The Power of Adaptability with Herman Pontzer

Wow.

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.

Some 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.

Hey, Chuckie baby.

Hey, what’s happening?

So, Gary, tell me about the human condition and what’s gonna happen today.

All 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’s, 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 shape, sizes, blood types and skin colors.

Yet, with all this uniqueness, we are 99.9% similar in our DNA.

So 999.

Nine years.

Yes.

Right.

Even more than 99.9.

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.

Who left town some years ago before COVID.

We hadn’t heard back from him.

Well, maybe he wasn’t as good a friend as you thought.

I’m thinking it.

You’re saying it.

Professor Herman Pontzer.

Welcome back to StarTalk, dude.

Hey, thanks for having me back.

So the last time you were here was like early COVID.

EC.

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, 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.

I love that.

That’s great.

And global health at the Duke University’s Global Health Institute.

You got your work cut out for you, dude.

I can tell you that right now.

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.

I 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.

Penguin Random House.

Yeah, interesting title.

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.

And here in New York City.

That’s right.

That’s right.

And coming over across town to hang out at the AM&H occasionally, some of our mutual friends.

Yeah, yeah.

We’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 about, 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?

Right.

How did we get here?

They got sharper teeth.

They got better eyesight.

They run faster.

Right.

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 super hero 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.

We’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 peripatetic-

That’s true, and the mitochondria in our cells are along for the ride as well.

Right, there you go.

That’s a smart bacteria.

They knew what-

Who to bet on?

Who to bet?

Well, 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 over, Ryan.

But you say in the subtitle of your book, why our biology unites us?

So 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?

Everything 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, you know, the diversity is the expression of the adaptability.

And so, you know, 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, man, I wanted to write this book.

When I was writing this book, OK, it was 2022, 2023.

And I thought, well, maybe this whole discussion about, you know, maybe this sort of universe wide discussion about diversity and all those debates are going to be passe by the time the book’s out.

And turns out, no, we’re still very much talking about all this stuff.

And so, I’m glad we did, 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.

You know, 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, you know, 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, just letting you know.

So, 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.

Arithmetic-ly, 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 what-

Oh, but here’s what I would say about that, Neil.

Yeah.

To push back a little.

And to agree with Gary, which I’m not sure if that’s a good idea yet or not.

You don’t have permission to agree with Gary and disagree with me.

We’ll see.

We’ve still got a way to go.

Yeah.

You know, my introduction to human diversity, well, I began an undergraduate in my coursework, but my actual physical hands-on introduction to this was dissecting a human.

Right?

And you, 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 of a little case and you start taking a person apart.

And, you know, three months and 160 pounds of human later, you’ve seen everything.

I know a couple of guys in Staten Island who do that for different reasons.

Yeah, but do they pay attention to the nuanced differences?

That’s what I want to know.

But what you finally, you know, what you learn very quickly and the reason, you know, you might think like, 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, you know, the branching of arteries through your torso as it comes out from your aorta and starts to feed all your organs, that set of branch, that pattern of branching, is not the same for everybody.

And in fact, you know, often you find a branching pattern in your person that you’re dissecting that doesn’t match any of the variants shown in your dissecting text, right?

And the nerves are the same way.

And, you know, that’s just the stuff you can see with your naked eyes, right?

That 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 disector piece for piece.

Because you might be right, you might be, you know, similar to the disector on 99% of them, but there’s 1% where you differ, it’ll be a different, 1% that I differ, et cetera, et cetera.

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?

Yeah.

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.

There 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, this sort of individualized expression of these common forces, right?

So it’s 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, that there’s no such thing as race, and 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 the biological level.

That was in the paper, too?

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, and here’s a kind of toy example, but it’s a real biological phenomenon, blood types, okay?

ABO 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.

Because all of us in this for 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.

We go by skin color, the amount of melanin in our skin, right?

Well, there’s differences in that, right?

Who has more melanin, who doesn’t have as much melanin.

And that might break us down differently.

So it’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, 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?

Yeah.

But instead, we call them a black president.

Because of the social norms in America.

Because he’s exactly half black, right?

