Original subtitles

In Java, scientists are looking for a strange species of ape man, a creature

that might link modern humans to our first ape ancestors.

From Asia to Africa, a few fragments of fossils are all that remain.

of perhaps the strangest episode in our evolutionary journey.

Yeah, this is modern.

No, no, no. No modern. No homo sapiens.

A time when we were no longer apes, but not yet human.

The greatest discoveries are sometimes a matter of pure chance.

I was flying up to Ethiopia from Kenya and we diverted slightly to the east of

normal track and we were flying up the eastern side of the lake and I was

looking out of the window.

The ground beneath the plain looked like the sediment left by an ancient

prehistoric river.

What we were flying over wasn't volcanic, as we'd always assumed, but

sedimentary exposures. And where there are sediments, you usually find fossil.

For millions of years, rivers have washed into Lake Turkana, a massive

water. on the remote Kenyan borderlands.

200 miles long and 40 across.

Until Richard Leakey's diverted flight, no one had thought to look for fossils

here.

The African fossil hunting dynasty of the Leakeys had spent years uncovering

extraordinary evidence of our earliest ape ancestors.

Fossils like this almost 3 million year old Australopithecine record the

earliest days of our evolutionary story.

But these ape -like animals were a long way from being human.

To understand how apes could become us, scientists needed fossil evidence of

creatures which had developed more human features.

But so far, only a handful of fossils had ever been discovered.

Determined to explore Lake Tsakana, Leakey made contact with a fossil hunter

called Kamoya Kimau.

Kamoya had trained with Richard Leakey's father, Lewis.

The initiate, we are going to dig human being bones.

All over the world, scientists have searched for something which might

our earliest ape ancestors to us, a creature they called the missing link.

Since 1859, when Darwin first published Origin of Species, people became

increasingly captivated by the idea of the missing link, the transitional form

that would link apes to humans.

And since that time...

Scientists around the world have looked for evidence of the missing link and for

remnants of the missing link.

One scientist, Eugene Dubois, traveled deep into Java convinced he could find

evidence.

This is the Solo River, the Bengawan Solo River in East Java near the village

Trinil. And this is one of the places where Dubois came in 1891 looking for

missing link. And as he marched along the riverbanks with his men, he spotted

what he describes as a thumb -shaped piece of bank sticking out.

And he had an intuitive feeling that that was someplace they ought to look.

The first discovery was only a single tooth.

But before a month had passed, they found this gorgeous thing.

A skull.

The skull of a creature that scientists

could tell was pre -human.

A big brow ridge on a small ape -like brain cave.

The next year, they kept working at Tranel and turned up this.

A virtually complete femur.

But unlike the ape -like skull, the leg bone was clearly human.

An ape head on a human body.

Dubois thought he had found the missing link, but no scientists believed him.

Human ancestors must have had human brains.

The thing that we value so much, that we felt set us apart from the animals more

than anything else, was our brains. That's when Dubois found an ape man.

that was ape -like in the brain and modern in the leg.

He was finding something directly contrary to everyone's expectations.

Today, we call Dubois' discovery Homo erectus, a species that lived over one

a half million years ago.

But further evidence was difficult to find.

What kind of creature this was, and what part it might play in our own

evolution, remained a mystery.

without more fossils.

The charming thing about fossils is they always surprise you. They always fool

you. They never look like what you think.

At Lake Turkana, Kamoya and his fossil hunting team began to search the western

shore.

Richard Leakey's instincts were right.

The long -deposited sediments of old river systems were just the place to

for fossils.

Kamoya will tell you that if you've walked to the right -hand side of a bush

day, the next day you'll walk to the left -hand side of the bush.

And if you've walked before lunch past the bush one day, the next day you'll

walk... So the light is different.

And he just thinks that it's diligence.

And he knows, he says, that you can find a fossil anywhere.

I mean, they're just there to be found. It's a question of how many hours you

put in.

But seeing the fossils amongst the rocks is difficult.

Aha, yes.

Piece of bone, you can see.

whether the fossils are human or animal.

This must be part of Mandible from Hippo.

