All language subtitles for BBC.Human.2025.1080p.x265.AAC.MVGroup.org_track3_[eng]

Where do we come from?

When did our story really begin?

Who were the first Homo sapiens?

Not just humans who looked like us,

but people who thought and behaved as
we do.

People we would recognise as truly one
of us.

We, Homo sapiens, first appeared over
300,000 years ago.

We were not the first species of
human.

We're not the biggest, we're not the
strongest,

we're just the latest in a long line
of other humans.

Yet, a few hundred thousand years
later, we are the only ones

left, and the most dominant form of
life on this planet.

How on earth did this happen?

I'm Ella Al-Shamahi, a
paleoanthropologist.

People spend their whole lives trying
to find

a fossil as significant as this.

You might think you know the story of
human evolution, but now

we are discovering it's stranger and
more dramatic than we ever imagined.

This was something that wiped out 13
people in the same family.

Thanks to ground-breaking new science,
we are

rewriting the story of our origins.

From our tentative first steps...

..to the migrations that carried us
across continents.

And our encounters with other human
species we met along the way.

It's small, it's really tiny.

I can see why you would call it the
Hobbit.

From the first marks we made on cave
walls...

..to the rise of cities...

..these are the unlikely events that
forged us.

Moments of chance, but also ingenuity,

of beauty and destruction.

This is us, this is our story, and
it's what happened

in the 99% of our history before the
invention of writing, when our

story wasn't written in books, but was
written in our bones and DNA.

This is the story of how we became...

..human.

This story begins in Africa, in a time
long ago...

..in a world before we existed at all.

In many ways, this world would feel
familiar...

..teeming with animals we'd recognise.

But there was one crucial difference.

This world was inhabited by not one,

but by many other types of human.

We're used to living in a world filled
with other species.

Over eight million share our planet
with us.

But there is only one of us, only one
human species, Homo sapiens.

And so, it's really easy to forget
that it wasn't always like this.

The world before us was alive with
other human activity.

Around six million years before Homo
sapiens appeared...

..some primates left the trees.

They started walking upright and over
time, began using stone tools.

These toolmakers became the earliest
form of human.

Over millions of years, these humans
continued to evolve...

..forming a diverse family tree of
different human species.

Who were these other humans and how
are we connected to them?

Well, they're all part of our extended
family,

so our parents, grandparents,
great-aunts, cousins.

Some were our ancestors, others just
relatives.

But all of them were part of our
lineage, our family tree,

that spanned millennia.

Around the time Homo sapiens
emerged...

..there were at least six different
human species.

And using the latest scientific data,

we can reconstruct what they might
have looked like.

There were so many species of human.

You had Homo erectus, an ancestor of
ours, and an incredibly

successful species, because they lived
for about two million years.

Now, Homo erectus was actually the
first in our genus to leave Africa.

And we also think that they were the
first to use fire.

There's also Homo neanderthalensis,

who you probably know as the
Neanderthals.

Neanderthals lived in Europe, all the
way into Central Asia.

They were cold-adapted.

And they were expert hunters.

There was also Homo floresiensis,

who some people affectionately call
the Hobbit...

..because they were only about a metre
tall,

so that's about three and a half feet.

Tiny, and yet adapted for living on an
island.

It seems like a fantastical world, and
I can't help it,

it reminds me of Lord Of The Rings.

Only, instead of a world with elves
and dwarves,

you had a magical place with other
humans.

The human family tree had many
branches.

But which branch did Homo sapiens
first emerge from?

We don't know for sure,

but we're getting closer than ever to
finding out.

For the longest time, we thought we
knew the origins of our species.

We thought we began 200,000 years ago
in East Africa.

But new revelations from out here in
Morocco,

from a part of Africa that people
weren't really considering,

are forcing us to rethink our very
first steps on this planet.

In a remote cave in North West Africa,

a chance discovery uncovered some
mysterious human remains.

Someone unexpected was living here...

..thousands of years earlier than we
imagined.

This is Jebel Irhoud 1, and it was a
complete mystery,

because some of its features are very
much like us,

very Homo sapiens, and others are much
older, much more primitive.

So, if you look at this individual's
face,

its face looks a lot like ours.

The Homo sapiens face is incredibly
gracile.

We have incredibly delicate features.

They, kind of, tuck in under our brain
case.

If you imagine a prehistoric human,

you kind of always imagine a much,
kind of more prognathic,

we say, much more kind of jutting
forwards face.

This individual's face is much more
tucked under, it's much shorter.

But there are some features that
aren't us.

Notice this brow ridge up here, this
supraorbital structure.

Now, look at me.

You don't get modern humans walking
around today with these

massive things on top of their eyes.

I mean, it would actually be quite
terrifying today if we saw that.

Now, the brain case is not us.

You see how round my brain case is?

It's globular, whereas this is almost
stretched out.

It's almost like somebody's got my
brain case but kind of

stretched the back of it out.

It's almost like straight-on, the face
is Homo sapiens,

but from the other angles, it's not
us.

These finds posed a mystery.

They were anomalies that didn't fit
neatly into the human family tree.

They looked partly like Homo
sapiens...

..and partly like an earlier human.

So, the question was, was this a
different species,

or could it be an early version of us?

Several decades after the initial
discoveries came a breakthrough.

Archaeologists uncovered another 16
fossils...

..all with the same blend of features.

With each new find, the evidence grew.

These were not some other species, but
Homo sapiens,

with hints of an earlier ancestor.

But it wasn't until archaeologists
were able to more accurately

date the remains that the final piece
of the puzzle fell into place.

The archaeologists, using new and
improved dating techniques,

were able to give us dates for these
fossils, and they tell us

that these individuals lived about
300,000 years ago.

And that is mind-boggling,

because we thought our species was
only about 200,000 years old.

What these fossils tell us is that our
species, Homo sapiens,

is 100,000 years older than we
thought.

We are a third older than we realised.

This fossil went from being enigmatic

and basically a mystery,

to being one of the most important
fossils in our whole field.

Thousands of miles from East Africa
where we thought we began,

and far older than expected...

..these are the earliest Homo sapiens
ever found.

And they have forced us to rethink
other finds across Africa...

..which are painting an entirely new
picture of our origins,

suggesting that Jebel Irhoud...

..was just one of many emerging
populations,

all in the process of taking shape.

It's...

It's a bit like having a peek behind
the curtain of evolution.

This is a stage in the journey to
becoming us.

I wonder what it would feel like to
come face-to-face with

one of the people from Jebel Irhoud?

If we were to look into their eyes...

..into those quite delicate features,

would we see ourselves within them?

The answer is, they were not modern
humans like us.

Not yet.

They were an earlier stage in our
evolutionary journey,

bridging the gap between us and our
ancient human ancestors.

Our emergence was actually slow, and
honestly, at the beginning,

we were just not that special.

Now, early iterations of Homo sapiens,
like Jebel Irhoud,

were popping up all over Africa.

We once believed in a single origin, a
sole cradle of humanity

in East Africa, but our story is far
richer and more interesting.

The latest evidence suggests we
emerged gradually,

across thousands of miles, and over
hundreds of thousands of years...

..appearing bit by bit...

..like a series of sparks...

..igniting across the African
continent.

THUNDERCLAP

And yet, Homo sapiens could have
easily vanished without trace.

Because just as we were finding our
place in the world...

..something threatened to wipe us out
altogether.

It's in East Africa's Great Rift
Valley that we can trace

the next chapter of our story.

This dynamic landscape holds some of
the clearest

evidence of the forces that set our
species on a radically new path.

When they say the Great Rift Valley of
East Africa is a dramatic

place, they're not kidding.

I mean, look at it.

I can literally hear it bubbling
behind me, and it's

the result of a geological process
that sees three tectonic plates

tearing away from each other, which
results in a dynamic landscape.

And even though this part doesn't look
that hospitable,

it has been a home to people for a
very long time.

This is one of the most fossil-rich
regions in Africa.

Its unusual geology has not only
preserved human remains,

but also offers a glimpse into the
forces that drove our evolution.

So, within the lakebeds here, if you
dig deep, you can

actually extract sediment cores.

Now, one here in Ethiopia was about
280 metres deep,

so that represents over 600,000 years.

And within that sediment, it's a bit
like a time machine,

because bits of ancient environment
are trapped.

By analysing these sediment layers,

scientists have uncovered a window

into the world some of the earliest

Homo sapiens were living in.

The information from those sediment
cores has been

collated into this graph, and when you
zoom out, it actually

paints a really interesting picture,
because for the first 300,000

years, you see a period of relative
climate stability.

But then, at around 275,000 years ago,
something shifts,

and we see a period of fluctuations,
volatility, between humid

and arid periods, in a way that just
wasn't happening before.

Now, East and West Africa are linked
in a kind of climate seesaw.

So, when one is humid, the other is
arid, and vice versa.

Over thousands of years, wild climate
swings engulfed Africa...

..plunging fledgling populations of
Homo sapiens...

..into a world of extremes.

Ecosystems were destroyed.

Rivers and lakes swelled...

..cutting people off from one another.

Elsewhere, grasslands turned to
desert.

Survival was a battle against
relentless change.

I do think that when we look at these
zoomed-out graphs,

we sometimes make a vital error.

We forget to zoom back in.

After all, human evolution is about
humans.

There are people like you and me
experiencing the peaks

and troughs of those graphs.

People who were suddenly facing
droughts, or flash floods,

or perhaps the disappearance of a food
source.

Entire communities...

..found themselves isolated.

Some populations dwindled.

The ones who couldn't adapt died out.

This struggle for survival could have
wiped

Home sapiens out altogether.

But it didn't.

It had the opposite effect.

It drove us forward.

Under pressure, isolated populations
learnt new skills.

Those who could adapt and innovate had
a better chance of survival.

Then, as the climate changed, groups
came back together.

They shared skills and crucially, they
interbred...

..passing beneficial traits on to
their children.

It was a process that began to change
us permanently.

The people who survived emerged
stronger than ever.

Today, most of us live in towns and
cities...

..and so, the reality of being
affected by the climate

as a result of being a nomadic person
kind of escapes us.

But you've actually got a really good
example here,

with the Afar people.

They are nomadic, and so they get
pushed

and pulled around the landscape.

And it would've been very similar with
our ancestors,

but actually in a more extreme
fashion.

These different groups, as they were
moving around,

would've at times met, and when they
did,

they would've, of course, shared
skills and knowledge and DNA.

It was this mixing of groups that
ultimately brought us

closer to becoming the Homo sapiens we
are today.

Our origins as a species are so much
more complicated and dynamic,

involving not just East Africa, but
the whole of the African continent.

Africa was a continent rich in
diversity, and climate acted

as a sort of catalyst, blending these
various groups together.

And so, we were formed as a result of
a mosaic of these

different populations across Africa.

It was our diversity, our resilience
in the face of climate change...

..it shaped us, our minds and our
bodies,

and transformed us into a new and
evolved human.

We all carry an echo of what happened
in Africa

at this pivotal moment...

..because what happened then changed
us forever.

What began as diverse, scattered
populations...

..in the face of adversity came
together...

..propelling us to become one
stronger, smarter species.

This is a museum that houses some of
the most important

fossils in the human story.

And one of those fossils is Herto 1,
easily one of the most

significant Homo sapiens fossils that
has ever been found.

And that's because this individual is
one of the very first

in our lineage that we can describe as
an anatomically modern human.

Its physical characteristics

and traits are overwhelmingly similar
to those of yours and mine.

And if you look at this individual
compared to Jebel Irhoud,

look how rounded it is.

Some people have put forward this
intriguing idea that perhaps

the shape of the skull reflects a
change in brain organisation.

This process of globularisation has
been linked to language skills

and coordination.

And it is really exciting to consider
that this

change in shape reflects a really
significant shift in the way

that Homo sapiens were starting to
think.

These larger, reorganised brains had
slowly

but surely opened a gap between Homo
sapiens and our ancestors.

But it wasn't only the size

and shape of our brains that set us
apart.

One of the lines of evidence for this
are actually the teeth.

Now, scientists have discovered that
if you look very

closely at the teeth, what you find
are very fine lines called

perikymata, that represent about a
week in the life of an individual.

So, that means you can count how long
an individual has been

alive, a bit like tree rings.

And so, if you look at a Homo erectus
individual

and compare it to, say, a Homo sapiens
living today,

our species takes an incredibly long
time to get to sexual maturity.

