NARRATOR: AUSTRALIA, ONE OF THE MOST MULTI-CULTURAL COUNTRIES ON EARTH.

A NATION OF IMMIGRANTS.

BUT FOR 50,000 YEARS, IT WAS THE VERY OPPOSITE-- A HOME TO AN ANCIENT PEOPLE CUT OFF FROM THE REST OF HUMANITY.

THEY WERE SO ISOLATED, THEY COULD HAVE GONE EXTINCT.

SO HOW DID THEY BEAT THE ODDS AND SURVIVE?

ESKE WILLERSLEV: ABORIGINAL AUSTRALIANS ARE DIRECT DESCENDANTS OF THE FIRST MODERN HUMAN EXPLORERS.

JOHN HAWKS: ONCE HUMANS REACHED AUSTRALIA, THERE WAS VERY LITTLE, IF ANY, CONTACT WITH THE REST OF THE WORLD.

THEY WERE REALLY IN IT BY THEMSELVES.

MAN: WITH MODERN-DAY SCIENCE, WE CAN FIND OUT MY ANCESTRAL BACKGROUND.

THAT'LL BE GOOD TO FIND OUT.

NARRATOR: ABORIGINALS AUSTRALIANS HAVE SOME OF THE MOST ANCIENT DNA IN THE WORLD.

THEY MAY HOLD THE KEY TO THE SURVIVAL OF OUR SPECIES.

THIS IS THE STORY OF OUR ANCESTORS, AS THEY SPREAD TO EVERY CONTINENT OF THE WORLD.

WHAT WAS THE SECRET TO THEIR SUCCESS?

THEIR STORY IS OUR STORY.

[DISTANT BIRDS SCREECHING] NARRATOR: SOUTHEASTERN AUSTRALIA, 42,000 YEARS AGO.

A MAN IS BURIED BY A LAKESIDE.

HE IS A CLAN CHIEF OR SOMETHING SIMILAR, IMPORTANT ENOUGH TO BE BURIED WITH CEREMONY.

[MEN CHANTING] NARRATOR: HE'S KNOWN TO ARCHAEOLOGISTS AS MUNGO MAN.

HERE, AT THE VERY ENDS OF THE EARTH, IS SOME OF THE EARLIEST EVIDENCE OF OUR YEARNING FOR SPIRITUALITY.

[SHOUTS] NARRATOR: MUNGO MAN WAS DISCOVERED IN 1974 BY GEOLOGIST JIM BOWLER.

NARRATOR: BOWLER CAME TO NEW SOUTH WALES LOOKING FOR EVIDENCE OF PREHISTORIC HUMAN LIFE.

HE FOCUSED ON A SERIES OF SANDY CRESCENTS.

HE REALIZED THEY WERE ANCIENT LAKEBEDS.

NARRATOR: TODAY, THIS IS A HARSH, OTHERWORLDLY ENVIRONMENT.

BUT THOUSANDS OF YEARS AGO, IT WAS WET AND LUSH... A GREAT PLACE FOR PREHISTORIC PEOPLE TO LIVE.

THE LARGEST DUNES MARK THE EDGE OF A LONG, DRY LAKE KNOWN AS MUNGO.

ONE SUMMER'S DAY IN 1974, BOWLER WAS RIDING HIS BIKE AT LAKE MUNGO WHEN HE SAW SOMETHING UNUSUAL ERODING OUT OF THE DUNE.

I SPOTTED, UM, A--A TIP OF--OF WHITE BONE EXPOSED ON THE SURFACE OF THE SAND, AND IT WAS OVER NEAR HERE... JUST THE TOP OF THE CRANIUM COMING OUT OF THE SAND.

AND WHEN I BRUSHED AWAY THE--THE LOWER PART, THE JAW WAS THERE, SO IMMEDIATELY I RECOGNIZED I WAS STANDING ON THE BURIAL OF, UH, OF--OF HUMAN REMAINS.

NARRATOR: THE BONES WERE 42,000 YEARS OLD, TWICE AS OLD AS REMAINS FOUND ANYWHERE ELSE IN AUSTRALIA.

WHAT WAS MOST STRIKING WAS THEY'D BEEN STAINED WITH A NATURAL PIGMENT-- OCHRE.

[HUMMING] BOWLER: THERE'S NO OCHRE WITHIN A HUNDRED KILOMETERS OR MORE FROM HERE.

THE OCHRE HAD TO BE BROUGHT IN.

IT HAD TO BE PREPARED.

ALL THAT PREPARATION FOR THE MOMENT OF BURIAL, THAT WENT ON FOR DAYS.

NARRATOR: HUMANS HAD ALREADY BEEN USING OCHRE FOR THOUSANDS OF YEARS IN AFRICA, AS A WAY TO DECORATE THEIR BODIES OR TREAT THEIR HIDES.

[CONTINUES HUMMING] [ALL CHANTING] NARRATOR: BUT HERE, IT WAS AN INTEGRAL PART OF AN ELABORATE RITUAL CEREMONY.

BOWLER: HE WAS LAID OUT AS THE WAY WE WOULD LAY OUT MY OWN FATHER IN HIS FUNERAL COFFIN, AND HE WAS THEN, UH, CEREMONIALLY, UM, FAREWELLED.

[SHOUTS] BOWLER: IT WAS NOT JUST THE MOURNING OF DEATH, IT WAS EVEN, PERHAPS, SOMETHING OF A CELEBRATION OF LIFE, REALLY.

NARRATOR: MUNGO MAN IS NOT THE ONLY BODY JIM BOWLER HAS FOUND BY THE LAKESIDE.

A QUARTER OF A MILE AWAY, HE DISCOVERED FRAGMENTS OF A FEMALE SKELETON THAT BECAME KNOWN AS MUNGO LADY.

BOWLER: THIS IS THE SORT OF HORIZON IN WHICH I FOUND THE BONES OF MUNGO LADY.

THE BEACH WAS JUST OVER HERE, THERE WAS A SOIL THERE, AND THE BODY WAS LOCATED HERE.

AND THEN THESE BONES WERE CEMENTED BY THIS WHITE, CHALKY CARBONATE.

THAT DIDN'T LOOK LIKE A BODY.

NARRATOR: WHEN ANTHROPOLOGISTS PUT TOGETHER ALL THE FRAGMENTS FROM MUNGO LADY, THEY HAD EVIDENCE OF ANOTHER FUNERAL RITUAL FROM THE SAME PERIOD-- 42,000 YEARS AGO.

