Original subtitles

What makes us human?

Where do we come from?

Ever since Darwin put forward the idea

that we evolved from apes,

scientists have wondered about those first creatures

that left the ape world and crossed into ours

In the last 50 years,

fossil finds have filled in some of the many blanks

in the story of our evolution

But the bones of our ancestors are few and far between,

allowing only glimpses of how we slowly changed

over millions of years

from ape

to human

Now, in South Africa,

in caves dangerously deep underground,

two new species of hominin, our human ancestors,

have been found

There it was,

right there:

one of the most spectacular early hominins ever discovered

lying on the surface of a cave

And not just a few bone fragments

It's everywhere

Here, there are thousands

It's just absolutely incredible

the amount of bone that's coming up

Oh, beautiful!

The first thing that came through my mind

was Howard Carter's anecdote

about opening Tutankhamen's tomb

It was Lord Carnarvon in the back saying, "What do you see?"

And Carter says, "Things, wonderful things"

We have found a most remarkable creature

and a most unexpected one

So we need a new kind of language to talk about this

These bones could finally bring our past into focus

What story will they tell about how we became human?

A new light shines at the "Dawn of Humanity,"

right now on this NOVA/ National Geographic special

The high plains to the northwest of Johannesburg

have been called the Cradle of Humankind

In the 1930s and '40s, fossil finds here gave us

the first important glimpses of our earliest ancestors

Then, for decades,

the discoveries seemed to dry up

It looked like the Cradle of Humankind

had little left to offer

Go get 'em, good luck

Happy hunting

But now, from deep caves in the Cradle

come two new discoveries

that could reshape the understanding

of our ancient past

What is it?

It has teeth

It's so solid!

There aren't just hundreds of bones;

there are thousands of bones

I had never seen or dreamed

of anything like the richness of this site

Bones that may end up illuminating

a critical million-year period in our evolution

that has long been a mystery

There's a big gap in the fossil record

with only a few little fragments

The fossil record suggests that

in that gap lies the dawn of humanity:

the birth of the genus Homo

It's perhaps the least understood

and most important episode in our evolution

Before it was the world of Australopithecus,

an ape-like creature with a tiny brain

Lucy is the poster child for the Australopiths

She walked upright, but belonged to the world of the apes

If I were to see an Australopithecus

at the end of a football field,

I would probably call the zoo and say,

"Hey, an ape has escaped"

The upper part of the body

in Australopithecus is, in general way, ape-ish

Go down, look at the pelvis, very human-like

An Australopithecus is sort of like a bipedal ape

If you went back in time

and saw them walking around the savannah,

you would see animals that stood up and walked like we do,

but they would've been smaller in body size

Their brains wouldn't have been as big,

so their heads would've looked smaller

Their jaws and teeth were very large

The fossil record suggests that

somewhere between two and three million years ago,

these ape-like Australopiths

evolved into the first recognizably human species:

Homo erectus.

They have big brains and small faces,

adaptations for using tools

If I were to see, say, Homo erectus

at the other end of a football field,

I would probably call 911 and say,

"Oh, there's a wild man over here,

and you know somebody should put some clothes on him"

So what went on in the transition

from Australopithecus to Homo erectus?

For years, the only species that filled that gap

was a creature called Homo habilis.

But so little of it has ever been found,

the origins of the genus Homo have remained an enigma

The greatest mystery facing paleoanthropology today

is to try to understand how, when, where the transition

from Australopithecus to Homo occurred

And what we don't know is what happened

between Australopithecus and early Homo

That's one of the big mysteries right now we're trying to solve

The prize would be to discover fossil remains

that could tell us about that mysterious transition

And now, they may have found some

There you can see two foot bones in articulation

Emerging from ancient caves in South Africa

are fossil finds of astonishing richness,

and not just fragments,

but virtually complete skeletons

From the very first block that we had,

we had a portion of the mandible, the lower jaw,

and we had a collarbone

and one of the bones of the forearm

So that was really, really exciting

She's in there

We have a skull, we have a mandible,

we have a complete scapula, we have a complete clavicle,

we have a complete arm, a complete hand,

and half of the pelvis, which we can,

with reconstruction, make into a whole pelvis

Will these skeletons live up to their promise,

offering us a new understanding of the dawn of humanity?

In August 2013, South African Pedro Boshoff was out of work

He had been a soldier, a prospector, an adventurer,

and even a part-time student of human origins

Now he wondered if he could earn some money

doing what he loves most: fossil hunting

Towards the end of August,

I approached Professor Lee Berger,

asking if there would be the possibility

of a position at faculty with him

Pedro Boshoff came into my office

and said, you know, "I really need work,

"and I have the same belief as you

that there is more out there"

Lee Berger started exploring the area of South Africa

known as the Cradle of Humankind in the early 1990s

After 18 years of searching,

he had found only a few isolated fossils

That's not unusual in the field of paleoanthropology

These early human fossils

are probably the rarest sought-after objects on earth

We in paleoanthropology sit in one of the few fields

that probably have more scientists studying objects

than there are objects to study

In fact, the vast majority of people who do what I do

will never find a single piece of one of these early humans

And if they do, it's going to be an isolated tooth

Probably 80 to 90% of our record

are just little bits of isolated teeth

Just to the northwest of Johannesburg,

the Cradle of Humankind is riddled with limestone caves

Some have already yielded fragmentary fossils

of our remote ancestors

Lee was convinced there were more discoveries to be made

I had known Pedro for 20 years and I said, you know,

"Go out there, enlist your caving buddies,

get underground, and see if you can find something"

And so I bought Pedro a motorcycle

so he could move around out here

Basically what he wanted me to do

is to go through the Cradle area,

locating and finding fossils

So I sat as I often do on a rock

and I contemplated how I'm going to approach this,

and then it dawned on me: I'm part of a caving society,

having caved in this area for years

And in there, I found Rick and Steven

I asked them to systematically

work their way through caves and holes

towards the east of the Cradle

while I was busy working in the west

We often don't look

in the places that are most familiar to us

because we think we know them well

I call it backyard syndrome

And so I said, you know, "Start right under our noses

Go to the most well-known places"

On September the 13th, 2013, Rick and Steve decided

to look into a cave system they thought they knew well

It's called Rising Star

It's an amazing cave

It's got a bit of everything

There's tight squeezes,

some great climbs, beautiful formations

Rick and Steve headed deep underground

I wanted to show Rick a great climb in the cave

called the Dragon's Back

We climbed up there

And in the process of taking some video

of the formations at the top of it,

Rick wanted to get past me

So I went down a small little crevice

basically so that Rick could crawl over me

I was just getting out of his way,

and as I went into it,

I noticed that there's still a little bit continuing down

Once in the crevice,

Steve realized there was nothing below his feet

He squeezed himself further down

Every time you go down, it just goes a bit further

and a bit further and a bit further down

You squeeze your body in so that you don't slip

and you feel around for a grip

So my legs were dangling down this last little bit

and you don't feel anything below you

And the only way to climb down

is actually to lower yourself as far as possible,

just keep on lowering yourself until you're literally

your arms are almost fully stretched out,

and then you start to feel a couple of rocks

that you can actually put your feet on

He emerged into an hidden chamber

He called for Rick to come down and join him

They could see massive rock formations above their heads

But the real discovery was beneath their feet

The floor of the cave was littered with small bones

We saw at first one bone lying around

We looked around a bit more and, well, another bone

We actually spotted teeth in the rocks

and realized we actually had found something

Followed by a skull in the ground

And finally, one of the most interesting ones

was a mandible with four teeth in it

Rick and Steve had no idea

what type of bones they were looking at,

but they seemed intriguing

They took pictures and decided to show them to Pedro

And I will never, never forget

when he came to me with his photos,

put it on the computer,

and the first thing I noticed was the jaw with the teeth

And I realized this is definitely a hominin

So needless to say, I called Professor Berger

He didn't answer his phone, and we decided

we're going to drive to his house

because now we're all excited, bubbling, of course

Arriving at his home, I rung the bell

and when he answered, my words to him was,

"Lee, you really want to talk to us!"