From the lines in their teeth, we know
that Homo sapiens

children were growing up much more
slowly than earlier humans.

The thinking behind it is that we
needed a really long time to

learn how to use these brains of ours.

And the longer that you exist in
childhood,

the longer you have to learn.

And so, this thing that is a real
headache to so many parents

out there today, that our children
take so long to become fully

formed, that might actually be a huge
key to our success.

Reorganised minds and longer
childhoods,

our brains and bodies had evolved.

At last, we were Homo sapiens who
physically looked like us.

What you might call, Sapiens 2.0.

It was some of these anatomically
modern Homo sapiens that

began to step out into the wider
world.

But beyond Africa was already home to
other humans.

Neanderthals had spread across Central
Asia and Europe.

Other parts of Asia were populated by
multiple species,

including Homo erectus.

And there is evidence in the Middle
East

of an early group of Homo sapiens...

..who followed in the footsteps of
these other human species.

I do love thinking about those huge
moments in our history,

like when Homo sapiens first left
Africa.

It was a massive achievement, even
though

they would've had no idea of the
significance of it.

And it's amazing to think that it
happened so early on in our story.

But it's in the Levant that I think
things get really interesting.

Evidence has been uncovered of a
community of Homo sapiens

living in caves, in what is now
Israel.

And it's in this place they would

have encountered something unexpected.

There is one mountain called Mount
Carmel where one cave,

called Skhul, has been found with Homo
sapiens.

And another cave on the same mountain,
called Tabun Cave,

has been found with Neanderthal
individuals.

And these two peoples were living at
the same time.

It is kind of wonderful to think
about.

And of course, the Neanderthals were
not an African species,

they were used to living outside of
Africa,

whereas for us, this was still very,
very new.

Two species sharing the same mountain.

We don't know if they interacted.

But we do know that while Neanderthals
remained

in the region, all traces of this
group of Homo sapiens vanished.

Their bloodline died out completely.

What is most fascinating about these
Homo sapiens isn't who

they met, it isn't even what they
achieved.

It's that all of these early
dispersals failed.

We know from genetic evidence that
those Homo sapiens are not

the ones who would go on to ultimately
populate the planet.

This failed migration was a stark
reminder of our fragility.

These people looked like us, but there
was something missing.

Because what really defines our
species isn't how we look.

It's not even the size of our brains.

It's something else altogether.

While these early migrants vanished...

..populations in Africa thrived...

..displaying that special essence that
makes us who we are.

A way of thinking and behaving that
would set Homo sapiens apart.

And some of the earliest traces of it
can be found in this

remote cave in Botswana.

- This is a very large natural
outcrop.

And as you can see, it goes on and on.

It's seven metres long.

The front has a natural slit for a
mouth,

and a natural depression for an eye.

And even if you want to go that far, a
nostril up at the front.

- Right.
- With the head rearing up, it does,

in modern eyes, look like a snake.

The overall form has been altered

to make it look even more snake-like.

There are over 300 indentations that
have been ground into the

surface over what is obviously an
extended period of time.

When the initial excavations were
conducted,

they absolutely revealed a number of
questions.

One of the things found was an
extremely large

number of tools that appeared to be
manufactured

and then just left there in pristine
condition.

- These look gorgeous. I mean, they
absolutely look stunning.

- Once they were manufactured, then
you did one of three things with it.

You either manufactured it perfectly
and just left it.

- Mh-hm.
- Or more interestingly, you burnt it.

But not burnt to just, like, throwing
it in a bonfire.

It's controlled burning.

And the third and most bizarre thing
that they did with them

is they made it, manufactured it
perfectly,

and when they were finished, turned it
over, smashed it in the middle.

- These are offerings, aren't they?
- Yeah.

The only thing that makes sense, the
on... The best fit

is that they're sacrifices, they're
offerings.

They're not doing it for fun.

They feel that coming up and doing
this act would satisfy some

kind of a need, some kind of, um, a
wish, some kind of a desire.

Although it's absolutely magnificent
during the daytime...

..it comes to life at night.

- We can't speak to these people, but
this...

..this whole place, it gets us

so much closer to what they were
thinking, what was going on inside.

- Yeah. We had always had the
impression that this type of

abstract thinking would've been beyond
the ancestors at that time,

and now we definitely have evidence
that that was absolutely wrong,

that they obviously had the ability to
hold abstract thought.

You make an offering and hope for
something back.

- Asking for probably some of the
things that we would ask for -

food, health, children, etc, etc - and
you just think,

"Oh, my gosh, that's some of the...
That's some of the earliest

"behaviour that we know so well."

Some believe the people who performed
these rituals must

have been holding abstract ideas in
their heads...

..imagining things they couldn't see.

A clue their minds were sparking and
forming connections in a new way.

When I see this, this is what moves
me,

because this is who we are, in a way

that feels more us than bones.

See, it is so familiar to us.

We know this behaviour. This is
ritual.

Whether it is religion and
spirituality, or things

like the handshake, or birthdays,
graduation ceremonies, Burning Man,

Glastonbury, New Year's Eve, we are,
as a species, obsessed with ritual.

It is profoundly and fundamentally
Homo sapiens behaviour.

It's us. We know it.

It was as if they were able to see
beyond the tangible.

They were thinking beyond what was
just in front of them.

They were venturing into the unknown
and into the unseen.

Behaviour like this marked a new
chapter in our species' story.

Our minds were awakening, opening up
to a world of possibility.

This wasn't confined to ritual.

It touched every part of our lives.

Around 70,000 years ago,

new weapons began appearing across
Southern Africa.

Homo sapiens were using abstract
thought to innovate.

Inventing complex projectile weapons,
like the bow and arrow.

We were seeing the world not just as
it was, but as it could be.

It takes a lot to see the potential in
a piece of wood.

Projectile weapons were revolutionary
technology for us

humans, because up until now, we'd
been using close-range

hunting strategies, which were less
effective, less lethal,

and yet more dangerous for the person
holding the weapon.

For over two million years, early
humans mostly relied on axes

and spears.

But Homo sapiens imagined unseen
forces like the power

held in wood and string.

Creating something entirely new.

If you look at this bow and arrow, you
can

see how much knowledge is required.

You need to know where to get the wood
for the bow, you need to

know about the glue, you need to know
how taut the string should be.

So many elements that require, not
just knowledge,

but the ability to pass that knowledge
on.

Something like this is not the result
of one person's genius.

It's the result of many, many people,
over many generations,

inventing, reinventing, perfecting,
tinkering.

We weren't just inventing.

We were adapting and expanding our
knowledge.

Human culture was becoming more
complex,

that technology was exploding.

Now, many of us think that this is a
result of something called

cumulative culture, the idea that you
accumulate culture, so every

generation builds upon the previous
generation's science and technology.

With cumulative culture, Homo sapiens
were becoming

collectively smarter with every
generation.

And as our numbers increased, this was
more powerful than any weapon.

A giant leap towards becoming the
species we are today.

When was our species truly born?

Was it when we first appeared?

Or when we started to look like modern
humans?

Or was it when our minds lit up?

Creating, inventing, and building on
our knowledge.

Each was a crucial step in our
evolution.

But none would be possible without one
special ingredient.

The glue that binds all of our
achievements together.

It leaves no direct fossil evidence,

but we can find traces of it in some
unexpected places.

In archaeology, sometimes the smallest
finds actually tell

the grandest of stories.

These are tiny marine shells,

and shells like this have been found
in caves in South Africa,

and they are just too small to have
been collected for meat.

If you look really closely, what you
see is that they have holes in them.

Now, some of these were collected
because they already had holes,

but others were perforated by Homo
sapiens.

And really close examination of the
shells in these caves show that they

had wear marks on them consistent with
having been worn on the body.

So, that, along with these holes in
them, well, it's really easy to

paint a picture of them having been
strung...

..and turned into jewellery.

These weren't just beads, they were
emblems.

Symbols of value and meaning...

..shared and understood by everyone.

They've been found with pigment on
them,

and it's always the same-coloured
pigment, it's red ochre.

Even though ochre comes in yellow,
black and red, it's always red.

Perhaps you were trading them for
food, for goods,

perhaps you'd give them as some kind
of a gift at a wedding,

perhaps they were just a sign of
friendliness.

And you can also imagine that people
would be wearing them

to make themselves look good, it would
perhaps be a sign of prestige.

The making and sharing of these beads
was one more

sign our species had made another
revolutionary leap.

The ability to pass on knowledge and
technology,

sharing rituals and traditions.

All these things suggest Homo sapiens
were passing

sophisticated ideas from one mind to
another.

Our species had unlocked the power of
complex language.

The most remarkable thing about these
shells is that they

have been found not just in South
Africa, but all over Africa,

from the south, all the way to the
north, in Morocco and Algeria.

Not just along the coasts, but all the
way inland.

And that, for me, is so exciting,

because when you look at this,

you might think, "Oh, my God, isn't
that amazing?

"Humans have a kind of cultural
expression

"that they never had before."

While earlier humans probably had
basic language...

..it's thought Homo sapiens were
speaking to each other

in a more complex way.

Weaving a shared culture.

And forging an invisible bond that
united our species

across the entire continent.

All over Africa, we understood the
cultural symbolism

of these beads.

Somebody was telling you, "This shell
is important, not that shell.

"Red is important, not the other
colours."

We had an understanding that wasn't
just you, me,

and our three families, you, me, and
the village next-door.

We had a kind of symbolism and
understanding

and interconnectedness that was
continent-wide.

This has never happened before.

For me, this is the birth of our
species.

Our species' birth wasn't a single
moment.

It unfolded over millennia.

Complex language and our powerful
shared culture finally set us

apart from humans before us.

We had become one connected,
cooperative species.

We had become Homo sapiens...

..the ancestors of us all.

Sometimes in life, things come
together,

and this was a coming together for our
species.

It was a perfect storm.

You had a change in brain, you had
language, increased numbers,

increased connectivity, cumulative
culture, better technology

and weaponry, and the right climate.

But through all of this, there is a
hidden thread.

Our secret weapon is that we are a
social, cooperative species.

Friendliness, it turns out, is our
superpower.

We are more than the sum of our parts.

Whether it's ritual, technology,
language,

all of it comes down to cooperation,
in my opinion.

And that's how you go from a species
that started off feebly,

unremarkably, to one that would

become so extraordinary,

one ready to explore this planet.

..we follow our ancestors as they
spread beyond Africa,

taking on extreme environments no
others could master...

..travelling beyond the realm of
another extraordinary

species of human - the Hobbit.

And eventually, even reaching the
distant land of Australia.

Over 300,000 years ago,

Africa was the cradle of humanity -

the place where humans evolved,

including the first of a new
species...

..Homo sapiens...

..our species.

From humble beginnings, our growing
culture

and connections helped us spread
across that great continent.

And then we ventured outwards,

away from our home, and into the wider
world.

Our ancestors did something which is
actually remarkable.

From a beach not unlike this one,

possibly quite close by,

they ventured out into an open ocean,

with only an empty horizon in front of
them.

And after many days and nights on the
water,

they eventually came upon this new
landmass that they would settle.

We call that landmass Australia.

It was a pivotal moment in the history
of our species.

But in so many ways, it's not actually
the destination

that's important.

It is everything it took -

all the challenges they had to
overcome

to make it so far away from where they
began, in Africa.

We were not the first humans to leave
Africa.

Long before we evolved,

the ancestors of our cousins,

the Neanderthals, set out.

And Homo erectus, one of the most
ancient humans,

had made it deep into Asia.

But none had ever made the voyage to
Australia.

Every other species of human reached a
point, and then they just stopped.

They faced a barrier that they either
could not or would not pass.

But not us.

This is the story of how, time and
again,

we took on perilous journeys -

how the last species of human to
evolve

took on environments like no others
had,

to become the only global species of
human.

That title is ours and ours alone.

This story begins over 120,000 years
ago.

As our species spreads beyond the
borders of Africa...

..they're blocked by expanses of
oceans on most sides.

One of the few places they can go is
east -

to the vast landmass that today is
made up of

Arabia and the Levant...

..at this time one of the few gateways
out of Africa

to the rest of the world.

Of all the species of human that have
ever existed,

I think we, Homo sapiens,

are the explorer species.

We can't help it - we have to wander.

It is in our wont to travel.

