ELLA AL-SHAMAHI: Where do we come from?

When did our story really begin?

Who were the first Homo sapiens?

Not just humans who looked like us, but people who thought and behaved as we do.

People we would recognize as truly one of us.

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

We're not the first species of human.

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

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

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

How on Earth did this happen?

♪ ♪ I'm Ella Al-Shamahi, a paleoanthropologist.

People spend their whole lives trying to find a fossil as significant as this.

Our story is stranger and more dramatic than most of us realize.

Thanks to groundbreaking fossil evidence, and advances in DNA science, we are able to picture the lives of our ancestors as never before.

From our very earliest origins to our migration to every corner of the globe.

From the first marks we made on cave walls to the rise of cities.

These are the unlikely events that forged us.

Moments of chance, but also ingenuity, of beauty and destruction.

This is us.

This is our story.

And it's what happened in the 99% of our history before the invention of writing, when our story wasn't written in books, but was written in our bones and DNA.

This is the story of what made us...

"Human."

"Origins."

Right now, on "NOVA."

♪ ♪ (birds chirping) (giraffe bleating) AL-SHAMAHI: We're used to living in a world filled with other species.

Over eight million share our planet with us.

But there is only one of us.

Only one human species, Homo sapiens.

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

The world before us was alive with other human activity.

♪ ♪ When Homo sapiens first emerged, there were at least six different human species.

And using the latest scientific data, we can reconstruct what they might have looked like.

There were so many species of human.

You had Homo erectus, an ancestor of ours and an incredibly successful species because they lived for about two million years.

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

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

There's also Homo neanderthalensis, who you probably know as the Neanderthals.

Neanderthals lived in Europe all the way into Central Asia.

They were cold-adapted.

And they were expert hunters.

There was also Homo floresiensis, who some people affectionately call "the Hobbit."

Because they were only about a meter tall, so that's about three and a half feet.

Tiny, and yet adapted for living on an island.

It seems like a fantastical world.

And I can't help it; it reminds me of "Lord of the Rings."

Only instead of a world with elves and dwarfs, you had a magical place with other humans.

♪ ♪ The human family tree had many branches.

But which branch did Homo sapiens first emerge from?

We don't know for sure, but we're getting closer than ever to finding out.

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

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

♪ ♪ But new revelations from out here in Morocco, from a part of Africa that people weren't really considering, are forcing us to rethink our very first steps on this planet.

In a remote cave in North West Africa, a chance discovery uncovered some mysterious human remains.

Someone was living here.

Thousands of years earlier than we imagined.

(speaking Arabic): ABDELOUAHED BEN-NCER (speaking Arabic): AL-SHAMAHI: BEN-NCER: AL-SHAMAHI: This is Jebel Irhoud 1, and it was a complete mystery, because some of its features are very much like us, very Homo sapiens and others are much older, much more primitive.

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

Its face looks a lot like ours.

The Homo sapiens face is incredibly gracile.

We have incredibly delicate features.

They kind of tuck in under our braincase.

If you imagine a prehistoric human, you kind of always imagine a much kind of more prognathic, we say, much more kind of jutting forwards face.

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

But there are some features that aren't us.

Notice this brow ridge up here, this supraorbital structure.

Now look at me.

You don't get modern humans walking around today with these massive things on top of their eyes.

Now the brain case is not us.

Can you see how round my brain case is, it's globular.

Whereas this is almost stretched out, so it almost looks like somebody has got my braincase, but kind of stretched the back of it out.

It's almost like... ...straight on the face is Homo sapiens, but from the other angles, it's not us.

♪ ♪ This skull was an enigma.

An anomaly that didn't fit neatly into the human family tree we thought we knew.

It looked partly like Homo sapiens.

And partly like an earlier kind of human.

So, the question was, was this a different species, or could it be an early version of us?

(tools clanking, dirt brushing) Several decades after the initial discoveries came a breakthrough.

