Fateful Planet (2024) Season 1 Episode 3 The Great Dying
Fateful Planet (2024) Season 1 Episode 3 The Great Dying
Around 540 million years ago, the ancestors of almost all complex organisms that exist today suddenly emerge in the shelf seas of the Cambrian. But plate tectonics and climatic fluctuations keep throwing the new life off track. Nevertheless, evolution progresses and even manages to make the leap onto land. But around 250 million years ago, life has to pass its biggest test, yet: massive volcanic eruptions trigger the most severe of all mass extinctions in Earth’s history.
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Around 540 million years ago, the ancestors of almost all complex organisms that exist today suddenly emerge in the shelf seas of the Cambrian. But plate tectonics and climatic fluctuations keep throwing the new life off track. Nevertheless, evolution progresses and even manages to make the leap onto land. But around 250 million years ago, life has to pass its biggest test, yet: massive volcanic eruptions trigger the most severe of all mass extinctions in Earth’s history.
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00:00Earth is born out of chaos and catastrophe.
00:07Despite such hostile conditions, life emerges on our planet.
00:14But it must withstand deadly disasters again and again.
00:20Planet Earth is a wild world, shaken by unimaginable impacts.
00:29Volcanic eruptions that flood the landscape.
00:34And drastic climate changes that lead to ice ages that freeze the world from pole to pole.
00:43Yet each assault creates a path for something new.
00:48Life always finds a way, despite being constantly put to the test.
00:56Without these catastrophes, life as we know it would not exist on our fateful planet.
01:11Life evolved on Earth 4 billion years ago.
01:16When a series of severe ice ages froze our planet, they almost destroyed everything alive.
01:23But when the last glaciation ended, Earth became a giant greenhouse.
01:29Oceans turned tropical and made way for an unprecedented explosion of life.
01:38This profound change marked the beginning of the Paleozoic Era, 541 million years ago.
01:47Life experienced significant evolutionary developments and took on much larger dimensions.
01:57Thriving in new forms and conquering new habitats.
02:04But during this era, which lasted close to 300 million years, the planet was stuck by deadly catastrophes.
02:14The last, and worst, was a mass extinction that wiped out almost all life on Earth.
02:22Scientists around the world are investigating how life in the Paleozoic evolved,
02:30and which events ultimately resulted in the disaster known as the Great Dying.
02:36Morocco. In this dry, dusty North African landscape, there is fossilized evidence of the biological revolution
02:44that became known as the Cambrian Explosion.
02:49Paleontologist Philip Havlik is here to find out more about how that complex life evolved.
02:56The story unfolded underwater, in what was once a vast ocean.
03:03The Cambrian Explosion, being the beginning of the Cambrian Period, is the most exciting thing for any evolutionary researcher.
03:11It was the moment when almost all invertebrate animal groups suddenly appeared overnight, as if out of nowhere.
03:18They started to divide into all kinds of species.
03:21We found hundreds of species within a very short period of time.
03:24We still require an enormous amount of research on this, and still don't know exactly what happened.
03:30Philip has arranged to meet with a local fossil trader, who will help him decipher the story.
03:37Like many people in the area, Mohad Emadi has traded in fossils his entire life.
03:45Soon, the experts find something interesting.
03:49What do you think about this one?
03:51Yeah, yeah, that is good fossil, yeah. It's trilobite.
03:54It's almost complete, huh?
03:56Yes, it's complete, yeah.
03:58Trilobites are kind of like cockroaches among fossils. Their body is divided into three parts.
04:03We have the head, the cephalon, the thorax, the body, and the head.
04:09Trilobites emerged at the beginning of the Cambrian.
04:15These arthropods are one of the earliest and most diverse groups of multicellular organisms on Earth.
04:25Along with their unique body shape, trilobites have a very special shape.
04:31While trilobites were a huge part of the marine ecosystem, they weren't the apex predators of the time.
04:43A terrifying, giant, and very large, trilobite was the first fossil to be discovered.
04:49While trilobites were a huge part of the marine ecosystem, they weren't the apex predators of the time.
04:59A terrifying, giant, shrimp-like creature known as Anomalocaris claimed that honor.
05:10Anomalocaris was the fighting machine of the Cambrian.
05:13Four feet long, equipped with long eye stalks giving it 360-degree vision.
05:19It had large grappling arms at the very front.
05:22Anything that came close to it was eaten.
05:27Philip sees the Cambrian as more of a revolution than an explosion,
05:32because it marked the beginning of competition among living things.
05:38Some developed a shell, and others developed weapons to crack this shell.
05:42And so it came to an extreme arms race.
05:45One had stronger tools, the next had spikes and used them to fight back.
05:50And in the end, the sea creatures we know today emerged.
05:55Life exploded in the oceans.
05:58Rising oxygen levels, genetic inventions, and environmental changes
06:04created a complex cocktail that led to new and abundant diversity.