And this place was the landmass next
door.

You could see it from Africa.

And look at it! It is absolutely
breathtaking.

But it's not exactly welcoming.

Nothing about this place says home.

And so, the question is,

why did Homo sapiens come here?

We know they did,

thanks to finds from Israel and Saudi
Arabia,

to the Gulf States.

And even beyond - to the fringes of
Europe and Asia.

Which is hard to explain,

when today these lands look just as
much of a barrier as any ocean.

I always say archaeology is a bit like
a jigsaw puzzle,

and you're just constantly looking for
pieces of that puzzle

to help you get the full picture.

And this is one of those pieces.

This particular piece is

a copy of a tooth.

Now, it's a single tooth, which gives
you an idea

of how large this animal must have
been,

because it's bigger than a brick.
It's...

I mean, it's practically the size of
my head.

It is the tooth of an extinct
elephant,

and it was found in Jordan.

And we also have hippo fossils

from the Saudi desert.

Now, hippos and elephants

do not belong in this landscape.

Look around!

Where's the water?

Hippos actually need standing bodies
of water,

and they need greenery.

And that's the thing about some
fossils.

They tell us about what a landscape
used to look like.

Because these do not belong here.

These finds point to a very different
Arabia.

One that, if you know where to look,

you can see hints of to this day.

If you look over there, it almost
looks like a mirage -

that white and silver on the
landscape.

So that used to be a lake,

and the white and silver is actually
salt and gypsum

that was left behind when the water
evaporated.

And scientists are really interested
in not just ageing them,

but also working out these ancient
water systems -

these extinct water systems.

And so one of the ways they do this is
by just getting on the ground

and walking these beautiful but
incredibly intense landscapes,

looking at maps, looking at satellite
images.

And this is the result of some of that
work.

Now, if you look here,

this is a map of the region

just slightly north of here.

So this is Saudi, which is to our
east,

and that there is the Sinai of Egypt.

You can see it's basically shades of
beige and grey.

Now, look!

So this is about 125,000 years ago.

Water litters this landscape.

I mean, you can see the veins just
running through.

There is no way that this land

would not have been green.

There are paleo lakes and paleo rivers
absolutely everywhere.

And this is this region as we have
never known it.

Now, remember, this was a world
without borders,

and this was a land of plenty,

within easy reach.

And so why wouldn't Homo sapiens have
come here?

But what they didn't know,

what they couldn't have known,

is that this region would be a trap.

The green days of Arabia were
numbered.

The desert was on the march.

Subtle variations in the orbit of the
Earth

caused the climate to change.

Within as little as a few hundred
years, the rains vanished,

starving this entire region of
water...

..leaving humans at the mercy of the
desert.

If you set out to create an
environment that was completely

and utterly hostile to our biology,

you'd come up with this.

The heat is such a presence

that I can feel it on my back.

The sun, even at this time of the
morning,

feels like it's borderline torture.

And there is no water.

As far as the eye can see, there's
nothing.

And back then, it would've been so
much worse.

It wasn't arid.

It's what we call hyper arid.

It's thought that there was no
rainfall for years on end.

And so we go from seeing multiple
sites

where humans lived in this region, to
nothing.

We seem to vanish for thousands of
years.

And this could so easily have been the
end of our journey...

..defeated by the harsh desert.

We think that some Homo sapiens

clung on in pockets that we call
refugia.

Those are refuges where the climate is
milder.

But from all we can tell,

they would've been few and far
between,

and they effectively faded away.

And so, for all intents and purposes,

Homo sapiens outside of Africa had
failed.

And what's interesting is

other species of human had cracked

the code of living outside of Africa,
but not us.

And so how did this happen?

People like me, so many of you,

how did we become the only species of
human

who exists across the globe?

These brutal conditions

persisted for years on end.

Until finally, there was another
subtle change in climate...

..allowing conditions to become less
extreme...

..and giving Homo sapiens another
chance.

Occasional seasonal rains returned...

..just enough to bring precious water
back to the desert.

Now, the conditions here did get
better.

So, yes, you had desert and sand
dunes...

..but you also had lakes and rivers.

And that resulted in us being able to
exist in this place,

but not just exist here.

From an oasis here to a river and
spring system there,

we were able to actually leave the
Arabian Peninsula

and face the rest of the world.

As they did, these new waves likely
absorbed any small pockets

of Homo sapiens that had held on.

And now scientists studying the
genetic code

of people alive today believe this
moment

was a pivotal point in our history.

Our DNA has the power to tell stories
about us,

but some of them aren't just stories,
they're sagas,

and they're extraordinary.

And one of them is that every single
one of us

whose origins are from outside of
Africa

comes from a tiny population of Homo
sapiens.

We started in Africa, from multiple
populations across the continent,

but then only a small group of us left
-

perhaps as few as 10,000 individuals.

And so all of us from outside of
Africa

come from this minuscule population,

who went on to populate

not one, not two continents, but five.

But our journey through the desert...

..was only one of a multitude of
challenges

Homo sapiens would face

as we spread across the globe.

And because we were so few in number,

our very survival outside of Africa

was far from certain.

As this tiny population grew and
spread...

..they would crash into another
extreme environment.

One that had defeated all other
species of human -

a vast green wall.

Once beyond the desert,

our species found themselves in the
giant landmass of Europe and Asia.

To their north, lay high, cold
mountains.

So many spread eastwards and south,

down through what is now the Indian
subcontinent,

reaching modern-day Sri Lanka,

at that time joined to the mainland

by lower sea levels...

..and dominated by expansive dense
rainforests.

And while this may look so much more
welcoming than the desert,

nothing could be further from the
truth.

These leeches are absolutely
everywhere.

And when I say everywhere, I mean, one
has just got me.

And there are creepy crawlies
absolutely everywhere,

including in our trousers.

And they are actually quite
irritating.

This place is also full of mosquitoes.

We saw a viper, and a cobra.

And that's the thing about this place.

It is difficult to exist in.

It's hot, it's humid, it's oppressive,

and you have to constantly have your
wits about you.

This is one of the most extreme
environments on the planet.

So much of what grows here is
poisonous to eat...

..and there are few large animals to
provide meat.

Conditions so difficult

that, as far as we can tell,

no other species of human

ever made it past the fringes of these
rainforests.

Being here is a bit like stepping back
in time,

because about 50,000 years ago,

this place would have basically looked
the same.

This huge cave mouth would've been
here.

Only back then, the rainforest
would've been unbroken,

and it would've gone on for kilometres

in every single direction.

And yet, somehow, in this cave

and two other caves not far away,

we have found evidence of our
ancestors living here,

all the way back then,

in the heart of what would've been a
massive rainforest.

So how were Homo sapiens able to
plunge into a place no others had?

How did they find food - particularly
meat?

They did have the advantage of
bow-and-arrow technology,

which had arisen thousands of years
earlier.

But heavy, stone-tipped arrows

were less suited to firing into the
high canopy of the rainforest.

Their solution was uncovered thanks to
over 30 years of excavations

deep into the floor of this - and the
two other two caves.

Digs that reach all the way back

to 48,000 years ago,

when the pioneers of our species

first attempted to overcome the
challenges of this rainforest.

Starting with one of the most
difficult -

how to find enough meat to sustain
them.

Yeah. So, this here, that's where
somebody is cutting?

- Yeah, yeah.

- Yeah.

Yeah. It's funny, because I think
butchery marks,

often need to look at it through a
magnifying glass, but not always.

And actually, this one is quite clear.

And this is not the kind of thing that
you would see

if an animal killed it.

This is an indication that this is
killed by a human.

And so the question is how they killed
them.

Right.

So, that chip mark there...

..shows us that it was actually used.
- Yes.

- I mean, it's amazing, because this
is obviously...

I've got in my hands right now

something that was used 48,000 years
ago.

- Of course, of course.
- And it was absolutely revolutionary.

These bone points are only the tips of
the full arrowheads.

Many are chipped from actually hitting
prey...

..and each one would have been
attached to the end of a long wooden
arrow.

These hunters didn't invent a
brand-new technology...

..they adapted an old one.

These are some of the earliest
examples of bow

and arrows found outside of Africa...

..enabling Homo sapiens to hunt

with exceptional skill and efficiency
within the forest.

But we know that the humans living
here

were doing more than just surviving.

Oshan and the team also found beads
fashioned from shells.

Perhaps brought in through trade from
groups living on the coast.

A constant struggle to survive...

..doesn't leave much time for making
works of art..

..suggesting a long-established and
successful community existed here.

And for that, to turn this place into
a true home

would take something fundamental to
our species.

This is...

..a replica...

..of a tool that was found in the
caves

in this area, dated from about 40,000
years ago.

It is a monkey tooth, specifically a
canine, but that's been modified.

If you look here, it's been cut into,

to create a much sharper point.

And the reason for that...

..is that it's a tool used for
puncturing.

Oh.

It's not easy.

All right, look, I've finally managed
to make a hole.

And once you make a hole, you can then
use plant fibre,

animal sinew, as a string, start
stringing animal skins,

animal hide together, and create
clothes.

But actually, in so many ways,

that's not the most interesting thing
about this tool.

Because for me, the most interesting
thing is what this tells us

about the minds of the people who have
made it.

Because you have to be taught how to
use it.

You have to be taught how to make it.

So it actually tells us something much
deeper.

Throughout the years humans made this
cave their home,

countless elder generations

would have taught children these
techniques.

Something we still do to this day.

A communal passing on of knowledge
that is key to our ability

to master so many different
environments.

That engagement, constant engagement,

turns every generation of children

into a step in the evolution of
knowledge.

And for us Homo sapiens, that's
probably what adaptation is,

the evolution of knowledge,

because it's what turns a simple
projectile like a bow and arrow

into a weapon fine-tuned, honed, and
specialised for the rainforest.

And that constant innovation unlocks
resources that were

completely out of reach to other
species of human.

Resources like the rainforest.

And it's this ongoing evolution of
tools

and techniques that has allowed our
species, time and again,

to live and thrive even in extreme
environments.

That is the strength of our species,

that we were opening up so many new
environments,

places that previously other species
saw as impenetrable,

as too difficult, we saw as having
long-term potential,

and we were able to expand in number,

we were able to then adapt to it.

And as we grew, some people would
decide to move on

to yet another environment.

We were becoming a species with truly
global potential.

It was that ability to take on so many
different, challenging

environments that carried us through
so much of the world...

..by now, to the fringes of Europe...

..into the cold expanses of northern
Asia...

..and, within only a few thousand
years of leaving Africa,

deep into Southeast Asia.

Lower sea levels had created a single
region known as Sunda...

..where today there are sweeping
stretches of tropical waters.

Our wandering feet brought us to its
outer edge.

Beyond lay an ocean, dotted with
isolated islands.

There are these places that you turn
up to and you think,

"I'm on the edge of the world."

They are incredibly remote and
isolated,

and this is one of those places.

And it's been like this since the very
beginning,

since its formation,

because it's been surrounded by this
very deep sea,

which makes what was found here even
more intriguing,

because a mind-boggling, completely
unexpected human history

plays out here over hundreds of
thousands of years.

Even all those years ago,

the ocean could not stop the spread of
our species.

We reached these remote islands,
thanks to a technology that,

as far as we can tell, we are the only
humans to master.

This is a tuna fish bone.

This particular one happens to be
quite fresh.

It's a few days old.

But we have actually found tuna fish
bones on an archaeological site

on these islands that dates back to
over 40,000 years.

But tuna swim in open waters, and that
means that our ancestors,

over 40,000 years ago, they were
fashioning some kind of vessel,

and going out into the open waters,

and coming back again, and again, and
again.

We can't be sure what form these
vessels took,

since no evidence survives,

but they were probably simple rafts
made from available wood.

And they did more than just help us
fish.

There is a very interesting
archaeological site

on one of the neighbouring islands
that has this one layer

that is just filled with artefacts
belonging to Homo sapiens.

But the layer just before it,

immediately preceding it, is empty and
barren of those same artefacts.

So it almost suggests that our
ancestors just kind of turned up

overnight and spread rapidly through
these islands in large numbers,

just because of the sheer volume of
artefacts within that layer.

And none of that would really be
possible

unless you were skilled enough to
build robust craft,

you were skilled enough to navigate
treacherous waters.

But in a truly surprising twist, we
were not the first to reach Flores.

Somehow, someone made it here before
us.