Anatomist Alan Walker and Richard Leakey stayed in Nairobi, waiting for news

from the field.

After four weeks, they'd heard nothing.

We'd had Kamoia and the team in the field for about a month.

The intention had been to move southwards down the lake with a series

for about a month each to prospect and see if we could find any major fossils.

But Kamoia's team had found no fossils of any significance.

And with temperatures reaching almost 60 degrees centigrade, the others in the

team decided to take a rest day.

They always complain, why don't you rest?

I just find I can walk and see what was happening across the river.

Because I could see the whiteish which was, I knew there must be bones around

there.

Above the dried -out bed of the Nariokotomi River was a small hill and

single acacia tree.

That day I just came here looking for photos.

And I found a piece of skull.

I called Nairobi. I talked to Richard Leakey. I said, we have hominid. If you

can come, you can see.

But as soon as Alan Walker arrived from Nairobi, it seemed clear Kamoyo's

discovery was unlikely to lead to any more fossils.

He'd gone to a place that I'd never looked. I mean, there's a roughly piece

bed with old rocks and boulders.

No signs of any decent exposure, not the place where you'd find fossils.

But because a small piece of hominid had been found, Walker and Leakey were

forced to begin a complete excavation of the surrounding area.

My initial reaction was one of slight sorrows because it meant that we could

not now move camp.

We got to delay the whole thing while we did some fibbing.

After a day spent fibbing, Leakey was convinced there was nothing to find.

Richard said, if we come to that little tree there, Walker, and we don't find

any more, should we call it quits?

And I said, sure.

I was working under the tree amongst its roots, pulling out soil with a brush

and dental paper so that we could pass it through the sieve when I found the

first side of the face.

And Richard said, come here, Walker, look at this. Here's the face. And the

was stuck in the roots of this tree.

The tree had germinated in the only damp place in the desert, which was an

upside -down homo erectus skull.

Homo erectus.

was the same species as the fossils found in Java.

But would this discovery in Africa reveal more about the mysterious half

half -ape?

As the excavation continued, more fragments of skull began to emerge from

ground.

Slowly, the team began to sense what kind of creature Kamoya had led them to.

There are 70 pieces of bone that go into making the skull. It's a bone washed,

free of dust and dry, and then you find the pieces that go together and wish to

come together with ordinary acetone -soluble glue.

They say, oh, this part must come from the back of the skull.

The fragments of bone became a face.

The face of a young male.

A young male that was clearly on the way to being human.

The skull was miraculously complete, and now scientists were able to get closer

to this strange creature.

One of the major differences that one can see between a homo erectus skull and

modern human skull, I mean, you can look at mine as an example, is that he has

hardly any frontal lobes here, so he has next to no forehead from me. Above his

eyes, he just goes straight back, whereas in modern humans, we all have

lump of frontal lobe of the brain sticking up here giving us this more

forehead

although

fossilized

the boy's teeth were still perfectly intact and preserved with enough detail

provide scientists with vital clues

And we could see that this tooth, the second molar, had just erupted.

So we knew straight away that this was a youngster.

We'd had hints of that because the skull bones themselves weren't fused, and

that says that it wasn't adult quite.

But this told us that it was a child in human terms of about 12 years old.

But the child's teeth revealed more than just its age.

Around the jawbone here, there's a lesion. When he lost his milk teeth,

was a couple of fragments of tooth got left in the jaw, and they became sort of

an infection. And this lesion or depression on the jaw is where an

formed, and that caused that adult tooth to come through at an angle.

The fragments of the milk tooth would first have infected the child's jaw,

poisoned its blood.

It is possible from a dental infection of that kind that the infection passes

the rest of the body and becomes septicemia or blood poisoning.

This picture here shows the late stages.

What happens is that the person develops a very high fever, their heart rate

gets very high, they feel very ill, and then they begin to get a rash,

speckleding. This is actually blood clots under the skin, and then it forms

these wide lesion areas.

Without treatment, septicemia leads to a raging thirst, a sense of fear and

delirium.

