Original subtitles

LABOURED BREATHING

CRY OF PAIN

GRUNTING

GROANING

BABY CRIES

Around 30,000 years ago, a child was born into a new and lonely world.

They were the first child to be born onto a planet

in which we were quite alone.

This was the first time in history that only one species of human

walked this Earth.

All the others were now gone.

And in a tale written by the sole survivors,

it's actually quite easy to forget

that we weren't destined to be the only ones.

And yet here we are.

How this happened is one of the most poignant chapters

in the human story.

And it's one that's etched into the DNA

of every single one of us alive today.

For hundreds of thousands of years,

Homo sapiens evolved in Africa.

60,000 years ago, one group dispersed into the Middle East...

..and continued onwards as far as Australia.

But our ancestors didn't stop there.

Another group began to make their way north into Europe...

..where their story continues.

For thousands of years, Europe had been out of reach to Homo sapiens...

..repelled by its icy climate.

But now a shift in conditions opened up a route

into this new realm.

And some of our ancestors left the familiar behind...

..and stepped into the unknown.

We don't really know why they came.

Was it a romantic notion, like pure curiosity?

Or was it something much more practical? Say, the need for food.

Or perhaps it was the same forces that drive migrants today -

that need for shelter and safety.

We don't know the exact routes they took,

but by following rivers, coasts, or wandering across mountain ranges

like these, they found their way into this new world.

But not long after these migrants reached Europe...

..they would have encountered something unexpected.

When they got here,

they would have discovered that another species had beat them to it.

Two other human species were widespread at the time.

To the east, from Siberia to Southeast Asia,

lived the mysterious Denisovans,

known only to us from DNA

preserved in a few fossil fragments.

Across lands to the west, all the way from Russia

to the Atlantic coast of Europe, were the Neanderthals.

Homo sapiens were latecomers to Europe.

It had been home to the Neanderthals for almost 400,000 years

before we showed up.

Now these Homo sapiens venturing into Europe would have met

another sort of human.

People who looked a lot like us, but with obvious differences.

We can only imagine what our ancestors would have made of them...

..when our two cultures - perhaps just two families...

..encountered each other for the first time.

Neanderthals were close relatives of Homo sapiens,

but we had evolved along separate branches of the human family tree.

There's often this belief that we evolved from Neanderthals,

so we came from Neanderthals.

Actually, that's incorrect.

We shared a common ancestor with them.

And then, due to chance and the environment,

we went on these two really different evolutionary journeys.

So, we evolved - Homo sapiens - for Africa.

We ended up taller and leaner.

Now, the Neanderthals evolved for much cooler,

more wooded environments.

So they were shorter -

on average, they were about 5'5" -

they had bigger torsos, but shorter limbs.

They used a lot of brute force...

..because they were close-range hunters.

The Neanderthals were masters of their environment -

they had evolved here for hundreds of thousands of years -

whereas we turn up and we're immigrants,

we are ill-equipped and unprepared.

If you were going to place a bet on who would be left standing,

you'd probably bet on the obvious choice - and it wouldn't be us.

The Neanderthals had found a way to thrive here for millennia.

Yet in the 19th century,

when the first Neanderthal fossils were unearthed...

..we quickly made assumptions...

..that have persisted ever since.

As a result, Neanderthals haven't had the best PR.

If somebody calls you a Neanderthal, it's probably not a compliment.

And that stereotype of Neanderthals has been with us

since the very beginning.

And it kind of suited us to see ourselves as the pinnacle

of evolution, and them as these knuckle-dragging ape men.

But partly, that stereotype is actually just a mistake of science.

Palaeoanthropology at the time was quite a new science,

and when they came to reconstruct this one Neanderthal called

La Chapelle-aux-Saints, they portrayed it as kind of really

hunched over and knuckle-dragging, which was just wrong.

This kind of brutish, hairy Neanderthal,

looking like it's about to attack, it's incredibly aggressive.

And then Hollywood pick up this stereotype.

Some of these images are so ridiculous.

Very monkey-like Neanderthals.

That impression of Neanderthals just solidifies.

I personally love Neanderthals,

and the more we learn about them, the more we study them,

the more we discover about them,

the more we realise that this is actually incredibly incorrect.

This now outdated image of the simple brutish caveman is

finally being replaced...