Sometimes in this job, you get to
fulfil a lifelong dream,

and one of them is about to happen.

See, there's this cave in
palaeoanthropology that isn't

just fascinating, it's basically
explosive.

It started in 1950,

with this one priest called Father
Theodor Verhoeven.

Now, back in the day, it was actually
quite common

for priests and missionaries to also
dabble in archaeology,

so he was out here on Flores looking
for archaeological sites.

And in talking to locals,

he got told about this one cave that
had potential.

He turned up, it was actually being
used as an amateur school,

but just below the surface, he did
actually find archaeology.

Actually, it was stone tools belonging
to ancient humans.

Now, that in of itself is huge, it's
really significant,

but it would take another half a
century before we understood

just how important this cave was.

For over 20 years, a joint Indonesian
and international

team of archaeologists has been
excavating these caves.

They had been searching for evidence
of the spread

of Homo sapiens through the islands.

Instead, they found something
completely unexpected...

..a strange skeleton from at least
70,000 years ago.

So long before our species reached
this far from Africa.

I think the first thing obviously that
strikes you

when you see her is that she's very
short.

Um, what are we talking, one metre?

Right, so about three and a half feet?
- Yeah.

- It's got wisdom teeth.
- Yes.

- Yeah. I mean, the molars are... The
adult molars are there.

Yeah, yeah, yeah.

As soon as you look closely, this is
100% an adult.

- Yeah. Yeah.

- An adult, but the size of a child.

And that was only the first surprise.

The legs, they're quite short.
- Yeah.

- Whereas, with us...

Our legs are really long...

..compared to arms.

Yeah.

Yup.

Which is huge...
- Is huge, yes.

- ..because on me that would be about
that length.

I mean, this is one of those moments
in the history of the field

where I just wish I had been there.

I know she's a replica, but she's a
replica of the real thing,

and, yeah, it's...

It's giving me goose bumps.

This new species of human was a
revelation.

Named Homo floresiensis, after the
island,

they quickly became known to many as
"the hobbits," after the

heroes from the Lord of the Rings, who
were also small as adults.

It's likely they arrived entirely by
chance. Perhaps a few

individuals swept here on driftwood
from the islands to the north...

..more than 700,000 years ago.

Eventually becoming a unique species,

seemingly with a mix of modern and
more ancient characteristics.

Now, we can see obviously the brain is
small,

but how small are we talking?

That...
- That's right.
- How incredible.

Such a small brain, and yet they had
stone tools.

Before this, scientists assumed that a
human with such a small brain

could never have developed such tools.

One theory is that they were initially
a much larger

species, before the long isolation on
Flores caused them

to shrink, a process known as island
dwarfism,

where large animals get smaller due to
fewer resources.

At the same time, some small animals
actually get bigger,

due to a lack of predators.

So Stegodons generally are not the
size of water buffaloes.

- Exactly, yeah.
- But on this island...

- It's big one.
- ..they're the size of a water
buffalo.
- Yeah.

- And then on this island, you've got
humans that are a metre tall.

- Yeah, that small.

- What you're describing there is a
species that has been

shaped by this island, has been

shaped by the environment on this
island, and the result is this.

Long isolation allowed evolution to
tailor the hobbit

to this environment.

Their long arms, compared to short
legs,

a response to perhaps the steep
terrain,

or the lack of predators on the island
to run away from.

Physical adaptations that, along with
those simple stone tools,

helped them survive here for hundreds
of thousands of years.

You can see, it's like layers of cake.
- Yes.

- So every period has left a layer.

So this is like a snapshot in time,
telling us

a lot about different periods.

That's basically flow from volcanic
eruption?

- Yeah.

- Mm-hm.

Right.

Right.

So Homo sapiens.

That's really significant.

So the pyroclastic flow is when you
have the gas

and material that comes from a
volcanic eruption,

and really, I mean, that would just be
quite destructive.

- Yeah.

- We don't think that that final
eruption alone caused

the extinction of the hobbits.

It would have been a catastrophic
event here at the cave,

but we don't know how it affected the
rest of the island.

What we do know is that this shows the
time of the hobbits here

was coming to an end.

So you're looking at actually quite a
different world down there,

to up there. Yeah.
- Exactly, yes, exactly.

- This tiny island has been home to
two species of human.

One remains to this day.

One vanished long ago.

It is wonderful to imagine what this
place was like before all of this.

Thousands of years before our
ancestors, you had these

miniature elephant-like creatures who
wandered open grasslands.

You had actual dragons, the Komodo
dragons, who still exist.

And then giant marabou storks - storks
that were carnivorous,

that were my height or taller, and
could fly.

It was like a fantasy island.

And amongst all of it,

there were these humans who were tiny,
who came up to about my hip.

And those hobbits lived here on this
island for a staggering

length of time, potentially for more
than 700,000 years,

longer than we've existed as a
species.

And yet, there is this twist, because
so far,

we have found no evidence of them past
these shores.

Their whole story plays out only on
this island of Flores.

Our own species, in just a fraction of
that time,

was able to spread across a huge
portion of the globe.

Around 50,000 years ago, the climate
here became warmer and drier,

changing the environment.

At the same time, those violent
volcanic eruptions also struck.

Whatever the reason, it meant that
Homo floresiensis faced not

just change, but rapid change.

That meant that their physiology,
their physical adaptations,

that for so long had been a benefit,
were now a trap.

They were being left behind, because
it's actually incredibly

difficult to rapidly evolve your way
out of a sudden crisis.

And they couldn't behaviourally adapt
to this change either.

Nor could they, say, escape and move
to another island.

And so these wonderful, fantastic
relatives of ours vanished forever.

And in their place, Homo sapiens
appeared, making this island,

like so many places, their home.

So far, we've found no evidence that
our two species overlapped.

But for many, the final factor in the
hobbit's extinction

is likely our sudden arrival.

The hobbit simply couldn't compete

with this highly adaptable newcomer...

..a species able to change its
behaviour

to suit almost any environment and
condition.

The very characteristics driving our
continuing spread across the globe.

As we spread further and further away
from Africa,

entering into brand-new environments

that we had never experienced before,

we're not just surviving in these
places,

we're actually setting down roots.

And roots that would last us till this
very day.

There was one last part of this
journey to go.

We set out on a path no other human
species had travelled...

..perhaps following tantalising hints

that there was more land to explore.

Clouds on the horizon, returning
flights of birds...

..or maybe something much more
instinctive that inspired,

we think, dozens of families to strike
out on a voyage that

would carry them to a new continent...

..Australia.

Now, these were people who were
comfortable on the water,

they were going from island to island,

but Australia was something different.

We're talking about a journey that was
up to 100km,

60 miles.

That's days and nights on the open
ocean,

probably in something as basic as a
raft that was perhaps being

propelled and steered with just
paddles.

Launching out into that hostile and
expansive ocean,

that would be an expedition today, let
alone back then.

When I think about the risk involved,

when I think about the emptiness, it
is just absolutely astonishing.

The islands of Indonesia were another
waypoint

in our ongoing journey.

Our unique adaptability that helped us
cross the harsh deserts...

..and break through the barrier of the
rainforest...

..now carried us practically to the
ends of the Earth.

To Australia, around 9,000 miles from
where we began.

Which does beg the question, what kept
driving us on...

..ultimately inspiring us to take on
the dangers of the open ocean?

It's true that there will often have
been a push.

The simple need to find new resources

for our expanding population.

But I would argue that that is not the
full explanation,

that this is the most intangible part
of the story.

See, these people, in my opinion, were
just like us,

so they had the same fears and hopes
for their families.

We are clearly the explorer species.

I think that is beyond a doubt.

And, as a result,

we have been able to take on things
that seem absolutely impossible.

In that desire to understand what was
out there,

in the thrill and excitement of
understanding the unknown,

and the willingness to take risk to
know it.

See, wanderlust, creativity

and the imagination required to put
yourself in a different place,

into a different future and world, I
think that is fundamentally us.

We chart the spread of Homo sapiens
into the expanses of Europe

as our species struggles to survive in
the grip of a cruel Ice Age

and comes face-to-face with another
sophisticated species of human...

..the Neanderthals, who had long
mastered life in these cold lands.

In this episode, we filmed at a place
I've long dreamt of visiting,

one of the most important human
archaeological sites of all,

Liang Bua cave...

..where scientists are still trying to
solve the many mysteries

surrounding the hobbits, the ancient
humans that lived here.

In 2004, their discovery sent shock
waves through

the scientific community.

- So, the moment the paper's dropped,
it was massive.

It was all over the news.

It was all over the internet.

Everyone was talking about this tiny,

unexpected hobbit from Indonesia.

- Paige has known Thomas and the team
since 2017,

documenting their research.

Like many scientific breakthroughs,

the initial discovery created intense
controversy.

- The conferences got extremely
heated.

Sometimes there would be hobbit
sessions where within the same

session, you would have a few talks
would be sort of pro hobbit -

so, "This is a new species, this is
really exciting,

this is changing a lot of what we
thought we knew

about human evolution" -

and then in the same session,

you would have people that are saying,

"This is the biggest mistake

"that human evolution scientists have
ever made."

- Many argued that this was not a new
species,

but a Homo sapiens suffering from an
illness that caused its small

physical features and brain size.

Eventually that was discounted, and
Homo floresiensis was recognised

as a new species of human - raising,
if anything, even more questions.

- We still don't know, for example,

where they came from or who they're
closely related to.

So that question of the origins of
Homo floresiensis is still,

I would say, almost completely an open
one.

- It's possible they evolved from
another ancient

species of human, such as Homo
erectus,

which we know was in the area just
over a million years ago.

Perhaps carried to the island by
chance,

and then shrunk down over many years
of isolation.

But there is an even more
controversial idea.

- If you look really hard at a lot of
the characteristics,

particularly below the cranium...

..you see that this is a creature

that looks a lot more like some of our
really ancient ancestors,

more than two million years old, in
Africa.

And so maybe there was an exodus out
of Africa a million years

before we thought there was.

- This current dig might reveal the
answer.

With help from the Max Planck
Institute in Germany,

researchers are trying to collect
fragments of hobbit DNA.

- Ancient DNA is really helpful at
really laying out

relationships for us between different
species across time.

And so, because of the way that
mutations accumulate over time,

it allows us to kind of work backwards

and trace back when some of those
lineages would have split.

Homo floresiensis, and whoever their
closest ancestor is,

which is not a question we can answer
until we kind of

have some of that information.

- The problem is successfully finding
hobbit DNA will not be easy.

- Normally it would be impossible to
recover DNA from a situation

where it's this hot.

It's just too difficult.

DNA degrades really rapidly, and other
things move in

and muddy up the signal, like bacteria
and other things.

But in this cave in particular,

it is at a slightly higher altitude
than a lot of Indonesia is,

it's right up in the mountains,

and so it is a little bit cooler than
most equatorial areas.

And so there is a little bit of hope
that we might be able to

get a little bit of a signal from the
species.

- If successful, we might finally
solve the mystery of the hobbit.

Whatever happens, Homo floresiensis
will remain one of the most

important and unexpected discoveries
of recent history.

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.

For 270,000 years, our species, Homo
sapiens,

lived in a world inhabited by other
types of human.

We hunted and foraged for food,

alongside many of our human relatives.

But one by one, we out-survived
them...

..and spread across the planet as
small bands of nomads...

..until we'd reached almost every
corner of the globe.

But a great landmass still evaded us.

The Americas.

As we entered this new world, we would
face ferocious predators...

..and towering giants.

MAMMOTHS BELLOW

But how we took on these challenges...

..and the ways we began to tame nature

in our journey through the Americas...

..would set us on a path to how we
live today.

It's a chapter of our story

that begins in one of the coldest and
most dangerous times

humans have ever known.

At the height of the last Ice Age,

a time when sea levels were lower than
today,

people were spreading from East Asia

into a place that no longer exists.

A vast land bridge called Beringia.

WIND HOWLS

And in this frozen north,

small groups of travellers dispersed
ever eastward...

..and found themselves stepping into a
new land.

If you were asked to conjure up in
your mind

a world that was magical, that was
pristine, that was primal,

you'd imagine something like this.

The northwest coast of America
absolutely takes your breath away.

We don't exactly know when humans
first arrived in North America...

..but many archaeologists believe

it was sometime around 20,000 years
ago.

