0:00:03 > 0:00:04THUNDER CRACKS
0:00:17 > 0:00:19In the darkest hours of a winter night...
0:00:21 > 0:00:25..in a forested corner of southeastern Australia...
0:00:28 > 0:00:32..I'm on a mission to find an extraordinary creature.
0:00:35 > 0:00:41It's a bizarre animal, and one that few people have seen in the flesh.
0:00:41 > 0:00:45And it can help us unravel the mysterious history of Australia,
0:00:45 > 0:00:50perhaps the most surprising of all the continents.
0:00:50 > 0:00:53Australia is famous for its odd and unusual animals,
0:00:53 > 0:00:55but the one that I'm hoping to see tonight
0:00:55 > 0:00:58has got to be the strangest on the planet.
0:00:58 > 0:01:02This is a...is an ancient survivor,
0:01:02 > 0:01:07the rarest of beasts that goes back 160 million years to a lost world.
0:01:09 > 0:01:12A lost world, not only full of strange creatures...
0:01:13 > 0:01:17..but also a world where the shape and character of our continents
0:01:17 > 0:01:19was utterly different.
0:01:22 > 0:01:24This is the way to see rocks!
0:01:24 > 0:01:30I want to reach back in time using the clues that are hidden all around us...
0:01:30 > 0:01:33You don't get much clearer evidence than that.
0:01:34 > 0:01:35..in living creatures...
0:01:35 > 0:01:39There's one. Can you see that, just over there?
0:01:39 > 0:01:42..in landscapes...
0:01:43 > 0:01:45..and written into the rocks.
0:01:46 > 0:01:50The tiniest detail can reveal the history of a vast continent.
0:01:55 > 0:01:58I'm going to piece together these clues
0:01:58 > 0:02:01to uncover key moments in Australia's history...
0:02:04 > 0:02:06..and find out how Australia's journey
0:02:06 > 0:02:12has created the conditions that allowed people to settle this harsh land
0:02:12 > 0:02:15and shaped the lives of those who followed,
0:02:15 > 0:02:21but also how that journey continues to affect the destiny of people
0:02:21 > 0:02:25far beyond the shores of this island continent.
0:02:43 > 0:02:46I've come to the Yarra Valley in the state of Victoria
0:02:46 > 0:02:49to search for the creature that takes us back
0:02:49 > 0:02:52to the beginning of Australia's geological story.
0:02:54 > 0:02:56It is a legendary creature.
0:02:56 > 0:03:01I mean, it's described as venomous, egg-laying, duck-billed,
0:03:01 > 0:03:06beaver-tailed, otter-footed, mole-furred.
0:03:06 > 0:03:10Plus, it's odd, it lactates, but it's got no nipples.
0:03:10 > 0:03:12I mean, the lactating business means it is a mammal,
0:03:12 > 0:03:16but the egg-laying, that's much more like a reptile.
0:03:16 > 0:03:19It's a... It's an odd fusion of animal.
0:03:22 > 0:03:27I'm here with Josh Griffiths, a biologist who does regular surveys...
0:03:27 > 0:03:29So, have you caught them here before?
0:03:29 > 0:03:31Yeah, I've caught some just upstream here before.
0:03:31 > 0:03:34..to check on the welfare of these unusual animals.
0:03:34 > 0:03:39Just need to stretch this out and tie it up to the bank so it's nice and secure.
0:03:45 > 0:03:49This creature, which links back to Australia's past,
0:03:49 > 0:03:53lives today only in the wetter forested parts of the continent
0:03:53 > 0:03:55but it's hard to track down,
0:03:55 > 0:03:58because it leaves almost no detectable trace.
0:03:58 > 0:04:02So, we could be in for a very long night.
0:04:02 > 0:04:05Do you think they can see us? Do you think they're laughing?
0:04:12 > 0:04:17Finally, after seven hours, I get my first glimpse of an animal that few people
0:04:17 > 0:04:20have ever seen in the wild - a platypus.
0:04:20 > 0:04:22Oh, my gosh. That's incredible.
0:04:22 > 0:04:25This is what we've been waiting for. It's a male, is it?
0:04:25 > 0:04:27Yeah, it's a male. It's an adult one.
0:04:27 > 0:04:31Can I see his face? Can I see that classic, classic face?
0:04:31 > 0:04:36Three in the morning it is. You kept us up till three in the bloomin' morning.
0:04:36 > 0:04:39But isn't that worth the wait? Ah, no, absolutely.
0:04:39 > 0:04:40Can I stroke...? Yeah.
0:04:40 > 0:04:43He's perfectly happy, is he? Lovely.
0:04:43 > 0:04:46I mean, the fur is very mammalian.
0:04:46 > 0:04:48The fur's definitely mammal,
0:04:48 > 0:04:50and the way that they regulate their temperature.
0:04:50 > 0:04:52Right. Their eyes are quite reptilian,
0:04:52 > 0:04:55and the way their legs are splayed out to the side is like a lizard.
0:04:56 > 0:04:59This strange mix exists in the platypus
0:04:59 > 0:05:04because it's a link back to a world 160 million years ago.
0:05:04 > 0:05:11A time when our mammal ancestors were just beginning to evolve from early reptiles.
0:05:11 > 0:05:14Millions of years ago, we all would have shared a common ancestor,
0:05:14 > 0:05:16and it would have been very reptilian,
0:05:16 > 0:05:18and it would have looked a lot more like a platypus
0:05:18 > 0:05:20than it would look like you or me.
0:05:20 > 0:05:24I have to say, it's hard to imagine that we've got a common ancestor.
0:05:24 > 0:05:26It just looks so different from us.
0:05:26 > 0:05:29It certainly does now, but millions of years ago
0:05:29 > 0:05:31we all would have looked much the same.
0:05:38 > 0:05:41While the platypus survives in the backwaters of Australia,
0:05:41 > 0:05:44the common ancestor is long gone.
0:05:47 > 0:05:50All that's left are tiny fossil fragments
0:05:50 > 0:05:53that reveal creatures from that long lost world.
0:05:57 > 0:06:03The animal that gave rise to the platypus and to all of the mammals we see today
0:06:03 > 0:06:05might well have looked something like this.
0:06:08 > 0:06:12Crucially, their remains have been found across the globe.
0:06:14 > 0:06:17These creatures were living all over the place.
0:06:19 > 0:06:23And that suggests something highly intriguing.
0:06:23 > 0:06:26Just as all life has a common ancestor,
0:06:26 > 0:06:29so too does the land that we're standing on.
0:06:31 > 0:06:35To imagine that time, you've got to try to undo the shape and position
0:06:35 > 0:06:38of each continent that's been imprinted in your brain
0:06:38 > 0:06:42by every atlas and world map you've ever seen.