Pedro says, "You're really gonna want to let me in"

And, you know, 9:30 at night, and it's dark,

but I could hear that emotion in his voice

They flipped open a computer, and I saw something

I don't think I ever dreamed I would see

on a computer screen

A lot of swearing at first

Apparently that's his reaction when he sees fossils

But yeah, he immediately identified it as a hominid

That was a mandible

of what was clearly an early hominin,

the teeth just perfect

The next picture had a skull in it of a hominin

I could see it in outline

There were bones everywhere

They'd take

Every one of them I could see in the image

were hominin

I was a bit in shock

because it all went like a car crash for me, you know?

It really did, black and white,

and I have only visual, not audio

Hominins are all creatures in the human evolutionary line,

including Australopiths, Homo erectus, and us

When his shock faded, Lee immediately turned his mind

to the question of what type of hominin this might be

From what he could see,

Lee thought it was a single individual,

probably one of those Australopiths

that came on the scene some four million years ago

The photos were hard to make out

Lee wanted to know if the bones in the Rising Star cave

were similar to fossils he had discovered five years earlier

That was in a different cave just ten miles away,

also in the Cradle of Humankind

It was Lee's first big find

The story all began on August the 1st, 2008,

when I came into this valley following targets,

which were these trees above my head

that I could see on Google Earth

I walked up that old lime miners' track way,

which wasn't quite as clear as it is today,

mostly overgrown,

and I came into this grove and found this little hole

The little valley was called Malapa

Lee thought he knew it well

It was a Friday

Lee's nine-year-old son Matthew and his dog Tau were with him

I stood at the edge of this pit and I said, "Go find fossils"

With that, Matthew raced off into the bush here

I thought he was going to go chase giraffe or zebra

or something like that with Tau in tow,

and a minute and a half later,

he shouted, "Dad, I found a fossil"

Sitting right over by that lightning-struck tree,

he had stopped and found a little rock,

and I almost didn't go and look

because I knew he had found an antelope fossil

because that's pretty much all we ever find

I saw a fossil

I didn't think it was a hominin

I just thought it was an antelope

because we find thousands of those

I started walking towards him though

because I had to see what he had found,

and five meters away, I realized that

sticking out of that rock was a hominin clavicle

I couldn't believe it

I took the rock in my hand and I was turning it,

trying to think what else this could be

And as I turned the back of it over,

there sticking out of the back was a mandible and a canine

That's when I realized

that an extraordinary thing had taken place

After almost 20 years

of searching in the Cradle of Humankind,

Lee finally had a major discovery

He had his son to thank, but also a crew of Welsh miners

who had come through the valley a hundred years ago

And they'd come through this area

looking for limestone to build Johannesburg,

and they would blast these caves apart

looking for that rich, white, pure limestone,

and they'd burn it and make cement out of it

In the 1880s Johannesburg was a gold rush town,

little more than a collection of shacks

But it sat on some of the richest gold seams

ever discovered

As the gold kept coming, so did the gold prospectors

The town grew

and construction crews were desperate for limestone,

essential for cement and gold processing

Lime miners combed the high veld outside the town

looking for seams of limestone

Although they likely didn't know it,

these seams concealed remnants of ancient cave systems

and were full of fossils

When they found the limestone seam at Malapa,

they laid their charges as usual

They came in here and put in three,

at the most four, blasts

One right below me here, one over on the side,

one over there that I can see

Then, for some reason,

the miners never collected the blocks of lime

and left the blast hole largely untouched

I'm not sure why they did that,

but what they did do in that process

was expose just the edge of these remarkable skeletons

They damaged it just enough so we could find this site

and could make these fossil discoveries,

but not too much that they destroyed the evidence

It really is a miracle

It was in one of the rocks scattered by the blast

that Matthew found the collarbone of a child

But that was just the beginning

The hole where the miners planted the dynamite

would soon yield so much more

It was only once I had the permit

and we came back on September 4, a whole bunch of us

that we spent all morning looking here

and we found nothing

We were even thinking of leaving

because we thought there wasn't anything here

I stood over on the other side of this pit,

looking down into that pit,

and I saw something sticking out of the rock right down here

And what I saw stunned me

And I climbed down the pit and looked right over here,

and there sticking out of the wall

was the proximal humerus of a hominin

I couldn't believe it... I did my PhD on this

I climbed closer, and as I got closer,

I realized there was a scapula of the shoulder blade in place,

and I came even closer

and put my hand on the wall, right here,

and two hominid teeth fell into my hand

Then I said something,

and that started the second part of this remarkable story

Everyone piled down in here,

at my feet was a proximal femur in a block here

that clearly belonged to the child

What was amazing was it never crossed my mind

that this wasn't the child that Matthew had found

How could you find two skeletons in a site like this?

What it would turn out to be, of course,

was a second skeleton, the female skeleton

The child would be laying right here,

just lying in position here,

and it would turn out that there were other skeletons here

There's one sitting over there

There's a baby just above me here,

and who knows how many are in front of me here

It really is a treasure trove of paleoanthropology

One by one, they took out blocks of stone

they thought might have hominin fossils in them,

remnants of our ancient human family

The blocks were all taken back

to the University of the Witwatersrand

At the medical school,

Lee's wife, Jackie, a radiologist,

ran the blocks through a CT scanner,

allowing the scientists to peer inside

There you go, okay, that's good

What one of those blocks revealed was stunning

A slice came through,

and you could see an entire skull

I was dumbfounded

I could not in my wildest dreams believe an entire skull

could be sitting in this little rock

Then began the painstaking job

of freeing the skull from the rock

that had encased it for possibly millions of years

It took me three months to get it out

I was the first one that saw this

And you can't describe it to anybody

It's beautiful

I mean, it's been in the ground

for 1 9 million years,

and you're the first person to see that

I thought, "Well, you're beautiful"

I basically brought this boy back to life

Finally, the skull was free

Its small brain and forward-projecting face

made it clear that it was an Australopith

But details of the teeth and other parts of the skeleton

made it unlike any found before

Many types of Australopithecus once walked the earth

between about two and four million years ago

Lucy is known as afarensis.

There's also Australopithecus africanus.

This appeared to be an entirely new species

Lee called it Australopithecus sediba

after the waterhole near which it was found

In the local language Sotho, "sediba" means "wellspring"

The team was able to radioactively date

the limestone layers in the cave with great precision

The layer containing the sediba skeletons

was 1 97 million years old

That makes these creatures among the last of their kind,

living right at the end of the fossil gap

between Australopiths and Homo erectus.

