Januari 13, 2017
(dramatic music) - [voiceover] if you think that there are fearsome beasts on the planet today, just wait till you meettheir supersized forefathers from the ancient world. we're counting down the top 10 most extreme awesome ancestors to find out which modern animal has the greatest granddaddy of them all.
we'll reveal some reallybig family secrets when ancestors are takento the most extreme. earth is a planet of extremes, extreme places (funky dance music) and extreme animals. but some animals aremore extreme than others. join us as we count down to find the most unusual,the most extraordinary,
the most extreme. (fast dance music) what was life like 1,000,000 years bc? well, according to hollywood, our ancestors had fur bikinisand fought giant reptiles. (screams) well, humans were neverchased by dinosaurs. in the past there reallywere monsters. (shrieking) and some of these giant animals
have much smaller descendantsstill living today. our countdown takes uson a journey through time to find the greatestgranddaddy of them all. and we begin with the elephant. (ominous music) it's the largest animalwalking the planet today. and yet, compared to oneof its ancient ancestors, this jumbo sized mammalis just a pipsqueak. to find our first contender,
you need to wind backthe clock 10,000 years to meet the giant star of the ice age. - good job, ward. the mammoth is number 10 in the countdown because it could have been 50% larger than it closest survivingrelative, the modern elephant. standing four meters talland weighing over eight tons, mammoths once roamed bothnorth and south america. but it wasn't just their body size
that made them differentto modern elephants. mammoth tusks were farbigger and more curved, perhaps to scrape snow off their food. some mammoths were also covered in a 50 centimeter long fur coat, perfect insulation fromthe freezing temperatures of the ice age. the ears were the only part of a mammoth that were smaller than thosefound on a modern elephant.
that's because in cold weather, it pays to have bigger bodiesand smaller appendages. (wind howling) (growls) imagine if we spent a few thousand years living in an ice age. the shape of an animal's body affects the amount ofheat loss to the air. and since most heat islost through the skin,
it's a good idea to exposeas little skin as possible. that's why in cold climates, animals tend to have compact bodies, short limbs, a small nose, and tiny ears. it would also help if,just like a mammoth, we had a layer of insulating fat and grew a very thick fur coat.
so how do we know so muchabout these extinct animals? well, in the arctic, they keep turning up, often thanks to gold minerswashing away the frozen ground. this tusk could be 20,000 years old. and yet it and other mammoth remains have been perfectly preserved by being buried deep in the permafrost. scientists can evenexamine stomach contents to find out what grassesmammoths were eating.
some of these plantsare still alive today. and this has led a group of researchers in siberia to try to wind back the clock. it's a project that sounds like something straight out of a spielberg movie. welcome to not jurassic,but pleistocene park. (enchanting music) russian scientists havealready started work returning 160 squarekilometers of savannah
back to the ice age by repopulating it with plants and animalsthat would have lived there 10,000 years ago. one group of researchersbelieve that it may be possible to extract genetic material necessary to bring the mammoth back from the dead or, more accurately, a genetic hybrid of the extinct woolly mammothand a modern elephant. japanese scientists plan to extract dna
from sperm they hope tofind in a frozen mammoth. unlike the movie jurassic park, we still don't have the technology to rebuild an animal from dna alone. so the scientists plan to inject the sperm into an egg taken from amodern female elephant. using this existing technology, they hope to produce a hybrid offspring. by repeating the procedureover many generations,
the researchers hope toeventually create an animal that's mostly mammoth. at least we can still see the mammoth's slightly smaller descendants. but as our countdown continues, we'll discover that there can be even greater size differences between the animals we know today and their awesome ancestors.
in the forests of south america you'd think you'd be safe from predators if you're 30 meters above the ground. but here there's terror in the skies. the harpy eagle is oneof the most powerful birds of prey in the world. it's been recorded carrying away a six kilogram howler monkey. this harpy eagle chick will one day
have more than a two meter wingspan. that's relatively shortcompared to other eagles. but it gives it thespeed and maneuverability necessary for flying through the forest. those talons are the sizeof grizzly bear claws and can easily crush a monkey's skull. but even this powerfulpredator is no match for another eagle that ruledthe skies just 2,000 years ago. (swishes)
the forests of new zealand were once home to the largest eaglethe world has ever seen. flying in to number nine inthe coundown is haast's eagle. it was 60% heavier than a harpy with nearly a three meter wingspan. (shrieks) its legs and talons were farstronger than a modern eagle's, which meant it could huntanother extinct animal that weighed in at morethan 180 kilograms.