0:06:45 > 0:06:48If you turn back the clock through geological time...
0:06:50 > 0:06:54..you see Australia was once part of a huge landmass...
0:06:56 > 0:07:00..in which most of today's continents were joined...
0:07:02 > 0:07:05..and over which the platypus' ancestors roamed.
0:07:18 > 0:07:21It's hard to imagine what this ancient world looked like,
0:07:21 > 0:07:23and how our modern continents were arranged within it.
0:07:26 > 0:07:29But there are clues if you know where to look.
0:07:29 > 0:07:34And the first one comes from the substance that has helped to make modern Australia
0:07:34 > 0:07:36one of the wealthiest nations on the planet.
0:07:37 > 0:07:40This black layer that I've been following here is coal.
0:07:40 > 0:07:44This is a natural layer that's been exposed by the waves.
0:07:47 > 0:07:49Just a few miles away, though,
0:07:49 > 0:07:53there's vast diggers pulling this stuff out of the ground.
0:07:57 > 0:08:03Around one million tonnes of coal are exhumed from this land each and every day.
0:08:07 > 0:08:12But it has another value that goes beyond the financial.
0:08:13 > 0:08:18What I'm looking for is a fossil that's in here.
0:08:18 > 0:08:20There's a nice one, see that, just here.
0:08:22 > 0:08:25That's a little fragment. That's a nice one too.
0:08:26 > 0:08:30These fossils contain evidence of Australia's past
0:08:30 > 0:08:32and that of the whole southern hemisphere.
0:08:33 > 0:08:35But their importance was brought home
0:08:35 > 0:08:40only when almost identical fossils were found on a famous expedition
0:08:40 > 0:08:42to another continent entirely.
0:08:48 > 0:08:54On the 1st of November 1911, Robert Falcon Scott and his team
0:08:54 > 0:08:56set out across Antarctica
0:08:56 > 0:09:00on their ill-fated attempt to be the first to the South Pole.
0:09:01 > 0:09:07Their final days, in March 1912, are now legendary.
0:09:07 > 0:09:13Suffering frostbite, snow-blindness and malnutrition,
0:09:13 > 0:09:15they were only 11 miles from a supply base
0:09:15 > 0:09:20when a fierce blizzard hit and trapped them for ten days.
0:09:20 > 0:09:22Their last.
0:09:28 > 0:09:32Almost eight months later, when their frozen bodies were found,
0:09:32 > 0:09:35something extraordinary was laid out beside them.
0:09:38 > 0:09:4116 kilograms of fossils.
0:09:43 > 0:09:47Clearly Scott thought they were valuable. And he was right.
0:09:49 > 0:09:53They would help define the boundaries of the landmass in which Australia sat
0:09:53 > 0:09:57and the nature of the landscape that covered it.
0:09:59 > 0:10:04What I'm really looking for in these rocks is that exact same fossil that Scott found
0:10:04 > 0:10:06in Antarctica.
0:10:16 > 0:10:20For all those that think rocks are boring, look at this.
0:10:20 > 0:10:21Look, it's just beautiful.
0:10:22 > 0:10:26It just feels as though it was created yesterday.
0:10:27 > 0:10:30From these fossils
0:10:30 > 0:10:34I can find the type of vegetation that once covered Australia.
0:10:39 > 0:10:44Glossopteris, lost forests, fossils found in Antarctica.
0:10:47 > 0:10:50Just packed full of plant debris.
0:10:50 > 0:10:54These are leaves of a tree called glossopteris
0:10:54 > 0:10:58which formed 255 million years ago,
0:10:58 > 0:11:03and that means that 255 million years ago, this part of Australia was lush forest.
0:11:05 > 0:11:10It was these glossopteris forests that transformed over time
0:11:10 > 0:11:13into Australia's enormous coal reserves.
0:11:13 > 0:11:17And that's why the fossils are found inside them.
0:11:17 > 0:11:21But more importantly, because the exact same fossil was found in Antarctica,
0:11:21 > 0:11:23it means that Antarctica was also lush forest.
0:11:23 > 0:11:25But that's not all.
0:11:25 > 0:11:31Glossopteris fossils from elsewhere also reveal the extent of the landmass.
0:11:31 > 0:11:34In fact, glossopteris is found right across the southern hemisphere.
0:11:34 > 0:11:36It's found in southern Africa, it's found in South America.
0:11:38 > 0:11:40Thing is, the spores of these glossopteris
0:11:40 > 0:11:43just couldn't be transported across vast oceans.
0:11:43 > 0:11:48In other words, all those land masses must have been together.
0:11:51 > 0:11:55Glossopteris has helped reveal the arrangement of all the continents
0:11:55 > 0:11:58in the southern hemisphere at the time.
0:11:58 > 0:12:01Not only was Australia linked to Antarctica...
0:12:07 > 0:12:13..but also to Africa, India and South America.
0:12:13 > 0:12:17This vast landmass was called Gondwana,
0:12:17 > 0:12:21a supercontinent which was the southern half of the even larger landmass
0:12:21 > 0:12:23of Pangaea.
0:12:26 > 0:12:31The primeval land of Gondwana was on an almost mythic scale.
0:12:33 > 0:12:37It was carpeted with glossopteris trees.
0:12:37 > 0:12:42A forest more than four times the size of the Amazon Basin,
0:12:42 > 0:12:44stretching further than any eye could see.
0:12:55 > 0:13:00A tiny fraction of Gondwana's forest still remains today
0:13:00 > 0:13:04in a cool pocket of New South Wales
0:13:04 > 0:13:05in eastern Australia.
0:13:14 > 0:13:17It's quite an eerie sensation, really,
0:13:17 > 0:13:21to just be amongst these giant ferns and things.
0:13:21 > 0:13:25You know, you spend all this time studying rocks and fossils in the laboratory,
0:13:25 > 0:13:29trying to piece together the Gondwana forest, and here it is!
0:13:29 > 0:13:32Here it is, just all laid out for us.
0:13:32 > 0:13:35I've been dumped into the heart of Gondwana.
0:13:39 > 0:13:45This tiny remnant stands for a great phase in this continent's history.
0:13:48 > 0:13:54Australia was green and lush for over 300 million years.
0:13:57 > 0:14:00Enduring through the reign of the dinosaurs
0:14:00 > 0:14:03as well as the rise of the mammals.
0:14:06 > 0:14:10Gondwana was so huge that it was destined to break up.
0:14:10 > 0:14:14And it was that break-up that created the character of Australia.
0:14:20 > 0:14:25The mighty supercontinent of Gondwana and its fairytale forests
0:14:25 > 0:14:28would soon be lost for ever.
