Out of the Cradle (2018) - full transcript

(grand, epic music)

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.



(hominid grunting and panting)

(screams)

(tiger growls)

The species we descended from

were not the physically strongest.

In fact, they were among the weaker.

(grunts)
(cracking)

They survived periods of intense difficulty,

staging a series of amazing comebacks.

(epic, exciting music)

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.



(bird chirping)
(percussive jungle music)

(isolated ambient music)

Africa, the cradle of the human race.

The first hominids took their first steps

on this terrain.

(branch snaps)

Deep in the jungles lies an animal

that can help us imagine the origins of humanity.

(chimps hooting)

(chimps screeching)

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.

(bird chirping)

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.

(light, curious music)

This is an archeological site called Middle Awash.

(tools clinking)

(man speaking in foreign language)

You finished up here?

For many years, Tim White

has been leading an international team

in excavating this site.

Then we reach the fault.

(low, intriguing music)

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.

(contemplative African music)

A chimpanzee has a long and narrow pelvis.

(chimp screeching)

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.

(bird chirping)
(tinkling piano music)

(ramidus hooting)

(snorts)

(ramidus screeching and hooting)

(grunts)

When down on the ground,

ramidus is vulnerable to predators.

(birds calling)

(flies buzzing)

(careful, cautious music)

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.

(booming)

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.

(imposing, contemplative music)

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.

(ramidus panting)

Research has also uncovered a major development

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

(birds chirping)

(hooting)

(thunks)

Four million years ago,

ramidus seems to have had a family

much the same way as we do.

(gentle music)

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.

(chimps screeching)

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.

(gentle orchestrated music)

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.

(wildlife chattering)

(door slams)

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.

(isolated ambient music)

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.

(isolated harmonica music)

(afarensis grunting)

(curious, traditional music)

(chomping)

To make it through the dangerous savanna

while searching for food,

this early hominid species began to form groups.

(elephant roaring)
(elephant trumpeting)

(afarensis grunting)

(quick footsteps padding)

(afarensis screams)

(cat growling)

(wet squishing)

(uneasy ambient music)

(cat growling)

Even in groups, afarensis was still very vulnerable.

(flies buzzing)

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.

(tinkling, hesitant music)

How did the less robust homo habilis

win the battle for survival?

(flies buzzing)

Homo habilis lived 2.4 million years ago.

(flies buzzing)

(bird screeching)

(wind howling)

(habilis hooting)

(panting)

(animals calling)

Hyenas.

(hyenas vocalizing)

(habilis grunting)

(hyena whining)

(habilis hooting)

(hyenas barking)

(habilis hooting)

(habilis panting)

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.

(habilis hooting)

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.

(bow clacks)

(murmuring in foreign language)

When the Hasta eat meat,

they leave the same type of cuts on the bone.

(talking in foreign language)

(bustling traditional music)

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.

(light, clapping music)

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.

(bones rattling)

(habilis hooting)

(habilis grunting)

Marrow inside the bone is a valuable source of nutrients.

(light piano music)

(grunting)
(bone clacking)

(hooting)

(cracking)

(gasps and whines)

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.

(grunts and gasps)

Hominids of our lineage

had now begun to use tools.

(exciting percussive music)

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 erectus 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 erectus 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 erectus bones,

there were thousands of animal bones.

They belonged to large, plant-eating creatures.

Lordkipanidze says this is evidence

that homo erectus 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 erectus had started hunting,

and its unique body seems to have been

perfectly adapted to its hunting style.

(curious orchestral music)

This animal is injured.

A group of homo erectus are following it.

(hooves clomping)

(rising, exciting music)

Their hunting style was a waiting game.

They patiently chased their prey

until it became exhausted.

(animal whines)

(erectus vocalizes)

Hominids were once the prey of carnivores.

Now they had become the predator.

What a huge reversal.

(fly buzzes)

But how exactly do we know

that homo erectus was a good runner?

(animal whines)

(revertant singing)

One scientist came up with the answer,

Daniel Lieberman of Harvard University.

He says it's clear from homo erectus 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 erectus,

he would probably be pretty good runner.