..with a picture of a once vibrant, thriving culture.

There may be no Neanderthals left to tell their story...

..but thanks to the traces they left behind,

we can begin to imagine people who aren't so different from us.

We keep finding things at Neanderthal sites

that really challenge us.

Things like beaded shells with pigmentation on them,

almost like they're being used as necklaces.

Eagle talons that have been polished down.

And then there's my actual favourite, which is

evidence of feathers.

But not just any feathers.

No, the Neanderthals seem to be really

interested in iridescent feathers from things like red kites.

And you've got to wonder,

why were they so interested in those particular colours?

And it's presumably because they're high value.

They're beautiful.

You kind of have an impression of them as having these incredible

headdresses or maybe cloaks made of these brilliant, bright feathers.

When you put this all together,

you paint a picture of a Neanderthal, not as this

aggressive creature standing behind a rock with a massive club,

but actually as these beings very interested in adorning themselves.

Interested in looking beautiful with necklaces

and gorgeous coloured headdresses.

Suddenly you're looking at beings who aren't just

interested in food and shelter -

they're interested in the way they are seen by the world.

This - all this - makes them tangibly human.

For generations, Homo sapiens and Neanderthals lived

near one another.

But how close were we?

For decades, most assumed interbreeding

between our two species didn't happen.

But in the early 2000s, this was called into question...

..with the chance discovery of fossil fragments...

..which revealed humans with a mysterious mix of features.

It even smells like a fossil.

This, I assume, is Oase 1.

This one is Oase 1.

And that's Oase 2. Skull. That's Oase 2.

This is quite special because I've read about them.

I've studied them.

They're hugely significant fossils,

but I've never seen the originals.

I've never been this close to them. It's...

We excavated for two years.

We unearthed, like, more than 10,000 fossil remains,

mostly cave bear, but also Oase 2.

And it looks and it is modern Homo sapiens. Yeah.

But it has some features which are more like Neanderthal.

Yeah. Like this one. It's quite clear.

It's a mandible of a modern human with this chin.

Cos there's a chin. Yeah, a chin.

Yeah. And Neanderthals don't have a chin.

Neanderthals' chin kind of recedes.

But then you see the size of the molars... Yeah.

..which are really huge. More a Neanderthal feature.

Modern sapiens, but with Neanderthal teeth.

Yeah, Oase 2 has the same hybrid features. Mm-mm.

Like if you look at the face.

You look at that and you do think that's Homo sapiens.

And then it has these features on it, which are more Neanderthal.

Like this occipital bun here at the back,

that bulge at the back of the skull here.

Yeah, that's kind of strange.

It's not a Neanderthal, but it has Neanderthal features,

which prompt us to think about some sort of interbreeding.

Neanderthal, Homo sapiens interbreeding.

It was pretty controversial.

People thought it either didn't happen,

because we were too genetically distinct.

People were just not ready to accept that.

Interbreeding is not something uncommon in biology.

It happens with other species.

At that time, it was somehow taboo.

Around a decade later came a revolutionary breakthrough.

Advances in genetic analysis allowed scientists to extract

DNA from ancient fossils...

..proving these two species could - and did - produce offspring.

How did it feel to be proven right, to be vindicated,

especially over something so controversial?

We felt relieved. Yeah.

Like, "OK.

"Now you know."

Yeah, we were happy to be right.

Yeah.

How many generations ago was the Neanderthal ancestor?

We now know that this individual had

a Neanderthal ancestor somewhere back four to six generations.

One of the great-great-grandparents, potentially, was a Neanderthal.

Something like that.

You know, people spend their whole lives - their WHOLE lives -

trying to find a fossil as significant as this, and...

Wow, it's just amazing.

Since the discovery of Oase 1, evidence has continued to grow,

proving hybrids like this were not just possible,

but may have been relatively common.

We'll never know the full story of Oase 1 and the other hybrids,

and to be honest, we'll never know the full circumstances

under which they were conceived.

For all we know, it could have been nonconsensual, or it could have

been the result of a romantic notion like love,

or it might have been the result of a practical decision

like as part of a trade agreement.

But whatever it was,

what must it have been like to have been a hybrid child,

to have had a parent or grandparent or great-great-grandparent,

not just from a different race, but a completely different species?