0:14:28 > 0:14:32A great change was about to come across this land,
0:14:32 > 0:14:37an event that would transform Australia into the continent we know today.
0:14:39 > 0:14:41To piece together what happened,
0:14:41 > 0:14:44you need to travel deep into this continent's red heart.
0:15:22 > 0:15:26The interior of Australia today couldn't be more different.
0:15:29 > 0:15:32A vast, empty expanse.
0:15:32 > 0:15:36Thousands of kilometres of burning, barren earth.
0:15:38 > 0:15:43But as you fly deeper into the interior, there's an odd sight.
0:15:43 > 0:15:46Strange white pock-marks across the surface,
0:15:46 > 0:15:48hundreds of thousands of them.
0:15:50 > 0:15:55Each pock is an entrance to a hidden world beneath the scorched surface.
0:15:55 > 0:15:58And down there is where I'll find evidence of what happened
0:15:58 > 0:16:00when Gondwana broke up.
0:16:12 > 0:16:16This is the unusual country town of Coober Pedy.
0:16:22 > 0:16:26Unusual because the 3,000 people who live here
0:16:26 > 0:16:28mostly live underground.
0:16:36 > 0:16:39Houses, restaurants, hotels, churches.
0:16:39 > 0:16:42There's even a subterranean bookshop.
0:16:52 > 0:16:57The people here have dug out these caves to escape the desert heat.
0:17:07 > 0:17:11You know, at first, the idea of people living underground,
0:17:11 > 0:17:12modern-day troglodytes,
0:17:12 > 0:17:16just seems bizarre, really, and there's definitely odd things here,
0:17:16 > 0:17:19but actually, it mainly makes sense.
0:17:19 > 0:17:23It's not claustrophobic, it's cool and it's airy.
0:17:23 > 0:17:28And for a geologist like me, to be surrounded by rocks,
0:17:28 > 0:17:29just ideal.
0:17:33 > 0:17:36The reason the townsfolk go to such lengths
0:17:36 > 0:17:38is because this rock contains a treasure,
0:17:38 > 0:17:42one of the most precious jewels on the planet.
0:17:42 > 0:17:44For them it provides a livelihood.
0:17:46 > 0:17:50For me, it's a crucial clue to how this land changed
0:17:50 > 0:17:53when Gondwana broke up.
0:18:00 > 0:18:03And I'm on my way to see what everyone's digging for
0:18:03 > 0:18:05with straight-talking miner Kevin Swain.
0:18:09 > 0:18:12So this is it? Yep, this is it. No doubt.
0:18:12 > 0:18:14So, lift this over. Yep.
0:18:14 > 0:18:16Step through it.
0:18:16 > 0:18:20Yep, lift it a bit. Down.
0:18:20 > 0:18:24It's quite smooth. I like this. Sit square.
0:18:24 > 0:18:25Liking it less now.
0:18:25 > 0:18:28There's no-one to answer you. Stop talking to yourself.
0:18:28 > 0:18:29HE LAUGHS
0:18:36 > 0:18:41This is Kevin's patch for mining, one of thousands around Coober Pedy.
0:18:43 > 0:18:48A 22-metre shaft that takes me into a warren of tunnels.
0:18:50 > 0:18:52Oh, ho! Stop!
0:18:59 > 0:19:04Kevin spends every day down here, alone, digging for one thing.
0:19:05 > 0:19:09It's like a knife through butter. Very soft.
0:19:10 > 0:19:11Where's the valuable rock here, then?
0:19:11 > 0:19:15Well, right up there by the light, you can see it.
0:19:15 > 0:19:19There's, er... That kind of opaque, kind of...?
0:19:19 > 0:19:23Yeah. That's good quality stuff, that, there, yeah. Yeah. Yeah.
0:19:23 > 0:19:25It's opal.
0:19:25 > 0:19:30A precious gemstone that, at best quality, has more value than diamond.
0:19:33 > 0:19:35That's a good enough reason for miners to work here
0:19:35 > 0:19:38in these solitary subterranean conditions.
0:19:40 > 0:19:43This is no place for big mining companies
0:19:43 > 0:19:46because of the very small seams in which opal occurs.
0:19:48 > 0:19:50And how often do you strike lucky, hit a rich seam?
0:19:50 > 0:19:52Rarely.
0:19:52 > 0:19:54Does that mean five years, ten years, one year?
0:19:54 > 0:19:56No, it's unpredictable.
0:19:56 > 0:19:58If you work steadily at it... Yeah.
0:19:58 > 0:20:00..you get...you'll cover your expenses
0:20:00 > 0:20:03and every now and then, you have a surprise comes along.
0:20:03 > 0:20:07So, every time you come to work, are you hoping for that big find?
0:20:07 > 0:20:11Yeah. You wouldn't come to work if you didn't. Yeah.
0:20:11 > 0:20:14Pick's always sharp, bucket's always empty.
0:20:21 > 0:20:23Opals are extraordinary.
0:20:23 > 0:20:26The highly specific conditions in which they form
0:20:26 > 0:20:29have occurred only rarely in the history of our planet,
0:20:29 > 0:20:32and then, mainly here in the Australian outback.
0:20:36 > 0:20:39But they've also occurred somewhere strangely similar to here -
0:20:39 > 0:20:41the planet Mars.
0:20:41 > 0:20:45These distant places share a similar chemistry in their red rocky deserts.
0:20:47 > 0:20:49In Australia, opals only occur
0:20:49 > 0:20:53because of what happened during the demise of Gondwana.
0:20:53 > 0:20:54Ah, now, there's a bit.
0:20:55 > 0:21:00And I can figure out those ancient events by examining these gemstones.
0:21:02 > 0:21:04Silica.
0:21:04 > 0:21:06Sulphuric acid.
0:21:09 > 0:21:10Bacteria.
0:21:10 > 0:21:12An inland sea.
0:21:16 > 0:21:21What I love about opal is it forms through this peculiar set of conditions.
0:21:21 > 0:21:24You need two raw ingredients for it. One of them is silica...
0:21:26 > 0:21:28..and the other's acid.
0:21:29 > 0:21:31Now, the silica's pretty simple,
0:21:31 > 0:21:34it comes from minerals in the rock around here.
0:21:34 > 0:21:39But for the acid, you need a really strong acid like sulphuric acid,
0:21:39 > 0:21:41and the sulphur for that comes from bacteria
0:21:41 > 0:21:43that eat sulphur when oxygen's not around.
0:21:45 > 0:21:49Bacteria that live in the mud at the bottom of a stagnant sea.
0:21:51 > 0:21:54To turn that sulphur into sulphuric acid,
0:21:54 > 0:21:56you essentially need to put oxygen into it.
