Documentary, Evolution of Bears: Prehistoric Predator
#AncientEarth #Documentary #Dinosaurs #Prehistoric #Evolutionary
#AncientEarth #Documentary #Dinosaurs #Prehistoric #Evolutionary
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AnimalsTranscript
00:00On planet Earth, one creature embodies all that is amazing about survival.
00:09It has adapted to wildly varying habitats,
00:15and evolved weapons unique to the animal kingdom.
00:21Its greatest asset, a bone-crushing bite.
00:27This mystical creature has overcome extreme climate change,
00:32ferocious rivals,
00:36and the deadliest threat of all,
00:38to emerge as one of evolution's ultimate survivors.
00:5745,000 years ago.
01:02North America.
01:12Vast grasslands dominate the landscape.
01:16This is one of the most feared carnivores on planet Earth.
01:29The giant, short-faced bear weighs as much as a small car.
01:35For decades, scientists believed that this was the ultimate predator.
01:50The earliest paleontologists thought this would be an incredible runner.
01:53This was an animal well-adapted for high speeds,
01:56with long strides that could go really fast and chase down bison or mammoths
02:01and be an incredible super-predator.
02:05But the biggest bear that ever lived died out there.
02:10And yet smaller bears, its relatives, not only thrived, but colonized the planet.
02:19Few animals can match modern bears for versatility.
02:24They survive on meat,
02:27on vegetation.
02:30They can even survive on insects.
02:33They live in wildly different habitats,
02:36from the steaming subtropical forests of India,
02:40to the icy wastes of the Arctic.
02:43Paleontologists discovered that during man's quest to master nature,
02:52bears proved a formidable opponent.
02:58Yet the most formidable of all died out.
03:02What skills have other bears evolved to survive?
03:08The secrets of bear evolution lie buried in the Earth itself.
03:18Paleontologists are time travelers.
03:21They visit our ancient past by digging down into the Earth's surface.
03:27Each layer of rock is like a time capsule,
03:34recording major events in the planet's history.
03:37Asteroid strikes.
03:42Natural disasters.
03:46And climate change.
03:51It's all recorded in sediment.
03:55Planet Earth's DNA.
04:06The mystery of bear evolution starts 20 million years ago in Central Europe.
04:11Planet Earth is hotter than today and covered with forests.
04:26Man's rise is still many millions of years away.
04:34This is the first true bear.
04:36The dawn bear is the size of a fox terrier dog.
04:41It comes from a long line of dedicated carnivores.
04:46However, on the ground, life is dangerous.
04:49He struggles to compete with dogs,
04:52hyenas,
04:54and cats.
04:59Forcing him to take refuge in the treetops.
05:01But finding a steady source of meat up here poses a new challenge.
05:12Scientists are researching the genetic X factor that transformed a small dog-like creature into the bears we know today.
05:19Dr. Anjali Goswami of the University of Cambridge is an expert in mammal evolution.
05:39By comparing the skull of a modern bear to another typical carnivore like a big cat,
05:44she reveals the secret gift the father of all bears passed on to its descendants.
05:53Well, if you look at really a more standard carnivore, something like a tiger,
05:57you'll find that they have these really blade-like upper premolar.
06:01And that occludes with this really blade-like lower molar.
06:05And that creates a shearing action that's really well evolved for slicing meat.
06:14Now bears, although they've descended from these carnivorous ancestors,
06:19have actually done something quite different.
06:21So when you look at a bear skull, you can see that they've taken this premolar,
06:25and instead of having it blade-like, it's instead more triangular.
06:27So they have a dentition that's very well evolved for grinding.
06:33Well, having the ability to slice meat with these carnassial teeth,
06:37and having these really broad molars gives them a lot of evolutionary flexibility.
06:48Because bears have slicing and grinding teeth, they can eat meat and vegetation.
06:54Critical for the dawn bear, these teeth allow it to feed high up in the trees,
07:03safe from the ground predators.
07:09Dental flexibility is the crucial gift that the dawn bear passes on to all of its descendants.