The child's fossilized skull still retained a tiny detail of bone

that would provide new evidence for the mental capacity of these creatures.

While we were sticking this part of the skull together, I was particularly

interested to look inside this bone. And I could show you by showing you a

separate cast of that part. It's the same piece as that just above the left

And if we look inside here, we can see that this is the impression of the

The bone of the skull is curved.

to fit around a part of the brain called Broca's area.

And Broca's area has been known for a long time as one of the motor areas of

speech.

A large Broca's area like this is only found in human brains, not in the ape.

So when I saw a well -developed Broca's cap, is what we call it in our trade,

where there's a definite little bump,

Then I thought, aha, this was a child who could speak.

Here, with the evidence for speech, was a child that might communicate as we do,

thinking and feeling like us, one and a half million years ago.

But there was more than just a skull to come from the prehistoric shores of Lake

Turkana.

A few days after the discovery of the skull, the team found something

Long, thin fragments of fossilized bone curved and flat on two sides.

They were human -like ribs.

We never find ribs.

Ribs in humans, in primates in general, unlike those of, say, antelopes or

cattle, are very soft and very thin, and they've got lots of marrow in them, and

they're all crunched up by hyenas and carnivores and predators.

The survival of ribs that were a million and a half years old was a sign that

more bones might lie beneath the surface.

If you put ribs and face together, then the chances are there's going to be

more, and that was what... made us realize that perhaps we'd hit on

almost unique.

The team fanned out.

They began to probe the earth over a wide area with fine metal pick in search

the tiniest fragment of fossil.

And every time our little ice picks hit a bone, there was a ping and everybody

turned round and said, oh, you've got a bone.

Soon everybody was finding bones. It was quite remarkable.

There were half a dozen of us, Kamoya, me, Richard, myself, all sitting there,

each working on a Homo erectus bone and seeing one for the first time.

They had found the first complete skeleton of a creature one and a half

years old.

a creature existing at the midpoint of human evolution, exactly halfway between

us and our first ape ancestors.

The secrets of the Lake Turkana skeleton began to be revealed with an

examination of its spine, a spine that Alan Walker thought was normal, until he

took another look.

What I didn't notice was that the ends of these vertebrae, the spines are

twisted. You can see they're rotated.

And also, if we look end on, you can see that they're asymmetrical, that one

must gutter for the muscles on one side. These are muscles that hold the neck

up. He's deeper on the other side.

It's shallower. So there's an asymmetry in the way the spines are.

What impact this spinal asymmetry made on the child's anatomy was unclear.

Then Alan Walker noticed something else in the bones.

That there's crushing here that's matched on this vertebra too.

And if we put them together...

You can see that there's an extra facet, so rather than being like this, this

one is flipped right down, and this is the position in life.

Although it was over one and a half million years old, the fossil was so

preserved, scientists could unravel the mystery of the deformed spine.

This is an X -ray, a radiograph.

of an individual with a normal spine.

And here's the spinal column right here.

This radiograph, on the other hand, shows an individual who has scoliosis,

abnormal curvature to the side of his or her vertebral column or spine.

The bones of the boy showed that he was suffering from an acute scoliosis.

In the near economy boy, what seems to have happened with his scoliosis is that

it would have been caused by a traumatic incident, an injury, being fallen out

of a tree, being hit by another individual, having an encounter with an

perhaps. But it appears that with his scoliosis, it was a trauma -induced

Whatever the traumatic event, scientists knew only humans suffer from scoliosis.

Apes do not.

The bones, too, seemed to confirm the child was more human than animal.

And then the skeleton revealed something more remarkable.

And we found this thigh bone, the left thigh bone from the boy's skeleton. We

could see that it was a big bone, and we could see that it was still growing

because the growth cartilage was still open at both ends.

This crack in the middle is a break caused after the specimen was

that enables us to look at the cross -section of the bone in this region.

You take the cross -sections from fossil bones and you can analyse them using

engineering beam theory, which basically just tells you how strong the bone is

in compression and torsion and bending.

The engineering analysis showed that the bones of this 12 -year -old child were

quite different to those of a modern human.