0:21:56 > 0:22:00So, you need to take the sea away, exposing it to the air.
0:22:02 > 0:22:05So, now you've got sulphuric acid, and what that does is,
0:22:05 > 0:22:10it just leaches its way through the rock, picking up the silica
0:22:10 > 0:22:13and concentrating it into these narrow bands.
0:22:15 > 0:22:18What all that complicated chemistry tells us
0:22:18 > 0:22:22is that there used to be an inland sea here,
0:22:22 > 0:22:25but actually, down here, in a few places,
0:22:25 > 0:22:28the opal's preserved far more obvious evidence of that sea.
0:22:29 > 0:22:31Now, look at that - sea shells.
0:22:31 > 0:22:34You don't get much clearer evidence than that.
0:22:45 > 0:22:48It's hard to imagine now,
0:22:48 > 0:22:51but here in the dry, dusty interior of Australia,
0:22:51 > 0:22:55there existed, for just a while, an inland sea.
0:23:00 > 0:23:04This sea was created by an event of epic proportions -
0:23:04 > 0:23:07the break-up of Gondwana.
0:23:11 > 0:23:14Around 180 million years ago,
0:23:14 > 0:23:18huge upwellings of hot rock began to rise from the mantle,
0:23:18 > 0:23:20deep below the Earth's crust.
0:23:20 > 0:23:23These plumes wore away at weak spots in that crust...
0:23:25 > 0:23:31..until finally, 150 million years ago, they gave way.
0:23:31 > 0:23:34This was the beginning of the break-up of Gondwana.
0:23:41 > 0:23:43As the continents separated,
0:23:43 > 0:23:46new sea floor was created between them.
0:23:46 > 0:23:48This new material was hot,
0:23:48 > 0:23:52which made it expand and displace the seas above it.
0:23:57 > 0:24:00This was what caused global sea levels to rise
0:24:00 > 0:24:05so that water rushed into the flat centre of what would become Australia,
0:24:05 > 0:24:07creating the inland sea.
0:24:09 > 0:24:12And it lasted for over 35 million years.
0:24:16 > 0:24:18When it retreated, the sea left in its wake
0:24:18 > 0:24:21the specific conditions for the formation of opals.
0:24:23 > 0:24:28But the break-up of Gondwana also created something else extraordinary,
0:24:28 > 0:24:33something which would help people survive here millions of years later.
0:24:52 > 0:24:56The interior of Australia is harsh. Forbidding.
0:25:00 > 0:25:04When the Europeans first came here, over two centuries ago,
0:25:04 > 0:25:07they realised the key to settling this land
0:25:07 > 0:25:09was to find water.
0:25:12 > 0:25:16From the time the Europeans arrived in Australia, they had an obsession
0:25:16 > 0:25:21and that was to get in to the country's interior.
0:25:21 > 0:25:24They were absolutely convinced that somewhere in this vast landscape
0:25:24 > 0:25:27there had to be an inland sea.
0:25:27 > 0:25:30After all, all the other continents that they explored had one -
0:25:30 > 0:25:34the Great Lakes in the US, Caspian in Asia.
0:25:34 > 0:25:37Why should this place be any different?
0:25:42 > 0:25:47They were, of course, 100 million years too late to find Australia's inland sea.
0:25:50 > 0:25:52But they didn't know that
0:25:52 > 0:25:55and such was the importance of finding water
0:25:55 > 0:25:57that they kept on trying.
0:25:59 > 0:26:02From 1813, they launched a series of expeditions
0:26:02 > 0:26:06that aimed to chart rivers and find the inland sea.
0:26:09 > 0:26:15But time after time, the expeditions ended in failure and even death.
0:26:19 > 0:26:24The place names that they came up with gives you a sense of their desperation.
0:26:24 > 0:26:28There's Dismal Plain, Lake Disappointment, Mount Hopeless.
0:26:33 > 0:26:37But, of course, there was a people who had lived here for many thousands of years,
0:26:37 > 0:26:41and they knew a source of water that the Europeans didn't.
0:26:55 > 0:27:00These people had ways and means of finding that water in the desert.
0:27:02 > 0:27:04They saw it in the land.
0:27:06 > 0:27:08And they remembered it with the stars.
0:27:10 > 0:27:12And with their songs.
0:27:20 > 0:27:21..it's not difficult.
0:27:21 > 0:27:26Dean Ah Chee is an elder of the Lower Southern Arrernte people,
0:27:26 > 0:27:31and was schooled from earliest youth in the Aboriginal ways of finding water
0:27:31 > 0:27:32in this dry land.
0:27:32 > 0:27:34So, what is a songline?
0:27:47 > 0:27:49So, is it like a kind of...an aural map?
0:27:49 > 0:27:51Is it like a map of the landscape, but told?
0:27:51 > 0:27:53Right.
0:28:10 > 0:28:13And so do all the songlines relate to water?
0:28:19 > 0:28:23So, how far can you navigate on a songline? Is it...?
0:28:26 > 0:28:29So, how do you find it? Tell me the secrets!
0:28:35 > 0:28:37Ah!
0:28:37 > 0:28:38Right.
0:28:40 > 0:28:41Really? So, it's that important?
0:28:41 > 0:28:46It's that crucial that it's almost kept like a secret?
0:28:47 > 0:28:49Secret law.
0:28:59 > 0:29:00The Aboriginal people,
0:29:00 > 0:29:03for thousands of years, have used these songlines
0:29:03 > 0:29:07to lead them to a reliable source of water in the desert...
0:29:11 > 0:29:15..water that emerges from underground into what's called mound springs.
0:29:20 > 0:29:23So, is it cold or is it hot? It's hot water.
0:29:23 > 0:29:25It's hot? Yeah.
0:29:25 > 0:29:28Oh, it is! Ah-ha-ha! I tell you, it's the mud.
0:29:28 > 0:29:32Ah! That's a lovely temperature. No crocs, yeah?
0:29:32 > 0:29:34You sure?
0:29:36 > 0:29:38Whoa!
0:29:38 > 0:29:41Oh, that is lovely.
0:29:43 > 0:29:45Ah, yeah... Oh, yeah!
0:29:45 > 0:29:47I can feel... Look at this.
0:29:54 > 0:29:56What the Aboriginal people couldn't know
0:29:56 > 0:30:01was how their songlines, linking up one mound spring to another,
0:30:01 > 0:30:04echoed the geology below.
0:30:04 > 0:30:08Because deep in the ground, all these mound springs were linked,
0:30:08 > 0:30:11in a vast reservoir of water.
0:30:11 > 0:30:15What's really intriguing about these springs is just how many there are.