Here at last was a creature

that could tell us something about that transition

And the bones were not just fragments

Here were two remarkably complete skeletons,

a female and a child

Still encased in the rock at Malapa

are fragments of at least three more,

waiting to be excavated

This made sediba the most complete evidence ever found

for what was going on at the dawn of humanity

The Australopithecus sediba fossils

are some of the most spectacular skeletons known

for early hominids

They're absolutely amazing

We don't get two bones

associated with one another very often,

much less several bones, much less partial skeletons

So that makes these fossils really special

Sediba was exciting from the get-go

Right away, we knew that we had parts of the skeleton

and we had parts of the cranium,

which helps us figure out who this animal is

So that was really, really exciting,

and initially, these upper limb bones looked very primitive,

so we knew we were dealing with something

that looked like it would be a good climber,

kind of an ape-like creature

Peter Schmid's job is to reconstruct sediba's skeleton

Unlike past fossil finds,

here, the skeletons are so complete,

there doesn't have to be much guesswork

By scanning and mirror imaging,

Peter can fill in any missing bones with great accuracy

From the CT, we've got a few thousand slices now,

and Aurore has to put everything together to form a 3D model

And then we have to cut the model

because the pelvis we already casted,

so we only need the rib cage

But the right rib cage we have already,

but we need now the mirror image of that,

and the computer helps us to do the mirror image in a second

Layer by layer,

a 3D printer then slowly prints the rib cage in fine plaster

Beautiful

Finally, Peter has assembled a complete skeleton

It's highly unusual

All Australopiths are a mix of ape and human,

but sediba has a unique mosaic of features

scientists have never seen before in the same creature

The arm is very long, like in a chimpanzee,

but the hand is with short fingers

and a very long thumb, like a human hand

which was never found until now

because this is the most complete hand ever found

in this period

Job Kibii, who was with Lee and Matthew

when they discovered the skeletons,

has been working on the sediba hand

He's found an unusual combination

of ape and human features here too

What's special about sediba's arm and hand

is that we know sediba has a very long thumb,

which is more chimp-like,

but sediba has a very human-like hand

For example, sediba has a thumb

which is longer relative to the other fingers,

which indicates a human-like condition

Sediba's hand, with its opposable thumb

and forefingers,

is so human that it could've been a tool user

But since no tools were found,

that remains only an intriguing possibility

From the reconstructed skeleton, paleoartist Viktor Deak

can start to create a lifelike digital painting

By virtually applying tissue thickness markers

carefully calculated

from the known facial tissues of living primates,

he can build up a realistic impression of sediba's face

Once that was all done,

I have now gone ahead and created a body for it,

and if you want to see,

we can check all that by going transparent

and seeing, making sure that the bones and everything line up

in the proper spaces

So here we have a concept reconstruction

of how sediba potentially could look like

The step from there to a lifelike digital painting

is a short one

Finally, for the first time in almost two million years,

the face of Australopithecus sediba

looks out on the world once again

But the true revelations will come from the bones themselves

Because they are so well preserved,

these fossils will give scientists

unprecedented insights

into the lives of these ancient creatures...

Everything from what they ate to how they died

Such details might help explain the Australopiths' transition

into our genus: Homo

They might also prove or disprove

a highly influential theory about the dawn of humanity

A theory inspired by the very first discovery

of an Australopith fossil

The year is 1924

Anatomist Raymond Dart

teaches at the University of the Witswatersrand in Johannesburg

His hobby is fossil hunting,

but he never imagines he will find a human ancestor

Nobody at the time believes we had evolved in Africa

Well, in the late 19th century,

fossils were found in Europe with the Neanderthals

They were found in Asia

with the earliest known examples of Homo erectus.

No one really had a sense

that anything interesting occurred in Africa

Darwin and Huxley predicted that our origins

would be in Africa based on comparative anatomy

You know, they looked at the skeletons

of chimps and gorillas,

and they looked at ours and they went,

"Well, they're so close to us

"and they're more close than anything else,

so it must have been in Africa"

And then the sort of second generation

of evolutionary biologists shied away from that

They started to find fossils in Europe

They started to find fossils in Asia

And, of course, that tied in very nicely

with sort of racist, imperialistic thoughts

of the day

They couldn't abide the thought of it being in Africa

In late 1924, Raymond Dart receives a package

He sees it's from the mining town of Taung

in South Africa's Northwest Province

And in that box is a fossil,

and this is a game-changing fossil

It's been sent to him by miners

who noticed what looks like the skull of a small ape

encased in the rock

Dart is fascinated

He begins the long, laborious process

of revealing the mysterious skull

He can see that it is the skull of a child,

but like no child he has ever seen before

It has ape-like characteristics, but also some very human ones

And so as he cleaned this fossil

and he saw the hole in the bottom of the skull

where the spinal cord enters the brain underneath

that he had something like a two-legged walker on his hands

And this he named Australopithecus africanus,

and what that means is "southern human of Africa"

Dart rushed into print with his find

He claimed it is proof that we evolved in Africa,

just as Darwin had predicted

He was unprepared for the firestorm his theory unleashed

The Taung child sparked an incredible revolution

Up to that point, everybody said,

"Let's look to Europe for our ancestors"

It was unthinkable that anything as important

as the emergence of humans could have happened in Africa

Raymond Dart was a feisty guy,

and when he was pushed back by the British intelligentsia,

he became feistier, more aggressive

in terms of his defending of his views

Most scientists disagreed with him

He really was seen as an outsider,

but it absolutely set the ball rolling

for, one, paleoanthropology as a field in Africa,

and, two, vindication of what Darwin and Huxley

had predicted with actual fossil evidence

It showed once and for all that our origins were in Africa

and only in Africa, and that's huge

It totally changed the field

Dart was sure he had discovered the missing link

between apes and humans

But it wasn't enough to know what they looked like

He wanted to know how they behaved

What sort of creatures were they?

He understood that these great questions about our ancestors

were also questions about ourselves

The reason we are interested in our own ancestry, I think,

is the reason that you or I want to know

who our parents were and who our grandparents were

or great-grandparents were, because somewhere in us,

we realize that there's a little bit of them in us,

so to understand the quirks of our own behavior

and why we do things,

if not just why we look the way we do,

comes from that ancestry

Paleoanthropology is just that in deep time

We're looking way back

And so we're looking at the things,

the sort of little bits and pieces

that drive why humanity is like it is today

Raymond Dart was building a theory

about how the Australopiths, our ape-like ancestors,

became human

His ideas about the dawn of humanity were the touchstone

for thinking about our origins for generations

In the 1940s,

more examples of Australopithecus

began to be found

And a key site not only had fragments of Australopithecus,

but also the bones of many other fossil animals

And Dart noted that these bones were broken in a special way

Dart became convinced they were weapons

made by our primitive ancestors

Was this the key to what first made us human?

Dart had been a young medic in World War I

He had seen firsthand

the barbarity humans are capable of

It made sense to him that the origins of humanity

were steeped in blood

Raymond Dart's experience in the World War

may have colored his interpretation

of what these bones and teeth meant

You know, it gave him a view

of the dark side of humanity and the violence of humanity,

and he came up with this idea that Australopithecus

had figured out that bones and teeth were hard

and could be used as weapons to kill other animals,

the sort of killer ape theory of early humans

Dart believed that the more aggressive

and adventurous of our ape-like ancestors

abandoned their forest environments

and moved into savannahs

There, they became hunters and predators

His theory that this violent transformation

gave rise to humanity soon found an audience

far beyond the small world of paleoanthropology

In the 1950s, there was a drama critic

and playwright named Robert Ardrey

who became very interested in human origins,

and he went to Africa and spoke with Raymond Dart

And Robert Ardrey, being a dramatist,

could write like anything, and he wrote this amazing book

published in 1961 called African Genesis.

