All language subtitles for Out Of The Cradle (2018) sync

The earliest known hominids

were born in Africa,

and we homo sapiens were also born here.

But the evolutionary path to our species

was neither flat nor straight.

Through the evolutionary process,

the relatives of humanity split

into roughly 20 species.

Some of them coexisted
and were fierce rivals

in the struggle for survival.

The species we descended from

were not the physically strongest.

In fact, they were among the weaker.

They survived periods
of intense difficulty,

staging a series of amazing comebacks.

Today, there are 7.6 billion
homo sapiens on earth.

We are the planet's dominant species.

How have we achieved this success?

We look for answers
at the dawn of humanity.

Africa, the cradle of the human race.

The first hominids took their first steps

on this terrain.

Deep in the jungles lies an animal

that can help us imagine
the origins of humanity.

These are chimpanzees.

Humanity's family tree
diverged from chimpanzees

about seven million years ago.

Chimps are our oldest surviving relatives,

so human evolution is often illustrated

with a stereotyped expression

of one single path,

from bent over chimps to
upright modern humans.

But the story was not so simple.

There used to be many other hominids

besides we homo sapiens,

and we continue to discover more.

We currently know of
roughly 20 different species.

At times, multiple species
are though to have coexisted.

The path leading to homo
sapiens looks like this.

The other lineages became extinct

without leaving evolutionary descendants.

An important hominid that
paved the way to our existence

was ardipithecus ramidus.

A. ramidus is the oldest hominid species

confirmed to be bipedal.

It lived in forests

but started walking on two legs.

This was rare in the forest

and seemingly a disadvantage,

but A. ramidus won out
against the quadrupeds.

What was the secret to its success?

A clue to answering this question

was discovered in Ethiopia.

This is an archeological
site called Middle Awash.

You finished up here?

For many years, Tim White

has been leading an international team

in excavating this site.

Then we reach the fault.

Nice, baby monkey.

This is a Columbus monkey,
leaf-eating monkey.

Died 4.4 million years ago.

Finds made here by White and his team

have revealed that this
landscape was once a vast forest

and that it was home to an
ancestral hominid species

with some surprising features.

Yes!

Proximal hand phalanx,
ardipithecus ramidus!

Over a decade,

they restored hundreds
of hand collected bones

and revealed the bodily
features of an early hominid

that lived 4.4 million years ago.

Ramidus was approximately
120 centimeters tall.

It had an unusual body,

with a small head and long arms and legs.

Its feet were shaped like a monkey's

and were capable of grabbing things.

This indicates that ramidus lived in trees.

Its pelvis, however, is
different from an ape's.

Let's compare with a chimpanzee.

A chimpanzee has a long and narrow pelvis.

How about ours?

The human pelvis is broader.

It supports the organs that
move down when we stand up.

Ramidus has a rather wide pelvis

that more closely
resembles a modern human's

more than a chimpanzee's.

In short, ramidus was probably bipedal.

It started walking on two legs

while still living in the trees.

This overturned the common theory

that bipedalism started in the grasslands

after hominids left the trees.

And the evidence of ardipithecus

has revolutionized the way people think

about human evolution,

because you can no
longer think of something

halfway between a chimp and a human.

You have to think outside that box.

You have to think something unique.

And there are hundreds of individuals,

of monkeys and birds,

all of the mammals that lived here

as well as fossilized vegetation.

We have wood, we have seeds.

We have an environment
today that you need a hat in.

In the days of Ardi, you
wouldn't need the hat so much

because it was not a desert.

It was a woodland here

with ardipithecus both
able to move in the trees

and to walk on the ground.

Based on the latest evidence,

this is what the surrounding environment

probably looked like to ramidus.

When down on the ground,

ramidus is vulnerable to predators.

Ramidus wasn't as good at
climbing trees as a monkey

and it couldn't run very fast.

So how did it win out
in the race for survival?

That is today's first comeback story.

The key to ramidus's success

laid in the environment they lived in.

The era ramidus walked the forest,

there was a cataclysm in Africa.

It turned out to be a
lucky break for bipeds.

The earth's mantle shot up
and formed mountain ranges

that tore Africa apart.

These mountains blocked clouds.

The eastern part of the continent

became increasingly arid

and the forest dwindled.

A lush forest, a paradise for animals,

became something else.

Now, trees were sparse

and fruit and other food
was hard to come by.

The bipedal ramidus
suddenly had a great advantage

because it was good at
carrying food long distances.

A geological cataclysm proved to be

a huge break for a humble forest walker.

In the competition for survival,

ramidus won and unexpected victory

over other species
better suited to the trees.

Research has also
uncovered a major development

in ramidus's behavior
that is still with us today.

Four million years ago,

ramidus seems to have had a family

much the same way as we do.

Scientists are finding
the proof to back this up.

Owen Lovejoy is an expert in the analysis

of A. ramidus fossils.

One of the striking things that we find

associated with Ardi

and the appearance of upright walking

is the fact that there was
another, simultaneous,

major change occurring,

and that was in the dentition.

In other words, in the teeth.

In ramidus, the upper canine

and the size of the
crown is vastly reduced.

These are the canines of a male ramidus.

Compared to a chimpanzee,

ramidus has very small canines.

The canines of male chimpanzees are thought

to have developed as
weapons to fight over females.

The relatively small canines of ramidus

could be evidence that males
did not fight over females.

Dr. Lovejoy theorizes this would imply

that ramidus practiced monogamy.

In other words, it had
only one mate at a time.

This lifestyle would have been beneficial

for successfully producing offspring

in a dwindling forest.

What you're doing is instead
of wasting the male's energy

in simply competing with other males

for access to a female,

you're instead using his energy

to the reproductive vantage of the pair.

So there's really a fundamental
advantage of pair bonding

in terms of the rate of reproduction,

so we think that that would have increased

the level of cooperation amongst
the females and the males,

and that would have been
one of the reasons why

early hominids were so
demographically successful.

A natural event proved to be

a happy accident for an early hominid

that walked on two legs.

And this new natural environment
encouraged monogamy.

Hominids became creatures with families.