06:09Within just a few million years, mats of microbes covering the seafloor evolved.
06:17Simple unicellular organisms were replaced by highly mobile creatures
06:22that sported advanced anatomical features like legs and eyes.
06:27The Cambrian lasted until 485 million years ago.
06:32It was followed by the Ordovician, a second period of the Paleozoic,
06:37where life continued to diversify and evolve.
06:41A second period of the Paleozoic, where life continued to diversify
06:46through the emergence of new marine species and ecosystems.
06:50Organisms that were dominant in the Cambrian were now replaced
06:54by a wide range of new marine invertebrates.
06:57The Moroccan rocks have an exquisitely preserved record of the Ordovician.
07:03Mohan takes Philip to a site where he recently found a cephalopod,
07:08a squid-like creature that was even larger than Anomalocaris.
07:13That's what we found.
07:15Oh, wow. Wow, wow, wow, wow.
07:17It's actually a pretty nice piece. And do you know the biggest of this one?
07:20They reached up to nine meters and just a shell.
07:23It's Camaroceras. It was found in Russia.
07:26Camaroceras was the largest predator in the Ordovician.
07:30Ten tentacles projected from its cone-like body,
07:33allowing it to catch and feed on trilobites and other creatures.
07:39The tentacles grabbed the prey, then sucked it inwards to be devoured.
07:45This massive increase in size is attributed to the evolutionary pressures
07:50that develop in predator-prey dynamics.
07:54Being big can help creatures avoid predators
07:58or become more effective predators themselves.
08:02Scientists believe the environment also affected this growth.
08:08In the Ordovician, the first plants emerged on land,
08:12which increased the oxygen levels and thereby led to climate fluctuations.
08:16This, of course, is a trigger that significantly advances evolution.
08:20Life must deal with new situations time and time again.
08:25The Moroccan fossil record reveals a bustling Ordovician world,
08:30full of increasingly complex creatures.
08:34But about 444 million years ago, things suddenly changed.
08:42The fossils show that there was a massive die-off.
08:47Even with their new adaptations, more than 85% of marine life was wiped out.
08:55Philipp is searching for clues about what happened
09:00on the northern edge of the Sahara Desert.
09:04Here we have a seabed in which numerous different fossils are preserved.
09:09They indicate that we are exactly at the right point in time.
09:16But then he finds something unusual.
09:22Here I have a stone within a stone, and that shouldn't happen in this marine deposit.
09:27We are relatively far out at sea here, so there simply shouldn't be any pebbles,
09:32especially not angular ones.
09:35There is only one way to get them so far into the sea.
09:38A small iceberg must have drifted out here.
09:43When glaciers move over land, they grind rocks beneath them,
09:48picking up and transporting bits and pieces until the ice melts.
09:53Havlik believes that when an iceberg melted in the Ordovician Ocean,
09:57it dropped this pebble here about 444 million years ago.
10:02A glaciation event seems to be the only explanation for the pebble trapped in older stone.
10:11We also find such evidence in other places around the world,
10:15not only in North Africa. It's also in South America.
10:18It's the same in Southern Europe. It's something that appears everywhere.
10:22That means the moment there is large-scale cooling,
10:25most creatures, at that time only sea creatures, have no chance of survival.
10:30In other words, most of them simply go extinct.
10:34Complex life was flourishing until suddenly everything changed.
10:41Because the glacial deposits occurred at the same time as the mass extinction event,
10:47it seems plausible that an ice age was responsible for the death of so many new species.
10:54But how did the climate suddenly change from tropical to arctic?
10:59Iceland.
11:01To uncover what could have caused such a huge glacial event,
11:05geologist Professor Colin Devey has come to a unique place.
11:10We're in the Silfra Gap, and this is where you can really see plate tectonics in action.
11:15You can really see one side of the Earth moving away from the other side of the Earth.
11:21This is where tectonics really happens.
11:24Rocks here reveal how Earth is shaped by internal forces deep below its crust,
11:31the thin outer shell of our planet.
11:34Colin believes these forces played a crucial role in the extinction event at the end of the Ordovician.
11:40Iceland is a place on the planet where you can see where tectonic plates,
11:45where the surface of the Earth actually splits apart.
11:49Tectonic plates provide clues about what's happening beneath the surface of Earth.
11:55Today, we have seven major plates and numerous smaller ones.
12:00They all rest on the molten rock of Earth's mantle and fit closely together.
12:06The tectonic plates move due to heat from radioactive processes inside Earth.
12:12At times, they move closer together, and at others, farther apart.
12:20This is the edge of a plate. This continental drift is what this is all about.
12:26This is the result of Europe going that way and America going that way.
12:31Not very fast. It's about as fast as your fingernail grows.
12:35The gap is part of the mid-Atlantic ridge between the North American and the Eurasian tectonic plates.
12:43Okay, that was the easiest transatlantic flight I've ever done, and the quickest.
12:48Probably not the warmest, but hey, you can't have everything.