A time when this would have been a
challenging place to live.

They were here at one of the coldest
moments Homo sapiens had ever known.

And the landscape would have looked so
different.

There would have been very few trees.

And, as far as the eye could see,

there would have been barren, icy
rock.

They knew how to survive

in the barren lands of Beringia that
they'd come from.

But their new environment was
different in a few crucial ways.

The northern half of this continent

was covered in a vast, towering ice
sheet.

From here in the northwest,

this wall of ice blocked routes into
the deep interior...

..largely confining people to the
ice-free land nearer the coast.

WAVES CRASH

All that's left from their time here

are footprints, stone tools, and
animal bones.

Now, we know that they sometimes would
have hunted seal,

they would have eaten fish,

they would have eaten seabirds if they
could catch them.

GULLS CRY

Only tiny fragments of evidence
remain...

SLIDE PROJECTOR CLICKS

..that hint at how they survived.

And whilst this northwest coast

offered them steady but limited
sustenance,

the strip of land between the shore
and the ice sheets

promised new opportunities to find
food...

..but also hid unexpected new dangers.

Oof.

This is a now-extinct predator,

and it would have roamed these parts
in the northwest

when the first people arrived in the
Americas,

and they actually call it the
short-faced bear.

And there is nothing short about this
bear.

When it stood on its hind legs,

it would have been about 11, 12 feet
tall.

That's about four metres.

And so it would have made the grizzly
bear look...

..actually somewhat manageable.

And then look at these teeth, look at
these canines.

The stuff that nightmares are made of.

And when it bumped into humans...

..it must have been absolutely
terrifying.

And just like those humans,

these bears, too, would have been
hungry.

But the early people of the northwest

did not run from the monsters that
roamed this land.

Instead, it seems, they went on the
offensive.

Signs of their bravery remain in caves
along the Canadian coast.

Here, archaeologists sift through the
muddy layers of time...

..to find out more about the risks
these early people took to survive.

You know when people talk about
archaeology?
- Yes.

- At the back of a cave, digging mud
is...

..is... This is the hard stuff.

- One thing that has been found

in a number of caves on the northwest
coast

is, er...spear points in association
with bear bones.

- Yeah.
- And these date as far back as 13,000
years.
- Mm.

So is this one of these spear points?

- This is a fragment of a spear point

that was found in a cave not too far
from here.
- Yeah.

- We have uncovered a bone in the wall
of this unit.

And it's, er, 20 centimetres below the
surface.

And, er, so I'm going to pull it and
we'll see if it moves.
- All right.

And we don't know what species it is
or what bit of bone it is?

- Er, there's not enough here to know
for sure.
- Yeah.

- But it is a pretty big mammal, for
certain.
- Oh, look at that.

THEY CHUCKLE
Oh, it's not ending.

- Just make sure it slides out.

- Ah, it's a rib, isn't it? Is it?
- It looks like a rib.
- Yeah.
- Yeah.

So that could be a bear rib.

It's probably most likely what it is,
cos it's quite robust.

- How amazing.

What age do you think it is?

- Well, we have some other samples
from above where this bone is.
- Yeah.

- And they're coming back, er, around
14,000 years old.

- OK. So it's old.
- So it could be the same age or
older.
- Yeah.

You know, one of the most wonderful
things about archaeology

is that sometimes you uncover
something

that hasn't seen the light of day in
thousands of years.

And in this case, well, maybe 14,000
years.

- Well, we're interested in where
bears were hunted in the past.

And in the winter,

when there's... There's not as many
resources around

and people are feeling a bit hungry,

knowing where there is a bear den is
quite a valuable thing,

cos you can come up there and dispatch
the bear.

You'll have a load of meat, fur, as
well as bones.

- One theory of how they hunted bears

would have meant getting perilously
close.

- Essentially, a hunter would go with
a party to a cave,

smoke the bear out of the cave,

and entice that bear to attack a
single hunter.

That hunter would be armed with a
bracing spear.

A bear would come, er, to take the
hunter up in a bear hug,

which is a common thing that they do.
- Yeah.

- And the idea is a bear would take
that hunter

and cru, er... essentially give him a
good crushing.

The hunter, at the same time, would
brace the spear on the ground

and aim it at the bear's heart.

And so essentially the bear would
take...
- Oh...

- ..the hunter and the spear into the
bear hug,

thereby spearing itself through the
heart.

- A successful bear hunt could have
meant food through the winter.

But not every hunter survived.

This is the bone cast of the oldest
adult

to have been found along this coast.
They were born 10,000 years ago.

And this individual has been given a
name - Shuka Kaa.

And there's so much we don't know
about this person.

We don't know about their family life.

We don't know if they had children.

But the amazing thing about bones

is that they can tell a story if you
know how to read them.

We know that this individual was a
male.

We can tell that from various
features,

like the squareness here of the chin,

like the back of the mandible,

like the angle here on the pelvis.

On a female, you would typically
expect that angle to be much wider.

And it's kind of sad

because you can also tell quite a
tragic story on the bones as well.

If you notice here -

that is a puncture wound,

and it fits quite well with the canine
of a bear.

And so we think that this individual
possibly met their demise

because they were hunting for bears.

The dangers early humans faced down in
order to survive

are hard to imagine now.

But their precarious relationship with
this unforgiving land

had begun to shift...

..thanks partly to a surprising form
of help.

WOLVES CHATTER

By hunting in packs,

wolves can bring down prey far larger
than themselves.

A person, especially on their own,
would be highly vulnerable.

- Good girl. Yeah.

It's unusual to have them all just
around, hey?

OK, come on. Let's go.

- Wolves are, and always have been,
wild animals.

Shelley, am I able to come a bit
closer?
- Yep.

- I think the question is, how close?

It's funny, I can feel it in my
shoulders.

My shoulders are a little bit tense.

But, given time, wolves are able to
habituate to humans.

Hello.

WHISPERING: Hello.

From around 40,000 years ago, probably
in Siberia,

before humans had even reached North
America,

the threat they faced from wolves

began to transform into something
different.

Now, we're not exactly sure of the
details,

but it might have gone something like
this.

Wolves would gather around human
campsites.

Now, at first, maybe humans were
terrified.

Maybe they thought that they wanted to
eat them.

But actually, some of those wolves
weren't interested in that at all -

they were looking for scraps.

And as they were doing that,

maybe they started fending off other
predators

and protecting our combined territory.

And because of this, humans started
tolerating

some of the least aggressive, some of
the most docile of these.

Maybe they even started feeding them.

We were reshaping wolves into dogs...

..and began to use them...

..to guard our camps...

..hunt prey...

..and pull sleds.

Generation after generation,

we selected the most docile animals
and reared their pups...

..driving the evolution of a
cooperative behaviour

that suited our needs.

This marked a turning point for the
human species.

Living with dogs helped us hunt for
food and survive.

It gave us this much-needed edge over
hunger,

but it also marked this profound and
completely unprecedented shift

in our relationship with nature.

Because never before had any living
thing,

whether plant or animal, been
domesticated.

This was a complete first.

Unbeknownst to us, we were becoming
curators of nature

and gaining more control over our own
fate.

But powerful forces far beyond the
control of any human

were about to open new gateways into
the North American continent.

And as people answered the call of the
interior,

far beyond the mountains and glaciers,

they would be forced to find entirely
new ways to survive.

A fresh wave of human innovation would
be triggered

around 15,000 years ago, when the
climate began to warm.

The ice sheets and glaciers started to
retreat.

And as they did, the last major
barrier

blocking routes into the continent
fell.

The first people to enter into the
Americas

were coastal people in the northwest,

but it's likely that they eventually
travelled

incredibly rapidly down south, all the
way to Central America

and then carried on all the way to the
tip of South America.

Because remember - they were coastal
people.

It's likely that they were using some
kind of seafaring method.

So, very early on,

some humans would have started to
enter the continent

from along this sea route.

But when the ice sheets eventually
started to retreat,

many new routes would have opened up.

More people started travelling into
the interior of the country

and finding these completely new
landscapes.

Some of the first humans to reach the
interior

left traces here in New Mexico.

SLIDE PROJECTOR CLICKS

Fossilised footprints.

Left in the muddy shore of an ancient
lake.

The people who made them

may have been part of one of the very
earliest waves

of what was to become 10,000 years of
human migration inland.

Where there is now desert, they saw
rich grasslands.

The fossilised footprints of these
continental pioneers

reveal what kind of a world they'd
stepped into.

These are the footprints of an actual
human being

who stood basically where I'm
standing.

And we think she was a female.

And if you look closely at those
footprints,

what you see is that, at times, the
footprints,

they get broader and they slip a
little in the mud.

SLIDE PROJECTOR CLICKS

And that's because

she was carrying a child.

Sometimes on this hip and sometimes on
this hip.

Then at other times, she stopped and
put the child down,

and you end up with two sets of
footprints.

SLIDE PROJECTOR CLICKS

And she walked for at least a
kilometre north,

and then heads back south.

I just can't think of anything
more...more human

than a mother and a child walking
together,

and a mother carrying her child.

And it's interesting, cos this whole
journey

has been us tracing the footsteps of
our ancient ancestors.

And in a moment like this, that's
actually literal.

Archaeologists are finding more of
these footprints,

left by a female or possibly an
adolescent male carrying a child,

hidden beneath the hard, packed sand.

It's allowing us to piece together an
ever more detailed snapshot

of what happened in the moments
captured here.

- Let's see if we can define the
footprint a little bit.
- Yeah.

It's always scary when you start these
things.

You've got to...

..take them out.

- There's a subtle difference between
the soil in the print...

- It's looser, it's a little damp, so
it's going to smear a bit today,

but it will come out.

- You see it so...

..so clearly.

OK. So how have you...? So you've just
traced along the...?

- I've just... I've literally just
broken the surface

with the dental pick.
- Yeah.

- And then this particular example

just brushes out with a little bit of
encouragement.
- Yeah.

- And you can see the contrast between
the white...
- Yeah.

- ..and the fill in there. I'm
removing the...
- Wow.

- ..the sediment that's blown into the
footprint.

- So we think she was walking quite
quickly, then?

- Yeah, she's walking at about 1.6,
something like, metres per second.

- Wow.
- And, and a comfortable, normal sort
of walk is about 1.3 to 1.5.

So she, she's moving. And this surface
is wet, it's slippy.

We do know that this was a mission.

They were on a mission.

They were moving quickly at speed, for
whatever reason,

and the footprint, um, tells that
story.

- Why that person was hurrying might
be explained by evidence nearby.

Other footprints, each one around two
feet in diameter...

..left by mammoths.

And crisscrossing the footprints of
the mother and child

are the tracks of a giant ground
sloth.

Out in the open, with dangerous
animals close by,

the mother was perhaps seeking safety
for herself and her child.

This landscape would have been filled
with mammoth and mastodon

and sabre-toothed cats - just huge
animals.

They would have dwarfed us.

The mammoth alone would stand at about
four metres high,

that's about 13 feet, at the
shoulders,

and the mastodon were only slightly
smaller.

For the humans here, this was their
new world.

The early people of the plains

would have given these prehistoric
mammals...

..a wide berth.

SLIDE PROJECTOR CLICKS

But they must have realised

that those animals also represented
opportunity.

That these grazing giants could
provide them with food...

..if they could find a way to bring
them down.

We know they eventually found a way to
do this

because they left a massive clue.

SLIDE PROJECTOR CLICKS

Skeletons of this megafauna.

Some clearly killed by humans.

Humans would have exploited some
megafauna,

some large land animals on the coast,

but it was once they hit the interior

that they saw them on a scale like
something else,

in terms of their sheer numbers, in
terms of their diversity.

But how on earth could people hunt
these giants?

BIRD CALLS

CRICKETS CHIRP

One animal still exists which gives us
a sense

of just how difficult that would have
been.

RUMBLING

HOOFBEATS RUMBLE

This beast can sprint at up to 40mph.

The male's horns are over two feet
long.

And, 14,000 years ago,

these bison had an even bigger
prehistoric relative

roaming these parts.

WHISPERING: Absolutely incredible, but
they're also so...

..big. They're about one tonne in
size.

And the giant bison, the one that's
now extinct,

but would have been around back then,

was up to 50... 50% bigger.