Ramidus shifted into family life

and eventually gave rise
to a few different species,

but only one offspring lineage survived,

from which australopithecus
afarensis evolved.

This hominid is the star
of our next comeback story.

Ramidus was about 120 centimeters tall.

The male afarensis stood
about 150 centimeters tall,

a difference of 30 centimeters in height.

Ramidus had feet like hands,

adapted to grab tree branches.

The feet of afarensis were
probably not as dextrous.

They were almost perfectly
adapted for life on the ground.

But afarensis was not notably fast,

nor did it have sharp claws,
fangs, or other defenses.

How did this vulnerable being
prove fit enough to survive?

Africa, approximately
3.7 million years ago.

The forest disappeared completely,

replaced by grasslands.

How did afarensis survive

in this predator-filled environment?

Scientists recently rediscovered
a clue to this mystery

as the Laetoli fossil
site in northern Tanzania.

Fidelis Masao, a Tanzanian
paleoanthropologist,

and his team made the find.

Over here, I found the most ancient

footprints of our earliest ancestors

that have never been found anywhere else.

The clue was the many footprints

that afarensis left in the savanna

approximately 3.7 million years ago.

He analyzed the size and numbers

of numerous fossil
footprints found in the area.

Studies of these footprints revealed

that afarensis traveled in groups,

sometimes of over a dozen.

This is believed to be the
one way afarensis survived

in the harsh conditions of the savanna.

They did not have any spears,

so they would depend on the number

in order to defend
themselves against predators.

Perhaps being able to pick up

branches of trees and rocks

to sort of defend themselves.

This is the savanna

that afarensis called home.

To make it through the dangerous savanna

while searching for food,

this early hominid species
began to form groups.

Even in groups, afarensis
was still very vulnerable.

After this, this lineage splits
into two major branches.

Genus homo, which had more slender bodies,

and genus paranthropus,
which had more solid builds.

Among others, homo habilis
and paranthropus boisei

were rivals who coexisted
for about 600,000 years.

Hominids of genus paranthropus

are also known as
robust australopithecines.

Their jaws were indeed powerful enough

to feast on hard beans and roots.

Here we have the skulls
of paranthropus and habilis.

The paranthropus had
very thick temporal muscles

that almost covered the entire head.

He could probably chew
three to six times stronger

than homo habilis.

But in the end, the paranthropus branch

of the family tree died out.

How did the less robust homo habilis

win the battle for survival?

Homo habilis lived 2.4 million years ago.

Hyenas.

Homo habilis seems to have
lived much like the hyenas,

as scavengers.

This lifestyle may have led
to an accidental invention.

It's thought to be the key

to the survival of homo habilis.

Henry Bunn of University of
Wisconsin found the evidence.

So here are some bones that are

almost two million years old.

Flat bone surface here, just on the sample,

you can see series of parallel cut marks.

This is a bone from a herbivorous animal

excavated at a homo
habilis fossil site in Tanzania,

prepared with a gold coating

for scanning electron microscopy.

It shows the many linear cuts on the bone.

Dr. Bunn thinks these
marks reveal the secret

of how homo habilis survived
to evolve into modern humans.

The Hadza are an African people

who live as hunter gatherers.

They helped Dr. Bunn
understand his findings.

When the Hasta eat meat,

they leave the same
type of cuts on the bone.

There's a strong similarity

between what was going
on in the early Pleistocene

nearly two million years ago

and what's going on
under direct observation

in the recent past among the Hadza.

And so we know from these that hominids

were making stone tools

specifically to butcher animal carcass.

The marks on the animal bones

at the homo habilis site

would seem to be cuts from a stone tool.

The marks match perfectly

with a stone blade like this.

The linear markings are convincing evidence

that homo habilis already used stone tools.

Our ancestors invented the technique

of making flake stone tools.

This was in response to a changing climate,

changing resources,

and their experiment in how

to forage for food more efficiently.

Homo habilis was physically weak,

but had stone tools.

That's how it pulled ahead
of the stronger paranthropus.

The weak-jawed homo habilis

accidentally invented stone tools

and turned the tables on its rival.

Marrow inside the bone is a
valuable source of nutrients.

The invention of flake stone tools

put sharp edged knives in the hands

of hominids for the first time,

where they could have a choice

between either continuing
on their foraging day

for predominantly plant foods

or they could use one of
those sharp edge flakes

to zip open the animal
carcass through the thick skin

and cut off all of the meat that they

and their friends could possibly use

in a matter of minutes.

Hominids of our lineage

had now begun to use tools.

Homo habilis created a huge revolution

with the invention of stone tools.

Afterwards, hominids took
an evolutionary leap forward.

By 1.8 million years ago,

homo erect us had arrived.

It grew as tall as 180 centimeters

with long, slender legs
and very little body hair,

not so different from us.

This allowed homo erect
us to outlive other hominids,

because its body was built for hunting.

Recent findings from
a fossil site in Georgia

shed light on this.

The Dmanisi fossil site
is 100 kilometers south

of Tibilisi, Georgia's capital.

Dmanisi has fantastic
preservation of bones.

An excavation team,

lead by David Lordkipanidze,

unearthed something here.

Alongside homo erect us bones,

there were thousands of animal bones.

They belonged to large,
plant-eating creatures.

Lordkipanidze says this is evidence

that homo erect us lived on animal meat.

I'm sure they could hunt,

and also they were scavenging.

They were meat eaters, they needed meat,

so they had lot of meat here

in this environment.

Homo erect us had started hunting,

and its unique body seems to have been

perfectly adapted to its hunting style.

This animal is injured.

A group of homo erect us are following it.

Their hunting style was a waiting game.

They patiently chased their prey

until it became exhausted.

Hominids were once the prey of carnivores.

Now they had become the predator.

What a huge reversal.

But how exactly do we know

that homo erect us was a good runner?

One scientist came up with the answer,

Daniel Lieberman of Harvard University.

He says it's clear from homo erect us bones

that have been excavated.

Where as this, this isn't.

This spine right here

is the insertion for the gluteus Maximus.

It's the biggest muscle in the human body,

and this muscle is important,
especially when you run.

So if you met a homo erect us,

he would probably be pretty good runner.