07:15Over the next six million years, planet Earth basks in warm temperatures.
07:28But then, the climate changes dramatically.
07:32And so do the fortunes of the early bear.
07:40Temperatures dip sharply 14 million years ago.
07:43Colder weather strips away the subtropical forests.
07:49The tree-dwelling dawn bear must somehow adapt to this almost treeless, grass-covered work.
08:06Fossil records revealed that 14 million years ago,
08:14two descendants of the dawn bear had spread all over the world.
08:18The ancestor of the giant panda.
08:22The giant short-faced bear.
08:23The giant short-faced bear.
08:24The giant short-faced bear.
08:25The giant short-faced bear looks like a bulldog.
08:29The giant short-faced bear.
08:30The giant short-faced bear looks like a bulldog.
08:44With its forest habitat vanishing, it takes to the ground in search of food.
08:47But the fossil records also present a mystery to be solved.
08:51They show that 14 million years ago, the lesser short-faced bear lives in North America.
08:52The giant short-faced bear.
08:53The giant short-faced bear.
08:54The giant short-faced bear.
08:55With its forest habitat vanishing, it takes to the ground in search of food.
09:00The giant short-faced bear.
09:01The giant short-faced bear.
09:02The giant short-faced bear.
09:03The giant short-faced bear.
09:04The giant short-faced bear.
09:05The giant short-faced bear.
09:06The giant short-faced bear.
09:07The giant short-faced bear.
09:08The giant short-faced bear.
09:09The giant short-faced bear.
09:10The giant short-faced bear.
09:11The giant short-faced bear.
09:12The giant short-faced bear.
09:13The giant short-faced bear.
09:14The giant short-faced bear.
09:15The giant short-faced bear.
09:16The giant short-faced bear.
09:17The giant short-faced bear.
09:18The giant short-faced bear.
09:19The giant short-faced bear.
09:20The giant short-faced bear.
09:21The giant short-faced bear.
09:26The giant short-faced bear.
09:27The giant short-faced bear.
09:28waterway known as the Bering Sea separates Eurasia from North America.
09:38How did the ancestors of the short-faced bear make this incredible journey to the New World?
09:47The answer to the mystery lies further north, in the Arctic.
09:55A cold snap 14 million years ago causes water in the polar regions to freeze.
10:09Ice has a profound effect on planet Earth.
10:15Water that normally flows down into the oceans remains frozen at both poles.
10:28This triggers a dramatic fall in global sea levels.
10:35Suddenly, land emerges out of the seas.
10:44Terrain appears between what is today Alaska and eastern Siberia.
10:50Known as Beringia, or the Bering Land Bridge, it stretches 1,000 miles from north to south
10:58and connects Asia to North America.
11:03Beringia, or the Bering Land Bridge, served as a corridor for the exchange of plants and
11:08mammals and eventually people between the Old and the New World.
11:12The ancestors of the bears probably came from Asia, crossed the Bering Land Bridge, moved
11:18into North America, and then bear evolution took place here.
11:26Fourteen million years before man makes the same epic journey, early bears take this bridge
11:32to the New World.
11:43However, over thousands of years, temperatures rise again.
11:51The polar ice melts.
11:54The seas reclaim Beringia.
11:59Lesser shore-faced bear is trapped in the New World, where the cold has also destroyed
12:07large areas of woodland.
12:20The shrinking wooded habitats of the lesser shore-faced bear, they see that there's all
12:24this ripe, fresh meat out on the open plains.
12:28Either does it evolve and go after that fresh meat, or does it hang out in the shrinking
12:34forests and perish.
12:40The short-faced bear must adapt to hunt on the plains, or face extinction.
12:52About 2.5 million years ago, one of the most cataclysmic climatic events ever strikes planet
12:59Earth, and dramatically alters the course of bear evolution.
13:05A cold current has isolated Antarctica from the influence of warm currents.
13:17Then, South America connects to North America.
13:22This isolates the Atlantic Ocean from the Pacific Ocean.
13:27Now the Arctic develops permanent ice.