0:30:15 > 0:30:21In this area there's a handful, but across the region, there's something like 700.
0:30:21 > 0:30:22What's even more remarkable
0:30:22 > 0:30:26is that I'm swimming above this enormous reserve of water
0:30:26 > 0:30:28that's deep down there
0:30:28 > 0:30:32and extends beneath almost a quarter of Australia's land surface.
0:30:40 > 0:30:44This reserve is called the Great Artesian Basin
0:30:44 > 0:30:47and, incredibly, it holds enough water to fill
0:30:47 > 0:30:5126 billion Olympic-size swimming pools.
0:30:56 > 0:31:02It's a giant aquifer - porous rock under the ground which holds water -
0:31:02 > 0:31:06and a key part of it exists here thanks to the ancient inland sea.
0:31:11 > 0:31:14Even before Gondwana began to break up,
0:31:14 > 0:31:18the first element of the Great Artesian Basin was in place.
0:31:22 > 0:31:26Deep underground, there were layers of porous sandstone rock.
0:31:26 > 0:31:31But any water which got into that rock would quickly escape again
0:31:31 > 0:31:33because there was nothing to contain it.
0:31:38 > 0:31:41The inland sea brought, and left behind,
0:31:41 > 0:31:44the crucial ingredient needed to trap the water inside.
0:31:46 > 0:31:47Mud.
0:31:49 > 0:31:53The mud hardened into a lid of impermeable rock,
0:31:53 > 0:31:56which lay across the top of the sandstone.
0:31:56 > 0:31:58So, when rainwater fell,
0:31:58 > 0:32:02it could trickle around the edges of the lid and get into the sandstone,
0:32:02 > 0:32:08but, crucially, that same lid prevented the water from evaporating away.
0:32:15 > 0:32:20At a few places, where the lid's broken, the water escapes.
0:32:20 > 0:32:24These are the mound springs that have sustained the Aboriginal people
0:32:24 > 0:32:26for thousands of years.
0:32:26 > 0:32:31And because these springs provide the only reliable source of water
0:32:31 > 0:32:33for much of inland Australia,
0:32:33 > 0:32:37they're a vital lifeline for wildlife here,
0:32:37 > 0:32:42as well as the great sheep and cattle stations of the Australian outback.
0:32:45 > 0:32:50It's an extraordinary thought that the muddy remains of a long-lost sea
0:32:50 > 0:32:53still provide water that sustains life here today.
0:33:01 > 0:33:06By around 100 million years ago, Gondwana had broken apart
0:33:06 > 0:33:10but Australia still didn't exist as a separate continent.
0:33:11 > 0:33:14There was one big split yet to come.
0:33:17 > 0:33:18One that would transform Australia,
0:33:18 > 0:33:20and lead to the evolution
0:33:20 > 0:33:24of one of the most spectacular animals on the planet.
0:33:32 > 0:33:37This is the Great Australian Bight,
0:33:37 > 0:33:41over one thousand kilometres of coastline on the southern edge of Australia.
0:33:44 > 0:33:46It's just vast.
0:33:46 > 0:33:51The cliffs themselves are 80 metres high, falling away to the sea.
0:33:57 > 0:34:02If I'd been walking along here 90 million years ago, then...
0:34:02 > 0:34:06there would have been no cliff, there would have been no ocean.
0:34:06 > 0:34:11Instead, I would have been able to take a single step from here,
0:34:11 > 0:34:13directly onto Antarctica.
0:34:23 > 0:34:28This is how the coastline of Antarctica and Australia joined up.
0:34:28 > 0:34:32Despite the inevitable erosion, it's still a neat fit to this day.
0:34:39 > 0:34:42Although these two continents are now almost opposites,
0:34:42 > 0:34:46back then, the story was very different.
0:34:48 > 0:34:51They were effectively identical twins.
0:34:51 > 0:34:54Both, temperate, forested lands,
0:34:54 > 0:34:57which lay together near the South Pole.
0:35:00 > 0:35:04And, like all twins, they weren't easy to separate.
0:35:04 > 0:35:06Although Gondwana was gone,
0:35:06 > 0:35:11Australia and Antarctica stayed close together for many millions of years.
0:35:16 > 0:35:20But the process that transformed them into radically different lands
0:35:20 > 0:35:22also had another consequence -
0:35:22 > 0:35:27the evolution of the largest group of animals that ever lived on the planet.
0:35:31 > 0:35:33Those great Leviathans of the sea.
0:35:35 > 0:35:37The filter-feeding whales.
0:35:40 > 0:35:42I'm off looking for whales.
0:35:42 > 0:35:45It's the perfect weather, perfect time of year, August,
0:35:45 > 0:35:49which is breeding season, so hopefully, fingers crossed,
0:35:49 > 0:35:50we'll see some mums and calves.
0:36:00 > 0:36:03Helping me locate them is local guide Rod Keogh.
0:36:17 > 0:36:19Oh, there's one. Can you see that, just over there?
0:36:19 > 0:36:21The black in the water. A black strip.
0:36:21 > 0:36:24Oh, there's two. A fin to the side of it.
0:36:24 > 0:36:26Oh, look, look, look! Look at the face!
0:36:26 > 0:36:29Can you see that? Yeah! Yeah! It's great!
0:36:32 > 0:36:35Just encrusted with barnacles, just coming up.
0:36:37 > 0:36:39WHALE CALL
0:36:39 > 0:36:44Did you hear that? "Hooonnn." That's the sound of a whale.
0:36:45 > 0:36:48Oh! Look at that!
0:36:48 > 0:36:49That was incredible.
0:36:50 > 0:36:54That was one of the mothers flicking her tail. That's Scottie.
0:36:54 > 0:36:55Scottie from the Antarctic, is that it?
0:36:55 > 0:36:58Yeah. She was...
0:36:58 > 0:37:03She was named short for "S-cot no friends" cos she was always by herself.
0:37:03 > 0:37:06And now she's back, she's still got no friends.
0:37:06 > 0:37:09So, I still call her Scottie. That's great.
0:37:09 > 0:37:10Now she's got a calf.
0:37:10 > 0:37:12Oh, yeah, see that.
0:37:14 > 0:37:18These whales spend most of the year in Antarctica feeding
0:37:18 > 0:37:21but at this time of year, August,
0:37:21 > 0:37:25they journey over 2000 kilometres here to breed.
0:37:28 > 0:37:32These are southern rights, third largest whale species on the planet.
0:37:34 > 0:37:36You're only seeing about 10% of the animal.
0:37:36 > 0:37:38The bulk of it, 90%, is underneath.
0:37:38 > 0:37:42These whales can grow up to 15 metres in length.