African Genesis became a pop science

publishing sensation of the early 1960s

Ardrey's ideas, building on those of Raymond Dart,

helped frame public debate about the dawn of humanity

for the next 20 years

The very first sentence in that book,

I remember it because I read it as a teenager

and was enthralled by it:

"Not in innocence and not in Asia was mankind born"

And in that one sentence,

he encapsulated Raymond Dart's ideas

that it was an African genesis, and that where we came from

was not from an innocent creature

but from the most violent of killer apes

One of Robert Ardrey's greatest fans

was the filmmaker Stanley Kubrick

At the time, he was planning a film

based on the science fiction novel 2001: A Space Odyssey.

It was to be a meditation on human technology run wild

On a mission to Jupiter,

the spacecraft's computer turns on the crew

At the beginning of the film,

our ancestors discover the first technology:

weapons

Eventually, they will use them on each other

This was the "dawn of humanity" imagined by Dart and Ardrey

And so this sets up then for Kubrick

the same conflict that Dart felt

For Dart, that first weapon

explained the emergence of human beings,

while at the same time,

it explained the atrocities of the 20th century

Are we killer apes at heart?

Is this what we will discover about our ancestors

at the dawn of humanity?

The discoveries at Malapa may finally provide evidence

to support or refute Raymond Dart's theory

The sediba skeletons are so well preserved,

they give the scientists a unique glimpse into their lives

And that's the story we're really after:

how did these individuals really live

out there in the environment?

What did they do on a daily basis?

Whether they were so-called "killer apes" or not

can be seen in what they ate

The first direct evidence comes from their teeth

At the Max Planck Institute in Leipzig,

Amanda Henry is analyzing calculus, or tartar,

fossilized along with sediba's teeth

Calculus is what happens when the bacteria in your mouth

form a film on your teeth

So it's this very thick, layered,

heavily mineralized material that forms around your gum line

and on all sorts of surfaces of your teeth

And as it forms, it traps bacteria and proteins

and remnants of your food inside

Just like the tartar dentists remove from our teeth,

the calculus from sediba's teeth

provides a snapshot of what they were eating

So once I have the calculus here in this little powdered form,

I'm going to dissolve it in a little bit of a weak acid,

and then we're gonna rinse that acid off,

and hopefully what we'll be left with

is micro-remains with this mineral matrix removed,

and then we'll look at that under a microscope

and see if we can identify what was in the calculus

Amanda can see what sediba was eating

when she discovers phytoliths,

the microscopic remains of plants

Well, this is a phytolith that we recovered

from the calculus of the sediba individuals,

and we have a couple of examples here

all from different plants that this individual ate

Here at last is evidence

that will help support or disprove Dart's theory

Well, this is the first time that we've had direct evidence

of the kinds of foods that any Australopith ate

We've had proxy information before,

we've had sort of vague categories

where the food's harder or tougher,

but this is direct evidence

That's exciting

What Amanda can see trapped in sediba's tartar

are microscopic remains of many different plants

We have phytoliths from grasses,

we have phytoliths from the bark or woody tissue of plants,

and we have phytoliths possibly from fruits,

so all the evidence suggests that

the foods that this individual was eating

was coming from closed forested regions,

so eating fruits, maybe chewing on stems,

eating the grasses that are growing in that area

The tooth evidence from sediba

indicates a diet very similar to today's chimpanzees

While they may have eaten some meat,

there's little to back up Raymond Dart's theory

that they were killer apes

So later scientists came and looked at the evidence

and found that there were tooth marks

in the skull of an Australopithecus individual,

and that was just really compelling evidence

that Australopithecus maybe, instead of being the predator,

was the prey

So our ancestors, or the early hominin in South Africa,

were the victims, rather than being the carnivores

that Raymond Dart wanted them to be

The caves in which he was finding

not only the remains of human ancestors,

but the remains of many, many, many other animals,

which he thought were being consumed

and devoured by our ancestors,

were actually all the victims of predators and carnivores

who were pulling all of those animals into the cave

It seems Raymond Dart's vision of our ancestors

as the first killer apes,

so famously portrayed by Stanley Kubrick, was wrong

The sediba skeletons are so well preserved,

they offer the team a chance to investigate

not just the lives,

but the deaths of these individuals

They can analyze the two-million-year-old death scene

almost as if it were a forensic case

I mean, we're looking at the preservation

of organic material here

These animals are articulated the way they died

The breakage patterns may often be a result

of the moments before or shortly after their death

So far, the team has excavated the skeletons

of a female adult and a child

So the female was this one

And the juvenile is all the bones in blue,

all of these

They were found very close to each other

Aurore Val has been creating a virtual reconstruction

of the scene at the bottom of the cave

Besides the sediba skeletons,

there are the skeletons of many other animals too

How did they all get there?

Two million years ago, Malapa was a much deeper cave

Landscape erosion has reduced it

to a small depression in the ground

But when Australopithecus sediba was around,

it was a cave system about 90 feet deep

Imagine a vertical shaft going up

There's probably water dripping down, roots hanging down

Right here is the curled-up body of the female,

lying right there is a child's body,

the 13-year-old boy

There are other animals, all being eaten by bugs

and going through the usual process of decay

This reconstruction shows the sediba death scene

in great detail

Now the team want to know how all these creatures died

Were they dragged in by predators, or did they fall?

The man to answer that question is Patrick Randolph-Quinney

He's an eminent forensic anthropologist

more accustomed to working on murder cases and mass graves

I'm involved in looking at homicides

and involved in looking

at the forensic identification process,

So, unknown remains,

giving them back their identity and their name,

that's what I do for a living

The skull of the child is the first piece of evidence

This is this fracture here,

and it's a fracture that's actually separated

part of the body of the jaw,

and it runs up through the tooth

And basically, if you're in an impact,

you jar your teeth together

and you create compression on the tooth row,

and that provides force, or generates force,

which goes down to the tooth roots

And what this has done

is actually split part of the corpus apart

So it's actually damage

consistent with effectively an impact on the jaw,

and the energy has come from the teeth

out into the bone around it

And that only happens mechanically with fresh bone,

so this individual was still functioning skeletally

when this happened

The mandible fracture is a green fracture

that happened when the bone was fresh, at or around death

It would be consistent with a fatal fall

The fractures to the forearms are even more telling

And if you look at MH2,

she's got a fracture that runs through the body of this joint,

where it articulates in the elbow with the humerus,

the bone of the upper arm

There are also other fractures associated with the wrist,

in this portion of the ulna and this portion of the radius

And we've actually got fractures

in the scaphoid and triquetral bone in the wrist as well

And what this appears to indicate

is putting your hand out to stop yourself

This seems to be good evidence

the individual was alive when she fell

The cave at Malapa was probably a death trap

Were they searching for water and lost their grip?

Perhaps they were trying to escape in terror

from some predator

Whatever the reason, they fell and died

either immediately on impact or soon after

It appears that mud then buried the bodies,

and as it hardened, kept them from disintegrating

This is why they were so well preserved

Then began the long, slow process of fossilization

in which all organic material in the bone

was replaced by minerals

Today, the sediba fossils are still yielding insights

into the Australopith world of almost two million years ago

But the most tantalizing question of all

is still unanswered

How did these primitive creatures evolve

into more advanced human ancestors?