Did these children feel like they belonged,

or were they teased and ostracised?

We'll never know, but what we do know,

because I held Oase 1 in my hands, is that they existed.

And so somebody loved them,

and somebody was raising them to adulthood.

And so we tangibly know that the Neanderthals

and the Homo sapiens, they didn't just meet - they joined.

We now know that, for a time at least, Homo sapiens

and Neanderthals managed to live alongside one another.

But a global change would push both species to the limits of survival.

It's likely Homo sapiens arrived here during a brief thaw.

And by doing so, they had walked into a trap.

Europe was plunged into winter.

Unrecognisable to us today, it became a barren and hostile world.

Rainfall in some areas fell to half its modern level.

And much of the continent became tundra.

A vast, inhospitable plain.

All of a sudden, Homo sapiens were confronted by

a completely different world.

Frozen, relentless,

and utterly unexpected.

There's no way for them to have known it,

but before the first Homo sapiens arrived,

most of Europe would have been in the depths of winter.

Ice sheets like this one would have spread from here

all the way down to Britain.

Homo sapiens evolved in Africa,

so these conditions would have been completely shocking to them.

It's currently minus eight degrees.

I am wearing so many layers, it's actually ridiculous.

And yet, I am still completely miserable.

It is so cold, I can't feel parts of my face.

These families, they were here

and they were trying to keep young children alive.

These conditions would have been life-threatening.

But while Homo sapiens weren't adapted for the cold...

..Neanderthals had evolved to survive brutal

winters for almost 400,000 years.

They knew where to shelter and hunt for scarce food.

But survival was also in their biology.

It's thought they evolved to store more brown fat than Homo sapiens.

This burns more calories and generates heat,

conserving energy in the cold.

And larger nasal passages acted like natural radiators...

..warming and moistening the icy air before it reached their lungs.

When the going got tough, Neanderthals were built to endure.

Without the Neanderthals' adaptations or knowledge,

these early European Homo sapiens would have been doing

everything they could just to cling on.

And yet the bitter cold was just the beginning.

This glacier is the remnant of an ice sheet that's incrementally

grown and shrunk for millennia.

Deep within are clues about the world our ancestors

would have found themselves in.

We're working in mountain glaciers like Folgefonna

because we can use the evidence of how the glaciers have changed

in the past to understand how they behaved

in response to climate change.

Many of the places we live in now, where I live in Bergen,

would have been underneath a kilometre of ice. Yeah.

I mean, there were times when Britain was part of that.

The ice sheet came as far south as about Birmingham.

Birmingham, my own hometown. There we go!

So, this is where we're drilling the ice core. Yeah.

So, it's manual drilling? Yes, exactly.

And there's blades at the bottom that are cutting through the ice.

How tough is that? It can be quite hard work. Yeah.

And then we lift it out, and we bring it over here.

We can see... Look at that.

If we hold it up to the light, we can see the air bubbles.

So basically, this is effectively a time capsule. Yes.

And this is young ice from Folgefonna glacier.

But if this was from Greenland and it was deep, old ice core,

those air bubbles would tell us about what the atmosphere

was like in the past.

We can look at what we see from the ice cores in Greenland.

And this shows us how the climate

changed through that period in the North Atlantic region. Yeah.

There was a relatively cold

but stable climate from 70,000 to 60,000 years ago.

And then between 60,000 and 30,000 years ago,

the climate in this region jumped by eight to ten degrees warmer over

maybe one or two decades. That's quite a lot.

It's huge. It's huge.

And that cycle is repeated all through that period.

And then it cooled again and then jumped.

And this carried on.

And we see then a cold, but slightly more stable,

climate before we then warm into the present day.

I mean, how do you exist

if the climate changes like that in such an extreme fashion?

Well, it's very challenging.

It's maybe not even possible because everything you know

about how to live, how to raise children,

becomes in 10-20 years... Yeah. Obsolete. ..totally changes.

Yeah, yeah, yeah. Totally changes.

Entire ecosystems collapsed.

Forests became barren plains.

Lakes dried up.

And rivers froze over.

The real enemy wasn't cold.

It was chaos.

As landscapes shifted, herds of animals disappeared.

And sources of food grew scarce.

People were driven into unfamiliar territories

and forced to compete for what little remained.