MUNGO LADY'S BONES HAD BEEN BURNT, PERHAPS TO MAKE THEM MORE BRITTLE.

THEN THEY WERE BROKEN INTO TINY PIECES.

LAKE MUNGO WAS CLEARLY A HOME FOR A COMMUNITY OF PEOPLE WITH A RICH, COMPLEX CULTURE.

BUT WHO WERE THESE PEOPLE LIVING AT THE EDGE OF THE WORLD?

WHERE DID THEY COME FROM?

WHEN DID THEY ARRIVE?

HOW DID THEY GET HERE?

NARRATOR: LAKE MUNGO IS TUCKED AWAY IN THE SOUTHEAST OF THE COUNTRY, AN ISOLATED CORNER IN THE WORLD'S MOST ISOLATED CONTINENT.

IT'S A MYSTERY HOW PEOPLE EVER REACHED MUNGO BECAUSE THERE'S SO LITTLE ARCHAEOLOGICAL EVIDENCE FROM THAT PERIOD ANYWHERE IN AUSTRALIA.

BUT THERE ARE CLUES TO BE FOUND IN DNA.

AT THE START OF THE 20th CENTURY, BRITISH ANTHROPOLOGIST ALFRED HADDON WENT TO AUSTRALIA TO RECORD THE CUSTOMS OF THE INDIGENOUS PEOPLE... AND COLLECT SAMPLES OF THEIR HAIR.

HIS COLLECTION REMAINED IN A MUSEUM, GATHERING DUST, UNTIL A DANISH GENETICIST, ESKE WILLERSLEV, GOT TO ANALYZE THE SAMPLES.

WILLERSLEV: THE BEAUTY ABOUT HAIR IS THAT IT'S NOT POROUS LIKE BONE AND TEETH, SO IT MEANS THAT ALL CONTAMINATION FROM ALL PEOPLE WHO HAVE HANDLED IT OVER THE YEARS IS ALL SITTING ON THE OUTSIDE OF THE HAIR, SO YOU CAN BASICALLY JUST PUT IT INTO BLEACH AND THEN GET RID OF THE CONTAMINATION, AND THE DNA REMAINING IS THE ONE FROM THE INDIVIDUAL HIMSELF.

THIS HAIR COLLECTION FROM CAMBRIDGE HAS-- PROBABLY MANY TIMES, PEOPLE HAVE ASKED THEMSELVES: "WHAT SHALL WE USE THIS HAIR FOR?"

AND THEN A HUNDRED YEARS LATER, I MEAN, THIS TURNS OUT TO BE, ACTUALLY, A--A PIECE OF GOLD FOR A GENETICIST.

NARRATOR: THE HAIR SAMPLE CAME FROM A MAN IN THE OUTBACK OF WESTERN AUSTRALIA, WHICH HAD BARELY BEEN VISITED BY EUROPEANS AT THAT TIME, SO THE DNA WAS PURE ABORIGINE.

THIS WAS THE FIRST TIME ANYONE HAD SEQUENCED AN ABORIGINAL GENOME.

FROM THIS ONE SAMPLE, IT WAS POSSIBLE TO UNLOCK THE ANCIENT HISTORY OF A PEOPLE.

WILLERSLEV: ARCHAEOLOGY TELLS US THAT HUMANS WERE PRESENT IN AUSTRALIA AT LEAST 40,000 YEARS AGO.

THE QUESTION IS, OF COURSE, WHO WERE THESE PEOPLE?

HOW WERE THEY RELATED TO PRESENT-DAY ABORIGINE AUSTRALIANS OR TO OTHER PEOPLES IN THE WORLD, FOR THAT MATTER?

AND THIS IS, OF COURSE, WHERE GENETICS COMES IN AS A VERY POWERFUL TOOL.

YOU CAN START TRACING THE ANCESTRY OF ABORIGINE AUSTRALIANS.

YOU CAN ACTUALLY FIND OUT WHEN DID THEY DIVERSIFY FROM OTHER LIVING PEOPLE?

WHEN DID THEY COME OUT OF AFRICA?

WE CAN LINK BIOLOGICALLY THESE INDIVIDUALS TO OTHER HUMAN BEINGS IN SPACE AND TIME.

NARRATOR: ANALYZING THE DNA WAS LIKE LOOKING INTO THE DEEP PAST, BACK TO THE FIRST WAVE OF HUMANS MIGRATING OUT OF AFRICA.

RATHER THAN EXPLORING ASIA, THE FIRST AUSTRALIANS HEADED SOUTH.

THEY SPLIT FROM THE REST OF HUMANITY 60,000 TO 70,000 YEARS AGO, AND THEN THEY WERE ON THEIR OWN.

[BIRDS CHIRPING] WILLERSLEV: ABORIGINE AUSTRALIANS ARE DESCENDING FROM THE FIRST PEOPLE MOVING OUT OF AFRICA AND GETTING INTO AUSTRALIA.

THEY ARE DIRECT DESCENDANTS OF THE FIRST MODERN HUMAN EXPLORERS.

NARRATOR: THESE EXPLORERS MUST HAVE REACHED THE SOUTHERN TIP OF ASIA.

INSTEAD OF TURNING BACK, THEY ADAPTED TO LIFE AT THE COAST.

NARRATOR: HUW BARTON IS AN ARCHAEOLOGIST AND AN EXPERT ON THE LIVES OF COASTAL HUNTER-GATHERERS.

BARTON: COASTAL ENVIRONMENTS LIKE THIS WITH, YOU KNOW, SORT OF WATER, LAGOONS, SORT OF BACK SWAMPS, UM, POTENTIALLY, UH, MUDFLATS, MANGROVES, THEY'RE REALLY GOOD PLACES FOR FOOD FOR HUNTER-GATHERERS.

THERE'S, UM, YOU GOT SHELLFISH, FISH, CLAMS, EGGS, WORMS, AND GRUBS, YOU KNOW.

THERE'S LOTS AND LOTS OF RICH, HIGH-ENERGY FOODS THAT PEOPLE CAN TAKE FROM THESE ENVIRONMENTS.

BUT IF YOU GOT A GROUP OF, SAY, 5 TO 10 PEOPLE, YOU MIGHT CLEAN OUT AN AREA OF ITS SORT OF HIGH-RANK, GOOD-QUALITY RESOURCES, YOU KNOW, WITHIN-- WITHIN DAYS OR WEEKS.