12:53When the plates move apart from each other, the land between them suffers enormous tension.
13:01A major earthquake eventually rips through the rock to release pressure,
13:05creating enormous fissures like the Silfra Gap.
13:13What's happening here normally happens on the seafloor at about 2,500 meters depth.
13:18In the Atlantic, even deeper, 4,000, 5,000 meters.
13:21This is how the Earth has changed its face, has changed life on Earth, has changed everything about the Earth.
13:29Since they first formed, the tectonic plates have continued to move around the planet.
13:35Over time, the continents they create also change.
13:39About 444 million years ago, our world looked very different,
13:45which could be important to the Ordovician mass extinction.
13:49Plate tectonics is the thing that drives the puzzle.
13:52It moves the continents around.
13:54At the end of the Ordovician, plate tectonics had pushed the continents together into a big lump,
13:59into a big massive continent called Gondwana.
14:02Gondwana was a supercontinent, covering almost one-third of the Earth's surface.
14:09The giant landmass almost stretched from the equator to the South Pole
14:14and included the modern continents of South America, Africa, most of Antarctica and Australia, and some of India.
14:22And life in the Ordovician was mainly on the shelves around the Gondwanan continent.
14:28Gondwana had moved quite a long way down south, so it was at the South Pole, or part of it was at the South Pole,
14:34and that seems to have set the world up for very bad environmental conditions for life in the oceans.
14:43Life thrived on the supercontinent.
14:46Sea animals like conodonts and trilobites flourished.
14:50But as the continent began to move farther towards the South Pole, it had a catastrophic effect on living things.
14:59And if the ice builds up, sea level drops, then those shallow water regions around the continent are all of a sudden dry land,
15:07and there's no place to live.
15:09And it seems like that was probably one of the pressures that really hurt life in the Ordovician Earth.
15:16Major glaciation at the end of the Ordovician caused sea levels to drop.
15:22The consequences were dire.
15:2585% of marine species were wiped out.
15:30It was a colossal loss of life.
15:34The Ordovician mass extinction led to the Silurian period that began 443 million years ago.
15:42It is characterized by the recovery and triumphant re-emergence of life after just a few million years.
15:50Creatures were rapidly evolving and becoming even more complex.
15:54They exploited new habitats, found new sources of food, and moved in new ways.
16:00The Silurian ended 419 million years ago and gave rise to the Devonian period.
16:07Back in Morocco, Philip Havlik has rejoined fossil trader Mohanimadi to investigate how life evolved in this important chapter in Earth's history.
16:18The Devonian is also well-preserved in Moroccan rocks.
16:22Over the years, Mohand has collected many fossils from this period, especially trilobites.
16:28Here is my Devonian stuff I collected a long time ago.
16:33So this is 20 years of collecting?
16:35Maybe more, yes.
16:39The trilobites in the Devonian in particular show an incredible diversity.
16:43There are some that have huge eyes with many complex facets on them.
16:47They can basically see everything.
16:49Some even have appendages on their heads so that they can swim through open water.
16:54There is really everything you can imagine.
16:56A biodiversity that we have never seen before and probably the greatest variety of trilobite species ever.
17:05But other animal groups also evolved rapidly during the Devonian to become more dominant.
17:12You could call it the age of the fish.
17:15These had an exoskeleton that consisted of a certain number of plates and so did the chewing tools.
17:22Dunkleosteus was one of the largest of these armored fish.
17:27It was a colossal sea creature that may have reached 26 feet in length.
17:33While ruling the oceans and devouring everything in its path.
17:38Dunkleosteus had a huge pair of crushing shears at the front which it could consistently resharpen.
17:45They simply crushed on top of each other.
17:47It cut through everything that got in its way.
17:53As the oceans grew busier during the Devonian, some creatures began looking for alternative, less crowded environments.
18:02A fish known as Tiktaalik attempted a revolutionary strategy.
18:08It tried to transition out of the water onto land.
18:16For a vertebrate, life in the water cannot be compared with life on land.
18:21If you make a swimming movement, you can have wobbly fins, but on land it's a completely different situation.
18:27You need a rigid frame so that you can move around.
18:30That's exactly what Tiktaalik had.
18:33It had fingers, it had arm bones, it had an internal skeleton.
18:37A spine that allowed it to use its four legs to move around perfectly.
18:45Tiktaalik was challenged to develop the ability to breathe air.
18:50But was successful, becoming the first vertebrate to conquer land.
18:55But just as animals and plants were gaining a foothold on land, a new threat emerged once again.
19:04Effenberg, Germany.
19:07Geology professor David de Fleischauer and a team of students are searching a quarry for clues about the fateful events that took shape at the end of the Devonian.
19:20This is the wall that we're going to sample today.
19:25As you can see, there are two very pronounced black shale layers that you can readily see.
19:31So when we find a black shale like this one in the geological record, it's a clear indication that we had low oxygen or even no oxygen condition in the seawater.
