The largest family tree in the world is growing.
Every second of every day, four new people join the human race.
Today we number five and a half billion.
We differ in color, costume, culture, and creed, yet we are one species.
Our origins have long intrigued scientists.
When did a primitive ancestor become human?
Important clues are coming to light.
Bone by bone, bit by bit, an anthropologist reconstructs a shadowy figure from our past.
It resurrects a distant relative with whom we have yet to come to terms.
How do we define human?
Is it anatomy or a distinct sense of self?
With new technology, a biologist explores the past.
Within us is an ancient tale written in genetic code.
A tale of simple creatures who once embarked upon a journey from which there is no return.
Creatures who crossed the threshold into human consciousness, who first asked the question,
where did we come from?
Who am I?
It was the dawn of humankind.
The Infinite Voyage is made possible by a grant from Digital Equipment Corporation through
its Digital Discovery Series, celebrating the arts, sciences, and humanities.
Digital and its employees invite you to join with them in supporting public television.
In southwest France, there is a region of limestone cliffs and deeply cut valleys.
Its natural beauty and quaint villages are popular with tourists, but the Dordogne has
another claim to fame.
It is the site of some of the earliest discoveries of prehistoric people.
Creatures are drawn here by a distinctly human fascination with the past.
Some take home postcards of caves painted nearly 200 centuries ago.
For others, it's a thrill just to walk in the footsteps of an illustrious ancestor.
By a fluke of climate and geology, conditions in southwest France are ideal for preserving
fossils.
The land is rich with traces of ancient lives.
Archaeologists have scoured the area for decades, and yet there is always something new to find.
This enormous cave is known as Le Placard.
Recently, French prehistorian Jean Claude began work here because of a remarkable discovery.
Le Placard was excavated repeatedly at the end of the last century, cleared with pickaxe
and shovel.
It was then abandoned.
Today's excavators use more exacting methods.
In a patch of undisturbed deposits, Claude and his team find clues to the people who
lived here some 19,000 years ago.
Reindeer bones speak of Ice Age hunters.
An exquisite spear point only hints at a stoneworking tradition honed over millennia.
Such were the prehistoric treasures uncovered during the early digs at Le Placard.
But one treasure was overlooked.
It was an extraordinary bequest from a people long vanished.
In 1987, a local archaeologist noticed something unusual.
This wall was finally etched over most of its length.
An expert in cave art, Claude was invited to examine the marks.
They seemed random, but were man-made.
A pattern began to emerge, a tail, hind legs, a swollen belly, the drawing of an animal.
But which one?
Claude and his colleague believe it is a pregnant mare.
At a glance, the images look jumbled, etched one on top of the other.
To make sense of the patterns, each line is meticulously traced on a sheet of plastic.
Granted, the drawings are subtle.
Still, how could early archaeologists have missed them?
Those engravings had never been found before, and that is one of the interesting psychological
facts about prehistory, and we might say even about the modern world.
It's that the people in the last century didn't see them because at that time prehistorical
art had not been recognized as such.
So in 1870s here, those people didn't know that some prehistorical wall art could exist,
and so they didn't see it.
They couldn't see it because the concept did not exist, and they didn't see it.
They were blind to it.
The tracings reveal the work of a skilled artist, a wild horse, reindeer antlers and
a stallion's head, a young doe, and most mysterious of all, an abstract T-shaped sign, ghostly
images of a lost age.
What do they mean?
That function, we are pretty sure, is, let's say, magical or religious, which is the same
thing for those times, but beyond that, there are theories but no hard facts.
Some people have argued that it was a means of communication to help the children get
the knowledge of their fathers and things like that.
It may be the case.
That it is religious in nature is certain because people who have got the same sort
of civilization, that is, say, hunters, gatherers, all over the world, which have been known
for the past, let's say, 200 years, the people who do the rock art always do it for religious
purpose or most times.
So it is a religious art.
But what sort of religion was practiced?
What were the rights that were enacted, the myths they corresponded to, and also what
happened around it, let's say, the dances, the songs, et cetera, that we shall never
know.
Still, one thing is clear.
Those who lived here crafted fine tools, created art, worshiped gods, features unique to modern
humans, homo sapiens sapiens.