To find out, scientists need to find

perhaps the most elusive fossils of all:

the first members of our genus Homo

For decades, the only fossils that came close

were the fragmentary remains of a creature called Homo habilis:

handyman

In the early 1960s, fossils discovered

from Olduvai Gorge in Tanzania by the Leakeys

led to the definition of a new fossil species

in our evolutionary tree: Homo habilis...handyman

And what was significant about that

is that stone tools were connected

with what Leakey proposed as the first human,

a member of our lineage, the genus Homo

Like most scientists at the time,

Louis Leakey thought our evolution

was probably a gradual, linear process:

a single chain of species

becoming progressively more human

He decided the key event

that made our ancestors cross the threshold to humanity

was not the invention of weapons,

as Raymond Dart believed, but tools

Since Homo habilis seemed to be the first toolmaker,

he declared it the first member of our genus: Homo

Here at last was the link

between the ape-world of the Australopiths

and the human world of Homo erectus.

So there was always this gap between Australopithecus

and later members of the genus Homo,

like Homo erectus and Neanderthals,

and we didn't really know

what species in that gap would have looked like,

and then along in the 1960s, along comes along Homo habilis,

and it's slightly bigger brained,

it's probably a bit more bipedal,

and of course it had these stone tools associated with it,

and it was argued very strongly to be a contender

for early Homo, and it was instantly controversial

and it's still controversial to some people today

It's a bit of a mess

Because it became clear probably in the 1990s

and moving into the early 21st century

that Homo habilis, we really didn't know what that was

One of the main reasons for classifying it as human

was that it was found with tools

But that is now looking less like a defining characteristic

of the genus Homo

We now know that even the more primitive Australopiths

had the capacity to use stone tools

Zeresenay Alemseged, who discovered

a three-million-year-old Australopith

called Dikika child, has found what he believes to be evidence

of stone tool use in the same period

If you were defining Homo habilis as a toolmaker,

tool user, then what do you make of it

when you see that Australopithecus

was doing the same thing?

We know that there is rudimentary stone tool use...

Not stone tool but stone use... Among living chimpanzees

The confusion surrounding Homo habilis has grown

It has been compounded

by the fact that so little of it has ever been found

Colleagues have said, you know, if you had a shoebox,

you could put all those fossils that might be early members

of the genus Homo into it

and still have room for a good pair of shoes

With so few fossils to go on,

scientists had little they could say for sure

about the first members of our genus, Homo

This was the situation

when the two young cavers, Rick Hunter and Steven Tucker,

made their discoveries in the Rising Star cave

When Lee saw the photos from the fossil chamber,

he could only hope they would clear up the confusion

Was it another sediba or was it even Homo habilis?

The only way to find out was to bring up the fossils

Lee knew there was no time to waste

I had to make a decision,

and about, oh, just before 1:00 a m,

I decided that history would never forgive me

if I did not act right then

Just five weeks later,

the Rising Star excavation was beginning to take shape

Its planning had taken some ingenuity

Lee knew he would never be able

to get down to the fossil chamber himself

In places, the chamber entrance

was less than seven inches wide

I put a call out on Facebook saying,

"I need skinny scientists

"who are not claustrophobic, who are cooperative,

"who can work together

"in a dangerous and difficult environment

And I need you available by the first of November"

I saw Lee's Facebook post, actually,

and on a whim I applied for it, and then the next thing I know

I got asked to interview and from there,

just things started happening really quickly

I saw a call that came out on Facebook from Lee

that was looking for skinny scientists,

skinny paleoanthropologists,

that weren't claustrophobic and that would be able to fit

into a slot that was about 18 centimeters,

and that was very intriguing

I didn't say what had been discovered

I didn't say anything about what I thought it was

They only knew it was me in South Africa

and it was clearly underground

I thought I'd get three, four, five applicants, I really did

I mean, how many people in the world could be qualified

and fit that criteria?

Within ten days I had 57 qualified applicants

from all over the world, most of them women

One morning I woke up and there was a call

for tiny, experienced archaeologists from Lee Berger

and I thought, "That's me"

I received the Facebook post

via a friend who saw that it was an ad for a small archaeologist

with caving and climbing experience

and she said, "That's you!"

I'm almost finishing a PhD in physical anthropology,

osteology, so this is my area

I'm an archaeologist,

so I can study up quick on the paleo stuff

I'm a Ph D candidate

specializing in evolutionary biomechanics,

so more on the paleo- anthropological side of things

It really seemed perfect, in fact

When I read the callout to my husband, he said,

"Well, they might as well have just meant, you know,

written: 'Marina is wanted over here ""

So

The Rising Star expedition

was to be a new kind of paleoanthropology

tailor-made for the age of social media and the Internet

I held Skype interviews, and I did a few things in that,

with the 11 people I'd short-listed

out of this spectacular list of applicants

Lee explained a little bit about how the cave was found

and shared with us some video footage

and the initial photographs that Steve and Rick took

And he told us about the conditions of traveling

into the cave

So, you know, he wanted to make sure that we really knew

what we were getting into

It was mysterious

It was very enticing for that reason

You know, sort of wondering what sort of circumstances there were

that necessitated asking for small people

with excellent paleontological skills

In the Skype interviews,

I wanted to see these people face-to-face,

but I also wanted to test some things

I needed to know that if I shut the cameras off,

which I did for many of them,

I want to hear if they could respond to me

Because I had already designed by then

this system of communication, I knew

I knew I was never going to

I will never set foot in that chamber

Then maybe a day after that, I was told I was a go

It was so fast, so fast

And I sent off emails saying,

"Congratulations, pack your bags

Expect to be here in the first week of November"

Then I got the email that said that I got it

and then characteristically I bust out crying,

and just kept reloading my email to make sure,

refreshing it, just like, really, it's really there,

it's really there, and I screamed so loud

It was a very quick process

The ad went up

and then the interviews happened the next week,

and then I learned a day later

that I was accepted to the project

All of a sudden I was rearranging my schedule

and waiting for the plane tickets and packing up

and reading quickly everything that I needed to know and

so it was fast and furious getting ready for this

My brain was just like a flurry,

like an explosion of glitter and confetti

Just

It's everything, it's like every best birthday and Christmas

and Hanukah and Kwanzaa and it's everything, all at once

I figured if he thought I could do it,

if Lee thought I could do it, then I could do it

I had no illusions that this was going to be easy

Nothing like this had ever been done,

certainly in the African context I knew, perhaps ever,

anywhere, and I knew I had to have everything

from medical support to safety support to the design

of the infrastructure underground and above ground

and all the things that go on with a scientific expedition

Yeah, let's get a bag

As the camp was set up, Pedro, Rick and Steve readied the cave

for the excavators

Safety lines, lights, cables and cameras were installed

The possibility for accidents was ever present

Lee rehearsed safety procedures over and over again

Critical issue is, no one panic

Yeah, yes, we see you

A command post was set up from which he could watch

virtually every part of the cave

I really began to get a feel

for what I was putting these young women into

as the cavers who were laying over two kilometers of cable

And I think they were terrified and I was terrified,

They were still untested

We took them through the caves testing their capabilities

in this system

And so we reached the 10th,

which was my intended day of going in

and we tested systems, everything worked

It was a little sloppy but it worked

We tested safety, it all worked,

and by the early afternoon we were ready

You'd be surprised, I'm actually a person of gentle soul

Is it weeping in the corner like a Gollum?