Archaeologists uncovered another 16 fossils.

All with the same blend of features.

And taken together with the old finds, a fuller picture started to emerge.

BEN-NCER: AL-SHAMAHI (speaking Arabic): BEN-NCER: AL-SHAMAHI: BEN-NCER: AL-SHAMAHI: BEN-NCER: AL-SHAMAHI: With each new find the evidence grew.

These were not some other species.

But Homo sapiens, with hints of an earlier ancestor.

But it wasn't until archaeologists were able to more accurately date the remains, that the final piece of the puzzle fell into place.

The archaeologists, using new and improved dating techniques, were able to give us dates for these fossils.

And they tell us that these individuals lived about 300,000 years ago.

And that is mind-boggling because we thought our species was only about 200,000 years old.

What these fossils tell us is that our species, Homo sapiens, is 100,000 years older than we thought.

We are much older than we realized.

This fossil went from being enigmatic and a, basically a mystery, to being one of the most important fossils in our whole field.

♪ ♪ Thousands of miles from East Africa where many anthropologists thought we began, and far older than expected, these are the earliest Homo sapiens ever found.

And they have forced us to re-think other finds across Africa.

Which are painting an entirely new picture of our origins, suggesting Jebel Irhoud... ...was just one of many emerging Homo sapiens populations.

It's... (exhales) it's a bit like having a peek behind the curtain of evolution.

This is a stage in the journey to becoming us.

I wonder what it would feel like to come face to face with one of the people from Jebel Irhoud.

(wind blowing) If we were to look into their eyes... ...into those quite delicate features... ...would we see ourselves within them?

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

(fire crackling) They were an earlier stage in our evolutionary journey, bridging the gap between us and our more ancient human ancestors.

Our emergence was actually slow, and honestly, at the beginning we were just not that special.

Now, early iterations of Homo sapiens like Jebel Irhoud were popping up all over Africa.

Many anthropologists once believed in a single origin, a sole cradle of humanity in East Africa, but our story is far richer and more interesting.

The latest evidence suggests the traits that make us who we are today, emerged in different places, across thousands of miles, and over hundreds of thousands of years.

Appearing bit by bit.

Like sparks igniting across the African continent.

♪ ♪ (thunder rumbling) And yet, Homo sapiens could have easily vanished without trace.

(lightning striking, thunder rumbling) Because just as we were finding our place in the world... ...something threatened to wipe us out altogether.

It's in East Africa's Great Rift Valley that we can trace the next chapter of our story.

This dynamic landscape holds some of the clearest evidence of the forces that set our species on a radically new path.

When they say the Great Rift Valley of East Africa is a dramatic place... they're not kidding.

I mean, look at it.

I can literally hear it bubbling behind me and it's the result of a geological process that sees three tectonic plates tearing away from each other, which results in a dynamic landscape.

And even though this part doesn't look that hospitable, it has been a home to people for a very long time.

In fact, the conditions here for fossil preservation are so good, we know that is has been a home to people for millions of years because of the wealth of archaeological evidence found here.

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

Its unusual geology has preserved human remains, but it also offers a glimpse into the forces we think drove our evolution.

So, within the lake beds here, if you dig deep, you can actually extract sediment cores.

Now one here in Ethiopia was about 280 meters deep.

So that represents over 600,000 years.

And within that sediment, it's a bit like a time machine because bits of ancient environment are trapped.

By analyzing these sediment layers... ...scientists have uncovered a window... ...into the world some of the earliest Homo sapiens were living in.

(thunder rumbling) Over tens of thousands of years, wild climate swings engulfed Africa.

(splashing footsteps) Thrusting the different fledgling populations of Homo sapiens... (thunder rumbling, lightning striking) ...into a landscape of extreme and unpredictable change.

♪ ♪ (waves crashing) Ecosystems were transformed.

Rivers and lakes swelled.

Cutting people off.