It was a brutal time to be alive.

Imagine what it would be like for our ancestors to live in this

world where the land of their grandparents was not

the land of their grandchildren.

And when that happens, intergenerational knowledge -

knowledge that's passed on from one generation to the next,

that's so important for survival in these environments -

suddenly that knowledge isn't actually very useful

because the plants, the animals, the landscape, it's all different.

To survive, each generation had to discover the world anew...

..roaming further in search of dwindling resources

that might not be there.

Homo sapiens and Neanderthals would have been forced to find

shelter wherever they were able to...

..seeking refuge in the few habitable places they could find.

55,000 years ago,

the south of France was still in the thick of the Ice Age.

Yet, compared to the deep freeze of the north, it was

one of the more bearable places in an otherwise hostile landscape.

And here at Grotte Mandrin...

..archaeologists have spent over three decades

unearthing its secrets...

..layer by layer...

..revealing a place that was home to Neanderthals for more

than 80,000 years.

Shoes off. Yes. There we go.

Yeah.

Uh-huh.

So, what you're seeing here is phases of occupation

over 80,000 years. Yeah.

And because you've got incredible resolution, you can

really hone in on that.

Each layer has preserved a moment in time.

And from the treasures buried within,

it's possible to piece together different chapters of history.

For millennia, this cave was home to Neanderthals.

But one layer stood out, containing finely crafted tools.

Small and precise.

Techniques that suggested they were made not by Neanderthals,

but by Homo sapiens.

A suspicion confirmed when the Earth revealed another treasure.

That then is conclusive evidence that that layer with those

strange, unusual stone tools is definitely a Homo sapien layer?

Yes.

These discoveries tell us a story of one group of Homo sapiens.

Among the first to come to Europe...

..they had ventured into Neanderthal territory...

..seeking refuge in this cave in the depths of the Ice Age.

When we imagine the past, we often don't imagine children.

We imagine, well, a man, a caveman, right? Yeah.

But, actually, these were cave children. Yeah.

And you imagine what they were doing, were they playing?

They were playing.

But imagine to have been born, the first of your people

to turn up there - and we don't know,

they might have been born somewhere else - but... Yeah.

..it's fascinating.

Wow.

Using advanced dating techniques, a team were able to uncover

even more precise details about the people who lived here.

So people were building fires... Yeah.

..the fire created soot that would end up on the roof. Exactly.

And then bits of the roof would collapse

and end up in your archaeological layers? Yes.

It's literally telling you when they're using this place. Exactly.

By counting the microscopic layers of soot

deposited on the cave ceiling,

the team could tell how often these people came here.

But what happened to them?

This exceptional site tells the story of a group of Homo sapiens

pioneers who lived here in between tens of thousands

of years of Neanderthal occupation.

But then all traces of them vanished.

It's one small but very important chapter in our bigger story.

We don't know what happened to that particular group of Homo sapiens

from Grotte Mandrin, but it's likely that their story

reflects what was unfolding across the continent.

This wave of Homo sapiens was lured into Europe during a warmer spell.

They were pioneers for sure, but they were trying to

survive in a brand-new environment as best as they could,

as best as they knew how, really, finding temporary places to shelter

before in the blink of an eye moving on -

or worse, dying out completely.

Because that band of Homo sapiens from Grotte Mandrin

would be the last of our species found on this continent

for thousands of years.

Perhaps unprepared for the harsh environment they faced,

this early wave of Homo sapiens in Europe did not survive.

Once again, and for the next 9,000 years,

it became exclusively Neanderthal territory.

Neanderthals had survived while Homo sapiens died out in Europe.

Yet today, we're the only ones left.

How did our stories end so differently?

Part of the answer can be found deep

within the forests of northern Spain...

..where evidence hints that the grip of the Ice Age was

taking its toll on the Neanderthals.

A struggle uncovered in a cave known as the Tunnel of Bones.

Oh, wow.

So this is the famous El Sidron Cave. It is, yes.

It's got more character than I was expecting, actually. Yes.

And how did you find them?

Wow.

Such a diverse group in terms of individuals...

..all found in one spot.

And, you know, when you say that one of those people had red hair,

it suddenly brings what are just fossils, really, to life.

It's a cave that's filled with ghosts.