(exciting, epic music)

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 erectus 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.

(animal whines)

Around the same time

homo erectus began to hunt,

another astonishing change happened.

This change happened on the inside.

(tool clacking)

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 erectus, however,

the rate of enlargement suddenly accelerated.

A major factor was a change in diet.

When proto-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 erectus

had different human characters,

including social relationship,

and taking care in groups, helping each other.

Dr. Lordkipanidze believes

compassion began to bloom in homo erectus.

(serene, compassionate music)

Hominids turned to meat eating

when other food was scarce,

and an unintended consequence

was the development of human emotion and intelligence.

(fire crackles)

Homo erectus left Africa

and eventually spread to various parts of Asia.

The fossil hominids known as Peking Man and Java Man

are both homo erectus.

In Africa, a new species called homo heidelbergensis

evolved from homo erectus.

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.

(still, ambient music)

It did not have a major effect on temperate Asia.

Java Man, a group of homo erectus 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.

(wet stabbing)
(mammoth wails)

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.

(isolated, howling music)

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.

(rising orchestral music)

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.

(light, pensive music)

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.

(rattling)

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.

(woman speaking in foreign language)

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?

(traditional percussive music)

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?

(epic traditional music)

(baby coos)

(isolated, intriguing music)

Jerusalem in the Middle East

has long been the crossroads of civilization,

and this region is likely where neanderthals

and homo sapiens first met.

(reverential chanting in foreign language)

The evidence is a discovery made in 2015

at the Manot Cave in northern Israel.

(murmuring)
Uh-huh.

(man speaking in foreign language)

(archeologists speaking simultaneously)

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.

(mysterious, tinkling music)

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.

(low orchestrated music)

The two branched off from a common relative.

(rising orchestral music)

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.

(deer vocalizing)

(wind blowing)

(neanderthal shouting)

(rapid footsteps padding)

(neanderthal shouts)

(speaking in imagined language)

(ghostly music)

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.

(scraping)

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.

(traffic honks)

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

maybe it's because of other reasons.

(exciting percussive music)

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.

(light, thoughtful music)

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.

(tense, still music)

They're setting up an ambush.

(neanderthal speaks in imagined language)

(rhino snorting)

Can they take down a beast that big?

(rhino grunting)

(tense, exciting music)

(neanderthal grunting)

(rhino grunting)

(neanderthal speaks in imagined language)

(rhino wails)

(grunting)

(rhino snorting)

(neanderthal shouting)

The fearless hunting of the neanderthals wins the day.

(wet stabbing)

(still, pensive music)

What about homo sapiens?

They had slimmer bones,

and thus were probably weaker than the neanderthals.

(human speaks in imagined language)

They had to employ a different hunting style.

(human speaks in imagined language)

After they moved to Europe,

their skin and hair color began to change.

(cautious world music)

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?

(reverent world music)

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.

(animals braying)

(whistle blowing)

(whistle blowing)

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.

(ATV motor humming)

(energetic world music)

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

and with more power.

(spear thuds)

The atlatl was an amazing breakthrough.

With an atlatl, you didn't need

to get too close to your prey.

(animal whines)

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.

(ghostly music)

What about the neanderthals?

(footsteps crunching)

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.

(speaking in foreign language)

DNA analysis found

that the inhabitants were all related.

This suggests that neanderthals

lived in small family groups.

(nostalgic, curious music)

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.

(both women chuckling)

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.

(stuffed toy squeaks)

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?

(baby coos)

The yellow doll.

Okay.

All right.

And when the colors are switched.

(reverent world music)

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.

(simmering, pensive music)

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.

(speaking in foreign language)

400 people, many of them not related by blood.

This is a true community.

Why would homo sapiens gather in such large groups?

(rising orchestral music)

Unearthed ornaments provide a possible answer.

(speaking in foreign language)

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.

(gentle, somber music)

(speaking in foreign language)

Much evidence has been found

of humanity's growing spirituality in the era.

Cave paintings include depictions of mystical creatures.

(awed woodwind music)

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.

(lonely, percussive music)

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.

(fire crackling)
(chanting)

Lit up by the fire,

the wall paintings look magical,

almost surreal.