moa were huge, flightless birds that browsed on the forest floor. since new zealand was once aland without predatory mammals, the eagle had no competition. so the bigger it grew, thebigger the prey it could kill. it's this diet of enormous birds that let the haast's eagle grow into number nine in the countdown. it became so big thatit must have terrified
another kind of two legged prey. the first humans to arrive in new zealand must have seemed like atasty treat to a giant eagle. and yet it was the humans that survived because when they cleared the forests and killed off the moa, this awesome ancestor disappeared forever. and that would havemade collecting firewood a whole heap more relaxing.
if you think it would have been scary living in a world with bigbirds and massive mammoths, just imagine what it would have been like to go swimming with a fish that could have eaten jaws for breakfast. and later, we'll travel back to a time when giant insects ruled the world. our countdown of the mostextreme awesome ancestors continues in africa whereit's hard to sleep tight
because it's not justthe bed bugs that bite. these are driver ants, andthey're looking for food. if you can't get out of their way, driver ants have beenknown to kill humans. (groaning) a colony of driver antscontains 20,000,000 jaws. and while they may be blind, thanks to their extremesense of smell and touch, they have no trouble tracking down prey.
in a single raid a colony can dismember more than 100,000 animals. it's awesome destruction. and yet these workers are a little more than a couple of centimeters long. imagine what would happen ifthese ants were twice the size, just like their awesome ancestors that once swarmed acrosseurope 49,000,000 years ago. crawling in to numbereight in the countdown
are prehistoric giant ants. they were the biggest ants in history, the queen having a wingspanof about 13 centimeters. that's bigger than some hummingbirds. the world had never seen anythinglike these deadly swarms. never before had insects ganged up to overwhelm much bigger prey. so why were these ancient animals so much bigger thantheir modern descendants?
was there something in the air? well, it seems that theanswer could be yes. the amount of oxygen in the atmosphere has changed dramatically overthe history of the planet. if we traveled back 300,000,000 years, we'd find the air containedalmost twice as much oxygen than there is today. and this could make bugs grow much bigger thanks to the way they breathe.
take a close look at an ant and you'll see there's a rowof holes along its abdomen which leads into a network of tiny tubes. since it doesn't havelungs, it has to rely on air diffusing through thesepipes into the body. the longer the pipe, the lessoxygen gets into the system. and that's one reason why you don't get ants the size of elephants. however, imagine whathappens if you change
the concentration of oxygen in the air. twice as much oxygen should be able to diffuse twice as far down the tubes. in theory, this means the insect would be able to grow much bigger. you can see a similarthing happening today, not in the air, but in the icy waters around the north and south poles. that's because the lower the temperature,
the more oxygen can bedissolved in sea water. that's why creatures living near the poles tend to be bigger. under the ice there'srelatively more oxygen to be absorbed into an animal's blood, which is why sea spiders canbe up to 1,000 times heavier than those living in warmer waters. perhaps with a little more oxygen modern ants would one day become as large
as their prehistoric ancestors, although they'll never be as big as the monsters imagined by hollywood. (grunts) our next contender would bequite at home in horror movies, since it would have no trouble swallowing the world's fiercest fish. if you think that fighting ants and fighting birds are scary,
still to come, we'll meet anancient australian monster that still gives people nightmares today. and later we'll dig upthe truth about a tooth. just when you thought it wassafe to get back in the water, along comes the nextcontender in our countdown of the natural world'smost awesome ancestors. its modern descendant is the most terrifyingpredator in the sea. (splashes)
the great white shark canbite off 20 kilograms of meat as easily as you might take amouthful of an overripe peach. the movie jaws did irreparable damage to the great white shark's reputation. but imagine if spielbergdecided to make a film about the shark's long-lost ancestor. our skinny body is usuallyless than two meters long. a great white shark can be six meters long and weigh two tons.
but 15,000,000 years ago there was a shark that was 15 meters longand weighed 50 tons. (bubbling water) with jaws two meters wide,it could swallow a human and a great white shark in a single gulp. swimming in to numberseven in the countdown is megalodon. today you can still findits fossilized teeth washed up on beaches.