Where did they come from?
Were they the first modern humans?
In the last century, the answer seemed simple.
In 1868, the French railroad system reached a town called Les Aisies.
While laying tracks, workmen cleared out a rock shelter at a place called Cro-Magnon.
To their surprise, they unearthed an amulet carved of mammoth tusk and the bones of an
infant and several adults.
Scientists recognized them as prehistoric humans and called them the Cro-Magnon.
Anatomically, they resembled modern Europeans and were accepted as direct ancestors.
Found at sites throughout Europe, their tools of stone, antler, and bones were testament
to their craftsmanship and advanced intellect.
The Cro-Magnon appeared in Europe some 35,000 years ago.
Although their image has been romanticized, their artistic achievements are undeniable.
To a 19th century mind, the Cro-Magnon were proof that modern humans and the roots of
modern culture had originated in Europe.
But the idea was soon complicated by the discovery of another creature, one who had lived in
the same valleys and caves as the Cro-Magnon.
With flattened skull and massive brow ridges, huge teeth and protruding face, this was Neanderthal.
These fossils would startle a world in which the concept of human evolution was brand new.
Neanderthals left no cave art, no carvings, no hints of higher culture, only simple stone
tools.
By the turn of the century, they were viewed as members of an ancient and primitive race,
dim-witted, heavy-browed, and brutish.
Their characterization stuck.
Neanderthals gave popular culture an enduring stereotype of the caveman.
Would creatures this primitive be our ancestors?
Or were they a branch on the family tree that went extinct?
A century of research has helped separate fiction from fact.
The human story has humble beginnings.
Sixty-five million years ago, the dinosaurs vanish.
Mammals flourish.
Soon primates appear, small tree-dwelling creatures.
Some thrive in tropical forests.
They become the African apes.
Around five million years ago, a group ventures into the margin between forest and savanna.
Although they have the face and the brain of an ape, these creatures take the first
step toward humanness.
They walk upright.
Called australopithecines, or southern apes, they are our earliest known ancestors.
By three million years ago, they evolved into at least two distinct types.
Some have powerful jaws and large teeth.
They probably live on a diet of coarse plants and seeds, with little meat.
The fossil record suggests they go extinct.
Their cousins have smaller teeth and a more varied diet, perhaps higher in meat.
They may be more adaptable.
By two million years ago, our ancestors stand only four or five feet high, but now they
have brains double the size of any living ape.
They make the first stone tools.
For this achievement, they are called homo habilis, which means handyman.
Their descendants have brains nearly twice as large, members of a new species, homo erectus.
They stand well over five feet, make better tools, and use fire.
They are also the first to leave Africa.
By 400,000 years ago, small populations are scattered across Africa, Asia, and Europe.
They look enough like us to be called archaic humans, a primitive form of homo sapiens.
They acquire one feature no previous ancestor possessed, the anatomy for human speech.
At Mount Sinai Hospital in New York, anatomist Jeffrey Lateman studies the upper respiratory
tract of human infants.
He found that the voice box, or larynx, is critical to the way newborns breathe and swallow.
Like most apes and other mammals, human infants have a larynx positioned high in the throat,
but the same region in a human adult is quite different.
During the course of our development, something occurs that is unique among mammals, and indeed
is one of the most fascinating things about human development.
We're going to totally change the location in our throat of our larynx.
This is unheard of in other mammals.
This is a massive change.
Our larynx is literally going to go down in the throat.
I like to say that it's a voyage that is often more dangerous than going to the dark side
of the moon.
Newborns can breathe and swallow at the same time.
The high position of the larynx creates two separate pathways, one for air and one for
food and drink.
Near the age of two, the larynx begins to drop.
That change may aggravate ear infections and colds, but it heralds more articulate speech.
Baby.
Lion.
Rabbits.
By adulthood, the larynx is so low, the two pathways cross.
Unlike other mammals, humans can easily choke to death when food goes down the wrong pipe.
The larynx descending in the neck, however, has produced one feature of enormous positive
value.
That is a large resonating chamber, a large pharyngeal area of space, which opens up above
the level of the larynx.