Lieberman also believes

that the lack of body hair

was beneficial for long distance running.

Most mammals have too much body hair

to effectively lower
their body temperature,

so they can't stay active for too long

under such scorching African sun.

Running long distances,

their body temperature will rise,

and they'll easily suffer heatstroke.

But homo erect us had
relatively little body hair.

When sweating, their body
temperature will quickly drop.

There are no other animals

running the Tokyo marathon, right?

It's just humans.

If you took your dog,
your dog wouldn't make it.

And the reason for that is that

when humans run long distances,

we run at speeds that require other animals

to have to pant to cool down.

We use a combination
of tracking and chasing,

running and walking.

Eventually, you can drive that animal

into a state of heat stroke.

Around the same time

homo erect us began to hunt,

another astonishing change happened.

This change happened on the inside.

We can see this from the skull excavated

at the Dmanisi site.

The skull has no teeth.

It's believed that this
one died at an old age.

How did he survive after losing his teeth?

It means that this individual

survived several years without teeth.

So explanation could be that

this individual had help.

So it may be first traces
of solidarity, compassions.

What triggered this change?

Hominid brains have grown larger

down through the ages.

With homo erect us, however,

the rate of enlargement
suddenly accelerated.

A major factor was a change in diet.

When pro to-humans were depending on fruits

and other food with high fiber content,

they needed a longer digestive tract.

They spent a lot of energy on digestion.

But when their staple food shifted

to nutrient-rich digestible meat,

they came to have a shorter gut

and spend less energy on digestion.

This allowed hominids to have larger brains

and become more intelligent.

We can guess that one of the first

steps of humanities were
here in this time period.

So we can guess that homo erect us

had different human characters,

including social relationship,

and taking care in
groups, helping each other.

Dr. Lordkipanidze believes

compassion began to bloom in homo erect us.

Hominids turned to meat eating

when other food was scarce,

and an unintended consequence

was the development of
human emotion and intelligence.

Homo erect us left Africa

and eventually spread
to various parts of Asia.

The fossil hominids known
as Peking Man and Java Man

are both homo erect us.

In Africa, a new species
called homo heidelbergensis

evolved from homo erect us.

Some of them reached Europe

and evolved into homo neanderthalensis,

or simply neanderthals.

The ones that stayed in Africa

evolved into homo sapiens.

200,000 to 300,000 years ago,

at least three hominid
species lived on earth.

Homo sapiens emerged
in Africa later than others,

at the wrong time.

Very early in its existence,

it faced the threat of extinction.

The threat was climate
change on a global scale.

Around 190,000 years ago,
Earth entered an ice age.

It did not have a major
effect on temperate Asia.

Java Man, a group of
homo erect us living there,

was unscathed.

The neanderthals who had
been in Europe a long time

were already adapted to cold climates.

They were also able to
survive with no difficulty.

But homo sapiens, this
new species in Africa,

was in trouble.

During the ice age,
areas around the equator

got drier and drier.

Much of Africa's
grassland turned into desert.

With most of their habitats gone,

homo sapiens were driven
to the brink of extinction.

One of the places they
ended up was this cape,

Pinnacle Point on the
southern coast of South Africa.

Deep inside this cave,

we see the traces of that era.

Each one of these is a little layer.

And D.

One research project here

is headed by Curtis Marean.

That black material right there,

that is charcoal from ancient fireplaces.

There's a lot of stone artifacts in here.

This certainly is one of
the highest resolution sites

we have for that time period.

How did homo sapiens survive

this imminent extinction?

The most surprising discovery
at this site was seashells.

Earlier hominid species had lived

in the forests and the savanna,

so they had never eaten shellfish.

And the brown mussel is the most abundant

shellfish that you see here today.

This is the one they were collecting

in the oldest sediments,

at 160,000 years ago.

Africa actually has extremely few

shellfish habitats.

To its great fortune, homo sapiens arrived

at the rare place where
shellfish were abundant.

But who would try this new, unknown food?

Perhaps only the most
curious of our species survived.

Around this time, the
homo sapiens' population

dropped sharply to less than 10,000.

Evidence of that is etched in our genomes.

Today, there are seven
billion people on earth,

but their genetic
differences are very small.

This suggests that the humans of today

are descended from a very small population.

A sharp decrease, and
then a sharp increase.

This bottleneck event resulted

in lots of people with similar genes.

The coastlines that are rich for foragers

would places where people would find refuge

during glacial phases.

The genetic evidence that we have suggests

that it was during that glacial phase

that the lineage that leads
to all modern humans,

everybody alive on the
planet today, originated.

What helped the survivors

was their curiosity to try new foods.

We are all descended from these survivors,

these people with curious minds.

Our long journey through
human evolution further continues.

What dramatic events await our ancestors

as they venture out of Africa

and come face to face with neanderthals?

Homo sapiens and the neanderthals,

the two species lived side
by side for 10,000 years

and jockeyed for supremacy.

Neanderthals were brawny,
highly intelligent hunters,

but they disappeared from this planet

while homo sapiens survived.

This is one of the greatest mysteries

of human evolution.

If a neanderthal and modern human

were to fight hand to hand,

the neanderthal would win.

There's another mystery
that's been uncovered.

Neanderthal DNA lives
on in humans to this day.

I was very afraid that it was some error,

but one mixed with neanderthals,

and they contributed DNA
to to people who live today.

How exactly did this happen?

Jerusalem in the Middle East

has long been the
crossroads of civilization,

and this region is likely
where neanderthals

and homo sapiens first met.

The evidence is a discovery made in 2015

at the Manot Cave in northern Israel.

I'm looking at a piece of bone,

it's a finger bone, could be human.

Paleontologist Israel Hershkovitz

leads an international
team excavating the site.

Here, the place.

Deep inside this cave,

important fossils were found.

These remains show that
homo sapiens lived here

55,000 years ago.

And a mere 40 kilometers away,

traces of the neanderthals
had also been found.

Here, bones from 18 bodies were unearthed.

It was previously
believed that in this era,

homo sapiens and the
neanderthals lived far apart.