Elsewhere, grasslands turned to desert.

Creating a struggle for survival.

That could have wiped Homo sapiens out altogether.

(baby crying) But it didn't, it had the opposite effect.

It helped drive us forward.

Under pressure, isolated Homo sapiens populations both learnt new skills and genetically adapted to the challenging conditions.

People with minds able to innovate had a better chance of staying alive.

Then, as their climate continued to change, the surviving groups came back together, they shared skills, and crucially, interbred.

Passing their unique genes onto their children.

(water trickling) It was a process that began to change our ancestors permanently.

The people who survived emerged stronger than ever.

(animal bleating) Today, most of us live in towns and cities.

And so, the reality of being affected by the climate as a result of being a nomadic person kind of escapes us, but you've actually got a really good example here with the Afar people.

They are nomadic and so they get pushed and pulled around the landscape.

And it would have been very similar with our ancestors, but actually, in a more extreme fashion.

These different groups, as they were moving around, would have at times met and when they did, they would have, of course, shared skills and knowledge and DNA.

It was this mixing of groups that ultimately brought us closer to becoming the Homo sapiens we are today.

There's this new exciting theory that suggests that our origins as a species are so much more complicated and dynamic, involving not just East Africa, but the whole of the African continent.

Africa was a continent rich in diversity, and climate acted as a sort of catalyst, blending these various groups together.

And so, we were formed as a result of a mosaic of these different populations across Africa.

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

It shaped us, our minds and our bodies and transformed us into a new and evolved human.

(goats bleating) We all carry an echo of what happened in Africa at this pivotal moment.

Because what happened then, changed us forever.

♪ ♪ What began as different, scattered populations... ...in the face of adversity, came together.

Propelling us to become one, stronger, smarter species.

♪ ♪ This is a museum that houses some of the most important fossils in the human story.

And one of those fossils is Herto1.

Easily, one of the most significant Homo sapiens fossils that has ever been found and that's because this individual is one of the very first in our lineage that we can describe as an anatomically modern human.

Its physical characteristics and traits are overwhelmingly similar to those of yours and mine.

And if you look at this individual compared to Jebel Irhoud, look how rounded it is.

Some people have put forward this intriguing idea that perhaps the shape of the skull reflects a change in brain organization.

This evolution of a rounder skull has been linked to coordination and language skills.

And it is really exciting to consider that this change in shape reflects a really significant shift in the way that Homo sapiens were starting to think.

These reorganized brains had slowly but surely opened a gap between Homo sapiens and our ancestors.

But it wasn't only the shape of our brains that set us apart.

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

Now scientists have discovered that if you look very closely at the teeth, what you find are very fine lines called Perikymata; they represent about a week in the life of an individual.

So that means you can count how long an individual has been alive, a bit like tree rings.

The teeth can also reveal when they erupted.

That timing can be used to estimate how close a child is to becoming an adult.

And so, if you look at a Homo erectus individual and compare it to, say, a Homo sapiens living today, our species takes an incredibly long time to get to sexual maturity.

From the lines on their teeth, we know that Homo sapiens children were growing up slower than earlier humans.

♪ ♪ The thinking behind it is that we needed a really long time to learn how to use these brains of ours.

And the longer that you exist in childhood, the longer you have to learn.

And so, this thing that is a real headache to so many parents out there today, that our children take so long to become fully formed.

That might actually be a huge key to our success.

♪ ♪ Reorganized minds and longer childhoods.

Our brains and bodies had evolved.

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

What you might call sapiens 2.0.

♪ ♪ It was some of these modern, evolved Homo sapiens that found their way out into the wider world.

But beyond Africa was already home to other humans.

Neanderthals had spread across central Asia and Europe.

Other parts of Asia were populated by multiple human species, including Homo erectus.

And there is evidence in the Middle East of an early group of Homo sapiens.

Who followed in the footsteps of these other human species.