SO THAT CAN BE A REAL TRIGGER POINT FOR PEOPLE DECIDING, "AND, WELL, WE NEED NOW TO MOVE ON TO A NEW LOCATION."

NARRATOR: FOR HUNTER-GATHERERS LIVING AT THE COAST, RELOCATING COULD MEAN A TRIP OFFSHORE.

BARTON: PERHAPS YOU CAN SEE SMALL ISLANDS, YOU KNOW, NOT TOO FAR AWAY, SO PEOPLE WILL GO OUT AHEAD, THEY'LL FIND OUT, THEY'LL COME BACK, THEY'LL COMMUNICATE TO THE GROUP INFORMATION ABOUT WHAT THEY FOUND, AND THEY MIGHT MAKE, THEN, A DECISION AS A GROUP TO GO ON TO POTENTIALLY-- OR MAYBE HOP ACROSS TO ANOTHER ISLAND.

NARRATOR: ONCE PEOPLE STARTED ISLAND-HOPPING, BARTON THINKS IT WAS ONLY A MATTER OF TIME BEFORE THEY STUMBLED ON A WAY TO REACH AUSTRALIA.

BARTON: MOST OF US LOOK AT THE OCEAN NOW, KIND OF SEE THAT AS A REAL BARRIER, AND IT'S KIND OF TO BE AVOIDED.

YOU KNOW, YOU WANT TO BE ON THE LAND 'CAUSE THAT'S OK, THAT'S SOLID, YOU KNOW, BUT IF YOU GOT A GROUP OF PEOPLE THAT-- MAYBE THEY GOT SOME SIMPLE WATER CRAFT, THEY'RE OUT, THEY'RE FISHING; YOU KNOW, ONCE THEY'VE GONE OUT AND THEY'VE GONE OUT, WHO KNOWS?

MAYBE THEY WERE, UH, BRAVE ENOUGH TO GO OUT OVERNIGHT.

BUT THEN SUDDENLY THEY START TO PICK UP SIGNS THAT MIGHT TELL THEM THAT POTENTIALLY THERE'S A LANDMASS OUT THERE.

COULD BE CLOUD, COULD BE BIRDS, YOU KNOW, IT COULD BE DRIFTWOOD.

YOU KNOW, THEY MIGHT THINK, "YOU KNOW, ACTUALLY, MAYBE IT'S WORTH KIND OF PUSHING ON A BIT HERE."

MAYBE FOR 20 YEARS, 100 YEARS, YOU KNOW, THEY DON'T REALLY GET THERE, BUT AT SOME POINT, YOU KNOW, SOMEONE GOES THAT LITTLE BIT FURTHER, JUST TAKES THAT FURTHER RISK, WHATEVER THE CIRCUMSTANCES, GETS ACROSS.

THE NEXT THING YOU KNOW, THEY'RE BUMPING UP AGAINST THE COAST OF AUSTRALIA.

YOU KNOW, IT BECOMES FEASIBLE.

YOU CAN CONCEPTUALIZE HOW THAT KIND OF-- THAT VOYAGE, THAT JOURNEY MIGHT HAVE HAPPENED.

NARRATOR: TODAY, THIS WOULD BE A 350-MILE JOURNEY, BUT IN PREHISTORIC TIMES, THE COASTLINES WERE VERY DIFFERENT.

60,000 YEARS AGO, THE PLANET WAS IN AN ICE AGE.

AS GREAT ICE SHEETS WERE SPREADING ACROSS THE NORTHERN HEMISPHERE, SO MUCH OF THE WORLD'S WATER WAS FROZEN; SEA LEVELS HAD FALLEN BY 400 FEET.

THE GAP BETWEEN SOUTHEAST ASIA AND AUSTRALIA HAD SHRUNK.

WHEN PEOPLE MADE THE CROSSING, THE TWO CONTINENTS MAY HAVE BEEN AS LITTLE AS 60 MILES APART.

NO ONE KNOWS HOW MANY PEOPLE FIRST ARRIVED IN AUSTRALIA.

IT MAY HAVE BEEN DOZENS, HUNDREDS, PERHAPS A THOUSAND.

BUT ACCORDING TO THE GENETICS, THERE WAS JUST A SINGLE WAVE OF MIGRATION, WHICH THEN STOPPED.

WILLERSLEV: IT SEEMS LIKE THERE IS ONE ENTRANCE TO AUSTRALIA, AND THEN PEOPLE ARE, SO TO SPEAK, SPREADING ACROSS THE CONTINENT, OCCUPYING THE CONTINENT.

AND THIS, AS FAR AS WE CAN SEE, THAT ONLY HAPPENS ONCE.

NARRATOR: AROUND 55,000 YEARS AGO, HUMANS BEGAN EXPLORING AUSTRALIA... 40,000 YEARS BEFORE THEY REACHED NORTH AMERICA.

HERE, THEY WERE TRULY ALONE, CUT OFF FROM THE REST OF THE WORLD...

IN A VIRGIN CONTINENT.

A HUNDRED MILES FROM THE SEA, IN NORTHEASTERN AUSTRALIA, THERE'S STUNNING PROOF OF THEIR EXISTENCE.

NAWARLA GABARNMUNG... A MASSIVE SHELTER SHAPED BY THE WIND, BUT CARVED BY HUMAN HANDS.

IT MAY BE THE OLDEST MONUMENT IN THE WORLD, TEN TIMES OLDER THAN STONEHENGE.

THE LAND HERE HAS BEEN IN THE CUSTODY OF MARGARET KATHERINE AND HER ANCESTORS FOR GENERATIONS.

[CHANTING IN FOREIGN LANGUAGE] NARRATOR: EACH TIME SHE VISITS, SHE ASKS THEIR PERMISSION TO ENTER.

KATHERINE: MY ANCESTOR LIVED IN THIS PLACE.

MY GREAT-GREAT-GRANDFATHER AND MY NANA AND MY GREAT-UNCLE AND MY--ALL MY-- DAD AND NANA, THEY STAYED IN THIS GABARNMUNG FOREVER.

NARRATOR: THE WALLS ARE COVERED IN LAYER UPON LAYER OF ART...

DEPICTING ANIMALS TRADITIONALLY HUNTED BY ABORIGINES.

KATHERINE: HERE, WE'VE GOT A BIG BARRAMUNDI.

ON TOP OF THE BARRAMUNDI, THERE'S A BREAM AND LITTLE, TINY FISH THERE.

I SEE A CROCODILE HERE.

THIS ONE HERE, BIG PLAIN KANGAROO THAT TURN AND GO ROUND THAT WAY.