13:33The planet's temperature drops sharply.
13:40The ice age spells doom for hundreds of species.
13:47It wipes out the saber-toothed tiger, woolly mammoths, and the ground sloth.
13:57Only the toughest, most adaptable, will survive.
14:01Bears evolve some of the natural world's most ingenious tools.
14:08But not all the bear species will make it through.
14:17The ancestral dawn bear from 20 million years ago has now given rise to at least three separate
14:23species.
14:25The short-faced bear is trapped in North America.
14:32The ancestor of black and brown bears emerges in Eurasia, where the ancient panda makes an extraordinary
14:42transformation to survive the cold.
14:53First, the panda turns black and white.
14:57Scientists believe to act as camouflage against snow and rock.
15:05When its meat supply vanishes, the panda evolves a simple but ingenious solution to hunger.
15:11First, the panda turns black and white.
15:16Two million years ago, in China, he finds a potential food source, bamboo.
15:28There's lots of it, but the panda's a carnivore.
15:35There's another drawback.
15:38It literally can't handle this tough, chewy crop.
15:42The carnivore's paws are designed for hunting animals, not for breaking off vegetation.
15:50But hunger is often a major driving force in evolution.
15:59The panda has five claws, but they can't grip a thin bamboo shoot.
16:07To counter this, evolution exploits a bone below the claws.
16:12It grows into a bump that acts as an opposable force to the five claws.
16:19It's known as the panda's thumb, which allows the bear to grip and snap stalks of bamboo.
16:29Now, the bear's crushing jaw and grinding teeth play their paw.
16:38Pandas have to really break up the bamboo as much as possible before they digest it in order to withdraw as many nutrients as possible.
16:45So having this very, very strong bite force and this really strong grinding dentition allows them to do that and subsist on this otherwise very nutrient-poor diet.
17:00The panda solves its food crisis.
17:05Now, elsewhere in Asia, another group of ancient bears must do the same.
17:15Huge glaciers spread through the Himalayan mountain range, driving a group of bears into the temperate forests of India.
17:30Here, the carnivores struggle to eke out a living.
17:38Wolves and hyenas beat them to the available meat.
17:44To survive, these bears evolve a bizarre and amazing set of tools.
17:53Two million years ago in the temperate forests of India,
18:00a group of starving bears stumbles across an unusual but untapped source of food.
18:14To exploit it, the species relies on its ancient gift, an adaptable mouth and teeth.
18:27It develops a long tongue, a larger snout, and loses its first pair of incisor teeth, thereby sacrificing the bear's trademark bite.
18:43It becomes a new species, the sloth bear.
18:52It's evolved this unusual aural toolset to target a particular source of food.
19:01The sloth bear has found a different source of food that actually does maintain a steady supply throughout all the different seasons.
19:09And that's ants and termites.
19:14It has very strong claws that it uses to actually break the top of a termite mound.
19:18And by using its very mobile nose, it can actually create a suction across the top of the termite mound,
19:27close its nostrils, and almost vacuum out the termites from the mound.
19:33The sloth bear, like the panda, adopts an extraordinary strategy to survive the ice age.
19:42Two million years ago, in the middle of the ice age, another bear has adapted to the cold by becoming massive.
19:56We know this because of a spectacular fossil find.
20:11In a river in the Yukon region of Canada, a gold prospector finds an enormous skull.
20:24It looks like the skull of some sort of legendary monster.
20:33Paleontologist Grant Susula has a cast of the giant skull at his lab in the Yukon town of Whitehorse.
20:53It's huge size tells me that this animal is built for power and intimidation.
21:02We can see this large muscle attachment that runs down the back of a head.
21:08The muscles attached to this jaw were powerful. Powerful if they could bite through almost anything.
21:17And these carnasial teeth, these cheek teeth here, would have been amazing bone cracking hammers.
21:23So if they came across a carcass, a bison, a nice-aged mammoth, or a horse, they could crack that bone, get at the marrow, and eat the fat in the marrow.
21:31It was an amazing adaptation to take apart carcasses, an amazing carnivore.