HOOFBEATS RUMBLE, BISON SNORT

It's one of those things, I think -

today, you can romanticise the idea of
these hunts

and you think about them as some kind
of,

you know, adrenaline-filled adventure,

but it's harder to grasp that,
actually, back then,

it would have been filled with fear
and risk.

Only a powerful spear thrust could
penetrate the giants' hides...

..so hunters needed to get close.

ALARM CALL

Many hunts ended in failure.

They needed a technology upgrade.

Up until this time,

the way spear points were attached to
their shafts

was a serious weakness.

SLIDE PROJECTOR CLICKS

Spear points frequently broke on
impact...

..until the design was altered.

A subtle shift at first glance,

but one that would change everything.

This is special.

So, it's about 18 centimetres long.

It's pretty sharp.

If we look at the shape,

it's long and narrow with the broadest
point being quite low down.

Notice also this thinning here
compared to the middle.

It's thought that the shape might help
with the penetration of hide,

and it's thought that this might help

with reducing shattering on impact.

We call it a Clovis point,

because it was found near Clovis in
New Mexico.

The narrow base of the Clovis points

allowed them to be slotted firmly into
the spear shaft,

better absorbing the force of impact.

From archaeological finds,

we know this new design rapidly spread
across the continent...

..and the technology continued to
develop.

Within 500 years, these points had
evolved

into more slender and sharper forms...

..able to penetrate deeper into
prey...

..and archaeologists think these spear
points

were delivered with such lethal force

because of another piece of
technology...

..whose use was exploding.

So this is a replica spearhead,

and it's been hafted or attached on to
a wooden shaft.

So, this would have been quite an
effective weapon,

but this is where technology gets
really interesting

because it's thought that one of the
ways that they threw these spears

is with a spear thrower.

So you'd attach it to the top here,

and then you would effectively use it
to...

..propel the spear forward.

At that velocity, you're more likely
to pierce the hide of an animal.

And to me, it's...

It's especially interesting because
what you get with this

is the ability for female hunters to
be more effective,

because suddenly it's not just about
strength, it's also about skill.

The new hunting technologies

allowed people to take down the
largest animals in their world.

Humans had become the apex predator of
the plains,

and now feasted on a glut of meat.

Our hunting prowess was shaping
society here.

This is absolutely stunning.

It's one of the most striking
spearheads I've ever seen.

It's... It's so well-crafted, and it
shines,

and it looks like it was made of glass
-

but actually, it's made of quartz,

so it's incredibly strong and it's
sharp,

and yet it doesn't have any signs that
it was actually ever used,

and that, along with the fact that
it's so beautiful,

suggests that it was ceremonial.

Now, when you've got an everyday
object

and it's made to look so... so
beautiful, and so striking,

it implies that it had become a
symbol.

We're not sure of what - perhaps of
how important hunting was,

but perhaps of a cultural identity,
perhaps of who they were.

Feasts began to bring different
communities together...

..and cement social ties.

Sharing meat fostered cooperation.

Food was fuelling a culture.

In the midst of this abundance,

it must have felt as if it would go on
forever.

But their world was changing.

The end of the Ice Age

that had gifted them this warm world
of plenty

was now beginning to have an effect
they could not have foreseen.

It's thought that melting ice at the
poles disrupted ocean currents.

Temperatures in the northern
hemisphere

rapidly cooled by several degrees.

Across North America,

the vegetation had begun to alter in
unpredictable ways.

In some areas, trees and shrubs

began to replace grassland and tundra.

SLIDE PROJECTOR CLICKS

Woolly mammoths could not effectively
chew or digest

these woodier plants...

..and as their environment
transformed...

..the giant herbivores dwindled.

Over the space of just a few hundred
years,

three-quarters of the large animal
species in North America

became extinct, vanishing forever.

I imagine it must have been a shock
for the early people here

to witness the megafauna disappearing,

because that's what they would have
seen -

and they're such a part of your
culture and your diet

and your lifestyle, and suddenly
they're not.

That... That must have been quite
difficult to comprehend.

Now, the main cause of the giant
megafaunal extinction

is climate change, but it's likely
that human hunting played a role,

that it was this final nail in the
coffin -

and so, perhaps unknowingly, we humans
tipped the balance of nature.

The once bountiful land of giants

had become a pile of bones.

All the hunting technology in the
world

could do nothing to reverse this
catastrophe.

The people here were plunged back to a
time before the feasts.

With these animals gone, how would
they now find enough food?

A clue lies in ancient holes carved in
the rock.

People needed to branch out

and exploit every part of the food
chain,

all the way through to something you
probably don't think of as food -

and that's acorns.

Now, these are incredibly bitter
because they're full of tannic acid,

and to get rid of some of that,

what they would do is they would
firstly get rid of the shells,

and then they would grind the nuts up

with water in the hopes of getting rid
of some of that bitterness.

And...honestly, acorns sound
disgusting

and they taste disgusting.

They're still incredibly bitter -

and yet it's likely that the flour
from these and the paste from these

were some of the earliest processed
plant food.

We actually have some of the grinding
stones

preserved in the archaeological record
-

and if you look at all this, it seems
so clever,

it seems so inventive,

and yet it's a lot of effort to go to

for what are essentially some really
unpleasant calories.

If you were starving, no question
you'd do this...

..and with the loss of the megafauna,

people's survival now hinged on
smaller game

and foraging for plants.

But there had to be another way.

The solution people came up with in
the Americas

would be found in tropical forests to
the south.

This place, it has...

It has real challenges.

There are plants - so many of them
look edible,

and yet some of them are definitely
poisonous.

It requires a process of trial and
error to find the actual food.

It was in a forest, archaeologists
think in present-day Mexico,

that a momentous change took place -

and it began with the simplest of
actions.

Every so often, someone would have
come across a plant

that was safe to eat,

and would have sought out more of it.

An example of this is this grass
called teosinte.

Now the seeds are incredibly small and
hard,

but they can be ground up into an
edible flour.

So, that same ingenuity that humans
brought to acorns,

they were now bringing to this grass.

Where people found teosinte growing,

they encouraged it by weeding out
other plants...

..and collected the seeds for food.

This may have continued for
centuries...

..until one individual would have
become the first person

in the Americas to do something
completely original

with a teosinte seed.

There is something so magical about
planting a seed, watering it,

and hoping that it sprouts

and becomes a tiny little delicate
green shoot.

And there would have been somebody

who planted the very, very first
seed...

..and they would have - they would
have known

that it would require effort and care

and protection from herbivores

if it was to ever become something big
enough

to feed their families with.

And anybody who's ever had an
allotment, or a garden,

or a balcony knows how much care and
commitment goes into it.

This was an idea whose time had come.

Because humans all over the planet
started to plant seeds

and grow them for food...

..and it was an experiment that began
to pay off.

Because across the world, the people
who did this

were creating a more dependable way of
feeding their families,

and so triggered a pivotal moment for
our species.

In different places all over the
Earth,

humans were inventing farming.

Probably first around 10,000 years
ago,

in the Fertile Crescent of the Middle
East,

where we domesticated wheat...

..then rice in China...

..sugar cane in present-day New
Guinea.

Farming emerged independently

in separate locations across the
globe...

..Central and South America among the
first.

Here, people created what would become

one of the three most important staple
crops

for feeding the world...

..because as the early farmers planted
and harvested teosinte...

..they began to shape it into a new
kind of plant.

Every so often, a genetic mutation
would arise in teosinte

that would actually be quite
beneficial for humans -

that would give rise to, say, larger
seeds,

or more seeds, or sweeter seeds -

and, perhaps most important of all,

would get rid of the hard seed
covering,

and humans started selecting for these
better varieties,

and over thousands of years, they
created something new,

that looked very different from
teosinte -

because they created maize.

It was no longer a wild plant.

It was now a domesticated crop.

The invention of farming was to set in
motion a change

that would go far beyond how we fed
ourselves.

The clue is in that word, "plant" - to
be put down in one place -

and just like the plants that they
grew,

those early farmers would have had to
have adopted

a very similar lifestyle.

Because you couldn't exactly keep
moving

if you had to tend to your crops,

and so, for the very first time since
the birth of Homo sapiens,

we were no longer a completely nomadic
species.

More and more of us were quite
literally putting down roots.

Farming supercharged our capacity to
fuel human activity...

..and what emerged was extraordinary.

Here in South America,

there's a place where they began a new
way of living

on an unprecedented scale.

The stepped pyramids of Caral were
once lost under the desert sand.

Archaeologists are now uncovering a
vast complex of structures.

And what made it possible to build
these extraordinary edifices...

..were the fields of crops that
surrounded them.

Caral became an immense hub for
trading food.

It represented a new path humans could
take

towards permanence and stability...

..but for our species to choose that
path

was not a foregone conclusion.

I just can't help but think,

what would it have been like

for people visiting it for the first
time back then?

Because they would have never seen a
city before.

It must have been so alien to them.

It must have looked like a place from
a different world.

This was a commitment to a static way
of life -

and yet we don't consider how
tumultuous

the process might have been,

how much social upheaval might have
been involved -

because for those who chose to lead
this life,

it must have come with a huge cultural
shift,

because humans were becoming an urban
species

for the very first time.

Humans across the planet stood at a
fork in the road.

For almost 300,000 years,

we had survived as nomadic
hunter-gatherers...

..but settled lives as farmers

promised a more reliable way to feed
ourselves

and plan for the future.

The choice most of our species took

would bring dilemmas and dangers we
could never have imagined.

In the final chapter of our Human
story,

we begin to live together in ever
larger numbers -

but open a Pandora's box...

..of death and chaos...

..as we seek ways to harness human
knowledge

on our path to the modern world.

In this episode, we filmed at a place
I'd long dreamt of visiting.

White Sands in New Mexico.

Underneath the surface of the desert
are sets of fossilised footprints.

They've become the subject of some of
the most ground-breaking

but also most hotly debated research
in archaeology.

In 2018, the discovery of the double
footprints,

possibly a mother and child,

revealed vivid details about who the
early people here were...

..and what animals roamed alongside
them.

- When we first started seeing the
human prints

walking alongside a mammoth print,

when I'd first seen it, I was like,
"Uh, that's not possible,"

but it takes a while to understand
what you see,

and then you go back and you start to
understand them.

- But the prints themselves were just
the start -

because, in 2021, new research on
their age

sent shock waves through the
scientific world.

- There's been a lot of ideas when
people got to the Americas.

Some of the main theories is there's a
large ice sheet

and people weren't really able to
enter this area

until about 14,000 years ago, until
that ice sheet melted.

- When humans first arrived in North
America,

an ice sheet covered the northern half
of the continent.

If no humans had been able to
penetrate the interior

until it had melted,

then the oldest the footprints could
possibly be is around 14,000 years -

but the dating of the footprints

seemed to overturn that conventional
view.

- We put in a trench at the edge of
the lakeshore

and we're finding prints

that were dated above and below the
prints,

so we can see the soil chronology.

- The footprints themselves can't be
carbon dated -

but fossilised plant seeds

trapped in the mud near the footprints
can be,

and carbon dating of seeds

in the layers above and below these
footprints were explosive.

- So, we don't know exactly how old
they are,

but we're looking at the lake
sediments,

and what we see is there's at least 11
different layers right now,

and those range from the top of the
sediment to the bottom,

from 21,000 to 23,000 years old.

- The dating research suggested the
footprints

went as far back as 23,000 years ago.

If true, it would mean humans had set
foot in North America

thousands of years earlier than many
scientists had long believed.

- So, at White Sands we see people
here

before the last glacier maximum,

before there was these last ice
sheets,

people were already here.

- The very early dates are
controversial.

Further research will be needed

to confirm how old the White Sands
footprints truly are.

If they date to before the melting of
the ice sheets,

did those pioneers travel around the
ice?

Despite the debate,

the footprints remain one of the most
important archaeological finds

of recent history,

with huge significance for the entire
question

of when humans first set foot in the
Americas.

Around 300,000 years ago,

our species, Homo sapiens,

evolved in Africa.

For generations,

small bands of hunter-gatherers
explored the planet...

..learning to survive.

Many other species of human walked the
Earth alongside us,

but one by one, we supplanted them...

..until only we remained.

For most of our history, our
population was tiny and fragile.

Every aspect of our lives determined
by the natural world.

And yet...

..everything would change.

Today, there are about eight billion
of us,

most of us living in cities, like this
one,

able to connect in an instant with
people across the planet.