Yes.

So in one of my books, I forgot which he, imagine him running for president in an African country.

As the white guy.

As the white guy.

That’s hilarious.

That is so funny.

I mean, historically, it’s even crazier.

Like there were people who, groups who now we consider as sort of obviously white in the US.

People from Ireland, people from Italy, who in late 1800s would have been considered black.

Yeah.

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?

So Herman, 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, yeah, yeah, yeah.

If you were dulicocephalic or brachiocephalic or all these things.

Yeah, I remember that.

So almost all of those variations are just noise and slosh and genetic mutation that’s tolerated because there’s no strong selection to get rid of it.

So a lot of the variation that we see, the superficial variation, a lot of that is just 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 or particular pressure.

So latitude is a great one.

So 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.

Yeah.

I just add to that that one way to lose that game is to die.

The other way to lose that game is to not have any kids.

Or not have as many as your neighbor.

You don’t send your DNA into the future.

Right.

Got you.

Pick it up.

Sorry.

Latitude is a great example of a pressure that’s stable over time.

The Earth has been spinning on the same.

The equator has been the equator for a long, long time.

It has been hot at the equator for a long, long time and colder towards the poles.

That heat differential, for example, has shaped body size and proportions.

We see populations near the equator that are, on average, tend to be taller, thinner.

Populations near the poles tend to be a bit stockier and heavier.

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.

The physics of that, I think we have an explainer on it, where if you are rounder, you are better insulated against losing heat.

How are you going to lose heat?

Through your skin, basically.

The more round you are.

Yeah, and if you ever see a pigeon in the winter, they puff up, they’re very round.

Or cats.

That, too.

Cats do the same thing, they make themselves round.

Round.

When they’re cold.

And we do that, too.

We’ll bring our arms in.

The fur and the feathers come up and they trap a layer of air.

That helps, too.

Yeah, yeah.

But they also try to round themselves.

Whereas in the summer, the cat is all like Esplosiao on the pavement.

That’s so true.

And it’s so funny, when you look at lions, they lay stretched.

Yeah.

But when your cat is cold, and they’re very similar, they wrap up.

Yeah, yeah.

So I just want to make sure that the listener got the physics of what you just implied there.

Absolutely.

Yeah, I got it.

So there’s a fun field story there, a piece of my research that’s had a touch on this in a way I wasn’t expecting.

We do research in northern Kenya.

There’s a population there, they’re called the Dasnitch.

They live with their goats and camels and cattle.

It’s a pastoralist group.

They like the Maasai.

You might have heard of the Maasai.

It’s a similar kind of population.

And we started to 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 Illoret.

There’s this German charity.

We’re talking to the head of the charity, and because we wanted to get a health and nutrition research project started, we thought we should talk to people who have been doing health and nutrition outreach.

And he said, oh, it’s terrible.

It’s terrible here.

Everybody, all the kids, 70% of the kids are malnourished here.

And we thought, oh my gosh, that is really terrible.

And so we thought about that and kept that in our minds.

And as we’re 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 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 have been measured from the day they’re born every few months to the time they’re five or six years old.

And 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 or 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, that ratio looked bad.

It made them look malnourished, too thin, too light.

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, yeah.

So had the Kenyan anthropologist gone to Germany, they would say, y’all are some fat ass folk.

Right.

Too much brats.

Too many brats, guys.

Got to 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.

They don’t share that same, to the same extent, that same kind of tall, thin body build.

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, right?

So like the whole, 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, one 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 and those populations aren’t well studied.

So we don’t know a whole lot about that physiology.

The Himalaya, right, Tibetan Nepal, and that’s been well studied.

We know a lot about that.

And the Andes in South America.

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 percent 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.

And so everybody’s oxygen star up at these high, high altitudes.

And so there have been independent evolutionary changes, adaptations to this same, this real challenge of getting enough oxygen.

In the Himalayas, there is an allele that helps determine how much red blood cells you make.

So, 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, 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.

And 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 of the allele that has been gone to fixation, is completely the norm, the norm genetic variant in the Himalaya that helps them deal with oxygen debt without over producing red blood cells.