21:46This amazing carnivore lived 200,000 years ago in the Yukon.
21:52It's still the Ice Age.
21:57Grasslands have blanketed the landmass, triggering a population explosion of hoofed animals.
22:08The short-faced bear has become the giant short-faced bear, the largest ever to stalk the Earth.
22:23It's colossal, weighing almost 2,000 pounds, standing 11 feet tall on two legs.
22:36It can reach higher than a basketball hoop.
22:43More importantly, it has evolved a set of lethal weapons.
22:50Slender legs mean it can run at over 30 miles per hour, faster than most horses.
22:57Inside its forehead, the organ that controls smell is enlarged, allowing it to sniff out a carcass six miles away.
23:06Combined with a bone-crushing jaw, the giant short-faced bear looks every inch the ultimate hunter.
23:16Ultimate hunter.
23:29Evolution makes him massive, with good reason.
23:33Competition for meat on the plains is intense.
23:37This guy evolved huge because it needed to defend itself from other scary predators like lions, wolves.
23:46When lions and wolves were running around the landscape, they lived in packs.
23:47But short-faced bears were actually solitary creatures.
23:48So they needed to be huge and intimidating to defend themselves.
23:49and their food.
23:50And their food.
23:51The chicken!
23:52The chicken!
23:53This guy evolved huge because they needed to defend itself from other scary predators like lions and wolves.
24:00wolves when lions and wolves were running around the landscape they lived in packs
24:10but short-faced bears are actually solitary creatures
24:13so they needed to be huge and intimidating to defend themselves and their food
24:21the giant short-faced bear will need its extra size for another reason
24:25life on the open prairie is about to get tougher soon it will face a battle for territory with a
24:34powerful rival history repeats itself once again 50 000 years ago frozen water at the poles resurrects
24:55the long disappeared land bridge between asia and alaska beringia is back
25:13beringia becomes a lush haven for migrating species from asia
25:17lions elephants early man but most importantly the ancestor of black and brown bears
25:35the black bear simply can't compete on the plains of beringia with big cats
25:40and larger bears
25:56however the ancient grizzly is feisty and powerful he challenges his distant cousin
26:02but the giant short-faced bear has no plans to share this fertile new land with a smaller rival
26:24the most dramatic phase of bear evolution starts 50 000 years ago
26:29back then beringia is a land mass that links what is now alaska to siberia and acts as a gateway to the new world
26:44the ancestor to the grizzly wants to migrate from asia to this fertile new land the native giant
26:51that short-faced bear bear is bigger stronger and has no plans to share
27:01it's a clash of the titans that will have only one winner
27:12the fossil record confirms that the brown or grizzly bear
27:32vanishes from beringia 35 000 years ago the giant short-faced bear
27:38of the grizzly bears
27:53the dramatic change in the fossil record of bears and beringia is incredible the short-faced bear
27:58population seem to explode while we have no record of grizzly bears at all
28:01it seems like the competition for food resources amongst the carnivores was just too high for the grizzly bears
28:09they had to leave beringia
28:12the giant short-faced bear dominates north america for over one million years
28:20yet we know that ultimately the grizzly bear returns to populate
28:25and conquer north america
28:33somehow it has found a way to overpower its larger enemy
28:40something unique will tilt the balance of survival in favor of the grizzly
28:4521 000 years ago the story of bear evolution in eurasia and north america takes a dramatic turn
29:02the brown bear the ancestor of the grizzly has been muscled out of beringia for thousands of years
29:08defending the corridor to the new world is the seemingly invincible giant short-faced bear
29:21but 30 000 years after they first face off there's a rematch and this time a remarkably different outcome
29:32once again the beringia fossil record reveals what happens
29:39it shows that suddenly 21 000 years ago
29:45brown bears lived all over beringia
29:50while the previously dominant giant short-faced bear has vanished
29:59something compelled these mighty bears to abandon their own territory
30:08grand zazula finds clues to the mystery in the spectacular local topography
30:26halfway through the pleistocene epoch
30:27bear evolution is altered completely by the dramatic events in these mountains
30:36on these mountains surrounding beringia here these were the accumulation centers for all the glacial