SEE THE TAIL AS HE GO ROUND HERE.

AND HIS FACE AND HIS TWO EARS.

NARRATOR: THE ART ON THE WALLS IS A MIX OF THE MODERN AND THE VERY OLD...

BUT HOW FAR BACK DOES THIS TRADITION GO?

SINCE 2010, ARCHAEOLOGIST BRUNO DAVID HAS BEEN WORKING HERE, TRYING TO UNRAVEL THE HISTORY OF NAWARLA GABARNMUNG.

DAVID: PEOPLE HAVE COME INTO THE SITE, CAMPED ON THE GROUND, SO THROUGH TIME, YOU HAVE HAD A SERIES OF LAYERS OF SAND AND ASH THAT HAVE BUILT UP, GRADUALLY, LIKE LEAVES IN A BOOK, AND THOSE--THOSE SEDIMENTS THAT HAVE BUILT UP HAVE CAUSED THE ARCHAEOLOGICAL MATERIALS IN THE GROUND TO BE BURIED.

[INDISTINCT] ARE 27.

SO WE STARTED ON THE SURFACE, WHERE WE HAVE MATERIALS THAT MIGHT BE A HUNDRED YEARS OLD, 200 YEARS OLD, GONE FURTHER AND FURTHER BACK IN TIME, AND AT THE BOTTOM, A PERIOD SOMEWHERE BETWEEN 48,000 AND 50,000 YEARS AGO, WE HAVE THE OLDEST EVIDENCE OF HUMAN OCCUPATION AT THAT SITE.

NARRATOR: THE DATES ARE BASED ON FRAGMENTS OF CHARCOAL LEFT BEHIND BY EARLY AUSTRALIANS.

THEY SUGGEST PEOPLE WERE HERE AT LEAST 6,000 YEARS BEFORE THEY WERE AT LAKE MUNGO.

ARCHAEOLOGISTS HAVE YET TO FIND ANY HUMAN BONES HERE, BUT THEY HAVE FOUND EVIDENCE OF ART GOING BACK AT LEAST 30,000 YEARS.

DAVID: IT'S ONLY A TINY FRAGMENT OF THE ORIGINAL PAINTED SURFACE, BUT WHAT WE CAN SEE ON IT IS A SERIES OF LINES, SO THERE'S A STRAIGHT LINE CROSS-CUT BY A CURVED LINE.

WHAT THE ORIGINAL IMAGE WOULD HAVE BEEN LIKE, WHO KNOWS?

[BLOWING] NARRATOR: THE PIGMENT USED BY THESE PREHISTORIC ARTISTS WAS OCHRE...

THE SAME PIGMENT USED TO BURY MUNGO MAN.

IT SEEMS TO HAVE HAD NO PRACTICAL VALUE FOR THEM.

[BLOWING] ITS POWER WAS SYMBOLIC.

ON THE WALLS ARE PAINTINGS OF SPIRITS KNOWN AS MIMIS.

ABORIGINAL AUSTRALIANS BELIEVE THE MIMIS TAUGHT THEIR ANCESTORS HOW TO HUNT, COOK, AND PAINT.

KATHERINE: HERE WE HAVE A MIMI LADY RIGHT HERE.

THERE SHE IS, STANDING.

YOU CAN SEE HER THERE.

AND THE OTHER MIMI LADY HERE, SHE'S GONE THAT WAY.

AND THAT ONE OVER THERE IS A BIG ONE.

HE'S BY HIMSELF OVER THERE.

HE'S A GENTLEMAN.

WHEN I CALL OUT TO THEM, I CAN FEEL THEIR PRESENCE NEARBY ME, AND IT MAKE ME CRY, 'CAUSE I AM NOT WITH THEM.

I AM HERE, ALIVE.

BUT WHEN I AM GONE, I'LL BE HERE WITH THEM.

NARRATOR: 6 MILES FROM NARWALA GABARNMUNG, THERE'S ANOTHER PAINTED ROCK FACE.

IT ONLY HAS A COUPLE OF PAINTINGS, BUT THEY MAY BE OF AN ANIMAL THAT NO LONGER EXISTS.

THE GENYORNIS, A KIND OF GIANT EMU THAT WENT EXTINCT 40,000 YEARS AGO.

THE PAINTINGS ARE A VIVID GLIMPSE OF THE ANIMALS EARLY AUSTRALIANS WOULD HAVE ENCOUNTERED.

THE REMAINS OF SUCH ANIMALS STILL EXIST... AT NARACOORTE CAVES... A LABYRINTH OF STALAGMITES AND STALACTITES IN SOUTH AUSTRALIA.

ROD WELLS HAS BEEN EXPLORING IN THIS CAVE SINCE HE WAS A TEENAGER.

WELLS: SQUEEZING THROUGH SOME OF THESE SPACES REQUIRES A CERTAIN MENTAL DISCIPLINE.

[SIGHS] YOU HAVE TO REMAIN CALM AND COLLECTED AND RELAXED AND GRADUALLY EASE YOUR WAY THROUGH.

NARRATOR: HE DISCOVERED HIS FIRST FOSSILS HERE IN 1969.

WELLS: WE WERE ABOUT TO GIVE UP ON A SUNDAY AFTERNOON, AND A DRAUGHT OF AIR CAME OUT THROUGH THE ROCK PILE.

IT SIGNIFIES THAT THERE IS A CAVE BEYOND, PERHAPS QUITE A LARGE CAVE BEYOND, AND THAT IS THE EXCITEMENT OF EXPLORATION.

AS I SWEPT THE LAMP ACROSS THE SURFACE OF THE SEDIMENT HERE, I SAW THESE FUNNY PATTERNS.

I THOUGHT AT FIRST THEY WERE BITS OF BROKEN CAVE FORMATION THAT HAD FALLEN TO THE FLOOR, AND THEN I REALIZED WHAT I WAS LOOKING AT WERE TOOTH ROWS.

WHEN I LOOKED MORE CLOSELY AND LOOKED AT THE SHADOWS REFLECTED OFF THEM, REALIZED THAT THEY WERE ACTUALLY SKULLS OF EXTINCT ANIMALS THAT HAD BEEN LYING THERE FOR GOODNESS KNOWS HOW MANY THOUSANDS OF YEARS.

NARRATOR: IN A CONTINENT WITH SO LITTLE ARCHAEOLOGICAL EVIDENCE, THESE BONES ARE A TREASURE TROVE...