Marina, Becca, and Hannah have been chosen to go down first

Still, nobody knows exactly what they will find

I've seen a skull, I've seen the other pieces

I am pretty sure that we have got quite a lot of a skeleton

of at least one hominin

That of course waits to be seen,

and it's going to happen pretty fast now

over the next several hours

Anxiously watched by Lee and the team in the command post,

Marina, Becca and Hannah make their way

deeper and deeper underground

The descent is difficult

And as I looked down there I thought, oh, you know,

I don't know if I'm if I can do this,

but then once I was committed to go down, it was actually

much, much easier than I was dreading

just trying to also slow it down a bit

because I've got the GoPro running

It was just an amazing, an amazing feeling to realize

how far away you are from everyone up top

in the command center, and to just fully realize

what you are down there to do

I became a little bit overwhelmed,

but you also have to turn that off in some sense

because you're only down there for a limited amount of time

and you have a job to do, a very important job to do

Going down the chute for the first time was

honestly it wasn't as bad as I thought it was going to be

And then you come into a landing zone

and there's a hallway to pass through

It's not really a squeeze,

but it's a narrow passage to pass through

and then the chamber opens up again

This is the entrance to the cave here

So you start by descending down, you know,

a fairly narrow shaft and some tunnels

You get down into an area here

This is what we call the Superman crawl,

which is a very narrow crawl

You have to crawl on your stomach for about three meters

Then you enter into another chamber

This is what we call the Dragon's Back,

so that's the ridge climb

with the sort of four- or five- meter drop on either side

You get up to the top of Dragon's Back and you end up

at the top of the chute,

which is another sort of tunnel access

that then you start the 12-meter descent into the chamber,

so that's this area here

Once you drop into the chamber,

you're actually just in a landing zone

It's another sort of antechamber

You then go through another passageway

into the main chamber,

which we call UW-101, or the fossil chamber

Marina is the first to enter the chamber

There was a little bit of trepidation, I have to confess,

and a lot of excitement

to be the first of the advance scientists to go into the cave

The first thing that came through my mind

when I went through the final slot

into the actual final chamber was Howard Carter's anecdote

about opening Tutankhamen's tomb

I think it was Lord Carnarvon in the back saying, you know,

"What do you see?"

And Carter says, "Things, wonderful things"

And it was that feeling

God, this place is beautiful

First of all, the cave is beautiful,

just geologically beautiful, and then you look down

and it was just a sea of bone

and it was obviously just not regular bone

So, yeah, it was amazing, amazing

And then I saw them enter this chamber

We got the cameras set up and you could see their feet moving

And it was surreal

Fantas

Fantastic!

There we go

Skull is being flagged

You can see the skull here

She's now flagging the mandible

And then the process started

The process of doing science began

So we'll put pin #1 right beside the mandible

and that's where we'll concentrate

Okay

Okay, das ist super.

Okay, thanks

Bye

Yeah, that's perfect right there

Okay, going to start scanning

Okay, scan

The first foray into the fossil chamber lasts only a few hours,

enough time to start scanning and flagging bone fragments

as well as to test the safety systems

Okay, how did that go?

Let's see

It's mapping right now

Finally it's time to bring up the first precious fossil,

the mandible

Uh, there, there, coming

I see what looks like a mandible in the middle there

On the right

That looks fantastic

It's Becca who will take care of it on the ascent

All right!

You got the fossil, huh?

Yes, I got the fossil

Well done

Here you go

And we have everyone else

Everyone's out Rick's out safe

They're all out Well done

And so first their safety, in that they were out

was just this enormous emotive relief,

and then the sense that they had actually got this thing,

so now I was going to see for the first time

what all of this was about

When they opened that little box and we unwrapped this thing

that they collected,

every great idea we had

went out the window, gone, you know

Suddenly we didn't know what we had

When he had first seen the jawbone

in Rick and Steve's photos,

Lee had decided it probably belonged to an Australopith

One of the most striking characteristics

of an Australopith's face is its large, apelike jaws and teeth

As the Australopiths transitioned

into the genus Homo, their faces shrunk

Jaws and teeth became smaller

When he finally had the jawbone in his hands,

Lee saw it was too small to be an Australopith

It seemed quite human

Could it be a new specimen of Homo habilis?

Or could it be a new transitional species

between Australopiths and early Homo?

These are the questions on anatomist Peter Schmidt's mind

as he studies the mandible from Rising Star

You have this molar teeth

and the very strange use of the frontal part here

And luckily we got another piece

so with these two pieces we have a hemi mandible

which is complete and then we can put on the mirror image,

and we have sort of outline

Peter can then compare it to the mandible of Homo habilis.

I will take this away

and you see this is the tooth row of Homo habilis.

You see also that these are massive teeth, but the tooth row

is straight and we have a very strong shelf here

The mandible from Rising Star is clearly more curved

It's not Homo habilis, and it's not an Australopith

They don't know what it is

This is pure confusion

We don't know what to make of it

We realize all of our preconceived notions

have to be tossed aside

We can't go into this thinking it's going to belong

in this group or belong in that group

We just have to start from literally scratch

The team hopes that as more fossils emerge from the cave,

the confusion will clear up

It's so solid

There is reason to be optimistic

Each descent reveals more bones

Where once they thought there might be one individual,

they now see evidence of a whole lot more

It was probably a couple of hours into the first day

when we realized it also wasn't one skeleton

Another femur

If I remember, right,

it started with a second femur from the same side

and since there has never been a three-legged hominin,

we knew there were two, and then there were three

And I think it was by day two, there were four

And we realized we were

in something very, very, very special

All right, good luck with that, Becca, we can't wait to see you

You've got something we want to see

Every time the scientists in the cave remove a piece of bone,

they find more bones beneath it

It's everywhere

I mean, it's all strewn, all throughout

Not just the chamber, but the passages leading to it

are littered with bone fragments

At the landing zone where they stopped,

I'd get a call on the intercom

"We found another tooth"

It was just sitting there

I was trying to find a nice place to sit, and there it is

It just caught my eye

Rick was sitting there as a safety caver waiting,

and he kicked the dirt and hominins fell out

You have to pass me up some flags

Do you have enough flags?

By the afternoon of day 14 in the expedition,

we were overwhelmed

I'd started with one safe to hold one skeleton,

day three we had two safes, day four we had three safes,

day six, people were going, "We need more safes"

Woo-hoo!

Tooth und more

I don't know whether you should hug me

for someone finding something in the other spot

Oh, man

By day 14, as we would get fossil after fossil,

we were getting 40, 50, 60, 70 elements a day,

all that was flashing through my mind as I was doing that

was that famous scene in Jaws where Roy Scheider is chumming

and they hadn't yet seen the shark

And he's sitting there chumming

and all of a sudden this gigantic shark appears

And he goes, "We're going to need a bigger boat"

We're gonna need a bigger safe

It's extraordinary

I think this year at Christmas I'm just going to hang

one of these instead of a stocking

As the fossils accumulate in ever-greater numbers,

a picture of the creature of the Rising Star cave

begins to emerge

This is part of a juvenile pelvis

Thigh and hip bones tell them it was an upright walking biped,

but its gait was primitive

From what they can see of the exposed skull, it is small,

not much bigger than a chimp's

I'm gonna have to tell them to leave that alone

But the teeth and jaws seem more advanced: Homo-like

The team's excitement grows

It's beginning to look as if they have found another species

from the dawn of humanity

But on which side of the Australopith-Homo divide

will it fall?

One of the key fossils that will tell them that is the skull

They are saving that until last

Distance is perfect

And I can see marker two

Record

Recording

In the meantime,

another extraordinary fact is becoming evident

There are no other animals in the cave

All the fossils are human ancestors

This is unheard of

It was pretty surprising

that something completely normal to every other excavation

I have ever been in on the continent of Africa,

everyone I have ever heard of on the continent of Africa,

wasn't happening here

We weren't getting anything else other than hominins

When early hominins are discovered in caves,

they are always found along with the bones of other animals

that have either wandered in and died

or been dragged there by predators

They're mixed with antelopes generally in huge abundance

Then you get, depending on the circumstance,

some carnivores and other bits and pieces, and rodents,

and the stuff that accumulates when things die

and are eaten and are dragged into caves

Apart from the bones of a solitary owl,

there's not a single other animal

in the Rising Star chamber, only hominins

So how did these creatures get in there?