This was not a natural death.

Cracked skulls and precise cuts on the bones...

..suggest that this was a brutal massacre.

13 people killed by another Neanderthal group.

But closer analysis of their remains...

..revealed an even darker truth.

So what do the bones actually tell us?

They were really eating these 13 individuals? Yeah, yeah, yeah.

So how do we know that this was cannibalism as opposed to

just straight up murder - or, for that matter, an animal coming?

So you're looking for something sharp?

And now, you have a... Yeah, that's it, let's see.

Yeah. Yeah, yeah, yeah, yeah, yeah, yeah.

Yeah. So, they're focusing on the areas where there's muscle,

where there's meat, effectively. That's it.

Yeah. Oh!

Yeah, if you're getting bone marrow... That's it, yes.

..that is an indication of cannibalism, for sure.

Yes, it is, sure. Yeah.

This murder/cannibalism of 13 members of a family group

isn't the only dark thing that's happening here.

That's unusual, that's a congenital anomaly.

So, basically, you've got an inbred population.

It's painting a picture, isn't it?

Of those...those final thousands... Yes.

..thousands of years before they eventually became extinct.

Yeah, it's a silent killer. You're right.

The El Sidron bones hint at more than the suffering of one family.

Because this pattern of starvation, cannibalism

and violence was happening across Europe...

..this was a species in free fall.

This is a haunting place.

It's not exactly Neanderthals in their heyday, is it?

If anything, it's kind of like the end of days for them.

They've been driven into this evolutionary cul-de-sac,

reduced to eating each other

and having children with their relatives.

And that inbreeding would have made them more susceptible to disease.

If, on the evolutionary timescale,

12:00 midnight represents extinction for the Neanderthals,

this site is past 11:30.

This once resilient species...

..was now reduced to just a few isolated groups...

..turning on one another.

But any chance Neanderthals may have had of weathering this storm...

..was shattered by the return of another species.

Homo sapiens.

9,000 years after Homo sapiens had disappeared from Europe,

waves of settlers returned.

A new generation...

..who, even though the climate was as volatile as ever...

..were undeterred.

These were survivors, and they were here to stay.

Some archaeological finds,

their significance is immediately obvious, but others you don't

necessarily know what you're looking at until you suddenly do.

And this is a really good example of this.

This might not seem like a lot,

but actually it represents a massive step forward.

So what you're looking at here is

the imprint, in clay, of weaving.

Now we don't know if it was intentional -

it might have just been that there was some material on the floor

and somebody just happened to throw down some clay,

but they actually think that this may have been made with nettle.

And you're probably thinking, "Well, nettle, really?"

Well, that is probably a by-product of the modern world

and all the fabrics that we use, but actually this here is made of

nettle, and this is the woven fabric that they were able to make from it.

If you can make this, you can suddenly make better clothing...

..and you're able to protect yourself so much more from the cold.

Maybe those young children in a cold spell might have survived

a bit better if their clothing fitted better.

But you can't just think about weaving as being about clothing,

because if you can weave, suddenly your nets, your traps, are better.

You're able to get more food.

You're potentially able to make better shelter.

Whenever we talk about Palaeolithic technology,

you're probably thinking about spears or stone tools.

It's always weaponry, right?

Well, actually, this stuff might have really given them

the edge, as well.

It's likely the ability to make better clothing increased

infant survival, even in the harshest months.

Each advance, however small, added up...

..giving Homo sapiens the one thing Neanderthals lacked...

..strength in numbers.

The Neanderthals had existed for over 400,000 years...

..developing a rich culture...

..and withstanding brutal conditions for millennia.

But the relentless climate, dwindling resources...

..and another species growing in strength pushed them to the brink.

But what delivered the final blow?

How does an entire human species disappear

from the face of the Earth?

Part of the answer may lie in the smallest of things...

..the genes we exchanged in the form of our hybrid children.

I'm going to try and do a demo to explain genetics.

So let's see how this goes.

Let's say that these are the Neanderthals,

and these are the Homo sapiens,

and they interbreed.

We don't know where the hybrid children ended up.

Did they end up with the Neanderthals,

or did they end up with the Homo sapiens? So, let's just say,

they went back 50-50.

And we see a little Homo sapiens DNA in the Neanderthal group...