EVIDENCE OF AUSTRALIA'S EXTRAORDINARY ISOLATION.

50 MILLION YEARS AGO, WITH THE SHIFT OF TECTONIC PLATES, AUSTRALIA SPLIT FROM ANTARCTICA.

EVER SINCE, IT HAS BEEN APART FROM ANY OTHER LANDMASS, AND ITS WILDLIFE EVOLVED IN ISOLATION, PRODUCING SPECIES UNIQUE TO AUSTRALIA... BEASTS LIKE THE GIANT MARSUPIAL, DIPROTODON.

WELLS: TO JUST GET AN IDEA OF HOW LARGE THESE ANIMALS ARE, HERE IS THE FEMUR, THE THIGH BONE, OF DIPROTODON.

WE'RE LOOKING AT AN ANIMAL 1.8 METERS TALL, AND IT'S GONNA BE THE BODY MASS OF SOMETHING LIKE A BLACK RHINOCEROS, SO THESE ANIMALS ARE WEIGHING IN AT AROUND 1 1/2 TO 2 1/2 TONS.

EVEN AMONGST THE KANGAROOS, WE SEE EXAMPLES OF GIANTS.

HERE IS THE SKULL AND JAWS OF A MODERN WESTERN GREY KANGAROO... AND HERE, UH, THE SKULL AND JAWS OF ONE OF THE EXTINCT KANGAROOS.

QUITE A MARKED DIFFERENCE IN SIZE.

TRULY A MEGA KANGAROO.

NARRATOR: THE FIRST AUSTRALIANS HAD DISCOVERED A PARADISE, A VERDANT LAND WITH ANIMALS TO HUNT AND FOOD TO EAT.

AND WITH SO FEW PEOPLE, THERE WAS LITTLE, IF ANY, COMPETITION FOR RESOURCES.

NOWHERE SEEMS TO HAVE BEEN A BETTER PLACE TO LIVE THAN LAKE MUNGO.

IT WAS FILLED WITH ENOUGH FISH AND MARINE LIFE TO SUPPORT A THRIVING COMMUNITY FOR THOUSANDS OF YEARS.

ABORIGINAL RANGER TANYA CHARLES WORKS AT MUNGO AND FINDS EVIDENCE OF THE PAST EVERYWHERE...

SCATTERED AMONG ANCIENT FIREPLACES.

NARRATOR: THE SKELETON OF MUNGO MAN PROVIDES AN INSIGHT INTO LIFE AT THE LAKESIDE.

MIKE WESTAWAY IS ONE OF VERY FEW SCIENTISTS ALLOWED TO EXAMINE THE BONES.

WESTAWAY: THERE'S A LOT OF INFORMATION THAT WE CAN ACTUALLY RECOVER FROM THIS-- THIS FOSSIL THAT TELLS US A LOT ABOUT THE LIFE OF MUNGO MAN.

IT'S VERY CLEAR THAT HE'S AN ADULT MALE, IN HIS 40s, PERHAPS OLDER.

HE WAS A VERY LIGHTLY BUILT, UM, INDIVIDUAL, BUT HE'S ACTUALLY A VERY LARGE MAN, AROUND 6 FOOT TALL.

NARRATOR: EACH PART OF THE SKELETON HAS A STORY TO TELL...

BUT NOTHING IS MORE REVEALING THAN ITS TEETH.

THERE IS AN EXTRAORDINARY PATTERN OF WEAR ON HIS MOLAR TEETH, AND THIS SEVERE ANGLE OF WEAR PROBABLY RELATES TO SOMETHING DRAGGED REPEATEDLY ACROSS IT; PROCESSING FIBER, PERHAPS, TO MAKE A NET.

THE OTHER REALLY INTRIGUING FACTOR ABOUT MUNGO MAN'S JAW IS THE CANINE TOOTH AT THE FRONT OF THE MOUTH HAS BEEN REMOVED, UH, INTENTIONALLY, IT WOULD APPEAR.

IT COULD HAVE HAPPENED FROM AN ACCIDENT, BUT WE DO KNOW THAT TRADITIONALLY, UH, ABORIGINAL PEOPLE DID REMOVE, UH, THE INCISOR OR CANINE TOOTH OF YOUNG MEN THAT WERE ENTERING MATURITY.

SO THERE IS EVIDENCE HERE THAT PERHAPS THIS RITUAL REMOVAL OF ONE OF THE FRONT TEETH ACTUALLY OCCURRED IN MUNGO MAN 42,000 YEARS AGO.

NARRATOR: HERE AT LAKE MUNGO, HALF A WORLD AWAY FROM THEIR AFRICAN HOMELAND, THESE PEOPLE DID MORE THAN FEED THEMSELVES.

THEY CREATED A CULTURE AS ADVANCED AS ANY WE KNOW OF FROM THIS TIME... [SHOUTS] WITH RITUALS THAT STILL RESONATE AMONG ABORIGINAL PEOPLE TODAY.

BUT THEIR WORLD WAS ABOUT TO TURN TO DUST.

AT THIS TIME, THE ICE AGE WAS BECOMING MORE SEVERE.

SO MUCH WATER WAS TRAPPED IN THE ICE, THERE WAS LESS MOISTURE IN THE ATMOSPHERE; FEWER CLOUDS AND LESS RAIN.

PARADISE BECAME HELL.

AS RIVERS DRIED UP, FORESTS DISAPPEARED, AND GRASSLAND TURNED TO DESERT.

AUSTRALIA'S GIANT BEASTS WENT EXTINCT.

HUMANS, TOO, BECAME AN ENDANGERED SPECIES HERE.

ACCORDING TO THE GENETICS, 60% OF THE AUSTRALIAN POPULATION DIED OFF DURING THE ICE AGE.

FOOD AND WATER WERE NOW AT A PREMIUM.

HAWKS: AS THE CLIMATE STARTS TO CHANGE AND THE CENTER OF AUSTRALIA'S BECOMING MORE ARID, THEY HAVE TO SEEK OUT RESOURCES THAT ARE HARDER FOR THEM TO GET.

IT TAKES MORE SPECIALIZED KNOWLEDGE FOR THEM TO FIND THE RESOURCES THAT THEY NEED.

NARRATOR: AT LAKE MUNGO, THERE'S ARCHAEOLOGICAL EVIDENCE FOR THE RESOURCEFULNESS OF ICE-AGE AUSTRALIANS.

NARRATOR: AS PEOPLE TRAVELED FURTHER IN SEARCH OF FOOD, THE POPULATION SPLIT INTO SMALLER GROUPS, CUT OFF FROM HUMANITY AND CUT OFF FROM EACH OTHER.