We're so used to living in a world with borders that it is easy to forget that Homo sapiens at the time had no concept of Africa.

And so, if the climate allowed, they ventured out and expanded into new territory.

I do love thinking about those huge moments in our history, like, when Homo sapiens first left Africa.

It was a massive achievement, even though they would have had no idea of the significance of it.

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

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

♪ ♪ Evidence has been uncovered of Homo sapiens living in caves in the Levant in an area now part of Israel.

And it's in this place, they would have encountered something unexpected.

There is one mountain called Mount Carmel, where one cave called Skhul has been found with Homo sapiens, and another cave on the same mountain, called Tabun Cave, has been found with Neanderthal individuals.

And these two peoples were living at around the same time.

(fire crackling) It is kind of wonderful to think about.

(tapping) Two species perhaps sharing the same mountain at the same time.

We don't know if they interacted.

But we do know that while Neanderthals remained in the region, all traces of this group of Homo sapiens vanished.

Their bloodline died out completely.

What is most fascinating about these Homo sapiens isn't who they met; it isn't even what they achieved.

It's that all of these early dispersals failed.

We know from genetic evidence that those Homo sapiens are not the ones who would go on to ultimately populate the planet.

This failed migration was a stark reminder of our fragility.

These people looked like us.

But we don't know if they thought like us.

Because what would come to define our species wouldn't be how we look or even the size of our brains.

But something else altogether.

While these early migrants vanished... ...populations in Africa thrived.

Coming together to manifest some behaviors that feel very familiar.

(insects chirping) These behaviors would set Homo sapiens apart.

And some of the earliest traces of this can be found in a remote cave in Botswana.

Sheila Coulson has been studying this cave since 2004.

And she has an intriguing theory about what might have taken place here.

COULSON: This is obviously a very large natural outcrop.

And as you can see, goes on and on.

It's seven meters long.

The front has a natural slit for a mouth, and a natural depression for an eye and even, if you want to go that far, a nostril up at the front.

Right.

With the head rearing up, it does, in modern eyes, look like a snake.

The overall form has been altered to make it look even more snake-like.

(scraping) There are over 300 indentations that have been ground into the surface over what is obviously an extended period of time.

When the initial excavations were conducted, they absolutely revealed a number of questions.

One of the things found was an extremely large number of tools that appeared to be manufactured and then just left there in pristine condition.

These look gorgeous, I mean, they're absolutely stunning.

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

You either manufactured it perfectly and just left it.

Hm.

Or more interestingly, you burnt it.

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

It's controlled burning.

And the third and most bizarre thing that they did with them is they made it, manufactured it perfectly and when they were finished, turned it over, smashed it in the middle.

AL-SHAMAHI (voiceover): This behavior suggests that people were likely coming here to make offerings.

Which tells us something about how their minds worked.

COULSON: Although, it's absolutely magnificent during the daytime, it comes to life at night.

You make an offering and hope for something back.

Asking for probably some of the things that we would ask for: food, health, children, etcetera, etcetera.

And you just think, oh my gosh, that's some of the... ...that's some of the earliest behavior that we know so well.

(voiceover): Some scientists believe that the people who performed these rituals were likely holding abstract ideas in their minds.

(rock scraping) When I see this, this is what moves me, because this is who we are, in a way that feels more us than bones.

♪ ♪ We are, as a species, obsessed with ritual.

It is religion and spirituality, or things like the handshake or birthdays, graduation ceremonies, Burning Man, Glastonbury, New Year's Eve.

Profoundly and fundamentally Homo sapiens behavior.

♪ ♪ This intriguing site hints at how our mental abilities were developing.

Forming new connections that would embed abstract thought into our behavior.

And this wasn't just confined to ritual, it touched every part of our lives.

(insects chittering) (hoofbeats pounding) ♪ ♪ By 70,000 years ago, a sophisticated new weapon began appearing across southern Africa.