Actually, Manot is the
only fossil yet discovered

that represent this specific group

that start migrating out of Africa.

So in a way, Manot
give us the first evidence

of overlapping time and space

between anatomically modern humans,

or our own species, homo
sapiens, and neanderthal.

During the seven million years

since the first hominids emerged,

close to 20 species have lived and died.

The last of these were
neanderthals and homo sapiens.

The two branched off
from a common relative.

Some of them left Africa
and evolved into neanderthals

on the Eurasian continent.

100,000 years later, homo
sapiens emerged in Africa.

Homo sapiens then left Africa,

and surprisingly soon, they
encountered the neanderthals.

This group of homo sapiens

migrated from Africa in pursuit of prey.

Who were the neanderthals
that homo sapiens first met?

Paleontologists once
thought something like this.

Neanderthals were a kind of hairy ape man,

dramatically inferior to homo sapiens.

But now experts have a very different image

of their capacities,

both anatomically and culturally.

Neanderthal skulls reveal
something quite surprising.

The neanderthal skull is much larger,

much bigger than a modern skull.

Neanderthals had big brains.

Modeling from the skulls

shows that neanderthals had brains

more than 10% bigger than homo sapiens.

And a close examination of
bones in their throat and ear

indicate they could probably talk.

The evidence continues to mount

that neanderthals had their own culture.

This pendant found in Spain
belonged to a neanderthal.

It was made from a scallop shell.

This object made from eagle talons

is believed to be an arm bracelet.

It was unearthed at a neanderthal site

in Croatia in 2015.

Neanderthals also treated animal hides

and wore them as clothing.

One piece of evidence of
this is a tool found in France.

Marie Soressi is a
paleontologist at Leiden University.

She discovered a tool called a lissoir

at a Neanderthal site
dated to 50,000 years ago.

This type of tool was often
made from bison bones.

It's likely that
neanderthals used this tool

to make animal hides smoother.

We once thought they were strong

but unintelligent and incapable of speech.

But we now believe that they had brains

to go with their brawn.

We now understand that, yes,

neanderthals were much more
smarter than what we thought,

and actually were probably as smart

as were our direct ancestors.

We are here today,

only one human species on the planet.

But maybe it's not because
we were the smarter ones,

maybe it's because of other reasons.

How were neanderthals living

at the time they encountered homo sapiens?

These are sort of next to cranio...

This is paleontologist Stephen Churchill

of Duke University.

He believes that
neanderthals had well adapted

to survive in extreme cold.

The neanderthals
survived in glacial climates.

It was their body which was
adapted to glacial Europe.

It worked for them because
it's what they inherited

from their ancestors, and it worked.

Neanderthals thrived in Europe

during an ice age.

Winter temperatures dropped
to minus 30 degrees celsius.

Food was hard to come by.

Neanderthals developed unique traits

to survive in these harsh conditions.

Stephen Churchill analyzed
some 300 neanderthal fossils.

He discovered injuries and fractures

in many of the bones.

So this is a rib of a
neanderthal from Iraq.

He's got an injury here in the rib

where something has penetrated the rib.

Churchill thinks this is evidence

that neanderthals
hunted their prey up close.

The best evidence that
we have about hunting

suggests that neanderthals
were very close range hunters.

It's certainly the case that neanderthals

were strong, and powerful,

and able to exert a lot of
force on the environment.

The forests of Europe, 50,000 years ago.

They probably looked something like this.

They're setting up an ambush.

Can they take down a beast that big?

The fearless hunting of the
neanderthals wins the day.

What about homo sapiens?

They had slimmer bones,

and thus were probably
weaker than the neanderthals.

They had to employ a
different hunting style.

After they moved to Europe,

their skin and hair color began to change.

Lacking the physical strength
to take down big game,

they survived by capturing small animals.

But in the end, the weaker homo sapiens

displaced the stronger neanderthal.

How, exactly?

Several thousand years after homo sapiens

were chasing rabbits,

their hunting style has changed radically.

These hunters are working together

to herd a group of animals.

What enabled this change
was a revolution in toolmaking.

The real game changer
was this spear-thrower

called an atlatl.

It transformed the
lifestyle of homo sapiens.

Many types of atlatl have been found

at homo sapien sites from this period.

With a tool like this, you
can throw a spear twice as far,

and with more power.

The atlatl was an amazing breakthrough.

With an atlatl, you didn't need

to get too close to your prey.

Perhaps our ancestors' physical weaknesses

spurred them to create
these long distance weapons.

Homo sapiens made other
groundbreaking inventions

besides the atlatl.

They were geniuses at
improving their technology.

If we compare their stone
tools through the ages,

we can see they became
more and more refined over time.

Homo sapiens began making
razor-sharp stone knives

as well as complex
tools like bone projectiles

with stone blades.

Meanwhile, neanderthal
stone tools barely changed

for over a quarter million years.

They never developed sharp stone blades

or other advanced items.

What accounts for this difference?

To find clues, let's
compare some of the traces

left by the two species.

Abri Castanet in western France

was once inhabited by homo sapiens.

At the foot of this cliff
was a huge open space

of 500 square meters.

The number of tools and
human remains unearthed

suggest that as many as
150 individuals lived here.

What about the neanderthals?

This is El Sidron cave in northern Spain.

It was home to
neanderthals for a long time.

The bones excavated indicate
a much smaller population.

DNA analysis found

that the inhabitants were all related.

This suggests that neanderthals

lived in small family groups.

Why did the two species
come to live in groups

of such different sizes?

One possible answer has come from infants.

Karen Wynn probes the
traits of ancient hominids

by studying the behavior of infants.

All right.

Hi!

How are you today?

How are you today?
Say hi.

Okay.

Experiments with babies

less than one year old

reveal that homo sapiens has a trait

which favors living in groups.

Up goes the curtain.

The gray doll in the center

tries to open the box,

but the blue doll interferes.

When the gray doll tries again,

the yellow doll, in contrast, helps out.

Which one do you like?

Which do babies prefer?

The yellow doll.

Okay.

All right.

And when the colors are switched.

Which one do you like?

Now the blue doll is chosen.

Okay.

Wynn's experiment
found that almost all babies

prefer the doll that helps.