They produce enough to keep the oxygen going, but not over produce it and get sick.

They also have bigger lungs, they have a bigger spleen, which is this reserve blood, 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.

So 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 evolve in Africa about 300,000 years ago.

And as we sort of become so successful, so adaptable, our super power at full display, we get into Europe, we interact with the Neanderthals there.

What do we do?

We admixt 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 admixt with the Neanderthal implies the Neanderthals either left Africa earlier or evolved as Neanderthal in Europe.

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.

Whether it’s deeply in Europe or sort of into the Near East is much debated.

But yeah, it’s outside of Africa.

So humans and Neanderthals, of course, have a common ancestor about 600,000 years ago.

Those two branches go their separate ways.

Ours in Africa, theirs in the Near East, in Europe.

And at some point, they become what we would consider to be the Neanderthal gene pool.

And when our branch comes back in and over, intersects with them again, we have these matings and this admixture.

And so we are fertile with each other because we have the same common ancestor, even though we’re many, many years down from the line.

And an interesting fact that I discovered in my own work for Starry Messenger, the book, was we grew up with the archetype of this stupid backward Neanderthal.

Yeah, they’re the caveman that knows nothing.

That never stopped dragging its knuckles.

Then we find out that black Africans have no Neanderthal blood, yet there’s admixtures in current European white people.

And only then did papers, research papers, start saying how creative and inventive Neanderthals were.

There was a complete shift in the early 1990s.

Herman, am I right here?

Herman, talk to me, Herman.

Yeah, I mean, that’s one retelling.

I think that’s pretty, that’s fair to the history of what happened there.

I think there was already a re-imagining of what Neanderthals were like before that, but I take it point.

I saw, even Gary Lawson was full in on the backward Neanderthal.

Not to mention the Geico guys.

Yeah.

I would say that populations outside of Africa all have a little bit of Neanderthal in them because as we kind of get out of Africa into the Near East and those matings happen, those genes kind of get washed to every population that’s kind of downstream of that, right?

So Asians, Native Americans will all have a little bit of Neanderthal in them left over from that kind of crossing event that happens in the Near East and Europe.

That makes sense because those were the crossroads.

All those areas outside of Africa were actually the crossroads for human travel.

So it kind of makes sense.

Yeah.

So there’s this great example of another kind of discovery from ancient genome, but by the way, all of this is mind-blowing stuff.

It is from DNA that we’ve gotten out of fossils, right?

Which is sort of, that’s mind-blowing to me.

Very Jurassic Park.

Completely, completely.

And we’ve discovered a whole new species of human ancestor or human relative, I should say, that’s Neanderthal-like in Asia called the Denisovans.

Oh, I didn’t know anything about that.

No, I heard about that.

I didn’t know anything about that.

So the Denisovans, were they contemporary with the Neanderthal?

Yeah, that’s right.

That’s right.

Kind of Denisovans go one way, humans and Neanderthals the other way.

And then Neanderthals and humans split a little bit later.

So they’re even a kind of more distant relative of us, in a way.

So just, I’d like, because I’d like it, knowing, what’s the etymology of Neanderthal and the etymology of the Denisovans?

Denisovans.

So Neanderthals are so named because those initial fossil was found in the Neander Valley, and in German, valley is tall.

So it’s Neanderthal.

Oh.

And that’s why it’s Neanderthal and not Neanderthal, because T-H-A-L is tall in German.

That’s if you want to get pedantic.

This is America.

We pronounce it how we want.

That’s right.

That’s right.

That’s fair.

And then…

Don’t encourage him.

Don’t encourage me.

And then Denisovans are found that the site is, the original site is Denisova.

It’s a Denisova cave in Siberia somewhere, I believe.

Okay.

Yeah.

And they had just a couple finger bones.

And those aren’t really diagnostic.

You can’t figure out what species it is just from the bone, from the morphology, the shape of the bones.

But they drilled into it, got the DNA out and go, holy, this is a whole other group.

This isn’t Neanderthals and it’s not Homo sapiens.

It’s something else.

Right.

And that was the discovery that there is this, you know, unappreciated species that we didn’t even know about.