0:37:42 > 0:37:45And they can reach such a size because of what they eat,
0:37:45 > 0:37:48scooping up two to three tonnes of food each day -
0:37:48 > 0:37:52millions and millions of miniscule krill.
0:37:55 > 0:37:58How these great animals came to survive on these tiny creatures
0:37:58 > 0:38:03is a direct consequence of Australia's geological history...
0:38:05 > 0:38:07..and its separation from Antarctica.
0:38:13 > 0:38:1590 million years ago,
0:38:15 > 0:38:19something happened to finally separate Australia from Antarctica.
0:38:22 > 0:38:25Volcanic activity from deep within the Earth's mantle
0:38:25 > 0:38:27forced up a new ocean crust between them,
0:38:27 > 0:38:31creating a mid-ocean ridge which broke them apart.
0:38:35 > 0:38:39Australia was, at last, a separate island continent.
0:38:44 > 0:38:48And that left Antarctica sitting all alone over the South Pole,
0:38:48 > 0:38:50still temperate and forested.
0:38:52 > 0:38:55That was, until the isolation of Antarctica
0:38:55 > 0:38:59created an unusual effect in the waters around it.
0:39:03 > 0:39:06Normally, the wind drives surface currents,
0:39:06 > 0:39:10pushing the water onto shores like these, where the energy dissipates.
0:39:10 > 0:39:13But thousands of kilometres over there is Antarctica,
0:39:13 > 0:39:16and there, the situation's slightly different.
0:39:16 > 0:39:21The water goes round and round that huge mass, building up the flow.
0:39:21 > 0:39:24And without land to get in the way to disrupt it,
0:39:24 > 0:39:27the current just gets stronger and deeper.
0:39:33 > 0:39:36The oceans were free to flow all around Antarctica
0:39:36 > 0:39:38driven by the winds.
0:39:40 > 0:39:45And this was the beginning of the Circum-Antarctic Current.
0:39:45 > 0:39:47Its effect on Antarctica was profound...
0:39:49 > 0:39:53..cutting off the continent from the warm waters to the north.
0:39:58 > 0:40:01In just one million years,
0:40:01 > 0:40:05Antarctica was transformed from a temperate forested land...
0:40:07 > 0:40:10..to one entombed in ice.
0:40:13 > 0:40:16From now on, Antarctica would be a land of desolation...
0:40:20 > 0:40:23..inhabited by nothing bigger than a penguin.
0:40:31 > 0:40:35But in the ocean, this new current had a more positive effect,
0:40:35 > 0:40:37playing a significant role
0:40:37 > 0:40:40in the evolution of all filter-feeding whales,
0:40:40 > 0:40:43the southern right whale among them.
0:40:44 > 0:40:48The motion of this current forced up water from the depths of the ocean
0:40:48 > 0:40:53to the surface, carrying with it nutrients which support tiny creatures
0:40:53 > 0:40:55such as phytoplankton and krill.
0:41:05 > 0:41:09This was a rich source of food, just waiting to be scooped up.
0:41:21 > 0:41:24And, sure enough, around the time the current appeared
0:41:24 > 0:41:28sea-dwelling mammals began to develop a new way of eating,
0:41:28 > 0:41:32filter-feeding those vast volumes of krill.
0:41:39 > 0:41:42Giant whales to this day feed in the same way.
0:41:50 > 0:41:54I could watch them all day, just doing their stuff out there.
0:41:54 > 0:41:57It's lovely to think that it's the Circum-Antarctic Current
0:41:57 > 0:42:02that played such an important role in allowing these giants to develop.
0:42:02 > 0:42:03And also keeps them fed today.
0:42:05 > 0:42:09In a way, these whales are the last remaining link between two continents
0:42:09 > 0:42:13that started as twins and have grown so far apart.
0:42:18 > 0:42:23Australia's fate was to be very different to that of Antarctica.
0:42:23 > 0:42:27It too would change dramatically, but in almost the opposite way.
0:42:38 > 0:42:43While Antarctica turned to ice, Australia was turned to dust.
0:42:47 > 0:42:50It continued moving northwards
0:42:50 > 0:42:55and around 20 million years ago, Australia pushed into warmer latitudes.
0:42:59 > 0:43:03And this would have significant consequences for this land
0:43:03 > 0:43:04and anything trying to live on it.
0:43:09 > 0:43:14The forest died away, save for a few tiny pockets.
0:43:17 > 0:43:20It was replaced with bare, red land
0:43:20 > 0:43:23and the one tree that thrived in these new arid conditions -
0:43:23 > 0:43:24the eucalyptus.
0:43:28 > 0:43:33A tree that now accounts for almost 80% of the forest in Australia.
0:43:36 > 0:43:40For the animals, it was a brutal case of "adapt or die."
0:43:45 > 0:43:48Only a few were able to evolve quickly enough to survive.
0:43:50 > 0:43:53KOALA GRUNTS
0:43:56 > 0:43:59And a classic case of that rapid evolution
0:43:59 > 0:44:01is this fellow.
0:44:09 > 0:44:10(WHISPERS) He's big.
0:44:10 > 0:44:12He's really big.
0:44:12 > 0:44:13I'm assuming you wanted the big koala!
0:44:13 > 0:44:16Yeah, big koalas are good. I could have got a female.
0:44:16 > 0:44:18I didn't have, necessarily, a preference.
0:44:18 > 0:44:21OK. Just don't move, cos it can climb across.
0:44:21 > 0:44:22Over this way, sweetheart. Hiya.
0:44:22 > 0:44:24Good boy. Under his bum. He's not sure.
0:44:24 > 0:44:26Yeah, I've got him. Gosh! He's heavy.
0:44:26 > 0:44:29What's that? Did you say 11 kilos?
0:44:29 > 0:44:30About 11 and a half, Hank is, yeah.
0:44:30 > 0:44:32It's just...! Good boy.
0:44:36 > 0:44:39This feels really nice, actually.
0:44:39 > 0:44:43He's quite heavy, like a toddler size,
0:44:43 > 0:44:46and the fur feels absolutely lovely.
0:44:46 > 0:44:49It reminds me of holding the kids when they were young, actually.
0:44:49 > 0:44:52It's quite nice. I've not done that for years, and they're too big.
0:44:53 > 0:44:57Wow! Yeah, you go for it! Erm...
0:44:59 > 0:45:01I think koalas are great, actually, now.
0:45:01 > 0:45:04I mean, you know they're supposed to be cute...
0:45:04 > 0:45:06They do, they look cute.
0:45:08 > 0:45:11Looks like your iconic teddy bear, doesn't he?
0:45:11 > 0:45:14But he's not actually a bear at all.