The chamber is very inaccessible,

deep in the dark zone of the cave, with no entrance

other than the long, narrow chute

The team believes it likely was just as inaccessible

two million years ago

It is starting to look

as if the bodies might have been intentionally placed there

Could this possibly be some sort of burial?

There has never been evidence of anything like this

linked to such a primitive-looking ancestor

So we got that looming in front of us

and don't have an answer to it

Until now, the earliest known burials

are from about 100,000 years ago

and a much more advanced form of early human

The team doesn't have a date yet

for the fossils of Rising Star, but it seems unthinkable

that such a primitive-looking creature

could be disposing of its dead

But that's what it looks like

And the age ranges of the individuals are very similar

to what archaeologists find in cemeteries

At the early stages of this expedition,

they look like a cemetery population:

very young individuals and very old individuals

and nothing in the middle so far

It doesn't mean we're not going to find it,

but that's what you see in a cemetery when you dig it up

Right now it looks a lot like that

Will it hold out to be that?

That will be a mystery I want to see solved

And we're left with this conundrum of, you know,

is what we are looking at

You almost don't want to say it out loud

It's a mystery with profound implications,

but one that will require further analysis

before anyone is willing to back it wholeheartedly

The excavation is now approaching

its third and final week

Perhaps the most important bone

has been left until near the end: the skull

Its shape and the size of its brow ridges will be crucial

in telling them whether the creature of Rising Star

is Australopith or Homo: human

We're going to go ahead and bite the bullet

and take that skull out, okay?

Yes, yes, yes, yes, good, good

If only because it gets it out of the way

Yes, I know

Not because you want it out to see it, right?

Oh, I want it out!

A couple of reasons we want to get it out

One, the skull can tell you a lot

It can tell you cranial capacity,

start getting an idea of the shape of the skull

Is it Australopith-like and pinched in the front,

or is it rounded more like a human,

or is it something in between,

does it have a sagittal crest neck?

We want to see that skull

And also the skull was probably

the most complex initial extraction

It is fragile, it's a thin piece of bone,

and it could break apart

We need to know whether we could get something like that out

And we need to get it out to see what was underneath it,

whether this was a skeleton

or whether there were lots of individuals

associated with each other

So there was all this tension,

and it was a lot harder to extract than we thought

Oh, I'm sure you'll find plenty

All right, stage on in after her

Good luck, everyone

Have a blast, huh?

Thank you Will do All right

Let's get you something here

Go get 'em!

Good luck

Happy hunting Thank you

Enjoy topside

The skull is extremely fragile

The team carefully scans the area immediately around it

How big? Yeah, those are perfect

Then they begin the laborious process of removing

every tiny fragment of bone surrounding the skull

Oh, we've got medium bags now

Finally, they delicately scrape away the dirt to release it

We're done this easily

Got it

Everyone was feeling all these points of tension

around the science of the skull,

when we knew it was imminent coming out

We only had two people down on the bottom,

and they were working on it, Becca and Marina,

and working and working and working, and finally

we kept trying to call them out and they wouldn't come out,

because they knew they were that close to the extraction,

and eventually it did come out

That's it

That's it

It's so fragile

With everyone holding their breath,

praying that it doesn't break, the skull fragment is finally

lifted and delicately placed in a box

That's it

Then it begins its slow ascent, leaving the cave

for the first time in possibly millions of years

He's holding the box

Yeah, that's right, he's holding the box,

so he can't do this, he's gotta be much more careful than that

Yeah, all right, there it is, all right

How fantastic

Wow

And all of those scientists piled back in, all of the people

that spent so much time and so much energy

coming to this moment, went back in there,

and they lined up in the most difficult places

up the Dragon Back to Base 1 and they knew there was a risk

that it could get damaged, if dropped it could get destroyed

And this huge team effort occurred as they handed this off

from one to the other, as it moved its way

from this dark recess where it's been for however long it's been

to the entrance of the cave where those of us

not privileged enough to be able to get into this system

had to wait with huge tension, watching this passage

on the cameras until there it was

There you go folks, let's go get it

Great moment

It's like a Rocky moment

There is so much wonder, no one's bored,

no one's too academic to hold it in

Everyone is just brimming with childlike excitement

Would you hate me if I took this before I hug you?

Please take it

Oh, well done

I don't even want to hug you with that thing in your hand

I'm going to give this off to John

I'm constantly sitting there and stopping myself and going,

"Oh my God, this is like... It's old

"It's probably the first time this fossil has seen

the light of the day in millions of years,"

and so I'm continually sort of having to stop and just think

for a moment and sort of revel in it

It's the moment everyone has been waiting for

They hope the skull fragment will be the telltale piece

to identify the creature of Rising Star

as either an Australopith or a member of our own genus

Looking at a left frontal, so it's this part, the orbit,

and then part of the brain case behind the orbit

And that is a very important piece

Large orbital ridges with indentations behind them

would indicate Australopith

Smaller brow ridges

with evidence of a more rounded skull would say Homo

We do have our genus

We do?

We have our genus with that

Yes, yes!

The team's verdict is clear:

they have a new member of our genus

Did we do good?

We did good

Now the question is: what can it tell them

about the mysterious dawn of humanity?

We are certain that this is in the genus Homo, our genus,

and we are certain it's a new species

And that's where we are right now

The idea that we've discovered a large number of individuals,

males and females, young and old, of a new species

in the genus Homo

In the next phase, they'll have to piece together

and analyze the rest of the fossil remains

Already they have almost 2,000 bone fragments

from more than 12 individuals

The Rising Star discovery is one of the most startling

and amazing discoveries in all of hominin evolution

To have that many fossils in one place is unprecedented

and took everybody by surprise

The excavation was planned as a three-week operation

As it nears its end, the scientists know

they will have barely scratched the surface of what Rising Star

has to offer

I had never seen or dreamed of anything

like the richness of this site

There aren't just hundreds of bones,

there are thousands of bones, it's clear

You can't blow on the ground

and it doesn't uncover another one

They can't gently brush their hand across it, and teeth,

and long bones don't fall out, usually of another individual

This is going to take a long, long, long time

As everybody goes home, the Rising Star fossils are

carefully transported to the University of the Witwatersrand

It was here, 90 years ago,

that Raymond Dart sparked a firestorm

by declaring that the dawn of humanity was in Africa

It seems fitting that it is here too that the mysterious

early humans of Rising Star will begin to tell their story

At a symposium six months after the excavation,

researchers meet for an intensive analysis

of the fossil material

Yeah, yeah, yeah, yeah

They're in the analytical phase here,

they're in the diagnostic phase, and it's been an experiment

in, you know, working together, bringing together some of

the brightest minds on the planet with some of

the most current data sets

to analyze over 1,700 fossil hominin remains

that we recovered only last November

And it's been fantastic to watch

I mean it's this constant energy of science

And you can almost feel it in the room right now

We are total nerds, it's nerd heaven here,

but I mean it is an extraordinary experience

There's never been anything like this before in the field

of hominin paleontology, to get a group of young,

talented scholars together to bring their new techniques

and their fresh outlooks on the record

to newly discovered fossil hominin remains

This certainly never happened when I was a Ph D student

and I would have died to have done this

As the analysis goes on, the bones from the Rising Star cave

are finally ready to be presented to the world

We've got a new species of early human in the genus Homo,

and that's tremendously exciting

We've never had anything in that transition period

between the late Australopiths and the earliest members

of our genus in any kind of abundance,

and boy, we have it in abundance now

To members of the team, the fossils suggest a creature

unlike anything ever found before

We're looking at creatures that are humanlike in their feet,

humanlike in their hands, humanlike in their teeth,

everything that interacts directly with the environment

is Homo

And everything that is sort of central... you know, the trunk,

the architecture of the vertebral column, the brain...