And what this space can do, a space which is bounded by the back of the tongue and the
pharyngeal muscles, this space can take the sounds that are produced inside the larynx
and modify them to a greater extent than that possible for any other mammal or a baby human.
Without a larynx low in the throat, humans could not make the infinite variety of sounds
that are the basis of spoken language.
When did this unique anatomy arise?
The larynx is soft tissue and does not fossilize.
But an important indicator is the base of the skull.
In most mammals, it is flat.
In adult humans, it is bent.
The connection led Leitman to study fossils.
I've spent a lot of time examining the earliest of our ancestors, the australopithecine.
When one assesses the base of the skull of this individual, you find that it looks remarkably
similar, like a chimpanzee skull base.
Most australopithecines look like this as well.
In other words, we don't believe our earliest ancestors could speak the way we can today.
The question still remains, when did the pattern shown by modern humans come on the scene?
Our data suggests that this is not until the arrival of members of our own species, Homo
sapiens, who came on the scene some 300,000 to 400,000 years before the present.
It's with early members of our group that we find full bending of the skull base that
relates to a larynx positioned all the way down in the throat.
In other words, we believe that with the arrival of members of our own species, that a fully
modern vocal tract came to be, and thus the abilities for the full range of human speech.
That sounds were uttered by the first archaic humans, we will never know.
Their fossils are mute and few and far between.
Only one group of archaic people is well represented in the fossil record, the Neanderthals, who
appear throughout Europe and Eurasia some 150,000 years ago.
In the hands of today's scientists, a new portrait of the Neanderthals is coming to light.
For decades, most anatomical studies focused on their skulls.
At the University of New Mexico, anthropologist Eric Trinkas bases his work on the entire
skeleton.
Bones are pliable, shaped by the stresses placed on them in life.
Clues to the Neanderthals' behavior are etched in their anatomy.
One of the differences we see between the Neanderthals and modern humans is that they
are much more robustly built than modern humans.
In fact, the average Neanderthal would probably make Arnold Schwarzenegger look like a wimp.
What I have here is a thigh bone of a Neanderthal, and since this one and others were found we've
known for a long time that the leg bones of the Neanderthals are very heavily built.
They have large joint surfaces, and they have relatively large shafts, and it's also been
known that the shafts, if you look at them in cross-section, are quite circular, very
round.
And if we look at a modern human one, and this is one from the Middle East, they are
less heavily built, and they're kind of teardrop-shaped in cross-section with a crest on the back.
To understand these differences, Trinkas digitizes cross-sections of thigh bones.
Using the principles of biomechanics, he can estimate the kinds of stress involved in shaping
the bone.
In modern humans, the thigh bone is reinforced from front to back, a pattern caused by vigorous
walking or running.
In Neanderthals, the cross-section is almost perfectly circular.
Many of another kind shape their thigh bones.
They're very strongly built in an inside-outside direction, a side-to-side direction.
And what that implies to us is that during everyday activities, the Neanderthals had
a much higher level of side-to-side movement, the kind of side-to-side movement you would
get if you were running over a very irregular terrain, or that you were chasing something
that was moving, darting back and forth the way, say, a rabbit does when it runs away.
We don't know exactly what the Neanderthals were doing that made their reinforcement build
up in this way on the shafts of their thigh bones, but it's a consistent pattern that
the Neanderthals inherited from their ancestors, but it's one that changes with the appearance
of modern humans.
It's been known for a long time that Neanderthals have very large front teeth, and what we know
now is that by the time they reached the age of about 40, most of them had worn their front
teeth down to the roots.
And what you see here is a fair amount of wear on the cheek teeth, but the front teeth
are worn completely down to the roots and rounded off on the outside.
Microscopic studies of these teeth show that there are lots of chips on them and there
are lots of scratches, scratches that go from inside to out, as though they are holding
objects in their teeth and pulling on them, maybe shredding, maybe just using those teeth
as a vice, that is, as a third hand.
Defects in tooth enamel show Neanderthal children were often malnourished.
Most adults suffered at least one major injury.
Some lived with excruciating pain.
This heel shows bone spurs and a sign of severe arthritis.
Where cartilage wore away, bone ground against bone.
Only one in ten adults lived past the age of 40.
Yet as a people, they survived at least 100,000 years.