19:41And of course, that means that all the life that was living in the water column had a difficult time.
19:47Because all Devonian life, late Devonian life in the water column was dependent on oxygen.
19:54David and his team must collect rock samples to understand how the Devonian climate changed over time.
20:01They are time capsules of an ancient apocalypse.
20:06Back at the University of Münster in Germany, David and Ph.D. student Nina Wichern use a special x-ray device that allows them to analyze the rocks and draw conclusions about the prehistoric climate.
20:23So the sample we just analyzed came from a rock layer just below the black shale level.
20:31And what we've seen is very sharp transitions between humid phases and arid phases.
20:37So climate change was certainly going on and playing its role in the dynamics just prior to the anoxic event.
20:49David suspects that the alternating phases of wet and dry climates and the black layers of death follow a certain pattern.
20:58A rhythm that can be linked to a cosmic event.
21:04By the 17th century, scientists already realized that Earth doesn't follow a perfectly stable orbit around the Sun.
21:12And Serbian mathematician Milutin Milankovic later calculated how the Earth's astronomical position relative to the Sun changes over time, including the shape of its orbit.
21:27That's what we call eccentricity, and it's changing from a perfect circle towards a more elliptical form every 100,000 and every 400,000 years.
21:37This leads to fluctuations in how the Sun's energy gets distributed on the planet, which in turn triggers climate changes.
21:47In addition, the elliptical orbit coincided with an evolutionary development.
21:53During the late Devonian, vegetation on land flourished, and some trees grew to heights of more than 100 feet.
22:01Over time, ancient forests became established, transforming land that was once barren into a lush landscape.
22:10Our planet gradually emerged as the familiar green and blue Earth we recognize today.
22:16So during the Devonian, land plants really evolved widely and developed deep root systems.
22:21And that is important because deep roots, they create a lot of area where weathering and erosion can take place.
22:28And a lot of weathering and erosion, that means that a lot of nutrients and detrital material can be transported, for example, by rivers from the continent towards the ocean, towards the seas.
22:39At the same time, Earth's orbit was becoming more elliptical, which led to climate chaos.
22:48The combination triggered a catastrophic chain of events.
22:55And that is what we think is going on, an enhanced hydrological cycle, much stronger monsoons during those eccentricities.
23:04High eccentricity orbits, bringing those extreme precipitation events and flushing those nutrients towards the ocean.
23:12They're acting as food for everything that was alive in the water column.
23:18When that life decomposed, when it was sinking to the seafloor, it was consuming oxygen, thereby the oxygen levels in the oceans were going down and suffocating life.
23:31Ironically, it was the evolution of life on land that was responsible for the demise of life in the oceans.
23:39The astronomically forced climate change acted as a trigger, pushing the system past a tipping point and into chaos.
23:48Every animal in the intricate food web felt the impact as four extinction events took their toll.
23:56Ultimately, between 70 and 80% of all Devonian species vanished.
24:03Yet, life was not to be defeated.
24:07Despite the devastating mass extinctions during the Devonian, these catastrophic events paved the way for new species to emerge.
24:17It was the start of an evolutionary pathway that would one day lead to a new civilization.
24:24A pathway Philip Havlik is especially interested in exploring.
24:30Around 360 million years ago, in the Carboniferous period, life had really arrived on land.
24:38There were extensive swamp forests and everything was lush and green.
24:43And in the undergrowth, there was a lot of life, including huge insects.
24:48One of the most impressive is this little dragonfly I'm holding here, Meganeura, an animal that had a wingspan of 20 inches,
24:57so it was at least five times the size of today's dragonflies.
25:01They really got big.
25:07But while insects became supersized and amphibians ruled the ancient swamps,
25:12a new group of animals would make the most important evolutionary jump during this era.
25:19In the Carboniferous period, vertebrates had already conquered the entire coastal areas of the continents.
25:26However, a very important step was still missing in order to venture deeper onto land.
25:34Reptiles would make this leap.
25:36For the first time in the history of life, creatures would be able to fully live away from water.
25:43But how?
25:46The solution was as ingenious as it was simple.
25:49The vertebrates simply took the ocean with them.
25:52They packed it into a small bowl and were able to put it down anywhere on the continent.
25:57We still recognize the shell and the small ocean today,
26:01it is the egg, the amniotic egg.
26:05A key property of reptile eggs is an amniotic membrane.
26:09It's a protective envelope that surrounds the growing life from external influences.
26:14But another substance inside the egg is also critical to this evolutionary step.
26:21What's inside the egg is the ocean, what we call egg white.
26:25This transparent liquid enables the developing life to swim around in a small sea.
26:31Not only does this ocean contain the embryo, which is somewhere in the slippery stuff here,
26:36it also contains a huge food storage.
26:39The egg yolk must be enough to feed the little one until it is big enough to go ashore,
26:45survive on its own, crack the shell and start a new life.