So they got the DNA from the bone marrow?

Any of your bone material will have cells in it.

So yeah, that’s not just the marrow, but any of it.

Why does DNA last that long?

It’s a pretty delicate molecule, isn’t it?

It doesn’t last kind of fully intact.

So your DNA, if you stretch it, if you took all the DNA in your body and you stretched it out, you’d be dead.

That’s the first thing you should know.

But second of all, it would get to the moon and back or something like that, all your DNA stretched out.

Then we’ve discovered that not only is there this other species of human relative, but there’s evidence of mating with them as well.

So it wasn’t just Neanderthals, it was also Denisovans.

And then you find out that this gene variant that has been so key to the success of Himalayan groups, where did it come from?

It came from Denisovans.

Wow.

So there were these mating events with Denisovans.

That gene variant ends up in the human gene pool, sloshed around, doesn’t give you any advantage at sea level.

Only when those populations begin to go up at high altitude does it turn out, oh, by the way, that variant’s actually really good at high altitude.

And then it becomes the variant that everybody has because of the selective process of reproduction and survival.

So let me ask you this.

Just for the sake of people being able to visualize what we’re talking about, because it seems like you’re talking about different species, but what I’d like is if you were to take pictures of our DNA and superimpose them, what would that look like and how alike or different would we be?

Between us and the recent ancestors.

So Denisovans, Neanderthal, Homo sapien, and then you take those pictures, you superimpose them, what would it look like?

Yeah.

So this is exactly what we do when we get the genetics to begin with.

They’re trying to make sense of it.

The best way to picture it is like a tree.

Imagine a tree where all the branches are very hard and clustered very tightly around the crown.

That is the entirety of the human species over here.

And then there’s a branch that comes off real low and ends up over here somewhere.

That’s the Neanderthal branch.

And then it’s like you discovered, oh my gosh, I didn’t look closely enough.

There’s a branch that’s even lower and goes out even a bit further.

And that’s the Denisovan branch.

Okay.

Right.

And so if you were to overlay the A’s, T’s, C’s and G’s of the genome on top of each other, you’d find they’re very, very similar.

All of those individuals, you have to really compare them at thousands and thousands of base pairs to sort of see that clustering, just because all mammals are pretty similar.

All primates are real similar, you know?

And so all these human ancestors and relatives are real similar too.

Take me back to when we went from grunts to articulate speech.

Oh, that’s an amazing…

What’s up with that?

That’s very hard to know for sure.

You got Morgan Freeman on me.

What happened for us to have grunt vs.

speech?

Oh, yeah.

So the anatomy of that is pretty well known.

The anatomy of the vocal tract, for example, has changed, which allows us to have this sort of two-compartment vocal tract, right?

So your larynx is down here real low, and that gives you a vertical component to sort of shape the frequencies that come out of your lungs as you make noise.

And then you have this horizontal component from the mouth, and those get shaped differently and give you all the A-E-I-O-U sounds.

So we know the anatomy of speech very well.

When that evolved, right, that is really hard to know for sure.

And in fact, I don’t think anybody knows for sure.

Well, we know it had to be at least when homo sapiens made it with neanderthals, because somebody had to say, hey girl, what’s happening?

Bring your fine ass on over to this cave right here.

Let me holler at you.

Thank you, Chuck, for reenacting.

It’s like we were there.

It’s almost like we were there.

They say time travel is not possible, but I don’t know.

There you go.

I heard that our ability to form sounds, as you articulately described, the two-dimensionality, the frequency and volume and texture of our vocalizations, that this was a genetic defect, if you will, from whatever was going on in the grunting community.

There was some genetic alteration that changed it.

So, wait, we all share this mutation?

Yeah, it’s a mutation.

It’s a mutation.

Everybody else was like, and then somebody was just like, oh dear, you’re so gush.

My God.

Exactly.

What is it?

I mean, seriously, is this how we’re going to communicate?

So, we don’t want to think of speech as a mutation.

We want to think of it as an adaptation.

Maybe there’s no difference.

Yeah, we want it to be a feature, not a bug.