No small measure of success.
Neanderthals were the first humans to live in a glacial climate.
They thrived during Europe's ice age.
New studies of their technology reveal unexpected sophistication.
They knew how to maximize raw materials.
From a carefully prepared core of flint, they struck razor sharp flakes.
A single core would yield an entire tool kit.
This technique requires more than manual dexterity.
It shows a sense of economy and forethought.
But Neanderthal's concerns went beyond mere survival.
In 1960, archaeologists working in a large cave in Iraq unearthed several Neanderthal
skeletons.
Most had been killed when part of the cave collapsed.
But one was different.
A man in his forties had been placed on his side in a shallow grave.
The soil around him would reveal large quantities of fossilized pollen.
Sixty thousand years ago, a father or a brother was laid to rest on a bed of pine needles.
Flowers were placed on his body.
His passing was mourned.
Neanderthals buried their dead.
The discovery would narrow the murky gap between them and us.
Perhaps they were the direct ancestors of modern humans.
In 1932, British and American archaeologists were digging near Mount Carmel, 80 miles north
of Jerusalem.
They unearthed, in their own words, the world's oldest cemetery, ten skeletons buried with
stone tools, identical to those made by Neanderthals.
The remains were shipped to England and the United States for study.
Identifying the fossils was not easy.
Some looked primitive.
Others seemed modern.
Researchers concluded that they were Neanderthals in the process of becoming modern.
The idea was accepted for decades.
But at the University of Bordeaux, one anthropologist saw things differently.
Bernard van der Mirsch.
Over 20 years ago, he began to rethink the evidence from the Middle East.
Some of the fossils looked distinctly modern.
Perhaps they weren't Neanderthals.
To find out, he went to Israel in 1965 to re-excavate a cave called Kaphse.
He found what he came for.
Two beautifully preserved skeletons, a child of five or six, and a young woman buried together.
There was no doubt, anatomically, they were modern humans.
Yet they left no art, no signs of modern culture, just simple Neanderthal-like tools.
The discovery reinforced van der Mirsch's growing suspicion that two types of humans
had once inhabited the Middle East.
In 1982, he and a colleague, Ofer Bar-Joseph, began work in a nearby cave called Kibara.
Here they discovered one of the most complete Neanderthal skeletons ever found.
Another question of chronology remained.
In Europe, Neanderthals were older than modern humans.
But in the Middle East, van der Mirsch had his doubts.
At Kaphse, modern humans had been found in extremely ancient levels.
Van der Mirsch put forth an idea so radical, some colleagues questioned his reason.
The arguments began when, based on geological observations and fossil evidence, we proposed
with my colleague Ofer Bar-Joseph a very ancient date for the levels in Kaphse.
It meant we were saying that modern humans in the Middle East were alive at the same
time as the Neanderthals, even the Neanderthals of Europe.
It also meant we were saying that modern humans were much older than anyone had ever thought.
Neanderthals and modern humans alive at the same time?
The idea went against a view of prehistory held for nearly a century.
Absolute dates were needed, but traditional dating methods fell short.
Then in 1987, a new technology made it possible to date the stone tools from the Middle East.
At the Center for Low-Level Radiation near Paris, Hélène Vallada is a recognized expert
in a technique known as thermoluminescence dating.
The technique measures radioactive decay in flints that were burned in prehistoric fires.
Vallada grinds the flint into a fine powder.
Only a minute sample is needed.
Relative decay occurs naturally over time. To measure the amount of decay in the flint,
Vallada will heat the sample quickly.
As the temperature reaches 500 degrees centigrade, the flint will give off a visible flash of
light called thermoluminescence.
The brighter the flash, the older the sample.
In 1988, Vallada published dates for the stone tools from Kofse.
The results were startling.
Modern humans were living in the Middle East at least 90,000 years ago, far earlier than
any previous estimates.
Dates from Kabara showed that Neanderthals arrived in the Middle East much later, around
60,000 years ago.
These dates pushed the emergence of modern humans back from 35,000 to 90,000 years ago.
Neanderthals could no longer be considered the direct ancestors of modern humans.
Perhaps the Neanderthals were migrants, northern peoples driven south by the Ice Age.
