now you're a professor of evolutionary anthropology. Ooh. I love that. That's great. Ooh. Ooh. and global health at the Duke University's Global Health Institute. You got your work cut out for you, too. I can tell you that right now. Yeah. Yeah, it's a strange time to be in academia and public health. There's a funny intersection at the moment. Exactly. Okay. And you're a recognized researcher in human energetics.

3:13I love it. Human energetics and, of course, evolution, which is fundamental to that. Author of a 2022 book, Burn. and in 2025, Adaptable, How Your Unique Body Really Works and Why Biology Unites Us. Ooh. Cool. Penguin Random House. Yeah. Interesting title. Oh, yeah. So let me just say, you left town and you didn't tell me you left town because you used to be right here. Were you at NYU? Where were you? I was at Hunter College in the grad center. Here in New York City. That's right. That's right. And coming over across town to hang out at the AM &H occasionally with some of our mutual friends. Yeah, yeah.

3:54We're here in my office now at AM &H, American Museum of Natural History, for those who just tuned in. So can we think of our adaptability as some kind of superpower distinguishing us from all other animals on Earth? Because I've thought long and hard, what is special? We can't fly. We don't run fast. Almost everything that would kill us in the wild is because the other creature is better at it than we are. So to think of our adaptability as a unique feature of being human, I got to hear more from you on that. And by the way, what are we doing here seeing as though every other animal is better at something than we are?

4:40How did we get here? They got sharper teeth. They got better eyesight. They run faster. They can take to the skies. They can swim. They can breathe water. Like, what the hell? Breathe water. Yeah. In the pantheon of superheroes, like, you know. We suck. Yeah. Yeah, you know, we're the superhero that can, we're the shifters, you know, the change, the shape shifters, right? We can be successful anywhere on the planet because we've got this crazy kind of dual inheritance that we talk about. We have all these cultural things that we inherit from generation to generation about how to survive in different environments.

5:16We've got this body that's very, we might be generalists in a lot of ways, right? We're good at a lot of different things. Maybe we're not as good at sprinting as some animals, as good at climbing, but we can kind of do it all fairly well. And we end up getting everywhere across the entire planet. Think of another species, I don't know if you could, that's been as successful in as many climates. Wait, wait, wait, Herman, the bacteria in your gut are traveling with you. That's true. They're as peripotetic - That's true, and the mitochondria in our cells are all long for the rise. as well. Right.

5:46There you go. This was smart bacteria. They knew what... Who'd have bet on them? Who'd have bet on them? Well, you know, I wanted to call the book Protein Robot because I like to think of us as like these kind of damp RVs trundling along the earth, right, with all of our microbiome on board, like passengers with us. Damp RV. Damn, that sounds hard to clean. Yeah. I'm not writing that Uber right. But you say in the subtitle of your book, why our biology unites us. So where does that, what are we to make of that subtitle? Yeah, well, so I don't know of any other species that has a sort of adaptability range that we do, right?

6:29Everything from the ways that we learn how to make a living growing up, because we have these different cultures that help us adapt to different environments, to our physical characteristics that are a little bit different across the globe in different ways, often as a sort of local adaptation to different contexts. Skin colors are a great example of that. Body proportions are another example of that. And so we are, all of us, expressions of this sort of shared common superpower that our species has, right? That adaptability is actually the expression of this. The diversity is the expression of the adaptability.

7:01And so I think rather than thinking about it as dividing us, it actually is showing our common origins in a way. Yeah, I'm just going to let you know, you keep talking about diversity and some people are going to come after you, buddy. Well, you know, I mean, I wanted to write this book. When I was writing this book, okay, it was 2022, 2023. And I thought, well, maybe this whole discussion about, you know, maybe the sort of universe-wide discussion about diversity and all those debates are going to be passe by the time the book's out. And it turns out, no. We're still very much talking about all this stuff.

7:36And so I'm glad it came out when it did. I think, you know, the goal is to have it be this sort of common ground. I want people to understand how the bodies work, why we're all different, how diversity happens, and have it be a kind of common ground that we can talk about these kind of big, often polarizing ideas and discussions with a common set of facts, common evidence base. You have your work cut out ahead of you because everything you're saying that unites us, our culture uses to divide us. So you got some work cut out to you to change the definition of diversity in that way. Yeah. Just letting you know.

8:12So Herman, is there such a thing as a textbook average human? And what are the dangers if we start to perpetuate such a thought process? Yeah. So no, there's not, right? Wait, wait, wait, wait, wait, wait, wait. Arithmetically, there has to be an average. So your question should have asked, is there a normal person? Well, what's normal? Right, exactly. That's a different thing. There's always an average. You can always take an average. But it's - Oh, but here's what I would say about that, Neil. Yeah. To push back a little. Please. And to agree with Gary, which I'm not sure if that's a good idea yet or not.