Humans are such an
incredibly social species,

even very young children
will spontaneously help others

and wish to cooperate with them,

and since we also know that babies

have an understanding of what is helpful

and what is fundamentally cooperative,

that gives them a sense of
how to enjoin in that community.

And it may be that even
though we are much less strong

than many other species,

that it was our cooperative group nature

that gave us the edge.

Even infants who have
not yet learned to talk

are inclined toward cooperation.

That would same to be
why ancient homo sapiens

lived in larger groups
than the neanderthals.

One researcher found an answer

in a part of the human brain.

My name's Robin Dunbar

and my research is all about the evolution

of social communities

and how that relates to
the evolution of the brain.

Robin Dunbar has investigated

the link between social group
size and brain dimensions.

He compared homo
spaiens with the neanderthals

who lived in small family groups.

Neanderthals had very big brains,

very big back end to the brain.

Now the back part of the brain does vision.

They have bigger eyes,

and a bigger computer to process

the information coming through.

It's just to allow them to see better

in these dark conditions.

Homo sapiens, in contrast,

lived in much larger
groups of around 150 people,

and a different part of their brain

became more prominent.

This is a human brain.

This part at the front is the bit

that's important for
our social relationships,

and this bit is expanded much more

than any of the other bits in the course

of human evolution.

In our brains,

it's the frontal lobe and parietal lobe

that are highly developed.

Dr. Dunbar points to this as proof

that our homo sapiens ancestors

made heavy use of communication,

a skill required for life in large groups.

Their highly social
way of life allowed them

to keep innovating and
improving their tools.

The neanderthals just were not so good

at producing these kind of innovative tools

or spreading them around their communities

in the way that modern humans did.

Even if some neanderthals did manage

to invent a new tool,

it would only be shared
among a small group.

Homo sapiens would share new inventions

with lots of people who would
continue to improve them.

Homo sapiens were physically weaker

but they derived power from technology.

Information sharing
within large communities

gave rise to new inventions.

200 kilometers east of Moscow

we find the remains of a
35,000 year old settlement.

By that time, homo sapiens had come to live

in even larger groups.

400 people, many of
them not related by blood.

This is a true community.

Why would homo sapiens
gather in such large groups?

Unearthed ornaments
provide a possible answer.

These surprisingly elaborate ornaments

were all items found buried with the dead.

We can infer that some early form

of religion was coming into being.

Much evidence has been found

of humanity's growing
spirituality in the era.

Cave paintings include
depictions of mystical creatures.

For example, this strange being.

It has an animal body, but human limbs.

One theory is that it represents a shaman

performing a ritual.

The first primitive
religions were springing up

among homo sapiens.

This may be what brought people together

in even larger communities.

What's interesting about religion, though,

is that you can use religion
to create mega-communities.

In these deep caves, which are dark,

it's a little magical.

This all helps to create
the atmosphere for trance.

They had the religious beliefs come

from experiencing these trance states.

So I think being doing singing and dancing

for a very long time to
create a bonded group.

A religious ritual had started.

Lit up by the fire,

the wall paintings look magical,

almost surreal.

Sharing in these mystical experiences

would surely strengthen group ties,

ties that would help homo
sapiens in the years to come.

During the last ice age,

Europe was buffeted by
extreme shifts in climate

known as Heinrich events.

A colossal ice sheet covering
much of North America

would collapse into the ocean.

This would cause sudden,
drastic changes in ocean currents

and trigger violent temperature
fluctuations across Europe.

Severe cold alternated with extreme heat

from one decade to the next.

Forests were destroyed, wildlife perished.

Strong community ties were the key

to how homo sapiens survived

these catastrophic climate changes.

We have much bigger
communities, even beyond the 150.

The fact that we can create these kind

of extended tribes, really,

of up to about 2000 people

who cover many thousands
of square kilometers.

So members of our tribe
will be a very long way away,

and we can always go there
and live with them for a while.

Common beliefs bonded far flung groups

and helped them survive
violent changes in climate.

Homo sapiens rapidly extended its territory

while the neanderthals dwindled.

Neanderthals continued
to live in small family units.

They never developed
large, cooperative networks.

All they could do was stalk
the forests that remained,

hunting ever smaller numbers of prey.

And they continued their risky method

of close combat hunting.

Many neanderthals seem to
have been killed while hunting.

It is thought that few
lived beyond their 30s.

Eventually, they became
unable to find enough prey

to sustain their large bodies.

You might wonder how
is it that these weaker,

sort of scrawnier humans were able

to replace the neanderthals,

but I think really the
strength, and the power,

and the physicality of the
neanderthals worked against them.

Neanderthal life was very, very expensive

from a caloric perspective.

They had these big
bodies that they had to feed,

but it was a costly adaptation.

The British territory of Gibraltar

at the southern tip of Europe.

This is where the last
groups of neanderthals

are believed to have lived,

facing their end.

On the verge of extinction,

the neanderthals left
one last mystery here.

It was discovered in 2014.

So this is the special place

that we found a few years ago.

So we were actually excavating,

and here, where you hit
the bare rock, no sediment,

we found some marks.

Curious engravings in
shapes called hashtags.

They were made by
repeatedly cutting into the rock

with stone tools.

Many suggestions have been
made as to what this means.

One is maybe a map of the
stars or the constellations,

some other, like a map.

But another has been
suggested that it could be

a symbol of the clan.

The neanderthals, our closest relatives,

left these markings here.

Proof of their existence.

And then they vanished.

It's obviously very difficult to even

put ourselves in the situation

of that last group of neanderthals,

and how they saw the world,

and how they felt in those last days.

It's very difficult.

That they shared emotions like we do

of sadness, happiness and
stress, I have no doubt of that.

So I think it's a combination
of loneliness and fear

that would have prevailed,
predominated, if you like,

in that last individual.

Very sad as well.

Homo sapiens was now
the only hominid species

left on earth.

There were no rivals anymore.

Curiously, however,
that is when our ancestors

began engaging in a
completely new type of behavior.

It could have been warfare.

The evidence comes from
skulls found in a German cave.

Easy to see.