In the Middle East, they encountered modern humans.
The two may have lived side by side for thousands of years.
Usually populations who live in the same region with the same culture sooner or later interbreed
with each other.
That is a problem we have yet to resolve, but I am convinced we will find hybrids, evidence
of interbreeding.
The thing is, if interbreeding affected let's say 10% of the population, that means we'd
have to find at least 10 skeletons in order to find one hybrid.
And while we have many fossils, we have very few complete skeletons, and interbreeding
will never be proven from an isolated bone.
Whether or not they interbred is controversial, but a larger question remains.
If Neanderthal was not our direct ancestor, who was?
Who were the modern humans who lived in the Middle East 90,000 years ago?
People with simple tools and a culture no more advanced than the Neanderthals.
Where did they come from?
The southern tip of Africa is a place of spectacular and primordial beauty.
Archaeologist Hilary Deacon of the University of Stellenbosch near Cape Town has spent years
exploring this landscape.
Here near the mouth of the Classes River, a series of wave-cut caves punctuate the rugged
coast.
Since 1984, Deacon has conducted excavations at the Classes River mouth caves.
His work adds new pieces to the puzzle of human origins.
Places of human occupation are unmistakable.
The cave is filled with stone tools, animal bones, and food remains.
With meticulous care, the team works their way through the deposits one layer at a time.
Deacon has dated the earliest layers to over 120,000 years ago.
Although the occasional mammal bone turns up here, the most frequent item in the prehistoric
diet was shellfish.
In places, discarded shells litter the cave floor six inches deep.
A picture of the people who once lived here is slowly emerging.
Their stone tools were similar to those of the Neanderthals.
They lived at a time when the climate was gentler and antelope grazed the area.
They left behind no art, no burials.
Their culture was simple.
We're dealing with populations who were living on the southern part of Africa 120,000 years
ago living as hunter-gatherers.
They were exploiting a marine environment, they were collecting shellfish off the rocky
shore here, they were picking up seal carcasses, they were hunting.
I think they may have also been scavenging various kills.
They're also collecting plant foods, and these are people who could make fire at will.
Traces of their ancient fires have been found everywhere.
People lived in these caves for tens of thousands of years.
Their primitive hearths were built one on top of the other.
They tend to be circular hearths, they've got an inch in thickness of ash in a hollow,
and these have food remains on the edges of them, but the main food refuse is dumped in
particular areas away from the hearths, and this suggests that they organized their living
space much as modern people would do.
Who were these people?
The fossils are fragmentary, but telling.
This is perhaps one of the most impressive pieces of evidence that we're dealing with
anatomically modern people, in other words, people who in their physical morphology are
just like ourselves.
The tooth size is well within the range of tooth sizes of modern people, and the chin
here is quite prominent, which is also a characteristic of modernity.
The orbit, the eye socket is clearly visible, and then these are the nasal bones here, and
I think what's interesting about this particular piece is that there's a very small brow ridge.
If one compares this to some of the archaic kinds of humans, the brow ridge is very, very
much more prominent, so this is one of the features of modernity.
The people who lived here 120,000 years ago were modern humans, at least anatomically,
but in behavior and culture, they may have been as primitive as the Neanderthals.
It would seem a paradox.
For years, scientists had assumed that modern humans must have modern culture.
Discoveries in South Africa and the Middle East shattered that assumption.
The origins of modern humans seemed more perplexing than ever.
One word came from an unexpected quarter.
Bones and stones are no longer the only clues to human evolution.
At the University of Hawaii, biologist Rebecca Kan works with DNA.
She reconstructs the human family tree by studying our genes.
Biogenetic studies focus on the chromosomes in the cell nucleus.
Kan studies the DNA in tiny structures called mitochondria.
This DNA is transmitted solely from mother to daughter.
Over the generations, it changes slightly or mutates at a fairly constant rate.
In 1987, Kan and two colleagues compared the mitochondrial DNA of 147 people from all major
racial groups, so slight with the differences between them that all must have shared a very
recent common ancestor.
Kan then built a family tree.
Since Africans had accumulated the most mutations, it would seem their branch was the oldest.