And you might think it was inevitable,

the result of progress over time, but
surely, our story so far, if it

teaches us anything, it's that none of
this was a foregone conclusion.

So, how did we get here?

How did humanity transform from
scattered

groups of nomads into our modern,
interconnected world?

What happened in that final chapter of
our story

that took us on a path to this place?

On a remote hilltop, in the far east
of Turkey...

..stands a prehistoric monument
steeped in mystery.

It is so hard to stand here and not
have goose bumps.

This is the oldest temple unearthed
anywhere on this planet.

It was built 11,500 years ago by
hunter-gatherers.

That's 6,000 years earlier than
Stonehenge,

and yet somehow, our ancestors were
capable of making this.

This is Gobekli Tepe.

There are these incredible T-shaped
pillars,

which would've been holding up a huge
roof.

And then, if we look at them, they're
covered in these engravings.

So, this is a fox, there's vultures
here, there's bear,

there's wild boar, and here, this one
just has to be my favourite.

It's a leopard, hunting one of those
wild boars.

So, notice these holes here.

This was dressed with furs and they
were also painted.

So, you get the impression of this
place as being beautifully

coloured and textured.

And yet, this incredible feat of
architecture is not the most

revolutionary thing about this place.

Gobekli Tepe is not simply a temple.

It is a marker of a species on the
cusp of change.

In many ways,

these prehistoric builders lived as
their ancestors had for thousands

of years, their days spent foraging
and hunting to feed their families.

ANIMAL GRUNTS

But they'd made one fundamental
change.

After generations spent as nomads,
following the herds...

..here at Gobekli Tepe, they stopped
moving and settled down.

The evidence for which lies not in the
temple itself...

..but in the rubble surrounding it.

Now, this might not look like much
compared to that,

but this small square building is
actually

the remains of one of the first
permanent houses ever built.

That there is a storage vessel, this
is a grinding stone for wild

wheat, and this floor of plaster and
stone, this was somebody's home.

This is one of the first villages.

Archaeologists believe maybe a few
hundred people

were living here permanently...

..and calling it home.

For 300,000 years, Homo sapiens roamed
freely.

But now, they were gathering together
to put down roots.

And so, the question is, why?

And why now?

This was a world of plenty...

..warm and abundant.

But the planet had not always been
this way.

Only a few generations earlier, Homo
sapiens had been

fighting for survival...

..through the brutal peak of the last
Ice Age.

Now that local areas could provide
plenty of food,

people could spend longer in one
place,

and when large groups came together to
share their bounty, a feature

of our brain had an opportunity to
flourish like never before.

Our almost limitless capacity to
learn.

An ability with roots that can be
traced way back,

right to the beginning of the human
story.

As the distant ancestors of our
species were gradually evolving...

..they had begun developing larger
brains.

But as their brains grew,

the way they were organised was
evolving too...

..becoming increasingly adaptable, and
more able to

change in response to stimulation from
the outside world...

..until they became us...

..a species brilliant at learning,

both from our experiences and other
people.

The major thing that marks our species
as different isn't

just the size of our brain, it's also
the way they're organised

and their extraordinary flexibility.

Now, we call this flexibility
neuroplasticity,

because it's like our brains are
plastic.

They adapt, they alter and they
change.

It has some profound effects.

Humans have a natural affinity for
observing

and copying each other...

..giving Homo sapiens the ability to
have a

shared understanding of the world.

At Gobekli Tepe, the symbols of their
shared experiences

and beliefs are carved into the stone.

And these indicate a bigger shift in
our species.

The odd thing about being human is
that we are constantly

surrounded by a bunch of things that
are so all-encompassing, and yet we

never really think about where they
started or where they come from.

I'm talking here about culture.

Ritual, custom, language, art, stories

and ideas that have been passed down
orally through generations,

and have now found physical form.

Places like Gobekli Tepe became so
rich in meaning

that our ancestors never wanted to
leave, and culture flourished.

Cooperating and building connections

are what our brains are actually set
up to do.

Wherever humans settled down, an
explosion in creativity

followed, launching an era of
extraordinary innovation.

We can see the results of this shift
in the archaeological record...

..which begins to seethe with the
debris of new technology.

Our ancestors couldn't have foreseen
it,

but one innovation from around this
time was to have consequences

far greater than they could possibly
have imagined.

We start to see the first sparks of
something that would come to

shape the way we live today.

Wherever there were humans, there was

a dramatic rise in the bones of goats
and sheep...

..far outstripping the remains of the
species they hunted.

These changes reveal a key point in
the human story...

..the moment we began to farm
livestock.

The people had found a safe, reliable
way to feed themselves.

They'd stopped chasing their food and
started rearing it...

..providing a regular supply of milk,
cheese and yoghurt...

..and later, textiles like wool...

..season after season.

The farming of animals marked a
watershed moment.

The result of this, I don't think
could've been predicted.

This altered relationship that they
had with animals, altered them,

because not long after they learnt how
to do this,

something fascinating happened.

Their population started to boom.

Now, we're not really sure why this
happened,

but the strongest theory is that
people staying in one place

and not moving as much, but also
having more food, having more

calories, basically led to mums having
more energy for reproduction.

As our numbers rose, settlements began
springing up...

..scattered across an area which we
now call the Fertile Crescent.

As their populations grew, villages
transformed into towns.

And the largest of the towns of the
Fertile Crescent was Catalhoyuk.

An early prototype of urban living.

Wow!

Every single one of these is a house.

- That's right. And you have to
imagine, of course,

that each of these houses is a box,
with a roof.

But, uh, there's no space really
between them.

Like a beehive.

The fact that they're all tightly up
against each other means

that the whole thing is much more
structurally sound.

- There's literally no gap.

- The only way you can get in the
house is to move along the roofs

and go down through a hole into the
house,

because there's no streets.

- Each dwelling was small and had its
door in the ceiling.

The inhabitants lived much of their
lives up on the roofs...

..grinding grain, trading,

and feasting in the bright sunlight
above their homes.

In this honeycomb,

their animals were kept in pens right
next to the living quarters.

- Here, you can see bits of animal
bone. These are the sheep bones

from feasting and so on.

But also, there are lots of droppings

and so, this is telling us that, as
well as people

living in the village, they also
brought in domesticated animals.

- And these farmers left behind
intriguing signs

that they were here to stay.

What are those holes over there?

- These are the ancestors who are
buried beneath the floors.

In some houses, there are up to 62
people buried in them.

- I mean, Ian, 60-odd people being
buried,

that's a graveyard in a home.

- We've dug up hundreds of burials
here,

and what's fascinating is that people
were sleeping just

a few centimetres from the bones of
their ancestors.

- Between the dead, the living and
their animals...

..this thriving town was densely
packed.

At its height, some people think there
were 8,000 people

living at Catalhoyuk, so that's one of
the largest

settlements on the planet at this
point.

And so, it's so easy to imagine this
straight line from this

population boom to our own huge
population of humans on this planet.

And yet, that straight line was
severely interrupted,

because the formula for success that
was playing out here

also turned out to be a bit of a
disaster.

Our pioneering farmer ancestors
couldn't have known it...

..but they had opened Pandora's box.

Amongst the many burials of
Catalhoyuk...

..were skull after skull with clear
signs of violent impact.

And it's something not only seen at
Catalhoyuk.

In many early farming settlements,

we start to see the unmistakable signs
of violence...

..suggesting the two are connected.

Choosing to live like this, in such
close proximity with your

neighbours, with the animals which
you're breeding,

with your rubbish...

..in a way that has never been seen
before, leads to this cascade.

The densely populated towns had become
exposed to new dangers.

Living with their animals spread
disease.

Their dependence on crops made them
vulnerable to failed harvests.

And with ever growing competition for
the land near the settlement,

people were no longer just battling
nature,

they were battling each other.

Suddenly, it must have seemed like
this perfect world

they'd created was cursed.

Faced with all these challenges,

these towns didn't survive or grow
into great metropolises.

Instead, growth was followed by
collapse and exodus.

And as the early town dwellers left
their homes

and farms in droves, they faced a
choice.

To start again and risk failing, or
rejoin the vast

majority of humans across the globe
still living nomadic lives.

For me, this is one of the biggest
mysteries

in the history of our species.

Because for the very first settlers,
it was a disaster.

They were facing disease and famine,
and yet, at the very same time,

across the planet, hunter-gatherers
were thriving.

And that way of life we know works,

because today, millions of people live
like that.

They have made it to the 21st century
just like the rest of us.

And yet, we know how this story ends.

Most of us live in huge cities like
this.

So, what is it that turned a disaster
into a success?

Our early attempts to live together in
large numbers

had ended in failure and strife.

To make it work, our species would
have to find another way.

An answer would lie...

..along a great river.

There are bits of our story where
geography just does not

feel like a fluke. Where if it was
going to happen,

it was always going to happen here.

Because beyond the thin strips of
green that cut through this

arid landscape, there is very little
but sand and death.

This narrow strip of habitable land
was the only place to grow food

and rear animals.

But to produce enough, they had to
control this natural resource.

The people needed to direct the water
onto their fields,

and harvest en masse, once a year.

And so, they had no choice but to work
together.

Put enough effort in, and more and
more of this becomes

productive farmland, giving these guys
a massive food surplus

that would be collected in huge grain
stores, attracting more and

more people to come and settle here,
and join this growing revolution.

The people flooded into the Nile
Valley, jostling for space.

But now, instead of abandoning their
communities

when the towns became overcrowded...

..they restructured them.

When you live in a small group, you've
all got to be good,

or at least competent, at everything
to survive.

But living in a large group, you can
suddenly specialise.

Some of you might become really good
at a particular

kind of textile making.

Others might become stone makers,
butchers, bakers,

probably not candlestick makers yet.

All cogs in a huge machine,

at a scale that had never been seen
before.

The people of these busy settlements
were increasingly collaborating.

Becoming part of a social group

with hundreds or thousands of
strangers.

And in the process, laying the
foundation for something brand-new.

I know archaeologists are constantly
pointing at walls

and trying to convince people of how
important they are,

but this absolutely massive wall is
pretty much all that's

left of the original city of Abydos.

Abydos being one of the very first
cities in the whole world.

But walls like these also indicate a
momentous shift

in the way humans lived together,

because to be on this side of the wall
meant protection

and access to the grain stores,

but to be on that side of the wall
meant to literally be without.

Now, humans have always been tribal,
we've always been able to act

and think as part of a group, but what
places like this prove

is that tribalism was scalable to the
size of a city.

All along the great rivers of the
ancient world, huge cities began

to appear, as our ancestors cracked
the secret to living at scale.

A change which would propel us forward
at an astonishing rate.

As these newly emerging cities grew

and their communities became more
complex...

..they started to change...

..leaving evidence which can still be
seen here in Abydos.

Not in the city of the living, but in
the city of the dead.

This is Shunet El Zebib, and it's so
vast, clearly,

but it was actually originally
mistaken for a fort.

But it's a temple dedicated to a
human, a man called Khasekhemwy,

who's actually buried in a cemetery
over there.

Not everybody got one of these, which
means that around here,

there were now at least two classes of
people.

There was something about cities that
was the perfect breeding

ground for producing not just the
haves, but the have-a-lots.

We may never know why some people
became wealthier

and more powerful than others.

One theory is that those in control of
the water

could also be in control of the food
supply.

But so long as they shared enough to
feed the cities, the cities thrived.

Their newly specialised populations
invented, made

and traded an unprecedented number of
objects.

And in the process, created a tool,
unassuming at first glance,

that would become a powerful
instrument.

I know they don't look like much.

They look like just square pieces of
bone.

They were found in Abydos, in a tomb,
thought to be that

of a king known as The Scorpion King,
from about 5,300 years ago.

Now, some of these symbols are very
recognisable.

That's obviously a bird.

This is a plant of some kind.

And notice the holes in them.

These are effectively labels, or tags.

These tags were thought to have been
attached to offerings

buried in the tomb, but what they
reveal is something

happening in the world of the living.

And these symbols represented the
provenance where the

item that they were attached to came
from.

Perhaps they have a quantity as well
attached to them.

And then someone had this absolutely
revolutionary idea.

What if they strung them together?

With local agreement on their meaning,
symbols became words.

Gradually, the rows of images became
more complex...

..until...

..we stopped labelling and started
writing.

Detailed knowledge and culture that
had previously been

passed down generation to generation
to generation was now able to

be preserved in a completely different
way.