Homo sapiens were using abstract thought to innovate, inventing complex projectile weapons like the bow and arrow.

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

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

Projectile weapons were revolutionary technology for us humans, because up until now, we'd been using closer range hunting strategies which were less effective, less lethal, and yet more dangerous for the person holding the weapon.

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

But Homo sapiens took materials... ...and imagined how they could fit together ...to engineer a more powerful weapon.

One that is safer to use.

If you look at this bow and arrow, you can see how much knowledge is required.

You need to know where to get the wood for the bow.

You need to know about the glue.

You need to know how taut the strings should be.

So many elements that require not just knowledge, but the ability to pass that knowledge on.

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

It's the result of many, many people over many generations inventing, reinventing, perfecting, tinkering.

We weren't just inventing.

We were adapting and expanding our knowledge.

Human culture was becoming more complex.

The technology was exploding.

Now, many of us think that this is a result of something called cumulative culture, the idea that you accumulate culture.

So, every generation builds upon the previous generations' science and technology.

Homo sapiens were displaying a degree of cumulative culture that went beyond the other human species and was growing.

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

A giant leap towards becoming the species we are today.

♪ ♪ When was our species truly born?

Was it when we first appeared?

Or when we started to look like modern humans?

Or was it when our minds lit up?

(rock scraping) Creating, inventing and building on our knowledge?

Each was a crucial step in our evolution.

But none would be possible without one special ingredient.

♪ ♪ The glue that binds all of our achievements together.

It leaves no direct fossil evidence, but we can find traces of it in some unexpected places.

In archaeology, sometimes the smallest finds actually tell the grandest of stories.

These are tiny marine shells, and shells like this have been found in caves in South Africa.

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

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

Now, some of these were collected because they already had holes, but others were perforated by Homo sapiens.

(bird chirping) ♪ ♪ And really close examination of the shells show that they had wear marks on them consistent with having been worn on the body.

So that, along with these holes in them, well it's really easy to paint a picture of them having been strung... ...and turned into jewelry.

♪ ♪ They were also painted red; these weren't just beads, they were symbols of value and meaning, shared and understood by many.

(waves crashing) Perhaps you were trading them for food, for goods.

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

Perhaps they were just a sign of friendliness, and you can also imagine that people would be wearing them to make themselves look good.

It would perhaps be a sign of prestige.

The most remarkable thing about these shells is that they have been found not just in South Africa, but all over Africa, from the south, all the way to the north in Morocco and Algeria.

And that for me is so exciting.

Because when you look at this, you might think, oh my God, isn't that amazing?

Humans have a kind of cultural expression that they never had before.

Homo sapiens were now sharing complicated technology, rituals and traditions.

They were expressing sophisticated ideas that likely required language.

While earlier humans probably had basic language, it's thought that Homo sapiens were speaking to each other in a different way.

♪ ♪ Culture connected our species, possibly across the entire continent.

All over Africa, we understood the cultural symbolism of these beads.

Somebody was telling you, this shell is important, not that shell.

Red is important, not the other colors.

We had an understanding that wasn't just you, me and our three families.

You, me and the village next door.

We had a kind of symbolism and understanding and interconnectedness that was continent-wide.

♪ ♪ Our species' birth wasn't a single moment, it unfolded over millennia.

Complex language and our powerful shared culture were the final elements setting us apart from other humans.

No longer scattered groups, we had become one connected, cooperative species.

We had become Homo sapiens.

The ancestors of us all.

Sometimes in life things come together and this was a coming together for our species.

It was a perfect storm.

You had a change in brain.

You had language, increased numbers, increased connectivity, cumulative culture, better technology and weaponry, and the right climate.

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

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

Friendliness, it turns out, is our superpower.

We are more than the sum of our parts, whether it's ritual, technology, language, all of it comes down to cooperation, in my opinion.

And that's how you go from a species that started off feebly, unremarkably, to one that would become so extraordinary, one ready to explore this planet.

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