30:41ice that surrounded the continent of beringia this is where the ice age began for beringia
30:45massive sheets of ice accumulated here advanced over the landscape creating an incredibly harsh cold ice age environment
30:58well 21 000 years ago is considered the last glacial maximum this was the deep freeze that covered the earth
31:04this was the coldest time ever during the ice age probably the coldest temperatures that large mammals ever encountered
31:14the brown bear's teeth allow it to eat meat and vegetation
31:18now it thrives in beringia
31:25grizzly bears won here they they were able to survive and continue on until present day in beringia
31:33the extreme cold drives hoofed animals out of beringia
31:38the giant short-faced bear's food source has gone
31:41the carnivore the carnivore heads south of the glaciers to the warmer climes of what is today the united states
31:50leaving the gateway to north america wide open for brown bears
31:59over the next 11 000 years brown bears radiate all over north america
32:04america where they continue to battle for supremacy of the plains
32:14but by now bears of the new world face a new enemy
32:21it's possible that conflicts could have arose between short-faced bears and humans
32:24the brown bear the giant short-faced bear and now man
32:37are rivals for food and shelter
32:39the biggest of the three
32:51the giant short-faced bear will be wiped out
32:59yukon paleontologist grant zazula has a theory as to why this happens
33:04it has to do with one critical design flaw
33:12this evolutionary achilles heel turns its enormous size into a deadly burden
33:18the most striking feature of the short-faced bear skeleton is that it has this large bulky mass
33:24on its trunk its chest area but when you look at its long limbs they're incredibly long but incredibly
33:31thin these are spindly little legs it's not something that can accelerate fast from a standing position
33:38or something that can be running at full tilt and turn on a dime
33:43so predators today and predators during the ice ages needed to be able to have that explosive turning
33:48power and explosive speed to chase down the herds of bison and horses
33:51in other words unlike the brown bear the giant short-faced bear cannot chase and catch prey
34:05instead the giant bear evolves a different strategy to find enough food to survive
34:14a short-faced bear would travel around the landscape using its highly evolved sense of smell
34:19to smell the carrion these carcasses of mammoths and bison
34:26but those carcasses are also highly sought after by other predators as well the lions the wolves would
34:31have went after those carcasses for a free meal too so the short-faced bear had to be highly evolved to be
34:37really big so it can intimidate those other carnivores on the landscape scared away and had to look
34:44intimidating so this is an intimidating creature it was not built to fight it was built to look scary
34:48and that's exactly what it did when it got to its carcass and had to defend itself and defend its food
34:56the giant short-faced bear isn't a super predator
35:02it's a super scavenger
35:04stealing the kills from other creatures
35:18early man sets a trap for his greedy rival
35:20but which will triumph
35:29brain
35:32or brawn
35:42you
35:52the
35:55very
35:55the
35:56the
35:56the
35:56the
35:57the
35:57The climate is changing rapidly, the environment is changing rapidly and then people show
36:25up and it seems like a combination of several of these different types of factors may have
36:30been involved in the extinction of these guys.
36:37Ten thousand years ago, the giant short-faced bear vanishes off the face of the earth.
36:43In Eurasia, the cave bear has dominated the animal kingdom for tens of thousands of years.
36:57Now, it faces a new nemesis, early man.
37:03Seeing as that they lived in caves, there is a great potential for interactions with humans
37:08and humans have had negative interactions with many of the other large animals that were around at the end of the late glacial period.
37:17Resourceful early man plays a role, but there are other factors in the cave bear's extinction.
37:29There have been some studies that show that they did start to incorporate more carnivorous material into their diet,
37:34so potentially that could have brought them into competition with other carnivores and they could have simply been out-competed.
37:40Either way, we know that ten thousand years ago, man lived in caves
37:47and the cave bears were wiped out.
37:52Yet the smaller black and brown bears survive and flourish on both sides of the Atlantic.