(chanting in imagined language)

(reverent, ghostly music)

(hooves beating)

Sharing in these mystical experiences

would surely strengthen group ties,

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

(thumping)

(reverent, chanting music)

(ice rumbling)

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.

(simmering epic music)

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.

(neanderthal shouts)

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.

(mournful music)

(labored breathing)

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.

(gentle piano music)

Homo sapiens was now the only hominid species

left on earth.

There were no rivals anymore.

(sudden, mysterious music)

Curiously, however, that is when our ancestors

began engaging in a completely new type of behavior.

It could have been warfare.

(water drops plunking)

The evidence comes from skulls found in a German cave.

(curious, hushed music)

[German Scientist] 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.

(epic orchestrated music)

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.

(gentle orchestral music)

The neanderthal parts of our DNA

seem to play important roles.

(exciting percussive music)

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.

(awed world music)

7.6 billion people live across planet earth.

How did we homo sapiens achieve this astonishing expansion?

(epic world music)

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.

(cheering)

(hushed world music)

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.

(rising, exciting music)

Here, ancient fossil remains were found

during the construction of an airport.

(man speaking in foreign language)

(woman speaking in foreign language)

(man speaking in foreign language)

There were 19 human skeletons

from 20,000 to 27,000 years ago.

(speaking in foreign language)
Ah!

(man speaking in foreign language)

(woman speaking in foreign language)

(man speaking in foreign language)

(woman laughing)

(speaks in foreign language)

The number of bodies

suggests this was a grave.

(bones rattling)

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.

(speaking in foreign language)

Dr. Naomi Doi scans all of the bones.

(machine beeping)

(still, pensive music)

Using a 3D modeling software,

she attempts to piece the skull back together

to recreate its face.

(speaking in foreign language)

(speaks in foreign language)
Mm.

(Naomi speaking in foreign language)

(mysterious music)

Here is the facial recreation,

a face you might see today.

(pondering, percussive music)

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.

(energetic world music)

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.

(speaking in foreign language)

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.

(serene, pensive music)

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.

(low, pondering music)

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.

(men talking simultaneously)

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.

(thoughtful piano music)

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.

(rattling, exciting music)

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.

(exciting, orchestrated music)

(speaking in foreign language)

A huge experiment was held in 2016.

(awed world music)

(waves crashing)

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

(epic, seafaring music)

(speaking in foreign language)

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.

(splashing)

(man speaking in foreign language)

The group uses shells to cut reeds.

They were a common tool back then.

(man speaks in foreign language)

(bird chirping)

Vast numbers of reeds are needed to make a boat.

It takes 10 people over a week

just to gather the material.

(Yosuke speaking in foreign language)

Now that the reeds are cut,

it's time to build a boat.

But how do you do that with reeds?

(man speaking in foreign language)

(man speaks in foreign language)

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.

(stones whacking)

Reed boats look simple,

but require close cooperation among large numbers of people.

(stone whacking)

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.

(people talking simultaneously)

I'm okay.
Okay, okay!

(man laughing)

(shouting in foreign language)

(rhythmic clapping)

(waves crashing)

(man shouting in foreign language)

The rowers spent two weeks

practicing for today,

but just overcoming the waves is tough.

(chanting in foreign language)

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.

(chanting in foreign language)

In five fours, the boats should travel eastward,

that is, toward the right,

but keep drifting left.

(isolated ambient music)

The boats drag against the water.

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

(man speaking in foreign language)

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.

(man speaking in foreign language)

(speaking in foreign language)

(laughing)

(idle music)

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.

(speaking in foreign language)

(stone cracks)

(Yosuke speaks in foreign language)

They make stone tools.

(Yosuke speaks in foreign language)

(saw grinding)

These stone tools are used

to cut down bamboo for the boat.

(stone whacking)

(men speaking in foreign language)

(bamboo creaks)

(bamboo snaps)
(people exclaiming)

(Yosuke speaks in foreign language)

(men speaking in foreign language)

An indigenous group on Taiwan

called the Amis still make bamboo boats.

(hammer whacking)

They help the team build one.