26:50This key innovation represented a major transition in evolution.
26:55And because of it, reptiles were ready to conquer land.
27:01The continents aligned to form a new supercontinent, known as Bermuda.
27:07The Bermuda Triangle is the largest triangle in the world.
27:11It is the largest triangle in the world.
27:15The continents aligned to form a new supercontinent,
27:19known as Pangaea at the end of the Carboniferous period.
27:27This heralded the beginning of the Permian, 299 million years ago,
27:33and would be the final chapter in the Paleozoic era.
27:38South Africa.
27:41The Karoo Basin is one of the best places in the world to search for remnants of the Permian period.
27:47Paleontologist Professor Roger Smith is trying to piece together the evolution of terrestrial ecosystems
27:55by searching for fossils that illustrate changes.
27:59This level is at about 253 million years ago.
28:03You would have been standing on a vast, flat, featureless alluvial plain,
28:08but way off in the distance you would have seen a mountain range, the Gondwanite Mountains.
28:13The mountains were formed when the continent of Gondwana came together.
28:18Huge peaks were pushed up as the continental plates converged into a gigantic landmass.
28:24Millions of years later, when Gondwana began to break up into smaller continents,
28:30it created a huge rift valley.
28:33The rift widened and deepened over time,
28:36filling with sediments washed down from the surrounding mountains.
28:40What is left today is known as the Karoo Basin.
28:47In the late 1960s, near the town of Fraserbourg,
28:51an incredible fossil site was discovered by accident.
28:54It reveals a rare peek into the ancient past here.
28:59This is really an amazing paleosurface.
29:02It's a part of the ancient floodplain that has been captured and frozen in time.
29:09It's like a paleopolaroid of the Middle Permian period,
29:14showing us everything that was happening on those ancient Karoo floodplains.
29:19Look at these ripples.
29:21They are just as fresh and as sharp as if they were made just the other day.
29:28And there's the other right hand there,
29:31so it would have been a movement like this, rotate, this, this, rotate, this, rotate, this.
29:40The footprints may have been left by a moscops,
29:44an herbivore that weighed as much as two tons and reached 15 feet in length.
29:50This species belongs to the theropsids,
29:53a group of animals that represents a crucial step in the evolution of mammals.
30:00While not fully erect, theropsids already had a more upright posture and other mammal-like features.
30:07There was an abundance of food in this area 260 million years ago,
30:13and life thrived in the warm climate.
30:16Vegetation along the riverbanks fed the fast herds of grazing herbivores,
30:22which were dominated by moscops.
30:26But there were carnivorous theropsids too.
30:29Towards the end of the Permian, a new type of predator evolved, the gorgonopsians.
30:36They were large beasts with powerful jaws and distinct saber-like teeth.
30:42The masses of herbivores were the perfect prey for them.
30:46This is a gorgonopsian.
30:48It is a carnivore, clearly, because of its sharp, saber-like tusk or its canine
30:56and these intermeshing sharp incisors.
31:02With predatory carnivores and a vast array of potential prey,
31:06a dynamic and diverse food chain thrived here for millions of years.
31:11But the Karoo Basin also reveals that something changed around 252 million years ago,
31:23a dramatic shift that can clearly be seen in the rocks.
31:31We're now up at this dramatic color change, which I can see from a distance,
31:36and you can now see that this blue-gray wet floodplain mud rocks here
31:43have rapidly transitioned, rapidly at this point here,
31:47into something very red, very semi-arid, if you like.
31:53And the most likely cause of that drying out is climate change, rapid climate change.
32:00And the effect that that rapid climate change had on the environment
32:05and then on the animals and plants is quite dramatic.
32:10We can see that it's abrupt, it's very fast, and it could be as little as 10,000 years
32:17or up to 100,000 years, but it's in that time frame.
32:22The change in color not only marks a change in climate,
32:26it also marks a change in the amount of fossils.
32:31It's simple. Below this line, there are abundant fossils, and above it, almost none.
32:38This can only mean one thing. The change in climate led to a mass extinction.
32:45The effect of that rapid climate change on the animals and plants was dramatic.
32:51It's so dramatic that 95% of species worldwide went extinct.
32:56This is the worst mass extinction that has been recorded on Earth.
33:01The once lush Permian environment suddenly dried up.
33:06Something drastic happened that caused the extinction of most species on our planet,
33:12an event that became known as the Great Dying.
33:21Iceland, the land of fire and ice, offers scientists a first-hand glimpse
33:27of the tremendous forces our planet can unleash.
33:31In the barren landscape of Laki, geologist Colin Devey hopes to uncover remnants
33:37of a historic volcanic event.
33:39The Great Dying at the end of the Permian coincided with a huge volcanic interruption.
33:45And to get an idea of what might have happened then, I've come here to Laki on Iceland,
33:50where in 1783, a massive eruption covered the land here with lava,
33:56affecting the local population, but actually affecting half the globe.