You see some marks in the frontal bone,

here and here.

This is clearly a trauma.

Most of the skulls here

were damaged by some kind of blow.

So just the impression
that this was a massacre.

Looks like a conflict,
otherwise we wouldn't

see such trauma,

because this must be a kind of murder,

or conflict between some groups.

This site may reveal the earliest known

instants of clashes among homo sapiens.

Ironically, the strong social ties

among groups of homo
sapiens may have caused hatred

and even assault against other groups.

Unfortunately, the whole mechanism

we have for bonding communities

has built into it the negative consequence

that we treat members of
different communities then

as outsiders.

So you have kind of
built into that, naturally,

the risk that fighting between communities,

viewing other communities
as us versus them.

Tribal and territorial violence was evident

in human on human conflicts.

If so, the violence may
have been more intense

against our last hominid
competitors, the neanderthals.

Or perhaps not.

The history of humanity seems to be more

than just conflict alone.

The proof lies in our very genes.

The astonishing discovery was made

at the Max Planck Institute
for Evolutionary Anthropology.

They have the world's best technology

for analyzing prehistoric human DNA.

And we have Mezmaiskaya cave in Russia,

which is also a neanderthal.

Vindija cave from Croatia is exceptional,

and it's a female neanderthal

which is around 50,000 years old.

It took 14 yeas,

but researchers succeeded in reconstructing

the neanderthal genome.

The project was led by
geneticist Svante Pääbo.

He may well win the Nobel Prize someday.

Dr. Pääbo compared the neanderthal genome

with modern humans from
different regions of the world.

He found the peoples of Asia, Europe,

and most other parts of the world,

have about 2% neanderthal DNA on average.

The group of homo sapiens
that originally left Africa

was very small.

They soon encountered and
interbred with neanderthals.

So these early modern humans,

quite early after they left
Africa, mixed with neanderthals,

and became the ancestors
of everybody outside Africa.

And those babies became integrated

in the modern human populations,

and were successful enough
there to have babies in turn

and contribute to people today.

The neanderthal parts of our DNA

seem to play important roles.

Neanderthal genes helped our ancestors

survive in a new environment.

With neanderthal genes, they could cope

with the new local diseases
and weaker sunshine of Europe.

This genetic support played a key role

in the success of homo sapiens

all the way up to the present day.

This interbreeding happened.

Humans have always mixed,

so of course our origins
is sort of a mixture,

it's a mosaic if you like.

The neanderthals may be gone,

but their legacy
continues to live on in us.

7.6 billion people live
across planet earth.

How did we homo sapiens
achieve this astonishing expansion?

When homo sapiens
emerged 200,000 years ago,

they quickly spread across the globe.

The latest research and experiments reveal

how only homo sapiens crossed the seas

in ancient prehistory.

How did prehistoric man
cross the dangerous oceans?

An important clue to the answer

was found at a dig site in Japan.

Ishigaki island lies at
the southern end of Japan.

Here, ancient fossil remains were found

during the construction of an airport.

There were 19 human skeletons

from 20,000 to 27,000 years ago.

The number of bodies

suggests this was a grave.

From this site, Japan's
oldest complete skeleton

was also found.

It is rare worldwide that so
many skeletons from this era

were unearthed at one site.

Dr. Naomi Doi scans all of the bones.

Using a 3D modeling software,

she attempts to piece
the skull back together

to recreate its face.

Here is the facial recreation,

a face you might see today.

Analyzing the bones also
reveals lifestyle markers.

This hollow is an ear hole.

See the bony spikes inside?

They're known as surfer's ear,

found in the ear canal of those

who regularly swim in the sea.

This indicates that these people

spent a lot of time by the sea,

but there is a big mystery of anthropology.

Where on earth did they come from?

DNA tests could provide answers.

And the results showed
their genes have similarities

to southwest Asians of today.

The ancient Okinawans in Japan

seem to have crossed the seas

from somewhere in southeast Asia.

Back then, about 30,000 years ago,

southeast Asia looked like this.

The ice age lowered the sea by 80 meters.

A huge landmass called
Sundaland was exposed.

A series of paleolithic sites

have been discovered across this area.

The evidence shows that an extensive

cultural sphere had developed here.

An international research team began work

at this site in Indonesia in 2016.

It's lead by Dr. Adam Brumm

of Australia's Griffith University.

They found an elaborate piece of jewelry,

a rare find in Asia so far.

It's a finger bone from
a type of marsupial,

necklace, or it may well have
been attached to a bracelet

or an earring possibly.

We really don't know,

but it's clear evidence for
modern human symbolism.

Another astonishing find was made

in the Tempasing caves
a few kilometers away.

This is possibly the
oldest cave art in the world.

Some images are
stencils, like this hand print.

This depicts a local wild boar.

Nearby caves contain
images of fish and squid.

These discoveries overturned

current theories of human history.

It was thought the earliest human culture

began in Europe during this period,

as seen in the Chauvet and Lascaux caves.

But this Asian art is over 2000 years older

than that of the Chauvet cave.

A culture comparable to that of Europe

already existed in Asia.

Hopes are high for even
more amazing discoveries.

This is becoming one of the real hotspots

of prehistoric human archeology,

not only in Indonesia, but in the world.

Historically, most of the scientists

who have investigated
their early human past

have been based in Europe.

Now we're starting to see the same levels

of intensive investigation
in parts of southeast Asia

and elsewhere in this region.

So it's only now that we're really starting

to see these discoveries come to light.

Southeast Asia was also inhabited

by many early humans,

and those closest to Japan lived in Taiwan,

which was still part of
the Eurasian continent.

The Baxian Cave archeological site

is located on the eastern coast of Taiwan.

Many stone tools from
about 30,000 years ago

have been found here.

The date is close to that of fossils

discovered from the Ishigashi
Island in Okinawa, Japan.

Early humans seem to have first traveled

from the Japanese island from Taiwan,

but one barrier remained.

Over 100 kilometers of ocean
separates Taiwan and Japan,

and it's home to a very fast current

known as the Black Stream.

How they crossed this
perilous sea is a mystery.

To solve it, researchers
used drifting buoys

to map the current.