A feature, exactly.

All adaptations start off as mutations.

Oh, there’s another T-shirt.

So, natural selection is the survival of the fittest, but mutation is the arrival of the fittest.

Yo, that is dope.

Another T-shirt.

We’re in the mood for this.

The arrival of the fittest.

You need variation, you need mutations for natural selection.

You just go, oh, yep, that’s the one that’s going to work here, and that one’s not, right?

If there’s no variation, if there’s no mutation, there’s no way for natural selection to happen.

Let’s look at this situation of adaption, of our environment.

Yeah, the adaption.

Yeah, you said adaption.

That’s not a word.

I know, I’m making them up as I go along.

You’re embarrassing your fellow brits.

It’s our bloody language, but use it as we wish.

You’re sitting next to me, you are not uttering adaption.

I’ll see you after class, sir.

Okay, go.

So, our adaption is being forced to speed up because of the environments we’re being pushed into.

Out of rural farming, into town city, and cities in particular.

At a rapid rate, that is.

As a rapid rate.

But are we now being mismatched?

Are we being confronted with circumstances that, you know what, this body is a vote for this environment, not that environment?

I think the proof is already evident that we are mismatched.

And I think it’s more not the, I’m sorry, Herman, I’m answering the question.

No, no, no, no, Herman’s got an answer for this.

Chuck, I do this sometimes.

But I think it’s more not the circumstance, but technology and the circumstance together.

So, for instance, in disease, we have diseases now which are chronic and major, but how long ago were they not, Herman?

Oh, that’s, yeah, so the populations I live with, hunter-gatherer groups and even farming groups that I work with today, they are heart disease free, diabetes free.

So the things that we’re gonna die from, they’re protected against.

Of course, the flip side is the things that we’re protected against because of antibiotics and vaccines, that kind of stuff, really gets them.

But these lifestyle diseases were only an issue in the last couple hundred years.

Herman, if they’re an isolated community, that means there are no outside…

Influences?…

viruses, bacteria, other ailments that could influence them until they meet someone from the outside, such as yourself.

So, how many indigenous people have you killed with your…

Yeah.

That’s a lovely question, Neil.

I really appreciate you bringing that up.

See, at least he’s blamed you and not the British, because normally I am go-to for that.

We’re done blaming you guys.

It’s time to blame somebody else here.

So that question raises the point that I think people get wrong all the time, which is people think that any human population is ever isolated.

That’s never the case, right?

I mean, there are always interactions, there’s always gene flow and people flow and migration and movement.

So there are no isolated groups anymore.

Even these groups that we work with who are hunting and gathering or farming, it isn’t that they don’t interact with people who aren’t.

It’s just that they like to keep their old ways.

They’re basically the Pennsylvania Dutch of Africa.

No, that’s exactly it, actually.

That’s exactly what it’s like.

They live in a world that they interact with people all the time, but they prefer to keep their own culture.

So you raise this issue about accelerated adaptation.

It’s the brain, man, because we have…

Our brains are born unfinished, right?

We learn, we’ve created this entire cultural inheritance that we each inherit and learn.

It takes you 15, 20 years to learn it all, so you could be a proper adult, a functioning adult.

And so we have all this…

And that cultural evolution can happen much faster than our biological evolution can.

So we have these two parallel tracks happening all the time.

It’s a really fun thing about humans.

There was a study done in comparison on back in the day when there were bus drivers and conductors on board, and the health of the driver as opposed to the conductor, even though they go to the same place, they travel together all the time.

They breathe the same air.

They breathe the same air, they see the same people.

One is sedentary, the other is obviously mobile, stamping tickets and checking up and down on the levels of the bus.

These are situations now that we have not really been involved to have a sedentary lifestyle.

You talk about the hunter gatherers in Africa.

So what are the overall health implications for modern health now that we’re finding ourselves mismatched with?

Yeah, that was a seminal study in the 1950s showing that the drivers who sat all day ended up getting heart attacks at a kind of scary rate.

Their buddies who were walking up and down the aisles didn’t.

They had healthy hearts.