34:00That's Mount Laki, and I'm going to go to the top so I can get an overview of what this looks like.
34:07The event was called a fissure eruption.
34:12It occurs when an elongated linear crack opens on the Earth's surface,
34:18which allows magma to rise and erupt.
34:24Look at that. It's amazing.
34:27It's a row of volcanoes that disappear into the horizon.
34:32I mean, that's got to be 20, 30 kilometers long.
34:35The whole countryside is just covered in lava.
34:40I presume the lava has come out of these volcanoes.
34:47The eruption lasted eight months,
34:51and is thought to be one of the largest volcanic events ever recorded.
34:59I'm standing here right on the crack. This is where the magma came out.
35:03When the eruption was taking place, you couldn't be anywhere in here,
35:07because it's all full of magma.
35:09This was a magma channel.
35:11This one obviously produced a lot of magma, a lot of lava,
35:15that got out of this crack and covered the landscape around,
35:18what we saw from the top of the volcano.
35:23The amount of lava produced by the Laki fissure volcano in 1783
35:29over the course of eight months is staggering.
35:33It produced 14 cubic kilometers of magma,
35:37which is impossible to imagine.
35:40But if you were to actually spread that out over the whole of the USA,
35:44you'd have about like the icing on a cake,
35:471.4 millimeters of lava over the whole of the USA.
35:50It's a lot.
35:52But it's nothing compared to what took place at the end of the Permian.
35:57252 million years ago,
36:00252 million years ago,
36:02a massive volcanic event created
36:05one of the most extensive volcanic landscapes in the world,
36:09known as the Siberian Traps.
36:13This is miniscule compared to the Siberian Traps.
36:16This was 14 cubic kilometers.
36:18The Siberian Traps were 4 million cubic kilometers.
36:22So if you were to spread the Siberian Traps all over the USA,
36:27you'd not have 1.4 millimeters like you have with Laki.
36:32You'd have 400 meters of lava.
36:35It's a different beast altogether.
36:41Colin is looking closely at data from the Laki eruption
36:45to better understand the monumental impact of the ancient eruption.
36:51I found a really interesting but also very important document
36:56on what happened here at Laki.
36:58Normally, we geologists get to situations like this after the event.
37:02We can look at the rocks when everything's happened
37:05and try and find out what happened.
37:08But here, the pastor in a church 50 kilometers away from here,
37:14so near enough to be influenced by the eruption,
37:17wrote down what happened.
37:19He describes how the lava advances down the valley
37:22towards his church, towards his congregation,
37:25destroying farms, destroying people's livelihoods
37:28and actually killing those people because they just died of hunger.
37:31They died of starvation.
37:34In the summer of 1783, the earth shook with fury
37:39when Mount Laki erupted in Iceland.
37:43A 15-mile-long fissure tore open,
37:46spewing molten lava into the air.
37:49Villages were engulfed by the flows.
37:52People ran for their lives
37:54as their surroundings went up in flames
37:57and the sky turned blood red.
38:01The pastor also describes how both the animals and the people
38:06at that time, at the same time,
38:08started to develop what appeared to be strange diseases.
38:12They ended up with...
38:14The animals had deformed claws or very deformed teeth.
38:18The people also had lumps under their skin,
38:21also problems with their mouths and their teeth,
38:23and were dying.
38:24The animals were dying and the people were dying as well.
38:27And, of course, for people at that time,
38:30this was like a visitation from God.
38:33This was something they'd never seen before.
38:35This was the wrath of God, is what they thought.
38:39I really don't think that's the correct explanation.
38:43I think it's to do with how volcanoes work.
38:46Colin Devey examines the volcanic rocks
38:49for clues about why both humans and animals
38:52succumb to this strange, mysterious disease.
38:56What I can read in the rocks is that they're full of bubbles,
38:59and that's probably the most important thing
39:01because it says that these were very gas-rich lavas.
39:05Obviously, the gas is no longer in these bubbles now,
39:08but people have been able to analyze
39:10what gases came out of there.
39:12Along with carbon dioxide,
39:14traces of two other gases were found.
39:18The first one was fluorine.
39:21It's a poison, and the symptoms of fluorine poison
39:24are exactly the things that the pastor wrote about.
39:27That's what caused those deformities of animals and humans.
39:31The second gas was sulfur, sulfur dioxide.
39:37Now, sulfur dioxide spread around half the globe
39:40and caused in Europe, for example, a year without summer.
39:44Now, it does that because sulfur dioxide in the atmosphere
39:47connects to water and makes tiny, tiny droplets of sulfuric acid
39:51which block the sunlight.
39:53So they reduce the temperature of the Earth a year without summer.
39:57The plants don't grow as well.
39:59Harvests fail. People starve.
40:02These gases were also emitted at the end of the Permian,
40:06but on a completely different scale.
40:10Now, imagine that happening over a million years,
40:13over and over again.