All of the buoys are
swept away by the current.

Not one reaches Okinawa in Japan.

So simply drifting on the sea

would not lead you to the islands.

Then how did the prehistoric inhabitants

cross this challenging tide?

One clue was found in East
Timor, 3000 miles to the south,

on the edge of Indonesia.

The Jerimalai Cave site
contains many unusual items

left behind by its ancient inhabitants.

Here, Dr. Sue O'Connor discovered

very important evidence
of early seafaring abilities.

Even though, yeah,
it'll definitely save time.

This is some of the fish bone

that we've found this time,

are something like tuna.

The inhabitants ate a lot of fish,

and the important discovery
was about the types of the fish.

It's the first place in the world

where we've found
evidence of pelagic fishing,

which is fishing for fish like tuna.

Many of their catch were relative

to tuna and bonito, living in open water.

They couldn't be caught from the shore.

This has led Dr. O'Connor
to a clear conclusion.

They must have had complex
maritime technology like boats.

I think we can definitely
say that 40,000 years ago,

people were using boats.

But these travelers had only simple tools

made of broken stone.

We still don't know what
kind of boats they built

to reach deep water regions.

One researcher took a
unique approach to he mystery

by recreating the ancient
voyage across the Black Stream.

Dr. Yosuke Kaifu, an anthropologist

at Japan's National Museum
of Nature and Science.

He wants to learn how
people people traveled

from Taiwan to Okinawa's islands.

A huge experiment was held in 2016.

Dr. Kaifu formed a team of
60 researchers and volunteers.

The project aims at a full recreation

of a 30,000-year-old voyage.

The team will use ancient tools

to build a boat and cross the sea.

This approach is called
experimental archeology.

The group has found a type of reed

that grows in the region.

Bundled together, the reeds
could form a simple canoe.

The group uses shells to cut reeds.

They were a common tool back then.

Vast numbers of reeds
are needed to make a boat.

It takes 10 people over a week

just to gather the material.

Now that the reeds are cut,

it's time to build a boat.

But how do you do that with reeds?

The reeds must form dense bundles,

so they break into teams.

Some tie them with vines,

others hammer the reeds to make the bundles

more tightly together.

Reed boats look simple,

but require close cooperation
among large numbers of people.

And a single reed boat is not enough.

Establishing a population in a new land,

the number of new inhabitants is critical.

The team calculated the least necessary

number of travelers.

A single traveler couldn't
reproduce, of course.

Children from one set of
parents would eventually die out.

The research group used estimates

about birth and death rates at the time,

and they concluded that at least 10 people

would have been needed.

It means five pairs of young men and women.

The project decides to make two reed boats,

each carrying five people.

The boats are completed in two months.

In this experiment,
the team tries to travel

the 75 kilometers to Iriomote.

The starting point is Yonaguni,

an Okinawa island nearest to Taiwan.

I'm okay.
Okay, okay!

The rowers spent two weeks

practicing for today,

but just overcoming the waves is tough.

Sight lines are bad from the bobbling boat.

The target island is invisible.

To recreate a 30,000-year-old voyage,

the crew do not use
modern tools like compasses.

They must rely on the sun's position.

30,000 years ago, people did
know how to navigate this way.

In five fours, the boats
should travel eastward,

that is, toward the right,

but keep drifting left.

The boats drag against the water.

As their speed drops, the
current takes them off course.

In the end, the voyage had to be abandoned.

An additional ship towed
the reed boats home.

The team couldn't reach Iriomote Island

with their handmade boats.

In the attempt to reveal

how ancient humans crossed the seas,

Dr. Kaifu, the project leader,
tries another approach.

Now the team builds
a different type of boat.

They make stone tools.

These stone tools are used

to cut down bamboo for the boat.

An indigenous group on Taiwan

called the Amis still make bamboo boats.

They help the team build one.

Dr. Kaifu doesn't want them

to use modern hammers.

He asks them use stones.

A fast, dynamic bamboo boat is completed.

This time, they'll travel 40 kilometers,

from Taiwan's eastern coast
to Ludao, or Green Island.

The bamboo boat is definitely faster

than the reed canoes.

But they're caught in a sudden rain shower.

The sun and the island vanish.

There's no way to check their direction.

As they flounder on the sea,

the ocean current sweeps them off course.

Unable to maintain
speed against the current,

the boat has been carried away.

The experiment has failed again.

The second attempt to recreate

part of humanity's global travels

has just intensified the mystery.

Dr. Kaifu has one more
idea to solve the mystery.

How did the prehistoric voyagers cross

the powerful ocean current,

especially when the closest Okinawan island

can't be seen from Taiwan?

Some locals say they
haven't seen it in their lifetimes.

Under some atmospheric conditions,

it is possible to see the island off shore,

100 miles away.

30,000 years ago,

people may have seen the island

and decided to travel there.

Once they knew there was a new territory,

a burning desire to explore

perhaps inevitably drove
them to voyage across seas.

Reed boats failed,

so did the more buoyant bamboo boats.

Kaifu suspects that innovative tools

would be required for his next plan.

Evidence of such tools have been found

in northern territory Australia.

The Madjedbebe Rock Shelter

is the oldest human
occupation site in Australia

at 65,000 years old.

So these are the oldest axes in the world.

The other wonderful thing about this ax

is it has a very distinctive groove

running all the way around.

You can see it here as well,

this groove running down this side.

We just had no idea that people
were making axes so early.

Stone axes are the product

of the full ingenuity of early humanity.

The sharp edge is proof
this was a well made tool.

Axes have also been found

in the Jerimalai caves of East Timor.

This one also has a sharp edge.

It was made from a seashell.

Made of different materials,

but both axes had traces of handles.

This is an important point.

Previously we were wondering, yeah,

how did they make the boats?

They would have used
this for chopping wood.

Definitely, for sure.

An ax with a handle is far more powerful.

It can cut and shape hard woods.

A handle will increase the
smashing power nearly tenfold.

An ax can fell trees, and
hollow them to make log canoes.

Maybe the people who traveled
to Okinawa 30,000 years ago

used wood canoes.

It's a new possibility to consider.