..and a little Neanderthal DNA in the Homo sapiens group.

The Neanderthals lived in small, isolated populations,

but the Homo sapiens were probably a little bit better

at keeping their kids alive.

And also, importantly, they were constantly replenishing

from source populations in the Middle East, Africa, and elsewhere.

Numbers made all the difference.

As more Homo sapiens migrated into Europe,

Neanderthals were already declining.

So, when the two interbred,

the impact on Neanderthals was far greater.

If you're a huge population, that interbreeding doesn't have

the same impact as it does on the much smaller Neanderthal population.

It's already a little bit interbred.

Perhaps they were simply absorbed into the larger Homo sapiens

population that just kept on replenishing.

Over time, Neanderthal DNA became increasingly

diluted by the much larger Homo sapiens population.

So, it doesn't actually need to be this big act of aggression.

It might just be the fact that we were there, that we

were interbreeding with them,

and that we had large population sizes.

Perhaps that was enough to push the Neanderthals to extinction.

It was a perfect storm for Neanderthals.

By around 40,000 years ago, their gene pool was diminishing...

..until only a handful of distinct Neanderthal populations remained...

..hanging on in just a few isolated enclaves.

We don't know where the last Neanderthal outpost was.

It was likely a very remote part of Europe or Asia.

But around 40,000 years ago, that place probably

acted as a refuge to the very, very last of their kind.

Archaeologists have pieced together what may be among the final

moments of Neanderthal extinction.

Uncovering remains of what could be

the last surviving Neanderthal groups.

Some of that evidence has been discovered

in coastal caves in southern Spain.

We don't know what truly happened in those final moments,

or who was left at the end.

But there was an ending.

Because after that, our sister species,

who had existed for around

400,000 years...

..vanishes from the archaeological record completely.

It feels like a moment of loss.

We lost something.

But also...

..it's part of the human story.

It's our story.

These were our ancestors.

On the one hand, it's hard not to be impressed with Homo sapiens.

And if we hadn't have been so successful, if we hadn't have had

this hunger to innovate, to explore, would you and I even be here?

And yet, those same things that make us so remarkable

seem to be damning to those around us.

This is where this chain of events ends.

A slow, unwitting war of attrition against our sister species...

..until they simply faded away.

But this wasn't the only ending.

After the last Neanderthals, the Denisovans -

the species who once spanned much of Asia -

may have survived for another 10,000 years...

..until they, too, were overwhelmed by Homo sapiens.

This story starts with three species, but it ends with one.

And it's part of a wider pattern that always goes the same way -

the survival of our species leading to the demise of everyone else.

Today, these events have faded from memory.

But it's not quite the end of the story.

Because we carry a piece of this history within us.

One of the most striking revelations over the last few years

is that everybody from outside of Sub-Saharan Africa

has about 2% Neanderthal DNA.

And that DNA is associated with negative things

like Crohn's disease,

but it's also associated with all kinds of positives,

like being better adapted to the cold.

And now we know that Denisovan DNA

has been found in Homo sapiens populations.

It's as high as 6% in the Philippines.

And it's associated with things like

being able to survive better at high altitude.

And if you think about it, it actually makes perfect sense.

Because when we were leaving Africa, the Neanderthals

and the Denisovans had already spent hundreds of thousands of years

adapting and evolving to their local environments and pathogens.

And so what we were doing by interbreeding with them

was effectively a quick fix.

We were adopting adaptations that would ultimately aid our survival.

Depending on where you're from, you'll probably find

traces of Neanderthal or Denisovan DNA within you...

..a genetic echo of the human story connecting us

to this long line of distant ghosts.

2% might not sound like a lot, but my 2% is different from your 2%.

And collectively, all of that Neanderthal DNA

that exists within humans living today

would make up about two-thirds of the Neanderthal genome.

And so in a very real sense, Neanderthals

and Denisovans have been assimilated into our bodies.

And it's just the loveliest thought, isn't it?

That they live on and exist within us.

Our planet was once home to many human species.

Bit by bit, they've all disappeared, leaving only one...

..the inheritors of their DNA.

..as the Ice Age reaches greater extremes,

we step into an unexplored continent...

..where new dangers lie in wait...

..starvation threatens...

..and humans have to fight to survive.