they're easy to identify since they're up to 17 centimeters long. unfortunately, the megalodon's body hasn't been preservedas well as its teeth. sharks are made mostly of cartilage, a rubbery substance thatdoesn't make for great fossils. but paleontologists cantell a lot about a megalodon just from its teeth. imagine what it would belike to meet this monster.
scientists believe that megalodon looked like a greatwhite shark on steroids. they are, after all,pretty closely related. those massive jaws would have taken volkswagen sized bitesout of the large whales that were alive at the same time. scientists are unsure whymegalodon disappeared from the sea about 1,500,000 years ago. one theory is that whalesbecame trickier to catch
by migrating into colder,shark-free waters. they certainly wouldn'twant to move close to shore because that was home to ournext terrifying contender. (water splashing) this is a crocodile. it can grow over six meterslong and weigh nearly a ton. it's reputed to have thestrongest bite on the planet, estimated at nearly 280kilograms per square centimeter. for over 220,000,000years, the water's edge
has been ruled by differentkinds of crocodiles. and the biggest of them allonce lived in the waters of sub-saharan africa. it was as long as a city bus and ate dinosaurs for breakfast. roaring in to number six inthe countodown is sarcosuchus, a reptile so big that it couldswallow an adult human whole. more than twice the size ofthe largest modern crocodile, sarcosuchus also ambushedprey at the water's edge.
its two meter long jaws werestudded with over 100 teeth, including a row of enlargedbone-crushing incisors. (crunches) a computer animation of sarcosuchus can make it seem larger than life. but how can we know what an extinct animal really looked like? well, the secret is to take the old bones and compare them to livingexamples of similar animals.
the same technique can even be used to recreate our own ancestors. they say dead men tell no tales. and yet this ancient skull hasall the information necessary for forensic anthropologiststo bring a face back to life. these scientifically trained artists meticulously measure bonyattachments on the skull to calculate the musculature and then painstakinglylayer on modeling clay
as it if was real tissue. nasal openings in the skull can indicate a specific size range for the nose. it's even possible to inferthe thickness of the skin that covered the living face. similar techniques have been used to reconstruct not just the skulls, but the bodies of allkinds of extinct animals. these scientificallyinformed artistic recreations
can help us imagine what life looked like thousands or even millions of years ago. a forensic artist would have no trouble reconstructing the jaws of sarcosuchus. it uses much the same designas its modern descendants. however, not even its massive teeth can compete with the fangsof our next contender. we're nearly halfwaythrough our countdown. and already we've seen sometruly awesome ancestors.
but could any of them stand in the way of the tyrant lizard king? and later, can you reallydiscover your own ancient past using some cotton wool on a stick? it's hard to believethat the awesome ancestor of these little balls of fluff is one of the world'smost famous predators. the cubs are living ina house in nashville, a long way from their homein the jungles of asia.
they're being raised in captivity because they're one of therarest cats on the planet, the clouded leopard. you can identify them by takinga close look at their teeth. their canine teeth will oneday be five centimeters long. that's the same size as those of a tiger. even though the clouded leopardbody is 10 times smaller, it can open its jaws widerthan any other feline. and it's one of the bestclimbers in the cat family.
it has flexible ankle jointsthat can rotate backwards, which makes the cloudedleopard one of the few animals able to climb down trees head first. in the wild, adult clouded leopard ambush their prey from the treetops, leaping onto the victim's back and delivering one killing bite. however, it will be sometime before these cubs are ready to bring downlarge cattle and deer.
its fangs are lethal weapons, but they're nothingcompared to the dental work of the animal at numberfive in the countdown. dna analysis suggests that the cloudedleopard's closest relative can be found not in a forest,but in a concrete jungle. welcome to los angeles. it's the last place you'd expect to find one of america's most famous predators.
but take a trip down wilshire boulevard, and you can look througha window into the past. this is tar. when it started seeping tothe surface 40,000 years ago, it became a death trap. animals that wonderedinto even a shallow pool could get so stuck thatthey eventually died from thirst or starvation. for the paleontologists workingat the la brea tar pits,
the best thing about the black goop is that it preserves bones, especially the bones of thebig cat with the biggest teeth. roaring in to number five in the coundown is the saber-tooth cat. its 20 centimeter long canines were four times longerthan its modern descendant, the saber-tooth catprobably looked like a lion and was far too big toclimb trees like a leopard.