When my colleagues applied those analyses to the Narayakotami boy's legs

arms, they found that he was extremely strong.

are much stronger than you could expect a modern athlete to be.

The bones were not only strong, but much bigger than scientists expected.

In fact, we've estimated that had this individual lived to maturity, he would

have been well over six feet tall.

And it seems that many modern human populations have been dwarfed, that

much smaller than their ancestral populations were.

That life in the Paleolithic...

One and a half million years ago when these people lived was such that they

could grow tall and strong and that big bodies were a successful adaptation.

One and a half million years ago, giant human -like creatures had evolved,

larger and stronger than any human alive today.

In Java, just 30 miles from where Eugene Dubois dug up the first Homo erectus,

there are more discoveries.

The skull of a Homo erectus, one of many recent finds across Indonesia and

Southeast Asia.

When you find Homo erectus in Indonesia today, what you're looking at is

the local descendant.

of what originally was an African form, starting at places like Maricotomi in

eastern Africa and Kenya, and then migrating out across the old world and

spreading out wherever the habitat and the animals would allow them to go.

Pat Chipman thinks that they left Africa to hunt food.

We're looking at...

A highly predatory form.

You're looking at hominids who are really efficient hunters.

And you simply have to expand or you run out of game.

And you follow the herd. It doesn't matter to you if you're hunting an

or a deer.

Meat on the hook is meat on the hook.

Homo erectus was the first human -like creature to leave Africa.

Across the dangerous savannah, dense jungle, and vast mountain ranges, our

ancestors journeyed 6 ,000 miles from their African homeland.

Far more advanced than had once been thought, the missing link seemed much

closer to us than we had ever imagined.

It seemed the mysteries of our long -lost ancestor had finally been solved.

But doubts were beginning to nag Alan Walker.

Was there something about the boy he'd overlooked?

When you start on an enterprise like analysing the naryocotomy skeleton, of

course, you don't start with a blank slate. You have all sorts of

and prejudices.

And sometimes your preconceptions and prejudices are confirmed, and other

they're... that you have to get rid of them and start over again.

Alan Walker began to wonder if the boy was as human as he had first thought.

And thinking back to the excavation, he remembered a find he'd made.

When we were in the field in Narakotami excavating the specimen, I was working

next to Kamoya, and we excavated the...

last of the neck vertebrae. And one of the things we could see immediately is

that if I show you the end of the vertebrae, you can see the hole in which

spinal cord lives.

And I said to Kamiya, look how small that hole is.

And if I compare that with this white bone here, which is the bone of a modern

person, you can see that the hole in the naryocotomy is very, very much smaller.

The vertebrae of the spine carry the spinal cord nerves which lead from the

brain Although Alan Walker thought he had found evidence for speech in the

child's brain It was the amount of nerves in the spinal cord that would

determine what the child was really capable of The size of the vertebrae was

critical. So Walker asked another anatomist to take a look at them

Anne McLarnon is an expert on the function of the vertebrae and the spinal

in humans and apes.

The spinal cord provides the nerves to various things, including the muscles

between the ribs and in the front of the abdomen.

So it was a matter of looking at other functions of these muscles, and they

two, one of which is to do with coughing and defecation, so not something you

expect great change in human evolution, and the other is the control of

breathing.

The link to breathing was vital because it's this ability to control our

breathing that allows us to speak.

The fact that the Narikotemi boy has a smaller spinal canal means that he would

have had a more limited amount of nervous tissue in that region and

less sophisticated, less flexible control of the muscles in that region.

So he should have been able to communicate at least as well as modern

chimpanzees and so on, but without taking that further step forward that we

without being able to produce the kind of speech that we do, which gives us a

very sophisticated means of communication.

The fossil evidence that the boy could not speak forced scientists to reassess

their view of these prehistoric creatures.

It was a disturbing message for us that although this creature would have looked

human from a distance and had a human body, at least below the neck, to

know that probably they didn't have the capability for language.

Had the scientists been misled by the human -like appearance of Homo erectus?