Knowing the rate of mutation, Kan traced the mitochondrial genes of everyone alive today
to one woman who lived in Africa around 200,000 years ago.
I think in the origin of modern people, we will eventually find that this population
that gave rise to us went through a phase very much like an endangered species.
It doesn't mean that it was two people.
It means it could have been anywhere up to 4,000 people, but that's a relatively small
origin for a species in terms of a population size.
If Kan's time scale is correct, it means that only one small group of Homo erectus in Africa
became modern humans.
All archaic humans, including the Neanderthals, went extinct.
They did not interbreed with modern humans.
They were totally replaced by them.
The idea set off a heated debate.
I was somewhat surprised and taken aback by the level of controversy, but I think that
it's good and it should serve as an example to any beginning student that you take an
area where experts supposedly agree and you begin to probe and you find that there is
no real agreement.
It's important to think about how new technologies both allow you to answer old questions and
in themselves will raise new questions about old ideas.
Rebecca Kan's work has polarized current thinking about modern human origins into two
extreme and opposing theories.
At London's Natural History Museum, scientists have been collecting and classifying life
forms for over a century.
The human animal is the subject of paleoanthropologist Christopher Stringer's research.
He has spent over two decades analyzing hundreds of fossil bones and skulls.
Stringer feels Kan's genetic studies confirm what he sees in the fossils.
He is the best known proponent of a theory called Out of Africa.
The model begins around a million years ago.
Small bands of Homo erectus leave Africa.
They evolve into isolated populations of archaic humans.
Neanderthals in Europe, peaking men in China.
Then in Africa some 200,000 years ago, modern humans evolve.
Gradually they move into the Middle East, Asia, and beyond, replacing archaic humans.
They alone are the ancestors of people today.
Under the Out of Africa model, modern humans begin in Africa, they move to Asia, and Asia
becomes the secondary dispersal center.
On that basis, most of the racial differentiation we see today occurred in the last 50,000 years.
If we look at early moderns in Europe in relation to modern Europeans, early moderns in China
in relation to modern Mongoloid populations, early moderns in Australia in relation to
modern Australians, they form a reasonable group.
If you do an analysis of the distance between an upper Paleolithic from Europe and this
early skull from China, these are in fact more similar to each other than either of
them is similar to their supposed descendants.
Now that suggests to me that they're similar because they've had a recent differentiation
from each other.
They're coming from a recent ancestor, and racial differentiation is in fact only beginning
when these populations get to where they are.
At the University of Michigan in Ann Arbor, another anthropologist disagrees.
He has studied the same fossils as Stringer, and yet reaches a different conclusion about
the origins of modern humans.
Milford Walpuff questions the accuracy of the genetic studies.
He is an outspoken critic of the out-of-Africa model.
Walpuff proposes instead a multi-regional theory.
According to this model, our most recent common ancestor is Homo erectus, who leaves Africa
about a million years ago.
Groups evolve into regional populations of archaic humans who continue to intermingle.
Through gene flow, modern traits are carried from one people to another.
Eventually all archaic humans, including the Neanderthals, become modern.
If Africans came and replaced people as the earliest modern humans, then the earliest
modern humans should look more like these Africans.
Well, I'd like to ask, where's the beef?
And here's how I'd like to ask it.
Here are three modern craniums.
This modern North Asian combines a very high-rounded forehead, a lack of development of its brow
ridges, a very low nasal angle, and a vertical face, which is flat from side to side, that's
characteristic of most Asians today.
Whereas this Australian has the low, flattened forehead and extremely prominent brow ridges,
higher nasal angle, and very great facial prognathism, this muzzling-type effect of
the teeth, which is quite different.
And finally, this European has a high rounded forehead, prominent super orbitals, and a
characteristically very high nasal angle, very prominent bony part of the nose, and
a fairly vertical face, where the cheeks face more to the side than they face forward.
Now, Lu Zhang is one of the earliest modern humans that we know of in China, with the
same high rounded forehead, the same super orbital development as you see below, very
low nasal angle, very vertical face, very flat from side to side, which is characteristic
of these modern populations as they are today.
If we current to Australia, using a different specimen, this early Australian, about 10,000
years old, combines the flat forehead and prominent brow ridges, as you can see below,
with a very prognathic face here, and the same cheek and nasal angulations.