HAWKS: AUSTRALIA WAS A TREMENDOUSLY CHALLENGING ENVIRONMENT.

HUMANS HAD TO USE ALL OF THEIR ADAPTABILITY TO MAKE IT THERE.

BUT AUSTRALIA PROVIDED ANOTHER CHALLENGE THAT THEY COULDN'T ADAPT THEIR WAY OUT OF-- IT'S TREMENDOUSLY ISOLATED.

HAWKS: THERE WAS VERY LITTLE, IF ANY, CONTACT WITH THE REST OF THE WORLD.

THEY WERE REALLY IN IT BY THEMSELVES.

NARRATOR: A POPULATION THAT'S TOO ISOLATED FACES EXTINCTION.

WITHOUT NEW GENES, THE GENE POOL DRIES UP.

PEOPLE BECOME PRONE TO THE DANGERS OF INBREEDING.

EVENTUALLY, THEY DIE OFF.

TODAY, ONE OF AUSTRALIA'S BEST-KNOWN ANIMALS IS IN A SIMILAR SITUATION.

MAN: CAREFUL WHEN YOU JUMP IN THE WATER.

NARRATOR: ECOLOGIST JOSH GRIFFITHS IS TRYING TO CATCH A DUCK-BILLED PLATYPUS AND TAKE A SAMPLE OF ITS DNA.

PLATYPUSES ARE FOUND ONLY IN THE CREEKS OF EASTERN AUSTRALIA.

BUT NOW, THEIR EXISTENCE IS THREATENED BY A SERIES OF WEIRS THAT HAVE BEEN BUILT ACROSS THE RIVER SYSTEM.

GRIFFITHS: IF YOU THINK OF THE CREEK LIKE A ROAD, IT'S LIKE PUTTING A ROAD BLOCK THERE THAT ANIMALS CAN'T GO PAST.

IT FRAGMENTS THE POPULATION BELOW AND ABOVE THE WEIR, AND THAT STOPS ANIMALS MIGRATING, IT STOPS THE FLOW OF GENES ACROSS THOSE POPULATIONS.

SO THEY'LL LOSE GENETIC DIVERSITY, WHICH IMPACTS THEIR ABILITY TO ADAPT IN THE FUTURE.

NARRATOR: PLATYPUSES COME OUT AT NIGHT TO FEED ON THE CREEK'S INSECT LIFE.

THIS IS THE BEST TIME TO CATCH ONE AND RUN A GENETIC TEST.

GRIFFITHS: THERE'S MOVEMENT.

WE'VE GOT SOMETHING.

THERE HE IS.

HERE SHE IS-- ONE OF THE MOST AMAZING CREATURES ON THE PLANET, THE, UH, THE PLATYPUS.

YOU CAN SEE THE ICONIC DUCK-BILL THAT THEY'RE WELL-RECOGNIZED FOR.

WE'RE JUST GONNA TAKE HER WEIGHT AND A FEW BODY MEASUREMENTS AND, UH, TAKE A LITTLE DNA SAMPLE FOR OUR, UM, OUR SURVEY INVESTIGATIONS.

SHH, SHH, SHH, SHH, SHH.

OK. WHAT I'LL DO IS I'LL GET YOU TO RECORD THE DATA FOR ME AS WELL.

LOOK THERE.

NARRATOR: FOR PLATYPUSES TO THRIVE, THEIR GENE POOL NEEDS TO BE AS VARIED AS POSSIBLE, JUST LIKE HUMANS.

ISOLATED FROM EACH OTHER, THEY'RE IN TROUBLE.

GRIFFITHS: INSTEAD OF HAVING THIS NICE, CONNECTED, LARGE POPULATION OF PLATYPUSES, WE END UP WITH THESE SMALL, ISOLATED ONES.

NOT ONLY ARE--ARE THE SMALL ONES MORE VULNERABLE TO EXTINCTION, BUT THEY CAN ALSO, UH, END UP WITH GENETIC PROBLEMS.

THERE CAN BE PROBLEMS WITH INBREEDING BECAUSE THEY'VE, UH, YOU KNOW, GOT TO THEN BREED WITH RELATED INDIVIDUALS.

NARRATOR: A SMALL PIECE OF SKIN IS ALL THAT'S NEEDED TO ANALYZE THIS ANIMAL'S DNA AND COMPARE IT TO THAT OF OTHER PLATYPUSES IN THE SAME AREA.

GRIFFITHS: THAT'S HER ALL DONE.

LET'S GO PUT HER BACK IN THE WILD.

NARRATOR: IF DIVERSITY IS RUNNING LOW, GRIFFITHS AND HIS TEAM WILL INTRODUCE NEW PLATYPUSES FROM ANOTHER GROUP AND GIVE THE CREEK A GENETIC BOOST.

WHAT ABOUT EARLY AUSTRALIANS?

HOW DID THEY DEAL WITH THE SAME RISKS OF ISOLATION?

THE SECRET TO THEIR SUCCESS...

CONTACT.

THROUGHOUT THE ICE AGE, PEOPLE CONTINUED EXCHANGING BEADS, TOOLS, AND OCHRE ACROSS HUNDREDS OF MILES.

[SPEAKING] NARRATOR: THESE TRADING NETWORKS WERE A GENETIC LIFELINE.

HAWKS: AS PEOPLE SPLINTER INTO SMALL LITTLE GROUPS, EACH OF THOSE LITTLE GROUPS BECOMES GENETICALLY SOMEWHAT DIFFERENT FROM EACH OTHER.

[SPEAKING] HAWKS: THAT'S CREATING DIVERSITY.

BUT IN ORDER FOR THAT DIVERSITY TO SURVIVE, IT HAS TO BE TRANSMITTED FROM ONE GROUP TO ANOTHER, AND THAT TAKES CONNECTIONS.

HAWKS: THESE NETWORKS ARE SO IMPORTANT BECAUSE THEY'RE ALSO MATING NETWORKS.

[DISTANT CHANTING] WILLERSLEV: WHAT THEY DID WAS THAT THEY SPREAD OUT INTO SMALLER GROUPS THAT, TO A LARGE EXTENT, HAVE BEEN LIVING ISOLATED FROM EACH OTHER, BUT NOT COMPLETELY ISOLATED FROM EACH OTHER, SO THERE HAS BEEN GENETIC EXCHANGES BETWEEN THEM, YOU KNOW, MAKING SURE THAT YOU ARE GETTING FRESH BLOOD INTO YOUR POPULATION.