And the thing with writing is that
like

so many of the giant leaps forward
that we have made as a species, I'm

thinking here about the invention of
agriculture and metalworks

and the wheel, writing does seem like
an idea whose time had come,

because it doesn't just happen in
Egypt.

Again and again across the Earth,

we invented forms of writing.

Giving our facts, stories and ideas
lasting form.

And we still have no conclusive
evidence as to how or even

whether these events influenced each
other, or

whether they happened organically,

as a result of needing to keep track
of things at that scale.

But however it happened, once writing
was a thing, once it was

out there in the world, then nothing
would be the same ever again.

Now, laws, customs

and beliefs could be recorded
permanently in ink.

But with over 700 symbols,

this technology required years of
study to master...

..and so was the sole preserve of
those trained to use it,

scribes working for the ruling class.

And the ability to send out detailed
instructions to people across the

land gave the rulers enormous power to
influence, instruct and build.

In 2013, a team of archaeologists were
excavating

a cave on the Red Sea coast...

..when, hidden inside,

they found ancient fragments of
inscribed papyrus.

Preserved there for over 4,000 years.

It's believed to be the oldest ever
found.

And a time capsule from the reign of
an iconic ruler.

So, this is...this is your actual
excavation notebook from the time?

- Yeah, yeah. Every day, I was
recording the papyri,

and we were surprised to find most of
them have the name of a king.

And this pharaoh is Khufu, the builder
of the Great Pyramid.

- Not a small pharaoh.

- All the material is giving
information about this very

reign, which is the very beginning of
the Egyptian state, in fact.

- Yeah.

Khufu ruled Egypt for almost a quarter
of a century.

And one of world's most familiar
structures was built to

honour him - the first of the Great
Pyramids of Giza.

- We had to wait till the very end of
the excavation

to have the best-preserved papyri.

We only had a small piece left
untouched.
- No!

- And all the papyri were thrown
inside...

- Into that one spot that was the very
last spot

that you decided to look in.
- Yeah, yeah.

- The team discovered around 1,000
pieces of papyrus,

revealing a vastly complex
construction project.

Wow!
- Yeah.

It belongs to a kind of elite at that
time,

because we don't think that more

than 1% of the...of the population was
able to read and write.

It's a logbook, and I can see in the
small boxes

the number of the day of the month,
and for each day,

this official is giving information
about what he has done.

For example, here, on the first day of
the month, they are

sending a boat to Heliopolis, to fetch
the food for the workers.

And when it arrives, it's written in
red,

because it's much more important for
them than everything else.

About 40 days, you have a precise
record of what he is doing.

Egyptian extracted fine limestone
blocks that were used

for the building of the outer casing
of the pyramids.

So, what it is all about is that they
were bringing

stones from the Tura quarries to the
pyramid of Khufu at the end

of the reign of this king.

- So, this is...this is telling us how
they built the pyramids, basically.

- Yeah, basically, yeah.
- This is the administration behind it
all.

That... That's absolutely incredible.

So, this is a snapshot in time

of the building of the Great Pyramid.

- Mm.
- And you found it.

- Without all those records, I think

the pyramid would not have been
possible.

- You can't really overstate the
significance of finding

a document like that, one from such a
pivotal moment in history.

And when you read the translation, you
definitely do get

a sense of what a logistical feat it
was,

building these things.

But you do also get a real sense of
how mundane

and bureaucratic it all was.

Just kind of ordinary humans doing
ordinary human things.

Between the invention of writing and
the building of the pyramids,

there were no major technological
advancements

that we know of in Egypt.

And so, for 4,500 years, people have
looked at these and just had their

breath taken away, and wondered how on
earth were they built.

And perhaps the answer is just this
simple - writing built the pyramids.

And even though they were originally
built for the elites,

they actually became symbols of
national identity,

which bind huge groups of people
together on an unconscious level.

The unit of human cooperation had
grown from tribe, to village,

to town, to city...

..and now, to nation.

But alongside the emergence of these
nation states

was a more sinister development.

What had once been tribal skirmishes
became state warfare...

..recorded by the victors in art and
writing.

The emerging superpowers began
launching military

campaigns against their neighbours,
for land, resources and manpower.

Bringing thousands of captives back as
slaves.

Many of the early civilisations follow
this pattern of growth,

innovation, writing and an ever more
stratified society.

By 4,000 years ago, we'd clearly made
some massive strides to the

modern world, with the rise of these
civilisations that were supporting

so many more people, and about 70
million of us walking this planet.

But...

..the disparity in the human condition
had never been so wide.

Some people were living gods, and they
would go on to build

monuments like these to themselves for
centuries.

But many more were slaves, who were
forced to

live in the shadows of the splendour
that they'd helped to create.

And humankind's powerful new tool,
writing...

..still remained in the hands of just
a tiny number.

If we were going to get to the future,
the here and now as you

and I know it, it was going to require
a spark from somewhere else.

Almost 4,000 years ago, a small group
of our ancestors were

forced to make a journey to one of the
most inhospitable

places on Earth.

Through the baking, barren waste

of the Sinai Desert.

But here, in this desolate landscape,

they would change the world.

This place is stunning and yet, a
complete and utter deathtrap.

It was of very little interest to the
Egyptian elites.

That is until someone found something
in these mountains.

Lots and lots of copper.

And this stuff, turquoise.

Raw materials that could be
transformed into jewels

and ornaments of great value...

..if you could prize them from this
harsh landscape.

Far to the north was the tiny land of
Retjenu.

When Egypt demanded labourers for this
treacherous mining mission...

..it was the unfortunate people of
this small powerless state,

who had no choice but to answer the
call.

I can't imagine what it would've been
like to be dragged here

to work in the turquoise mines, in the
blazing heat,

in the middle of nowhere.

It must've been like being dropped
onto

the surface of a different planet.

And even the Egyptians probably
wondered

if they would make it back home.

The Egyptians turned to their gods for
protection.

And here, high up on a desolate
plateau,

at the furthest edge of their world,
they built a temple to ask for it.

A monument which has survived
remarkably

unscathed for almost 4,000 years.

Frozen in time by the bone-dry desert.

This temple is dedicated to the
goddess Hathor,

who is the goddess of turquoise and
miners.

And they were documenting and
celebrating their presence,

and worshipping their gods.

And each one of these pillars
represents one of the missions.

And they are hierarchical.

So, you've got the Pharaoh at the top,
and it goes through the ranks.

You've got stonemasons, etc, etc, etc,

until this is the brother of the
Prince of Retjenu.

Retjenu is where the miners came from.

And yet, the miners are not here on
this pillar, but they would have

come through here, they would've seen
this grandeur, this splendour.

Seeing these impenetrable Egyptian
hieroglyphics...

..the foreign workers also wanted to
immortalise their presence here.

But there was a problem.

They weren't part of the elites and so
they couldn't write.

So, the illiterate miners did what we
humans have always done.

They copied what they'd seen and made
it their own.

This is one of the turquoise mines,
and if you look, all over the walls

there are these scratches from where
the workers' pickaxes have been.

But here, something else is going on.

There are about 30 or 40 of them all
over this place.

Some of these have been copied from
hieroglyphics,

but some are completely new, and
here's how the system works.

You take the symbol and you say the
name,

but you only take the first sound, and
you discard the rest.

So, for example, this here.

This is an ox, you can see the horns
and the head here.

To the miners, this would be "aleph".

Now, aleph, just take the first sound,
"a", discard the rest.

This is another symbol. This is the
symbol for house.

To them it would be "bet",

so you just take the "be" sound at the
beginning.

And if you put these two together,

you start understanding what you're
actually looking at here.

This is the birthplace of the
alphabet.

This new script was simpler to learn
than hieroglyphics, because

the alphabet did not represent
complete words, but spoken sounds.

It was able to convey any thought with
only 20 to 30 symbols.

These miners are the ones who gave
birth to this,

and their legacy is still with us
today, and is so important.

In the centuries and millennia that
followed...

..nearly all the early written
languages

fell into obscurity as those
civilisations waned.

But the alphabet would only grow,
spreading across the planet,

reshaping and branching into many
different forms.

Eventually becoming the most wildly
used writing system

in the world.

Allowing millions, and then billions,
of ordinary humans

to access knowledge, to communicate
and to document their thoughts,

and their existence, in every corner
of the globe.

For me, this is one of the most
powerful moments in the human story,

because unbeknownst to the underdog,
they had changed the world.

One of civilisation's most profound
and revolutionary ideas didn't

come from an educated elite, it came
from inside these dark and miserable

mines, through the copying and
innovating of lowly migrant workers.

The invention of writing marks an
ending and a beginning.

Because prehistory, so the period
before writing,

we could only really piece together
using fragments and artefacts,

and now recorded time, history, had
begun.

And what we see is that as writing
spreads,

the pace of human innovation
accelerates.

Because that is the power of being
able to document

and lay down knowledge.

Generation after generation building
on the last, retaining

and accumulating knowledge.

Stone became bronze, iron became
silicon...

..and gradually, we built the future.

This is the very final bone of our
series.

This is actually one of the three ear
bones,

and just like every human bone we've
encountered,

whether Homo sapiens or otherwise, it
represents a person.

This individual had a family, parents,
perhaps children, friends.

But what's particularly remarkable is
how much

we now know about these ancient
ancestors of ours,

thanks to modern temples of knowledge,
like this one.

The scientists here are able to
extract DNA from an individual

who, in this case, lived about 1,600
years ago,

from a piece of bone that is so tiny,
delicate and precious,

and they're able to ask questions,
like whether industrialisation and

agriculture actually affected our DNA,
whether we're still evolving.

And to think that our knowledge has
got to the point where we're

even able to entertain such huge
questions

from something so tiny...

..for me there's a poetry in that.

We can look back on when nature and
luck were on our side...

..and when they weren't.

Where we made the right decisions...

..and where we went wrong.

But what underpins our story

and makes it unique is far more than
just our will to survive.

It's our cultural drive to come
together, to learn from

and inspire each other, to go further
than what has gone before.

We are the very last species of human
to walk this Earth,

and the most fascinating thing about
our 300,000-year-long story

is that we have no idea how much is
left.

Is this basically the whole of our
story, or are we on the first

act, or even prologue, with a long
future ahead of us?

We have no idea.

But we are one species with one
future.

Now, you could never have predicted
how we got here,

and where we go next is up to all of
us.

In this episode, we filmed at Serabit
el-Khadim,

a 4,000-year-old mining complex on the
Sinai Peninsula.

Where ancient messages were scrolled
on the walls of the mines.

The archaeologists who discovered this
mystery script in 1905

called it Proto-Sinaitic, but they had
no idea what it said.

And until they could read it,

they were ignorant of its true
significance.

A remarkable artefact, now in the
British Museum, would be

the vital clue to cracking the ancient
code.

- This amazing object was discovered
in the Hathor

temple in Serabit el-Khadim, close to
the turquoise mines.

It's a so-called sphinx and dates
roughly about 4,000 years old.

- Linguists already knew how to read
ancient Egyptian hieroglyphics.

What the sphynx gave them was a key to
decipher

the script they couldn't read.

- So, if you look at the piece, we
have inscription on both sides,

and I'll show you this side first,

where we only have the Proto-Sinaitic
script.

And then if I turn the sphynx, this is
the most important and most

fascinating side, because here we have
then two different scripts.

On the bottom, Proto-Sinaitic,

and then you see the hieroglyphic
right on top.

- The message in hieroglyphics at the
top was a dedication

to the goddess Hathor.

Linguists deduced that the script
below in Proto-Sinaitic

was saying the same thing.

- We can start with the hieroglyphs,
which reads "Beloved of Hathor",

so we have now the Egyptian goddess
Hathor.

Then we have a second part, which
allowed us to decipher

the Proto-Sinaitic language, because
we know it was the same message.

So, we were very lucky we found this
amazing object.

This is the kind of lottery win for
the linguists.

- These short, corresponding phrases
were the key to decoding

the miners' writing.

- The probably most important aspect
of Proto-Sinaitic is that

it's an alphabetic script, and if you
look at these signs,

you probably will not recognise any
alphabetic signs we use today,

but the cow head that you see here
becomes our A.

- Proto-Sinaitic gave birth to the
modern alphabet, and unlocked

the origins of the most widespread
form of writing in the world.