0:45:14 > 0:45:16The koala's teddy bear features
0:45:16 > 0:45:18and the anatomy that underpins them
0:45:18 > 0:45:21are the result of having only the eucalyptus tree to munch on.
0:45:22 > 0:45:24A very chewy tree at that...
0:45:27 > 0:45:30..as palaeontologist Mike Archer showed me.
0:45:30 > 0:45:32This is a modern koala. Ah.
0:45:32 > 0:45:37Most of this head has to do with smelling, eating, hold the teeth,
0:45:37 > 0:45:43and the muscles that drive the powerful jaws because these trees are hard to eat.
0:45:43 > 0:45:45So, basically, their head's a chewing machine.
0:45:45 > 0:45:48Exactly. Now, if you look at some of the fossils,
0:45:48 > 0:45:52these fossils are 20 million years old. Ah, cool!
0:45:52 > 0:45:55You've got an animal here that's about half the size of the modern koala.
0:45:55 > 0:45:58Yeah. So, this thing has become gigantic.
0:45:58 > 0:45:59It's a bigger and bigger face.
0:46:02 > 0:46:06The Eucalyptus trees didn't change only the koala's machinery for eating
0:46:06 > 0:46:09but also for communicating.
0:46:09 > 0:46:13This bubble of bone here is an echo-locating chamber.
0:46:13 > 0:46:16That's very good at picking up low-frequency vibrations.
0:46:16 > 0:46:18A low frequency sound? Yes.
0:46:18 > 0:46:23That weird sound they make transmits long distances, and they have to,
0:46:23 > 0:46:26because where they live here, the trees are far apart. Yeah.
0:46:26 > 0:46:29KOALA CALLS
0:46:29 > 0:46:33So, koalas have made this kind of alliance with this tree, really.
0:46:33 > 0:46:34I think so. And then eventually,
0:46:34 > 0:46:37that little niche is the one that then spreads.
0:46:37 > 0:46:39So, they're the lucky ones. They lucked out!
0:46:39 > 0:46:41They were the furry parasite that lucked out.
0:46:44 > 0:46:47The koala's face reflects the dramatic climate shift
0:46:47 > 0:46:50that Australia has undergone...
0:46:52 > 0:46:57..turning from verdant forest to mostly red, dry desert.
0:47:00 > 0:47:05The drying out of Australia is just one more phase in the changing history
0:47:05 > 0:47:06of this continent...
0:47:08 > 0:47:12..that was born in the arms of the giant Gondwana...
0:47:17 > 0:47:22..was flooded by sea when that supercontinent broke up
0:47:22 > 0:47:26and spent much of its life attached to an unlikely twin...
0:47:30 > 0:47:33..before finally becoming an island.
0:47:35 > 0:47:41Throughout all that, Australia has been relentlessly moving northwards
0:47:41 > 0:47:43and it's still going
0:47:43 > 0:47:47which means Australia's transformation isn't over yet.
0:47:47 > 0:47:49An unexpected fate awaits.
0:47:54 > 0:47:59You can already see signs of that future by looking beyond Australia
0:47:59 > 0:48:02to the Indonesian waters of the Banda Sea.
0:48:02 > 0:48:03Hi.
0:48:03 > 0:48:04Hi.
0:48:04 > 0:48:06Can I come in?
0:48:06 > 0:48:11This is Mang, a member of the Bajau, so-called sea-gypsies
0:48:11 > 0:48:14and masters of these waters.
0:48:14 > 0:48:18He's taking me on a fishing trip into the seas which are his home.
0:48:28 > 0:48:29He's completely gone.
0:48:45 > 0:48:48Mang makes it look effortless.
0:48:50 > 0:48:55And the Bajau can almost reach out and take all they need from the sea.
0:49:03 > 0:49:06Because with over 2,000 species of fish
0:49:06 > 0:49:09and over 600 species of coral, these waters,
0:49:09 > 0:49:15known as the Coral Triangle, are the most bio-diverse and productive in the world.
0:49:27 > 0:49:30That was great! Ahh!
0:49:33 > 0:49:35Fish caught,
0:49:35 > 0:49:39Mang takes me to his village, home to over a thousand Bajau people,
0:49:39 > 0:49:41all living off the fruits of the sea.
0:49:45 > 0:49:48So, there's lots of little fish swimming around.
0:49:51 > 0:49:55Hello.
0:49:55 > 0:49:58Hello.
0:49:58 > 0:50:01I love this place. I mean, once you get past the obvious oddity of it -
0:50:01 > 0:50:03all the houses are on stilts,
0:50:03 > 0:50:06and you get these treacherous planks that you walk across -
0:50:06 > 0:50:09what you get is this feeling of a real lively community.
0:50:09 > 0:50:11All these kids, it's fantastic.
0:50:11 > 0:50:15You just forget you're actually on the water.
0:50:15 > 0:50:16CHILDREN SHOUT
0:50:16 > 0:50:19But it means that all sorts of things turn up in your back yard.
0:50:19 > 0:50:21There is a snake. Andwa.
0:50:21 > 0:50:24Andwa? It's a snake, then? Yeah.
0:50:24 > 0:50:26Although Mang seems to relish that.
0:50:28 > 0:50:30CHILDREN SHOUT
0:50:31 > 0:50:32He's got the snake!
0:50:32 > 0:50:36It's not aggressive, but ten times more poisonous than a rattlesnake.
0:50:36 > 0:50:39Well done, sir. That's extraordinary.
0:50:39 > 0:50:42I'm not going to point out any other sea snakes from now on.
0:50:44 > 0:50:45But sea snakes can't faze a man
0:50:45 > 0:50:49who's spent more of his life at sea than on land.
0:50:50 > 0:50:54So, does anyone on this island not like fish?
0:50:58 > 0:51:01There's no vegetarians or vegans or something?!
0:51:05 > 0:51:08To find out why the waters here are so rich,
0:51:08 > 0:51:11and what this can reveal about the future of Australia,
0:51:11 > 0:51:16I'm going ashore, to the nearby island of Wangi Wangi.
0:51:19 > 0:51:21The Bajau villages are strung out
0:51:21 > 0:51:24all the way along the coast on this island.
0:51:24 > 0:51:27But I've come inland, up here into the hills,
0:51:27 > 0:51:29to look for something rather peculiar.
0:51:31 > 0:51:35Because, strangely, the key to understanding the richness
0:51:35 > 0:51:37of the waters down there
0:51:37 > 0:51:41is the rock on this hill up here.
0:51:41 > 0:51:45This is what I've been looking for here. It's coral.
0:51:45 > 0:51:47You can see a whole kind of colony of polyps.
0:51:47 > 0:51:49There's another one here and there's another...