And so that was one of the early clues that physical activity, daily physical activity is absolutely essential for keeping your heart healthy.

Well, why is that?

Well, because we’ve evolved for hundreds of thousands of years in our active lifestyle.

That’s the way our bodies are built.

That’s sort of the lifestyle our bodies expect.

So you’ve got paleo diets.

There’s no way we’re going back to a paleolithic lifestyle.

No.

So what’s our answer here?

Well, the London Bustard is a great example, right?

Because you have the benefits of activity without having to cause play as a Neanderthal or something like that.

It’s an example of how you can have physical activity in your daily life.

You know, you guys are New Yorkers.

You guys walk around the city and get lots of physical activity.

We meet our step minimum every day.

And it’s not just the steps.

The last study that came out about New Yorkers who tend to be thinner than most other places in the country.

It’s the pace at which New Yorkers walk as well.

New Yorkers tend to walk much faster than any other place.

So the two together, the fact that they walk everywhere and they walk briskly is what makes it.

We’re in a hurry even when we don’t need to be.

There’s a lovely study from the 70s by this husband and wife team.

They looked at the average walking pace of people down sidewalks and how big the city was.

They went all over the world to do this.

And the bigger, more denser your city is, the faster you walk.

Oh, cool.

Okay, that makes sense.

So, Herman, the history of anthropology has applied properly or improperly on our species or on our populations.

In almost every case led to some legislation, some laws related to those conclusions be it to justify slavery, to be it to limit immigration.

So is there a policy implication that your work would bring to the front that is either progressive or regressive in the history of this exercise?

I think it does have big societal sort of implications.

Right, when we think about how the body works and we have a fluency in how our different systems work, we use that fluency with how our bodies work to understand diversity, I think that absolutely it’s going to.

And what it’s going to do is, it’s going to inform how we move ahead from, you know, the really old school ways of thinking about the body, we’re very genetic determinist, right?

We move into the 1900s and even recent times, and it’s very environmental, you know, it’s all nurture and the nurture nature debate.

And I think we’re moving to a third period here, where we’re in a personalized era, right?

Whether it’s personalized genetics, or it’s personalized ways of thinking about my health, right?

And if we leave…

Personalized diet even, perhaps.

Personalized diet.

And if we leave that discussion just purely to the influencers, or purely to, you know, the political class that doesn’t have any fluency in how the body works, or these sort of old school ideas about these sort of caricatures about our diversity, we’re going to be in real trouble.

So, I think that the book does kind of help inform those big discussions we’re having right now.

Look, whether it’s IQ, whether it’s sex and gender, whether it’s health and vaccines, whether it’s, you know, all of these issues that are right, you know, in front of us today, they all fundamentally rest on how we understand how our bodies work, and how our bodies work differently.

And so, you know, the book isn’t trying to get anybody to, you know, I’m not trying to make anybody think like I think, but what I do want to have is people, a common evidence base for us to have those discussions, a fluency that we can have these discussions usefully and meaningfully.

So I think there are societal implications.

I think the way that they shake out are going to be, hopefully, make things better for everybody.

And because of that, I’m cutting your funding.

That’s it.

You no longer have a dime.

Yeah.

I would laugh harder if it was…

I was saying if it wasn’t so true.

If it weren’t so tragic and true.

So Herman, thank you for returning to StarTalk.

Yes.

Oh my gosh.

This was a fun conversation, guys.

Thanks.

We miss you.

You have a unique combination of expertise that deeply informs what we care about here on StarTalk Special Edition.

So that means we want to sort of have access to you further going forward.

Hey, I’m always happy to be your evolutionary anthropologist on a call.

I’m here.

Everybody should have ice ahead of them.

Now you say it.

I want one.

Dude, delight to speak to you.

Thanks for enlightening us yet again.

Thank you.

All right.

And of course, we’re all going to look for your book, Adaptable, How Your Unique Body Really Works and Why Biology Unites Us.

All right.

Word unite is something we need today.

So thank you for being a part of that conversation.

This has been StarTalk Special Edition.

Neil deGrasse Tyson here, your personal astrophysicist.

As always, keep looking up.