And finally, if we turn to the European, one of the earliest Europeans is this specimen
from Cro-Magnon, with the characteristic high rounded forehead, but very high nasal angle,
and vertical face that Europeans have today, exactly the features that we see in the specimen
below.
In each case, we find a line of regional continuity linking ancient people with modern people
in those areas.
We think at the same time, though, that there's clear evidence that people mixed and intermingled
during this period, so that at any one particular spot, we would say that living Chinese, for
instance, are not uniquely descended from ancient Chinese, there's also evidence of
genetic input from other regions, for instance, from Australasia, from Europe, and from Africa.
No population has been isolated, all have been connected, so we have the combination
of a main line of descent, but also genetic and cultural input from other areas, and this
is what we use in the multi-regional model.
Both models have their champions, but many scientists believe the truth lies somewhere
in the middle.
The question of our origins will not be decided by fossils alone, nor by genetics alone.
The gap between ancient bones and living genes may soon be bridged.
Scientists like Rebecca Kahn are now developing ways to combine the strength of fossil studies
with a resolution of molecular genetics.
Researchers in Kahn's lab are extracting DNA from human bones over 400 years old, bones
that are not yet completely fossilized.
Experts are hopeful that DNA can be retrieved even from very ancient fossils.
I think that people will be extracting DNA from Neanderthals.
I think that people will be extracting DNA from Australopithecines.
The problem will be, in the beginning, there'll be a lot of modern contamination, there'll
be a lot of soil DNA, DNA from microorganisms in the soil, and there'll be a lot of degradation.
The DNA will be very short, it will be small pieces, it won't be complete genes.
But ultimately, I think we can be confident that's where the field will go, and then
we'll be able to put genes and faces together.
A family tree of unprecedented precision may soon be within our grasp, but a greater mystery
remains.
The past does not yield its secrets willingly.
To coax it back to life requires hard work and infinite patience.
Jean Claude and his team seek clues to the last elusive milestone in human evolution,
a profound change that occurred not in human body, but in human mind.
For perhaps 100,000 years, anatomically modern people led a simple life.
Cultural change was imperceptible from one millennium to the next.
Then culture took a quantum leap.
It was heralded by the appearance of art.
We know that the art appeared, let's say, roughly between 30,000 and 40,000 years ago.
That we are sure of.
There is a second thing we are sure of, it's that it appeared all over the world roughly
at the same time.
When I say roughly at the same time, it's give and take 5,000 years.
That is to say, it's a time when there occurred the spread of our own species, homo sapiens
sapiens.
Let's say the same humans as we are, after the Neanderthals disappeared, or just when
they were disappearing.
Those two things we are sure of.
The last ice age held Europe in its grip.
The Neanderthals knew this world well.
The migrating herds and life giving rivers, the rock shelters and protective cliffs.
Then newcomers arrived, perhaps with better tools, more refined language, a stronger sense
of clan.
By 35,000 years ago, the Neanderthals and all archaic humans had vanished.
Only one player was left on the stage, homo sapiens sapiens.
All at once, culture accelerated.
Over 30,000 years ago, people began to depict the world around them.
They carved small portable objects from reindeer antler and mammoth tusk.
With a profusion of body ornamentation, they proclaimed a new sense of self.
They created their own symbolic universe of goddesses and gods.
Their world was filled with sacred places, infused with myth.
These underground caves were the cathedrals of prehistory.
Thirteen thousand years ago, three children walked here.
Perhaps entranced in the flickering light by images of dancing bison.
What brought about this great leap, we may never know.
The meaning of these images eludes us, but the message is clear.
We had arrived.
Today we are driven to the dark caves with the same undaunted curiosity as our ancestors.
Each generation embarks on the same quest.
Each wonders anew, where did we come from?
Where are we going?
The next generation will find their own answers and see the past in a different light.
Across the gulf of time, the visions of our ancestors still shine bright.
Their legacy lives on in us as we continue the journey of discovery.
The journey that began at the dawn of humankind.
The next generation will find their own answers and see the past in a different light.
Across the gulf of time, the visions of our ancestors still shine bright.
Transcribed by ESO, translated by —