40:15We know the Siberian Traps are a great big pile of huge lava flows,
40:18so maybe every 100 years, every 1,000 years,
40:21the world was faced with a global catastrophe
40:25of cooling, of no sunlight.
40:29Because of the simultaneous emission of CO2,
40:33a warm greenhouse climate was repeatedly established
40:37before it would give way to the next cold phase.
40:40And you've just got adapted to that,
40:43and then the world turns into a balmy paradise.
40:45I mean, how do you make that U-turn?
40:47It's like riding a roller coaster.
40:49You're on the steep hill, and all of a sudden,
40:51you're going up the other side in terms of climate and your environment.
40:55And that's probably like a heavyweight boxer.
40:59You know, the sulfur dioxide kind of pummeled you,
41:02and then the carbon dioxide took your chin off.
41:06This could be one explanation for the global mass extinction on land,
41:11but the Great Dying had an even greater impact on marine life.
41:15So, were the volcanic eruptions truly responsible for the catastrophe?
41:22Kiel, Germany.
41:25At the Gay-Omar Helmholtz Center for Ocean Research,
41:28geochemist Dr. Hanna Yarkova
41:31takes a close look at certain marine animals
41:34for clues about what led to the disaster.
41:40So, what we have here are brachiopods.
41:42These are really unique animals that have been around on Earth
41:45for more than 500 million of years, since the beginning of Cambrian,
41:49and they have changed very little since.
41:52By analyzing the brachiopods,
41:55Hanna hopes to find out how the worst mass extinction in Earth's history unfolded.
42:04So, these fossils that we have here were deposited at the bottom of the Tethys Ocean
42:09252 million of years ago,
42:12and what is really important is that some of them
42:15deposited before the Permian-Triassic mass extinction,
42:18and some of them, like this one, right after.
42:22The fossil remains of organisms like brachiopods
42:25contain clues about what happened on Earth in the past.
42:31By comparing the chemical composition of brachiopod shells
42:34that lived before the mass extinction and after the mass extinction,
42:38I hope to find out what caused the Great Dying.
42:43The brachiopods record a history of the ocean's acidity in their shells,
42:49and the analysis reveals that it increased significantly at the end of the Permian.
42:57Hanna can determine historic acidification in an experiment with living brachiopods
43:04by measuring the pH levels.
43:10Now I know that the ocean pH in the late Permian Ocean was around 8,
43:15in fact, very similar to what we have in the oceans today.
43:18Right after the mass extinction, the oceans have become very acidic,
43:22and the pH has dropped to values of 7.5.
43:26This has happened in a very short time, only maybe 10,000 of years.
43:30This is just a heartbeat in the geological time.
43:33It's way too fast for any organisms to really adapt to it.
43:36This was way too swift. This was a death sentence.
43:40Acid has dire consequences for animals that build calcium carbonate shells.
43:46Many organisms living in the late Permian Ocean build calcium carbonate shells,
43:51just like this coral over here.
43:53When the ocean becomes way too acidic, they can no longer build their shells or skeletons.
43:59Let's see what happens if we put some acid on this coral here.
44:05Hanna wants to show how acidic waters impact marine life.
44:10The experiment reveals the devastating effects of acidification
44:15on organisms that rely on calcium carbonate shells.
44:20The coral dissolves.
44:24Countless animals were doomed to die in the acidic oceans of the late Permian.
44:31Food chains began to collapse, and one species after another died out.
44:37It was the last gasp for prehistoric life on Earth,
44:42and the deadliest time in our planet's history.
44:46But what caused this massive acidification?
44:50Increased levels of CO2 in the atmosphere would certainly acidify the oceans.
44:56But was the CO2 released by the Siberian traps significant enough?
45:02From research we know today that the Siberian traps
45:05release more than 387 billion of tons CO2 to the atmosphere.
45:09For comparison, this is more than 40 times the amount of carbon
45:13if we were to fire up all the fossil fuels on Earth today.
45:18Despite the huge amount of CO2, Hanna knows that it wouldn't have been enough.
45:24Something else must have happened.
45:27Although this was unbelievably extreme,
45:29I do not think that the Siberian traps were enough to acidify the oceans in such a short time.
45:34The huge amount of CO2 must have come from lava burning
45:38available fossil fuel reserves on Earth during that time.
45:41I think that the late Permian world was just burning.
45:45When ancient fuels ignite, they set off widespread wildfires
45:50that release even more carbon into the atmosphere.
45:54As the oceans acidified, the land burned.
45:58It was hell on Earth.
46:00How could any life survive this inferno?
46:05In South Africa, paleontologist Roger Smith is trying to answer this question.
46:12The famous South African fossil hunter, James Kitching,
46:16left notes about a Gorgonopsian that he found in a Triassic formation.
46:21The scientific community believes that this predatory species
46:26did not survive the Permian mass extinction.
46:29So finding one in Triassic soil would be incredible.