instead, it relied onstealth to get close enough to launch a devastating attack. (shrieking) it's thought that thesaber-tooths used their canines to stab or rip at soft tissuesin the throat or stomach. compared to its awesome ancestor, the clouded leopard's teethare an orthodontist's dream. and since even this extraordinary overbite can't compete with the monstrous mouths
coming up in the countdown, it's well worth hangingaround a little longer. australia is home to somestrange and terrible creatures. yet far scarier animalsgreeted the aboriginal people when they first arrived 40,000 years ago. today, they still tell stories of these monsters from the dream time. and the worst of them all was the bunyip. it never appears inaboriginal art for fear
that its spirit wouldlive on through its image. when europeans arrived, theytoo returned from the outback with tales of a terrifying monster. the bunyip was rumored tolook something like this. meet the wombat. today it doesn't look much like a monster. modern wombats are peaceful vegetarians and are only about as big as a bulldog. these lumbering marsupialsare usually nocturnal.
and during the day they rest in burrows. to find their awesome ancestor, you need to travel to a muchbigger hole in the ground. this is one of the simplestdeath traps in the world. for animals that fall in,there's simply no way out. their bones lie undisturbedand are an amazing record of australia's ancient past. tens of thousands ofspecimens have been recovered from 93 different species,
many of which livedthrough the last ice age. it's also the last restingplace of the awesome ancestor at number four in the countdown. these skulls belong tothe largest marsupial that ever lived in australia. it's a wombat called diprotodon. this huge herbivore disappearedfrom the fossil record about 35,000 years ago, soon after humans arrived in australia.
could it be that thismega mammal was the bunyip that once terrified the aboriginal people? it's certainly an impressive size. but it would have been far less dangerous than our next contender. while we've learned a lotabout our last two contenders by looking at their bones, imagine what we'll findwhen we take a close look at a 10,000 year old scat.
and later, what on earth would send a saber-tooth cat running for its life? the next contender in our countdown of awesome ancestors is the lizard king. today's ruling reptiles arewithout doubt komodo dragons. these battling males arethe world's largest lizards, measuring up to three meters long and weighing over 150 kilograms. dragons are at the very topof this island's food chain.
even a 900 kilogramwater buffalo isn't safe. just one bite can injecta toxic brew of bacteria that eventually causesfatal blood poisoning. dragons are armed withlarge, curved, serrated teeth for ripping their prey apart. the komodo dragon is botha hunter and a scavenger, just like another giant reptile that once ruled america70,000,000 years ago. (birds singing)
thundering into numberthree in the countdown is tyrannosaurus rex. it's scientific namemeans tyrant lizard king. and while it certainlylooked like a tyrant, it actually wasn't alizard, but a close cousin. t rex was about 12 meters long and weighed up to 4,500 kilograms. that's almost 30 times thesize of a komodo dragon. the tyrannosaurus' jawswere 10 times more powerful
than any living carnivore. no wonder people once thought this was the world'smost ferocious predator. but could it be thatlike the komodo dragon t rex was actually a betterscavenger than hunter? modern scavengers, likevultures and hyenas, have a highly developed sense of smell. and scans on fossilizedtyrannosaurus' skulls reveal an overdeveloped olfactory bulb,
the part of the brainresponsible for smell. and its tiny front legs,smaller than a human arm, would have been no use for holding prey. we may never know for certain whether t rex was ahunter, scavenger, or both because reconstructing the behavior of extinct animals is difficult, especially when you can't compare them to their modern relatives,
thanks to visitors from outer space. 65,000,000 years ago,the tyrant lizard king disappeared forever when a meteorite hit mexico's yucatan peninsula. (explodes) the impact caused firestorms and tsunamis. it hurled so much materialinto the atmosphere that it created nuclearwinter type conditions on a global scale.
scientists think that the size and timing of the meteor strike explains the extinctionof not only the dinosaurs, but 70% of all speciesliving on the planet. and the scariest thing is that one day it will happen again. asteroids are chunks of rock left over from the formation of our solar system 4,500,000,000 years ago.