0:51:49 > 0:51:53I mean, essentially, all of the grey rock you can see is coral.
0:51:53 > 0:51:56Which is hardly something you expect to see at the top of a hill.
0:51:56 > 0:51:59And that's because this is an ancient coral reef
0:51:59 > 0:52:01that's been uplifted above the sea.
0:52:01 > 0:52:04It's absolutely spectacular.
0:52:06 > 0:52:08And by looking at this fossilised coral,
0:52:08 > 0:52:12I can find crucial clues to the future of Australia.
0:52:13 > 0:52:16Strontium.
0:52:16 > 0:52:19Three million years.
0:52:19 > 0:52:20A layer cake.
0:52:21 > 0:52:23The clams and corals in this reef
0:52:23 > 0:52:26are absolutely exquisitely preserved. Beautiful.
0:52:26 > 0:52:29But what's really interesting is the age of them.
0:52:29 > 0:52:34Scientists have dated these corals with a form of element called strontium,
0:52:34 > 0:52:37which builds up over time.
0:52:37 > 0:52:41And the age that they get is less than three million years,
0:52:41 > 0:52:44which makes this reef a geological infant.
0:52:48 > 0:52:51This means that this whole island came up above the waves
0:52:51 > 0:52:54no more than three million years ago.
0:52:55 > 0:52:59But the biggest surprise is what lies beneath this reef.
0:52:59 > 0:53:01A layer cake of ancient strata.
0:53:03 > 0:53:04Beds of sand and mud
0:53:04 > 0:53:07that have built up gradually over time
0:53:07 > 0:53:09in conditions of tranquillity and stability.
0:53:10 > 0:53:13Those conditions just aren't found, really,
0:53:13 > 0:53:15in the crumple zone of Southeast Asia.
0:53:15 > 0:53:19Instead, they're absolutely typical of one place -
0:53:19 > 0:53:20Australia.
0:53:23 > 0:53:26The implication's intriguing.
0:53:26 > 0:53:28These Wakatobi islands are in Indonesia,
0:53:28 > 0:53:32so you just assume that they're part of Asia.
0:53:32 > 0:53:35In fact, they're a fragment of the Australian continent.
0:53:42 > 0:53:44It all points to one thing -
0:53:44 > 0:53:50that Australia has moved so far north that it's colliding with Asia.
0:53:50 > 0:53:53Continent is now grinding directly against continent.
0:54:02 > 0:54:06The reason why the collision of these two continents creates such a bounty of fish
0:54:06 > 0:54:10for the Bajau here, is all down to the effect it has on the sea bed.
0:54:12 > 0:54:16As they smash together, the crust gets fragmented and broken
0:54:16 > 0:54:20because some parts are denser, stronger than others
0:54:20 > 0:54:23and the result is that the sea floor around here
0:54:23 > 0:54:25turns into this uneven patchwork of highs and lows.
0:54:27 > 0:54:29In a way, the sea bed around here's a bit like this.
0:54:29 > 0:54:32If I pour some water in to create a sea...
0:54:34 > 0:54:37When the sea level's low, you get a series of isolated pockets
0:54:37 > 0:54:40and each one of those has different conditions
0:54:40 > 0:54:41and so different species.
0:54:41 > 0:54:46But if sea level rises and the water spills across
0:54:46 > 0:54:48then everything gets mixed.
0:54:48 > 0:54:51The thing is, the sea floor around here is constantly shifting,
0:54:51 > 0:54:52constantly going up and down,
0:54:52 > 0:54:56and so you're always revealing new pockets.
0:54:56 > 0:54:58And it's that separation, mixing, separation, mixing,
0:54:58 > 0:55:01that drives evolution here so fast.
0:55:06 > 0:55:12And that's what, in turn, creates these phenomenally rich seas
0:55:12 > 0:55:14and a way of life for these people.
0:55:14 > 0:55:18CHILDREN SHOUT
0:55:19 > 0:55:24Being in this place, here, now, it's kind of a rare moment in time -
0:55:24 > 0:55:29a time when two continents are starting to directly collide into each other.
0:55:34 > 0:55:36But the effects of Australia's move north
0:55:36 > 0:55:42are much, much bigger than the fabulous haul of fish around these islands.
0:55:42 > 0:55:46They're visible all along the boundary where these two continents meet
0:55:46 > 0:55:50as a startling variety of dramatic natural phenomena.
0:55:58 > 0:56:03It's forced up many of the volcanoes of Indonesia, even whole islands
0:56:03 > 0:56:04such as Timor.
0:56:09 > 0:56:13And on the Pacific side, in Papua New Guinea,
0:56:13 > 0:56:17it's thrust up entire new mountain ranges as high as Europe's Alps.
0:56:25 > 0:56:27And the action isn't over,
0:56:27 > 0:56:29not by any means,
0:56:29 > 0:56:32because this is Australia's future.
0:56:32 > 0:56:35To effectively become a part of Asia.
0:56:38 > 0:56:42It's impossible to tell exactly how that collision will pan out
0:56:42 > 0:56:44but a likely version of events
0:56:44 > 0:56:49is that Australia crushes the islands of Indonesia into Vietnam,
0:56:49 > 0:56:52pushes on into China and sideswipes Japan.
0:56:54 > 0:56:55One thing's for sure -
0:56:55 > 0:57:00Australia's brief existence as an island continent
0:57:00 > 0:57:01is coming to an end.
0:57:07 > 0:57:10Australia's destiny is to become much more like this place -
0:57:10 > 0:57:13Indonesia.
0:57:13 > 0:57:18No longer isolated and with a lush climate once again.
0:57:25 > 0:57:29What's happening now is the biggest change in the history of Australia,
0:57:29 > 0:57:32and it's happening right before our eyes.
0:57:32 > 0:57:37Of course, eventually, all of this will be utterly transformed.
0:57:37 > 0:57:39For a geologist, it makes it just so exciting
0:57:39 > 0:57:44because this is one of the most dynamic places on the planet.
0:57:49 > 0:57:52And it's all down to the slow and steady movement of the one continent
0:57:52 > 0:57:57that's always been considered quiet and stable.
0:57:57 > 0:58:01For so long, Australia was thought of as dry, unchanging, isolated,
0:58:01 > 0:58:04but its story is so very different from that.
0:58:04 > 0:58:06In the past, it was twinned with Antarctica.
0:58:06 > 0:58:09And its future's in the making as it merges with Asia
0:58:09 > 0:58:13to become this tropical land of forest and mountains.
0:58:13 > 0:58:18That's why, for me, Australia is the most surprising continent of all.
0:58:41 > 0:58:44Subtitles by Red Bee Media Ltd