46:35Here we are on Fairydale, and this is that point on the map on James Kitching's map
46:40where he put the pencil mark and he had marked where the Gorgonopsian had come from.
46:45And that mark is just down over there, that's the position of it.
46:49So our job now is to see whether we can find another one.
46:54So students, this is a Gorgonopsian.
46:57This was the apex predator, and your mission today is to find more of this.
47:03So let's go.
47:07Dr. Julian Benoit from the University of Witwatersrand has done the research.
47:13His students have scanned the entire area marked by James Kitching,
47:18but didn't find anything resembling a Gorgonopsian fossil.
47:23Roger and Julian decide to examine the area themselves.
47:29So what's this, Roger?
47:31Yes, look at this. This is a sandstone tube going down into the floodplain mudrocks.
47:38You can see the levels of the floodplain, and this is definitely cutting down through it.
47:42It used to be an open hole, so it must have been dug by an animal.
47:47And if that animal was digging holes here, it must have been a survivor of the mass extinction.
47:54So we need to find this animal.
47:58The team hasn't found anything yet,
48:01but they are certain that the fossil remains of the tunnel-building animal in the Triassic Formation will be found nearby.
48:09And look, there's bone over there, Roger.
48:13Here, some bone there.
48:15Look at that, yeah.
48:17Yeah, something exposed right here.
48:20OK.
48:21What is that?
48:22I think that is a skull.
48:24Yes, this is the right orbit, or the right eyeball, and that's the top of the skull.
48:33And this must then be the snout.
48:35Yeah, it's the mouth coming in here.
48:38You know, I think this is Listerosaurus, and it could well have been the animal that dug that burrow.
48:50Like other dicynodonts, Listerosaurus only had two tusk-like teeth,
48:56which it used for defense and to tear apart small predators, even though it was a herbivore.
49:03It had a horny beak for snipping off parts of plants, and was about the size of a powerfully built pig.
49:11Its shoulders and hip structures indicate that it moved with a semi-crawling gait.
49:18Its front legs were even longer than its hind legs,
49:22and were used to create burrows where it sheltered and nested.
49:29Roger decides to bring the fossil to the University of Cape Town.
49:33Here, paleobiologist Professor Anousheh Chinzani-Turan will look at it
49:38to see if there are clues as to how the animal survived the mass extinction.
49:43Hey, Anousheh.
49:46So, I've just been out in the field and collected this for you.
49:51I haven't actually looked underneath it yet.
49:53It's all there, and lower jaws. Look at that.
49:56Wow, that's amazing.
49:59While Listerosaurus lived in the Permian, this one clearly survived the Great Dying.
50:05By taking thin slices of animal meat,
50:08By taking thin slices of its bone, Anousheh is able to learn more about the animal.
50:13So, when we look at the bones of the Triassic Listerosaurus,
50:18it clearly indicates that they had a faster growth rate than their Permian relatives.
50:23And this is an important adaptive strategy,
50:26because it means that they would be able to grow more quickly,
50:30reach adulthood quicker, and have a longer lifespan.
50:34They would be able to grow more quickly, reach adulthood quicker,
50:38and be able to reproduce quickly.
50:40And this is a very classic strategy for survivors of such a catastrophic event.
50:48But Professor Chinzani-Turan can determine more about this Listerosaurus
50:52from the makeup of its head.
50:54So, one of the very distinctive characteristics of Listerosaurus
50:58as compared to any other Dicynodon
51:01is the fact that its snout turns downward.
51:04So, if you look at the skull here, these would have been the orbits,
51:07and the snout actually turns down.
51:09So, compared to the other Dicynodons, where the snout actually projects forward.
51:15This immediately tells us that they were eating different food substances.
51:21The paleobiologist is certain that diet played a key role in the Listerosaurus' survival.
51:28When we think about the end of the Permian,
51:30we know that it was a very tough time for both the plants and the animals.
51:35And during the drying out times, only the really tough vegetation probably would have survived.
51:41So, if Listerosaurus survived, we think that it probably survived
51:46because it was able to eat the tough vegetation
51:49that may also have survived at the end of the Permian.
51:53The ability to dig tunnels for shelter from harsh climate shifts,
51:58along with the capacity to feed on the few things that remained,
52:02were essential for survival.
52:04Listerosaurus is a prime example of how life always seems to find a way,
52:10even in the face of the worst catastrophes.
52:15Throughout the Paleozoic era, many fascinating animals emerged,
52:20and the three major extinction events wiped out most of them.
52:25But even the Great Dying, the worst extinction in Earth's history,
52:30couldn't destroy all life.
52:33The emerging Mesozoic era would see the rise of the largest
52:38and most fearsome of all land creatures that ever roamed our planet,
52:43the dinosaurs.
52:46Each catastrophe and its extinction event drove evolution forward,
52:52and ultimately led to the life we know today.
53:15Transcribed by ESO, translated by —
53:45Transcription by ESO, translated by —