Kaifu's project to recreate
the prehistoric voyage

quickly began studying his new idea.

Can a stone ax truly bring down a tree?

The trunk must be a meter across

to fit a person inside it.

Time to experiment.

Six days later.

After the chop number 36,225.

They test their dug-out canoe.

Time to see if the canoe can outpace

the Kuroshio Current.

The test was a success.

Next year, they hope to
travel from Taiwan to Yonaguni,

one of the Okinawa's southernmost islands,

using this boat.

The secret of a perilous ancient sea voyage

is now being revealed.

The experiments suggest
the voyage 30,000 years ago

may have looked like this.

A group is transporting a log canoe.

Many people have to work together

to prepare the canoes.

A chosen number of young
people stand ready to go.

At least five pairs of men and women

are needed to ensure survival of offspring.

They set off for unknown lands,

ready to forge a new future.

And so humans arrived in Okinawa.

They traveled between the islands.

Many sites on Japan's southern islands

reveal humanity's earliest presence.

Throughout the world,

homo sapiens learned
to voyage across the seas,

and also to survive in
bitter, cold land crossings

in the Arctic.

We made it to the southern
tip of South America.

Humanity flourished in
every corner of the globe.

They also faced another challenge

in their travels across the planet.

It was extreme cold.

Today, it's 25 degrees celsius below zero.

It can go as low as 60
degrees below zero here.

This is one of the coldest places on earth.

There's evidence that human beings

already lived in the furthest
north 30,000 years ago.

Their footsteps have been found

in the Sakha republic of Russia.

The Yana RHS site lies at a latitude

of 71 degrees north.

It was discovered by Dr. Vladimir Pitulko.

Today, he shows us footage of the site

that has never been released before.

The ongoing dig began in 2003.

The permafrost is melted with water

and dug away during summer.

This is a mammoth bone suspended in ice.

An extraordinary number of mammoth

and buffalo bones have been found here,

along with over 100,000 manmade items.

They include stone tools, accessories,

and other valuable materials.

But why did homo sapiens travel

to this extremely cold region?

A mammoth.

This is what they were after.

The extreme north at the time was abound

with many large animals to catch.

Unexpectedly, a large amount
of food was available there.

The snowy ground made
it easier to spot prey.

There was another point in their favor.

The snow left easy trails to follow.

It's easy to spot prey.

Yet, however abundant
food may have been available,

the cold here was truly extreme.

So how did homo sapiens
overcome the extreme cold?

Among many items unearthed
at the site of Yana RHS,

Dr. Pitulko found an important one.

It's a tool that helped
humans survive in the far north.

Carefully stored inside a
casket made from animal bone

are sewing needles made
from bones of mammoth

and other animals.

A total of 103 needles have been found,

each five to 10 centimeters long.

Nowhere else have so many old needles

been found in one place.

Even today, traditional reindeer coats

are made by hand.

To keep out the chill and retain body heat,

the clothes must completely
cover you from head to toe.

To make such clothes, sewing
needles are very important.

This may look simple to make,

but in fact, a needle is
extremely difficult to construct.

First, a groove is carved
into an animal bone.

And a second groove is made here.

Then the bone is hammered
to create a thin shard.

This must be scraped
into the correct shape.

And the next step is to
make a hole for the thread.

It's painstaking, delicate work.

If the bone breaks, you
must start from scratch.

At last, it's complete.

Creating a single needle from bone

requires complex pre-visualization.

Research is underway to
reveal the parts of our brain

involved in this toolmaking ability.

Volunteers' brains are scanned

as they watch how to make a stone tool.

They get a virtual
experience of toolmaking.

In their brain, an unexpected
part has been activated.

It's Broca's area, which
controls language skills.

I think in the modern world,

most people would think of toolmaking,

tool use, and language

as completely separate
spheres of human activity.

And yet they both have a similar structure,

a kind of a hierarchical structure to them

in terms of the goals that we have,

so finding that in fact is powerful support

for that evolutionary hypothesis

about a shared origin between
toolmaking and language.

Dr. Stout thinks in
terms of brain activity,

speech and toolmaking has much in common.

Words or steps in a process

both require a meaningful arrangement.

Recent research suggests

that neanderthals also used language,

yet their language may have
been simpler than human speech.

So were their tools.

Homo sapiens had both language

and tools of high sophistication.

Their advanced tools, like sewing needles,

helped them even survive the extreme cold.

Homo sapiens invented
all kinds of new tools

to suit different environments.

But as we mastered the natural world,

we also had negative impacts.

Dr. Gavin Prideaux of
Flinders University in Australia

points out that Australia

was once a paradise of giant animals,

extremely diverse,

unique species that used to thrive here.

And all of these megafauna species

are now gone from Australia.

Dr. Prideaux's group has analyzed

when these megafauna,
such as marsupial lions

and giant wombats, died out.

They discovered extinctions happened

not long after the arrival of human beings.

We think that between
about time humans arrived,

maybe 65 or so thousand years ago

and about 40,000 years ago,

approximately 90% of the
megafauna species in Australia

became extinct.

So humans were the
decisive factor in Australia.

The most likely reason is hunting.

Another is that humans burned down trees

to broaden their habitat.

Animals couldn't survive
in the new environment.

Humans became a huge presence,

changing the environment around them.

We have an amazing ability

to not only modify our environment

to better suit our needs,

but we have the ability more importantly

to perceive that we're
modifying our environment.

We now have to go beyond just recognizing

that we are having an impact,

but actually doing something

about ameliorating that impact,

and living much more consciously

within the limits of the
natural environment.

Long ago, a peculiar type of animal

began walking on two legs in the forest.

They survived a geological
cataclysm and lived in families.

Hominids were prey of carnivores in Africa.

On the same continent,

the last hominid, homo sapiens appeared,

and narrowly survived harsh conditions

thanks to a series of fortuitous events.

They are our ancestors.

They formed community bonds,

won a survival race against rivals,

and expanded their dominion.

They continued to invent new tools,

and at last, we've been
thriving over the globe.

But at the same time,

we've also been making big changes to it.

We are the only surviving
hominid species on the planet,

and our future rests on
the choices we make now.