37:57Today, the brown bear is the most widely distributed bear on planet Earth.
38:07And for good reason.
38:10It can eat anything.
38:14To kill prey, it develops a large hump of muscle behind its shoulders.
38:18It's been known to break the neck or spine of a bison with a single blow.
38:25And its reflexes are so well honed.
38:29It's quick enough to stomp on mice with its feet.
38:36Its powerful legs and balance mean it can run faster than most horses.
38:41Well, the thing about the brown bears and the grizzlies, they're extremely adaptable.
38:56They have a behavior that allows them to be able to eat meat, eat plants, so they're an ultimate omnivore.
39:02But the brown bear's most dramatic transformation is arguably evolution's greatest story of all.
39:09The Arctic, 200,000 years ago.
39:23Brown bears regularly invade these icy wastelands to hunt.
39:29The appeal is large, clumsy prey.
39:36Seals, walruses, and even the occasional trapped whale.
39:42Then, a sudden change of climate traps these brown bears in the Arctic.
39:50They try, but fail, to make it back to their natural grassland habitat.
40:07A population of grizzly bears becomes isolated from the rest of the pack, somewhere in northern Eurasia in the Arctic regions.
40:13When they face a situation, they either evolve or perish.
40:17Their problems are numerous.
40:20They are visible against the snow.
40:23Prey can see them coming.
40:26Their fur is not designed for such extreme cold.
40:30There is little vegetation.
40:33Gradually, they start to die out.
40:37They have to figure out how to make a new way of life really fast, so this is rapid evolution at its best.
40:46To survive, the brown bear turns into a super predator.
40:51He evolves his nose to smell a seal 20 miles away.
41:01A huge stomach.
41:05He can eat 20% of his own body weight in one sitting.
41:09And he becomes invisible to prey.
41:14Trapped in the Arctic, the brown bear evolves into the polar bear.
41:25Despite its appearance, the polar bear's skin is actually brown.
41:33Each hair of its fur is transparent, designed to store heat.
41:38But the reflection of snow and sunshine makes it look white.
41:46It's strong enough to swim for 60 miles without taking a break.
41:56The journey it has made to get here is incredible.
42:00Twenty million years ago, the tree-dwelling dawn bear adapts to eat vegetation.
42:10The panda evolves to eat bamboo.
42:14The sloth bear, ants and termites.
42:18The short-faced bear masters the plains.
42:22The brown bear adapts to all these habitats.
42:26And to ice.
42:30Having endured so much, six bear species are now listed as vulnerable, threatened or endangered as a result of human activity.
42:41The panda is running out of bamboo.
42:45The sloth bear is running out of space.
42:49And because of global warming, the polar bear is running out of ice.
42:55In recent years, faced with a lack of partners and shrinking ice, polar bears have begun to evolve in a new direction.
43:08Polar bears are mating with grizzlies to form a new bear.
43:13Known as a growler.
43:15This growler was shot by a hunter in Canada in 2006.
43:21Well, a growler is a hybrid between a grizzly bear and a polar bear.
43:27And it's maybe a new species, something of a new type of bear that we've never seen on Earth before.
43:33It's evolution in action.
43:36And we're seeing it take place before our eyes.
43:38And it's not too often we get a chance to see evolution take place right in front of us.
43:41We're seeing it take place right in front of us.
43:42We're seeing it take place right in front of us.
44:11we're seeing it take place right in front of us.
44:14We're seeing it take place despite the coronavirus large background
44:16mentioned earlier,aina and orna.
44:17Saying it to the gotta be.
44:18Because it is Souls-a-bs.
44:20I'm a bummer, so it's gonna be andれる a portfolio of this.
44:23issues are not going to be.
44:25Yeah, and that's why it keeps entering a world if right behind us.
44:27No doubt it, but it keeps entering a place right.
44:29It can't take place right in front of us.
44:31Or here's what's going to be.
44:33No doubt it?
44:35Yeah, so I don't know it.
44:37Nothing, no doubt it.
44:38I would be here to be a bit close.
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