Was he closer to our ape ancestors than they had first thought?

In most sciences, there's a tremendous danger of seeing only what you want to

see. And it's particularly true in a discovery -driven science like

and paleoanthropology, where you make the discoveries, but the interpretation

them is what really gives them significance.

I think a rector spoke.

I'm almost sure of that. But can I prove it? Certainly not. It's a reaction from

the gut, not the head.

The question is, did he have language?

And could he make a stream of symbols in the form of sentences that you and I

can, or people all over the world can? And I still don't think.

that there's any evidence that he could.

And there was another doubt, based on the extraordinary size of the creatures.

We didn't suspect that the naryocotomy individuals, the population from which

this individual came, that they would be so big in the body.

And the bigger the body, the smaller, relatively speaking, the brain.

We know that mice have small brains and elephants have big brains.

The question is, what's the relative brain size?

And we, of course, can estimate the size of the body in this individual. We know

he would have grown up to be well over six feet tall.

And we can estimate the brain size, as you can see from the amount of skull

we've got, we can estimate the brain size quite accurately.

And when we look now with the complete skeleton from the arachotomy... and are

able to reconstruct better all the bits and pieces of other Homo erectus

individuals, we can see that they were all big.

So big that relatively their brain was tiny.

A chilling new glimpse of Homo erectus was emerging, bigger and stronger than

any living human, but a long way from becoming us.

They're like an adult human walking around with the brain of a one -year

baby.

One and a half million years ago the young boy at Lake Turkana was in the

stages of septicemia It's a

bacterial infection throughout the entire blood system and that's an

serious infection So he may have developed a very high fever

felt very confused, very agitated, lethargic, really extremely unwell,

eventually passed out and had a really quite horrible death.

Scientists found one final fragment of evidence.

Remarkably, it revealed the boy's last moments on the shores of the lake.

Since the lower teeth and upper teeth were together in one spot, we could

reconstruct how this dead child was lying.

And we knew for other reasons that it was lying in shallow water. So we can

imagine him lying face down in the water, very shallow water, but his head

be bobbing in the ripples.

as the wind blew across this shallow marsh.

And as his flesh rotted, the straight -rooted teeth of the incisors and the

canine slipped out into that one spot and were found there together.

And then gradually, as his skeleton, as the flesh fell off him and the catfish

sucked at him, his bones would be spread and kicked about by hippopotamuses. And

the skeleton moved nearer and nearer the shore, being stamped on and broken up,

the skull at one end of this long line of bones and the jaw at the other end.

and leaving the set of front teeth in this one little patch that we later

excavated and found was a hippopotamus's footprint.

Deep in our past, the harsh landscape of East Africa was home to the Nariokotomi

boy and his kind.

When the Earth finally revealed its secret, it gave us a very different view

how we'd evolved.

One and a half million years ago, almost all the characteristics of a modern

human were already in place, except one.

The thing that defines us as different from the animals, our brain.

Evolution doesn't take place all over the body or all over the physiology all

once. It's a mosaic process.

Darwin tried to put all of human anatomy and physiology into one thing. He said

that uprightness would free the hands and that would have a feedback mechanism

on the brain and we'd get big brain and so on. And we now know that people were

upright from at least 4 .2 million years ago.

So half of human history, we were upright, but it didn't affect our

We could have a human -looking body with the same sort of physiology and

gait, but without the brain in us or without the language capabilities.

They don't all have to come together.

The child found by Kamoya Kimau was, for all his human appearance, still an

animal.

Back one and a half million years ago, from a distance you'd recognize them as

person. When you got close, you might feel that when you got close, even

you might not know their language, that you'd see something human in their face

and you'd be able to communicate. But it was probably much more like the feeling

that you get when you come around a bush and you see a lion and you see those

big yellow eyes staring at you. And you know there's nothing there communicating

with you.

The boy who died in such agony by the shores of Lake Turkana was an

midpoint, a creature changing from ape to human, a unique species,

part human, part animal, our direct ancestor.

In the next program, we discover creatures that could love, a species

and hunted on the plains of Europe half a million years ago.