8:48You don't have permission to agree with Gary and disagree with me. We'll say, we've still got a way to go. Yeah. You know, my introduction to human diversity, well, began in undergraduate in my coursework, but my actual physical hands-on introduction to this was dissecting a human, right? You did that? Yeah. We were in medical school. I didn't go to medical school, but I took the medical school gross anatomy class at Harvard. And so it was me and 50 aspiring doctors, you know, disassembling a person on these big dissection tables. And every day you show up and you get your tools out a little case and you start taking a person apart.

9:24And, you know, three months and 160 pounds of human later, you've seen everything. I know a couple guys in Staten Island who do that for different reasons. Yeah, but pay attention to the nuanced differences. That's what I want to know. But what you learn very quickly, and the reason you might think, why do we bother doing this? It's kind of an old-fashioned way to do science or to learn medicine. But the reason you do it is that you immediately learn that the branching of arteries through your torso as it comes out from your aorta and starts to feed all your organs, that pattern of branching is not the same for everybody.

10:03and in fact you know often you find a branching pattern in the person that you're dissecting that doesn't match any of the variants shown in your dissecting text right and that the nerves are the same way and you know that's just the stuff you can see with your naked eyes right our diversity is down to the core and so i would say if you think about if you think about like a parts list for humans right maybe it's i'd be curious to think about this but maybe it's 30 ,000 different parts that all kind of come together to make you up. I would bet that just in the same way that there's like never been a perfect March Madness bracket, there is no human that all the pieces match a textbook dissector piece for piece.

10:46Because you might be right, you might be, you know, similar to the dissector on 99 % of them, but there's 1 % where you differ, and it'll be a different 1 % that I differ, etc, etc. So the mathematical way to say what you just did is whatever average you might obtain, it's not useful because the variance is so high on that average. Yeah. Because think about it. I mean, right? You can say an average, and you look for someone who matches the average, and no one does because everyone is scattered around to the left and right of the average on the chart. So, okay. I'm with you on that. How should that inform us on a sociological level?

11:24Yeah. So, you know, once you start to appreciate how diversity, what it looks like, that it's sort of multidimensional. It's not just, you know, for example, skin color in this country is historically used to divide us right into different categories. And if you're black or you're white, you're thought about you're in this category or that category. If you really understand human diversity, you realize that there are sort of subtle differences across all these different modalities, you know, in terms of the way our cardiovascular systems work, digestive systems, skin, of course, sure, nervous systems, all of it.

11:57There aren't sort of neat categories that we can box people into. And I think it forces us to kind of, to see diversity the way that it is, which is, again, the sort of individualized expression of these common forces, right? So it's a, it's a, an expression of our humanness, right? Rather than, oh, you're in this box and I'm in this box and we can kind of caricature it and pretend that we know something about you just because we put you in this particular box. That's not actually how the body works or how diversity works. So to that point, I read a pretty cool paper out of, I forget which part of Harvard, but was the basis for the predicate, there's no such thing as race.

12:40and that race is a completely manufactured construct. And it was based on what you just said, that which is there's no box in which you can put enough people to say, this is what white is or this is what black is. But the thing that I didn't really understand was how the scientists from Korea had more in common with one of the scientists from the Netherlands than one of the other scientists from the Netherlands on a biological level. Like that was part of it, yeah. Oh, okay. Yeah. So, I mean, it depends on what they're measuring, if they're measuring genetic differences or that kind of thing. But take this, here's a kind of toy example, but it's a real biological phenomenon.

13:28Blood types, okay? A, B, O, blood type, right? So I don't know if you know if you're type A or type B or type O, whatever it is. all of us in this four, the four of us sitting here might have all the same blood type, right? Maybe we're all type A. And that would mean that we have the same genetic variant. And in that way, in that particular locus, that gene, we're all more similar to each other than other people who have type B blood. All right? So in that measure, we're all a group and we're all different from somebody else. If we go by skin color, the amount of melanin in our skin, right? Well, there's differences in that, right?