Those sorts of things are more primitive

It's like evolution is crafting us from the outside in

We've called the species Homo naledi and "naledi"

means "star" in Sotho and we've called the chamber

that the fossils come from, it still has fantastic fossils

to be found, the Dinaledi chamber,

which means the chamber of stars

Homo naledi is a strange mosaic of ape and human,

small brained and small bodied with chimp-like arms,

but with human hands, teeth, small brows and long legs,

probably a long-distance walker

Naledi is

a surprise in very many ways

It's got an incredibly tiny brain,

a brain that's more than a third as small

as a modern human's brain is

Yet it's clear when you look at the cranial shape,

the dentition, the legs, particularly the feet

and even the hands, that this thing is part of our genus

Here are creatures on the cusp of becoming human,

but still very close to the Australopith world

It makes the question of how they got into the cave

even more intriguing

It looks like they got in there because somebody put them there

Now, if we say that, you have to understand

that's a very controversial thing to say

And in so we approach it very conservatively

We can show that there's no signs of predation

We can show that there's no predator that accumulates

only hominins in this way

We can show that they didn't all get there at once

We can show there's not a flow of material into the chamber,

and that's where we leave it scientifically

You know, we can say, the best hypothesis we can come up is

they were put there

If this is true, its implications are far-reaching

They now know that the Rising Star hominin had

a brain size in the range

between 450 and 550 cubic centimeters

That's just slightly larger than a chimp's

So if in fact the Rising Star hominins are purposefully

disposing of their dead, we're talking about

some small-brained hominins who are doing this

And that begins to change our thinking about sort of

the cognitive attributes and the neural machinery that you need

to engage in that kind of behavior

And that becomes really interesting

The accumulation of Homo naledi skeletons in the cave raises

the type of big question that Raymond Dart wanted to answer

What type of creatures were our primitive ancestors?

If the naledi skeletons have indeed

been intentionally disposed of, some sort of burial,

it would indicate already quite advanced social behavior

This fits with new ways of thinking about the transition

from ape to human

Many scientists now believe that a key element of that transition

was the growth of ever-stronger cooperation and social bonds

Psychologist Michael Tomasello has spent a lifetime

comparing the social behavior and capacities of chimpanzees

and human children

Well, there's social and there's ultra-social

And all mammals are social to some degree

Great apes are especially social in the sense that they form

long-term relationships with others

and have bonding relationships with others, and they groom,

they support each other in fights

So they're very highly social creatures, but a lot of it

is organized around competition, so a lot of it is organized

around coalitions to fight over food and so forth

And in humans we of course haven't lost our selfish

and competitive streak,

but we have become so much more cooperative

Not perfectly cooperative, but much more cooperative

The fact that we can

sit in an airplane

with 300 or 400 individuals of breeding age

that we aren't related to and not rip each other apart

is a uniquely human character and it was evolved

on this landscape behind me

Because Africa is a harsh place and we as early humans had

to evolve cooperation in order to survive here

We didn't have big canines, and sharp claws

We just had each other

Humans are the most highly social primates

ever to walk the earth

We bond and form relationships far more complex

than any other primate

So if the Rising Star chamber is indeed a burial,

perhaps this would suggest that here at the dawn of humanity

those more complex social bonds had begun to take shape

This possibility will generate fierce debate

as other scientists weigh in

But how do these discoveries change the narrative

of human evolution?

There is an old refrain in paleoanthropology

People always say we need more fossils, we need more fossils,

we need more fossils, but the fact of the matter is

more fossils just complicate the picture

One compelling question to be answered is

where do these new fossil ancestors fall

on our family tree?

Dating the fossils is proving to be difficult and complex

It will take time

The thing that's hard about it is we don't know how old

those fossils are, and we can tell what they look like

because we have so many of them, but if they're 3,000 years old

or if they are three million years old it's going to mean

a very different thing for how it changes our understanding

of human evolution

Because we have a date, things are a little clearer

with the Malapa finds

At 1 97 million years old, most scientists believe sediba

is too late to be a direct ancestor of ours

Our genus Homo was already established by the time

sediba came along

But even if sediba is not our direct ancestor,

it does show there were many different types

of primitive ancestors living together at the same time

Okay, yeah, yeah, keep pulling

Great, great!

The quality of the material that Lee is uncovering

is really phenomenal

Sediba shows that we had more than two or three species

in South Africa 1 9 million years ago

It's a very interesting find

It shows that there were diversity

It's a beautiful material, but I don't think that sediba

was ancestral to our genus Homo

Whether or not they are our direct ancestors,

the fossils at Malapa and Rising Star point us toward

a new way of thinking about human evolution

We have the strong tendency to want to draw simple lines

between species, and make nice family trees,

and we have to understand that that's our need

That's our desire

That's not necessarily the way that nature works

It's very natural to think about human evolution as a sort of

family tree in deep time

But evolution is much more complex than that

Evolution is bushy, there are different experiments,

populations try different adaptations,

they try different ways of being about the world

Paleoanthropologists talk about the bushiness of human evolution

as a metaphor for the many types of early hominins

and the difficulty of knowing which one led to us,

but even that metaphor may not do justice

to the way evolution works

Nature is messy

Nature is complicated

Nature does not really respect our desire to put fossils

into neat bins and to sort of name nice neat species

Both sediba and naledi have a mosaic of Australopith

and Homo features

They seem to show that at the dawn of humanity

there were multiple evolutionary experiments with small-bodied,

small-brained, upright-walking apes

Scientists now know some of these varieties

of late Australopith and early Homo lived together

at the same time

And some of them may have been interbreeding

These aren't fully formed species and there's a lot

of interbreeding between these groups

Some adaptive features are evolving in one group,

other adaptive features are evolving in other groups,

and by interbreeding those are coming together

And if that's the case we may never be able to draw neat lines

between any of these groups and later Homo

Perhaps now we need a new metaphor to help us

understand our evolution, one that expresses better

the dynamic and fluid nature of it

Now perhaps the best metaphor is a braided stream

And that's brought on by discovery of these

mosaic hominins like naledi, sediba, and others

They're showing us there's lots of experiments going on

Some of these evolutionary experiments died out,

others came together and interbred

The ebb and flow of genes through these groups

was probably so complex that we may have to give up hope

of discovering a simple linear evolution

So imagine in your mind a glacier in the top of a valley

and what happens is as it melts, it creates many, many rivulets

and some of them are large and some are small,

and they all move off down the valley

And almost inevitably at the end of that valley is going to be

a lake, of which some, maybe the majority,

but not all are contributing to

I think we have to begin looking at these species we're finding

as almost individual channels in a braided stream

It's clear they have something to do with the end-population

and that's us, the billions of human beings alive today

But it's hard to tell which one's the most responsible

for us being here

The new finds on the plains of South Africa are adding

a vital new chapter to the story of our origins

The tantalizing gap in the fossil record

at the beginning of our genus is being slowly filled in

Finally, there is light at the "Dawn of Humanity"