(hammer whacking)

(people talking simultaneously)

(speaking in foreign language)

Dr. Kaifu doesn't want them

to use modern hammers.

He asks them use stones.

(Yosuke speaks in foreign language)

(stone whacking)

(Yosuke speaks in foreign language)

(man speaks in foreign language)

(Yosuke chuckles)

(man speaks in foreign language)

(Yosuke chuckles)

(stones whacking)

(men speaking in foreign language)

(woman speaks in foreign language)

(speaks in foreign language)

A fast, dynamic bamboo boat is completed.

(tense world music)

This time, they'll travel 40 kilometers,

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

(speaking in foreign language)

(waves lapping)

(hushed percussive music)

(man shouting in foreign language)

(men shout)

The bamboo boat is definitely faster

than the reed canoes.

(Yosuke speaks in foreign language)

But they're caught in a sudden rain shower.

The sun and the island vanish.

There's no way to check their direction.

(Yosuke speaks in foreign language)

As they flounder on the sea,

the ocean current sweeps them off course.

(somber music)

Unable to maintain speed against the current,

the boat has been carried away.

(swelling, emotional music)

The experiment has failed again.

(speaking in foreign language)

(man chuckles)

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.

(speaking in foreign language)

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.

(cheering)

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.

(mysterious traditional music)

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?

Hmm.

The trunk must be a meter across

to fit a person inside it.

(light, pensive music)

Time to experiment.

(ax whacking)
(grunting)

Six days later.

After the chop number 36,225.

(ax chopping)

(whistle blows)

(man speaking in foreign language)

(younger man speaking in foreign language)

(tree cracking)

(thumps)
(leaves rustle)

(speaking in foreign language)

(gentle piano music)

(people speaking in foreign language)

They test their dug-out canoe.

(Yosuke speaks in foreign language)

Time to see if the canoe can outpace

the Kuroshio Current.

(speaking in foreign language)

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.

(low, simmering music)

The experiments suggest the voyage 30,000 years ago

may have looked like this.

(man shouting in foreign language)

(men shouting in foreign language)

(man shouting in foreign language)

(men shouting in foreign language)

A group is transporting a log canoe.

(gentle, awed music)

Many people have to work together

to prepare the canoes.

(men shouting in foreign language)

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.

(men shouting)

(shouting and cheering)

(epic, exciting music)

They set off for unknown lands,

ready to forge a new future.

(voyagers chant in foreign language)

(speaks in foreign language)

(shouting)

(gentle, serene music)

And so humans arrived in Okinawa.

(cheering)

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.

(ice crackling)

(frozen fish whacking)

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.

(machine buzzing)

The ongoing dig began in 2003.

(shovel scraping)

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.

(speaking in foreign language)

But why did homo sapiens travel

to this extremely cold region?

(light, pensive music)

(speaking in imagined language)

(mammoth grunts)

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.

(snow crunching underfoot)

There was another point in their favor.

The snow left easy trails to follow.

It's easy to spot prey.

(reverent world music)

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.

(ghostly ambient music)

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.

(speaking in foreign language)

Even today, traditional reindeer coats

are made by hand.

(awed music)

(woman speaks in foreign language)

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.

(singing in foreign language)

This may look simple to make,

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

(file grinding)

First, a groove is carved into an animal bone.

And a second groove is made here.

(stone whacking)

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.

(impressive orchestral music)

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.

(stone clinking)

(awed world music)

Volunteers' brains are scanned

as they watch how to make a stone tool.

They get a virtual experience of toolmaking.

(stone clinking)

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.

(mysterious ambient music)

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.

(leaves rustling)

Long ago, a peculiar type of animal

began walking on two legs in the forest.

They survived a geological cataclysm and lived in families.

(inspiring world music)

Hominids were prey of carnivores in Africa.

(hominid shouting)

On the same continent,

the last hominid, homo sapiens appeared,

and narrowly survived harsh conditions

thanks to a series of fortuitous events.

(light primitive music)

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.

(impressive world music)

We are the only surviving hominid species on the planet,

and our future rests on the choices we make now.

(epic, exciting music)