AND THAT IS REALLY THE RECIPE OF, UH, GENETIC SUCCESS OVER A LONG PERIOD OF TIME IN ISOLATION.

[ALL CHANTING] NARRATOR: WITHOUT REALIZING IT, THESE EARLY AUSTRALIANS FOUND A BALANCE BETWEEN BEING SEPARATE AND CONNECTED... AND THAT HELPED THEM FACE DOWN THE THREAT OF EXTINCTION.

NARRATOR: A SENSE OF CONNECTEDNESS IS STILL ENGRAINED WITHIN ABORIGINAL CULTURE.

NARRATOR: GALI YALKARRIWUY IS AN ELDER OF THE YOLNGU PEOPLE AND THE KEEPER OF THEIR CEREMONIAL KNOWLEDGE.

HE'S USING OCHRE TO PREPARE FOR THE ARRIVAL OF THE SPIRIT, BARNUMBIRR.

ACCORDING TO YOLNGU TRADITION, SHE CARRIED THE FIRST PEOPLE TO AUSTRALIA, FLYING ACROSS THE LAND, SINGING HER SONG.

BARNUMBIRR IS ALSO KNOWN AS THE MORNING STAR...

THE PLANET VENUS.

[GALI CHANTING] NARRATOR: GALI WILL DANCE ALL NIGHT UNTIL VENUS RISES, JUST BEFORE DAWN.

FOR THE YOLNGU PEOPLE, THIS SONG AND DANCE ARE A TYPE OF MAP...

CONTAINING INFORMATION ABOUT HUNTING SITES AND WATERING HOLES.

BUT THIS SONG DOESN'T BELONG ONLY TO THE YOLNGU.

THERE ARE VARIATIONS OF IT SUNG ACROSS AUSTRALIA, CONNECTING DIFFERENT TRIBES THROUGH A SHARED CULTURE.

NARRATOR: RITUALS LIKE THIS HAVE HELPED ABORIGINAL GROUPS COPE WITH THE IMPACT OF ISOLATION... AND ISOLATION HAS HELPED THE RITUAL SURVIVE.

WITHOUT AN INFLUX OF DIFFERENT PEOPLE WITH DIFFERENT IDEAS, THERE'S LESS PRESSURE FOR A CULTURE TO CHANGE...

SO THE SAME RITUALS GET PASSED DOWN THE GENERATIONS, INTACT AND UNALTERED.

THESE CONNECTIONS BETWEEN ABORIGINAL GROUPS ARE KNOWN AS SONGLINES.

NO ONE KNOWS HOW OLD THEY ARE, BUT THEY MAY DATE BACK TO THE ORIGINAL TRADING NETWORKS THAT HELPED PEOPLE SURVIVE THE ICE AGE.

FOR THOUSANDS OF YEARS, ABORIGINAL CULTURE FLOURISHED AND THE POPULATION BOOMED... UP TO A MILLION PEOPLE LIVING IN 300 DIFFERENT LANGUAGE GROUPS.

BUT IN 1606, EUROPEANS ARRIVED.

COLONIZATION WAS A DISASTER FOR ABORIGINAL PEOPLE.

THEIR LAND WAS TAKEN, THEIR FAMILIES WERE SEPARATED, AND THEIR CONNECTION TO THEIR ANCESTORS-- WHICH HAD BEEN SO FUNDAMENTAL-- WAS SEVERED.

BUT IT'S POSSIBLE THAT SCIENCE CAN NOW HELP THEM RECONNECT.

IN 2013, AN ANCIENT SKELETON WAS FOUND HERE, AT THE VERY BEACH WHERE EUROPEANS FIRST ARRIVED 400 YEARS AGO.

NARRATOR: THE FIND WAS SO POIGNANT, THE LOCAL TRIBE CALLED IN MIKE WESTAWAY TO ANALYZE THE BONES.

WESTAWAY: IN THE PAST, A LOT OF ABORIGINAL GROUPS WEREN'T SO HAPPY ABOUT THIS SORT OF RESEARCH; A LOT OF THE REMAINS HAD BEEN TAKEN WITHOUT THEIR PERMISSION OR CONSENT.

BUT THINGS ARE CHANGING AND, IN THIS INSTANCE, THE ABORIGINAL COMMUNITY WANTED TO KNOW MORE ABOUT THE ANCIENT REMAINS; THEY WANTED TO KNOW ABOUT THE, UM, THE AGE, HOW OLD THIS PERSON WAS, UH, WHEN DID THEY LIVE, WHAT SEX WERE THEY, AND ANYTHING ELSE THEY COULD FIND OUT.

NARRATOR: THE EXCAVATION OF THE SKELETON HAPPENED AS A CYCLONE WAS HEADING FOR NORTHERN AUSTRALIA.

WESTAWAY AND HIS TEAM HAD TO BATTLE THE ELEMENTS AND RESCUE AS MANY BONES AS QUICKLY AS POSSIBLE.

THE MOST IMPORTANT FIND WAS THE SKULL.

WESTAWAY: THE INITIAL DISCOVERY OF THE REMAINS REVEALED A FAIRLY COMPLETE INDIVIDUAL AND COULD SEE THAT THE SKULL WAS ACTUALLY QUITE LIGHTLY BUILT.

THE BROW RIDGES WERE VERY FINE, NOT HEAVILY BUILT, UH, AND GENERALLY THE--THE OVERALL ANATOMY OF THE SKULL INDICATED THE REMAINS ARE FROM A WOMAN, PROBABLY IN HER EARLY 30s.

NARRATOR: BY CARBON-DATING SHELLS IN THE SEDIMENT, THEY WERE ABLE TO WORK OUT THE AGE OF THE SKELETON.

IT IS 3 1/2 THOUSAND YEARS OLD.

THE LAND HERE IS OWNED BY THE FAMILY OF THOMAS WALES.

WESTAWAY: IT'S LIKE A CONCRETE PLATFORM HERE, THOMAS.

WALES: YEAH.

NARRATOR: HE'S BEEN CLOSELY INVOLVED IN THE EXCAVATION WORK SINCE IT BEGAN.

WALES: WE WERE LUCKY WHEN WE CAME OUT.

A WEEK AFTER WE EXCAVATED THE REMAINS, A CYCLONE CAME ALONG AND...DEMOLISHED SOME OF THIS BEACH DOWN BELOW.