most are kept at a safedistance from earth. but the gravitationalinfluence of giant planets, such as jupiter, can nudgeasteroids out of orbit and occasionally send themplunging toward earth. on march 23rd, 1989, a chunk of rock 300 meters in diameter missed the earth by 600,000 kilometers, passing through the exact position where the planet had beenonly six hours earlier.
since nobody saw it coming, we had as much warning ast rex about the possibility of an explosion that would have seen the end of the world as we know it. however, the meteorite thatwiped out the dinosaurs left the door wide open forour next awesome ancestor. in south america, there was a time when the land was ruled by a savage animal that ate saber-tooth cats for breakfast.
its descendants still huntin the grasslands today. meet the seriema. just like its awesome ancestor, it prefers walking to flying. it uses heavily clawedfeet and a robust beak to violently kick and pecksmall animals to death. today it stands one meter tall and weighs little more than a kilogram. but its awesome ancestorwas much, much bigger.
imagine being chasedby a 150 kilogram bird that could run twice as fast as any human. it was armed with 10 centimeter claws and a 60 centimeter long head that was practically all beak. no wonder this flightless hunter was called the terror bird. with the extinction of the dinosaurs, the terror bird grew to become
one of the top predators in south america, even capable of takingon saber-tooth cats. it's number two in the countdown because it was over 300 times the size of its modern descendant. however, there wasanother awesome ancestor on the plains of south america that towered over the terror bird. at more than 700 times thesize of its modern descendant,
it was the greatestgranddaddy of them all. (squeaks) we've seen the nine contenders. they're the best of the best. only one animal was abigger blast from the past. the modern descendant of the most extreme awesome ancestor in the countdown can be found hanging aroundin the forest of the amazon. it's the sloth.
it weighs little more than four kilograms. and 2/3 of that can be thecontents of its stomach. the leaves it eats providevery little nutrition and don't digest easily. so it uses a very large, specialized, slow-acting stomach to breakdown the tough vegetation. the digestive process can take more than a month to complete. that's why the sloth onlyneeds to make its way
down to the forest floor oncea week to go to the toilet. it's very particularabout its bathroom habits, just like its awesome ancestorthat once went to the toilet in this cave in nevada. (slow drum music) this poo is 11,000 years old and was deposited by anancient herbivore that was big, very big. the super pooper wasthe giant ground sloth.
it stood nearly six meters tall and weighed as much as a mammoth. it's number one in the countdown because it was 750 timesbigger than its descendant hanging from trees today. while both sloths used their claws to hang on to branches, the giant ground sloth coulduse its 50 centimeter claws to rip trees in half.
by analyzing dna samples takenfrom giant ground sloth dung, scientists have confirmedthat it's most closely related to the south american three toed sloth. however, paleontologistsare not the only ones using dna to uncover awesome ancestors. in san francisco, dr. jasoneshleman from trace genetics helps people follow their family tree back hundreds of generations. and all you need is alittle sample of dna.
- dna is the molecule, exists in virtually everycell of every organism, every bird, every flower, every person, that provides the blueprint or code for how that bird, flower, or person is put together biologically. - [voiceover] all humans share more than 99% of their genetic code. but every so often, asmall piece of dna mutates.
it's these harmless mutationsthat makes us all unique. by comparing these tiny differences, dr. eshleman and his team can create a map of who we're related toand where we came from. - when somebody is interested in investigating theirancestry through dna, it's a very simple process. we take a sample of them, painless method. we take a cotton swab, a glorified q-tip.
and they can just scrub off a few cells from inside of their mouth, mail it to us. we can take the bits ofdna that are on that swab, purify it, analyze it,and compare it to dna from people all over the world's to get an idea of where thedna that was on that swab in their cheek came from backthroughout human history. when using dna to look atancestry, there are surprises. somebody who thinks that they might be
entirely european in origin may be surprised to findout that they have genes that are also shared withpeople in eastern asia or genes that are alsoshared with people in africa. we're all fairly closely related, when you get right down to it. - [voiceover] and whilethe giant ground sloth is also fairly closely related to its modern descendants up in the trees,
it's much, much bigger. no other animal in the coundown has such an enormous difference in size. (tapping) and that's why when itcomes to awesome ancestors, the giant ground sloth really is
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