14:04Who has more melanin? Who doesn't have as much melanin? And that might break us down differently. So there's an unlimited number of boxes that you could. Exactly. And not only that, but there aren't even hard edges on the boxes because if you look at something like skin color, in this country, we often put people into sort of black or white, but of course, skin color is everything in between too, right? So especially if you look globally, there's no, you know, you get everything pretty dark because you have a lot of melanin in your skin. It's too very light because you have very, little and there's everything in between so there's no hard edge where you say okay now i stopped this category and i'm into that category and of course president obama could have legitimately been declared as a white president because he's exactly half white but by his european mother right right yeah but instead we call them a black president because of the social norms in america exactly half black right right yes so i in one of my books i forgot which he imagine him running for president in an African country as the white guy.

15:01As the white guy. That's hilarious. Oh, no. That is so funny. Yeah. I mean, historically, it's even crazier. There were people who, groups who now we consider as sort of obviously white in the U.S., people from Ireland, people from Italy, who in late 1800s would have been considered black. Yeah. Yes. They weren't white until the powers that be that are because it's a socially constructed power move to make these groups until the powers that be decided that they were in the white group, that they became white. Until they felt outnumbered. Yeah. They're like, we need some help. How do you guys like to be white?

15:49I'm Brian Futterman, and I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.

16:02So, Muhammad, if we look at the latitudes here on Earth, how have humans adapted in terms of their biology to survive at these different latitudes? Yeah, so that brings up an important point to start with, which is that a lot of the variation that we see in head shape, size, all the different physical characteristics we see, This is all the rage in the late 1800s was how long versus how wide your head was. Oh, phrenology. Oh, yeah, yeah, yeah. Yeah, if you were dulicocephalic or brachiocephalic or all these things. Yeah, I remember that. So almost all of those kind of variations are just noise and slosh and genetic mutation that's tolerated because there's no strong selection to get rid of it, right?

16:45So a lot of the variation that we see, the superficial variation, a lot of that is just sort of tolerated noise. Now, that said, there are cases where you have a strong enough selection pressure that's localized and strong enough and long-lasting for generations and generations that you get local adaptation to a particular circumstance, a particular pressure. So, latitude's a great one. I have to clarify something here. Correct me if I'm wrong, Herman. When you say adaptation, you mean those who don't have the variation die so they don't propagate their genes. So no organism adapts. You're talking about the ensemble statistics of a generation where only some that happen to have the variation walk through the proscenium into this next world where they can survive better.

17:39Yeah. I just add to that that you can, one way to sort of lose that game is to die. The other way to lose that game is to not have any kids. Right. Or not have as many as your neighbor. You don't send your DNA into the future. Right. Gotcha. Gotcha. Okay. Pick it up. Sorry. So latitude is a great example of a pressure that's stable over time. You know, the Earth has been spinning on the same, you know, the equator has been the equator for a long, long time. And it's been hot at the equator for a long, long time and colder towards the poles. And so that heat differential, for example, has shaped body size and proportions.

18:10We see populations near the equator that are, on average, tend to be taller, thinner. People, populations near the poles tend to be a bit stockier and heavier. And that's because you want to get rid of heat if you're in a hot environment at the equator all the time. You want to hold on to your heat if you are towards the poles. So the physics of that, I think we have an explainer on it, where if you are rounder, you are better insulated against losing heat. Because how are you going to lose heat? Through your skin, basically. So the more round you are. Yeah, and if you ever see a pigeon in the winter, they puff up.

18:49They're very round. Or cats. That too. Cats do the same thing. Yeah, yeah, yeah. They make themselves round when they're cold. And we do that too. We'll bring our arms in. But the fur and the feathers come up and they trap a layer of air. That helps too. Yeah, yeah, yeah. But also try to round themselves. Whereas in the summer, the cat is all esplageable on the pavement. That's so true. And it's so funny. When you look at lions, they lay stretched. But when your cat is cold, and they're very similar, they wrap up. Yeah, yeah. So, okay. So I just want to make sure that the listener got the physics of what you just implied there.

19:24Absolutely. Yeah. Yeah. So there's a fun field story there, a piece of my research that kind of touched on this in a way I wasn't expecting. We do research in northern Kenya. There's a population there. They're called the Dasnich. They live with their goats and camels and cattle. It's a pastoralist group. They're like the Maasai. You might have heard of the Maasai. It's a similar kind of population. And we started work there in 2017. And we were talking to one of the NGOs, the charities that had set up shop in this little village called Illaret. there's this german uh charity we're talking to the the head of the charity and because you know we wanted to get a sort of health and nutrition research project started we thought we should talk to people who have been doing health and nutrition sort of outreach and he said oh it's terrible it's terrible here everybody all the kids you know 70 of the kids are malnourished here and we thought oh my gosh that is really that is terrible and so we kind of thought about that and kept that in our minds.