WALES: WE WOULD HAVE LOST THE SKELETON.

WE WOULD HAVE LOST A PERSON.

SO WE CAME OUT HERE JUST IN TIME.

AND SHE'S IN, YOU KNOW, MUCH SAFER PLACE NOW, BEHIND ME IN THE BUSHES THERE.

NARRATOR: THE BONES WERE REBURIED, ACCORDING TO TRIBAL CUSTOM.

BUT NOT BEFORE A FEW FRAGMENTS WERE REMOVED AND SENT AWAY FOR GENETIC TESTING.

WESTAWAY: WE'RE TRYING TO GET ANCIENT DNA FROM ONE OF THE ROOTS OF THE TEETH.

THE INITIAL SIGNS ARE QUITE POSITIVE.

IF WE'RE ABLE TO RECOVER THE GENOME, OR THE FULL GENOME, IT WILL GIVE US A REALLY IMPORTANT INSIGHT INTO UNDERSTANDING POPULATION HISTORY TO THIS PART OF AUSTRALIA.

NARRATOR: THE WORK IS OVERSEEN BY ESKE WILLERSLEV, THE DANISH GENETICIST WHO SEQUENCED THE FIRST ABORIGINAL GENOME FROM A SAMPLE OF HAIR.

THE DNA FROM DUYFKEN POINT IS MORE THAN 3,000 YEARS OLDER AND MUCH HARDER TO READ.

BUT BECAUSE IT'S SO OLD, IT CAN PROVIDE MORE DETAIL ABOUT THE INTERCONNECTEDNESS OF EARLY AUSTRALIANS.

WILLERSLEV: WE WANT TO BUILD UP A MUCH MORE COMPLETE PICTURE OF HOW WAS AUSTRALIA POPULATED: HOW QUICKLY DID THEY SPREAD THROUGH THE CONTINENT AND HOW OFTEN DID THEY MEET; HOW MOBILE WERE THEY; HOW MANY PEOPLE CAME IN-- ALL THESE QUESTIONS, YOU KNOW, THAT STILL REMAIN UNANSWERED.

WALES: MOST OF US ABORIGINAL PEOPLE IN AUSTRALIA HAVE BEEN DISCONNECTED FROM THEIR ANCESTRY AND THEIR ROOTS BECAUSE OF COLONIZATION.

AND SOME OF US HAVE LOST THEIR... OUR WAY A LITTLE BIT.

WITH MODERN-DAY SCIENCE, WE CAN FIND OUT A BIT MORE ABOUT THAT PERSON.

THEN THEY CAN SEE HOW, MAYBE, CLOSE ME AND THE ANCIENT SKELETON ARE.

THAT'LL BE GOOD TO FIND OUT THEN.

NARRATOR: FOR ABORIGINAL PEOPLE TO DISCOVER HOW THEY'RE RELATED TO THE WOMAN ON THE BEACH, THEY NEED TO HAND OVER SOME DNA.

IF YOU CAN SPIT IN THIS TUBE AND THEN SEAL IT UP, THAT WILL GIVE US A SAMPLE.

NARRATOR: UNTIL RECENTLY, MOST OF THEM REFUSED TO DO THIS BECAUSE THEY DIDN'T TRUST THE SCIENTISTS.

THAT ENOUGH OR MORE?

NARRATOR: BUT THERE'S BEEN A CHANGE OF HEART SINCE THE SEQUENCING OF THE FIRST ABORIGINAL GENOME.

WILLERSLEV: FOR MANY OF THESE COMMUNITIES, THEY HAVE LOST THE MAJORITY OF THEIR CULTURE AND THEIR ORIGIN STORIES, AND THEY ARE INTERESTED IN GAINING INFORMATION ABOUT THEIR OWN PAST, AND ONE OF THE WAYS TO, YOU CAN SAY, REGAIN SOME OF THIS INFORMATION IS THROUGH, YOU KNOW, SCIENCE AND--AND GENETIC WORK.

NARRATOR: ALL DNA SAMPLES END UP HERE-- IN A FRIDGE IN DENMARK.

WILLERSLEV: THIS IS SAMPLES OF LIVING ABORIGINAL AUSTRALIANS-- I MEAN SPIT SAMPLES--AND IN HERE IS ALSO THE SAMPLE OF THOMAS.

AND, UH, IT'S SO USEFUL, THE MODERN SAMPLES, BECAUSE IF YOU COMPARE IT WITH THE ANCIENT SAMPLES, YOU CAN GET AN IDEA ABOUT HOW PEOPLE WERE MOVING AROUND IN THE LANDSCAPE THROUGH TIME AND ALSO HOW ISOLATED THEY WERE.

SO IF WE COMPARE THOMAS' DNA TO THE SKELETON FOUND IN THE SAME AREA, BEING 3,000 YEARS OLD, WE CAN DETERMINE WHETHER IT'S THE SAME PEOPLE OR NOT THAT HAS STAYED IN THE SAME AREA DURING THAT TIME SPAN.

SO IT'S REALLY THE COMBINATION OF THE MODERN GENOMES AND THE ANCIENT GENOMES THAT GIVES YOU THE POWER TO, UH, UNCOVER THE PAST.

NARRATOR: THE GENETIC STORY OF AUSTRALIA HAS ONLY STARTED TO BE TOLD.

WHEN THE WORK IS DONE, ABORIGINAL AUSTRALIANS WILL KNOW HOW CLOSELY RELATED THEY ARE TO THOSE THAT HAVE COME BEFORE.

BUT IT'S ALREADY CLEAR THEIR DNA IS UNIQUE...

ANCIENT, YET UNDILUTED.

WHILE THE REST OF HUMANITY WAS MIXING GENES, AUSTRALIANS STAYED IN SPLENDID ISOLATION.

IN THEORY, THEY SHOULD HAVE GONE EXTINCT, A HUMAN MIGRATION THAT REACHED A DEAD END.

THEIR SURVIVAL WASN'T DUE TO ANY SPECIAL TECHNOLOGY.

IT WAS THEIR ABILITY TO CONNECT WITH EACH OTHER, BUILDING NETWORKS ACROSS A CONTINENT.

[GONG DINGS] WHAT WAS TRUE THEN IS TRUE NOW.

WE ARE SOCIAL BEINGS.

WE SEEK OUT OTHERS AND FIND COMMON CAUSE.

IT'S WHAT MAKES US HUMAN AND HAS BROUGHT US SO FAR.

"FIRST PEOPLES" IS AVAILABLE ON DVD.

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