20:23And as we're kind of visiting that village and the surrounding villages, it doesn't square, though, with what we're seeing, because these kids don't look malnourished. These kids are running around, happy, laughing, you know, families are big, people look healthy. And so we thought if they say that they're malnourished, then that's important to know, but that seems, you know, counterintuitive based on just interacting with this population. Fast forward a couple of years, we've got ourselves a big data set on thousands of children who've been measured from the day they're born every few months to the time they're five or six years old.

20:57And what you can see when you look at these kids' heights and weights is that they're born around the same size as all the other kids in the world. And then their weight starts to fall off a little bit, but their height grows fast, right? So by the time they're three, four years old, kids in this population are taller than three or four-year-olds in most of the rest of the world because they have been adapted. That population has been adapted to be tall and thin. And so this German charity was looking at the ratio of weight, which was the same as everywhere else, maybe a little bit low, to height, which was tall because they were adapted to be tall.

21:36That ratio looked bad. It made them look malnourished, too thin, too light. They're just skinny. They're just skinny, but they're built, they're actually, they are built to be skinny. So once again, there's a European bias brought into Africa to pass judgment on who's there. Yeah, well, that'll be us. So had the Kenyan anthropologists gone to Germany, they would say, y 'all, some fat-ass folk. Right. Too much brats. Too many brats, guys. Gotta cut back. I mean, it even goes further because the folks from Nairobi who I was working with, those folks from Nairobi aren't part of that ethnic group.

22:13They don't share that same, to the same extent, the same kind of tall, thin body build. Right. And so I'm actually more similar to my Nairobi colleagues, even though our skin colors are different, on that dimension than either of us are to this northern Kenyan population that's tall and thin. So to even begin by using the kind of American racial categorization to try to make sense of what's going on there, you're sunk from the beginning. It's folly. Yeah. Isn't there an example of adaptability with people in the Andes? And then across in the Himalayas, they're living at a similar altitude, but one of them will suffer altitude sickness.

22:54One of them won't. Why? Yeah. What's up with that? Yeah. Yeah. So people, humans have gone into the high altitude parts of the world. Three big examples of this. The Ethiopian plateau in those populations aren't well studied. So we don't know a whole lot about that physiology. The Himalaya, right? Tibet and Nepal. And that's been well studied. We know a lot about that. and the Andes in South America. And these are all independent evolutionary forays into high altitude. And the problem is you don't have any oxygen up there. The air is still 21 % oxygen, but the air pressure is so low that there just aren't as many molecules of oxygen available for you to get into your bloodstream.

23:33And so everybody's oxygen star up at these high, high altitudes. And so there've been independent evolutionary changes, adaptations to this real challenge of getting enough oxygen. In the Himalayas, there is an allele that helps determine how much red blood cells you make. Okay, let me back up. Red blood cells are the cell that carries oxygen. You need that. And they have a tough job at altitude because there isn't enough oxygen to go around. And so what most people do and most populations do at altitude, you make a lot more red blood cells. Your body responds to the oxygen debt by making more red blood cells.

24:12And that's good for a while, but it makes your blood thicker and can lead to altitude sickness. And we still see a lot of altitude sickness in the Andes, for example. They haven't kind of, their bodies haven't figured out how to deal with that. In the Himalaya, they don't have this issue of altitude sickness. Why not? Because it was an allele that has been gone to fixation. It's completely the norm, the norm genetic variant in the Himalaya that helps them deal with oxygen debt without overproducing red blood cells. They produce enough to keep the oxygen going, but not overproduce it and get sick.

24:47They also have bigger lungs. They have a bigger spleen, which is this reserve red blood cell tank that we all carry around. So there's a whole bunch of adaptations that go to try to get enough oxygen in. So where do the Neanderthals fit into that particular scenario in the Himalayas? Yeah, I wondered if you wanted to go there. Let's do it. Let's do it. Call them out. So the first thing you have to understand is that humans historically have slept with anything that they encounter. Don't look at me and say that. And so humans, right? Homo sapiens, we evolved in Africa about 300 ,000 years ago. And as we sort of become so successful, so adaptable, our superpower at full display, we get into Europe.

25:32We interact with Neanderthals there. What do we do? We admix with them, to use the sterile scientific term, and we have children. And we can still see the genetic evidence of that today. A quick question. I have to slip in there. You said 300 ,000 years ago, we come out of Africa, get into Europe, and admix with the Neanderthal implies Neanderthals either left Africa earlier or evolved as Neanderthal in Europe. Yes. Now, we know from DNA testing that pure Africans have zero Neanderthal DNA. So there must have been some deep European origins of the Neanderthal. Is that correct? Yeah, that's right.