Woolly Mammoth: Secrets from the Ice Page #2

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This wall of ice marks the point

two thirds of the way up

the Athabasca Glacier,

which is about four miles in length

and feeds off the huge

Columbia Icefield in Western Canada,

but even that would have been dwarfed by

the huge ice sheets of the Pleistocene.

In places the ice would reach

up to 13,000 feet thick.

These glaciers are really beautiful.

Really craggy. You look down into the

crevasses and they're deep blue inside.

They're rivers of ice.

It's incredible to think that most

of that would have been under ice,

with just perhaps a peak of the highest

mountains popping out above the ice sheet.

This is amazing!

Wow! Oh!

The ice sheets locked in so much water

that they created cloudless, blue skies.

At latitudes below the ice,

this provided perfect growing

conditions for shrubs and grasses,

creating a vast grassland,

known as the mammoth steppe.

The steppe proved to be a massive

untapped food supply

for any animal able to adapt

to eating its plants.

This newly available niche

drove the mammoths

to evolve from their origins in the

warmth of the southern hemisphere.

At London's Natural History Museum,

Professor Adrian Lister

has traced those origins

through his collection of bones,

tusks, and, in particular, teeth.

What we've got here is a lower jaw,

or mandible, of a very early mammoth.

So here's the jawbone,

and this is a kind of molar tooth

that is adapted for eating plant

matter, as all elephants and mammoths do,

and, by counting the number

of enamel ridges in this tooth -

this one's got about ten -

we get an idea of what kind

of plant food these animals ate.

This one would suggest that this creature

was eating the leaves of trees and shrubs,

quite soft vegetation.

Teeth like this show that mammoths

shared a common ancestor with living

elephants about six million years ago.

Over the next three million years,

mammoths separated into different species

as they moved north

from their Southern African origins.

It was the early mammoths

that grew truly huge,

some standing over four metres tall

at the shoulder,

and weighing twice as much

as an African bull elephant.

From about three million years ago,

we pick up the first remains of the

mammoth line out of Africa, north of Africa.

As they moved through

the Middle East and into Eurasia,

mammoths evolved very quickly.

Adapting to the cooling conditions,

their tails and ears shrank

to conserve heat.

Woolly mammoths eventually ended up

the same size as Asian elephants.

Just like elephants, they probably

spent most of their day eating,

but the plants of the steppe

were far tougher than

those available in the tropics.

Mammoths had four molar teeth.

To cope with the wear and tear

caused by their new diet,

these molars evolved to have

more ridges and higher crowns

than seen in their relatives.

And so we have fossils

like this molar, from Siberia,

and that is just about as far

as it got, that's the limit.

So you can see that there's

about 26 of these enamel ridges.

They're very closely packed.

This is an almost 100% grass eater,

which is a late Pleistocene woolly

mammoth. This is from the last ice age.

As members of the elephant family,

it's believed that mammoths would have behaved

in a very similar way to their modern relatives.

They would have lived

in extended social groups,

females of all ages,

young males and infants.

Now,

remains from the Siberian permafrost

are revealing far more than

just teeth and bones ever could.

The frozen baby Lyuba shows that

mammoths possessed an unusual tool,

perfect for feeding on the steppe.

She's got this very particular shape

to the end of her trunk,

which is quite different

from modern-day elephants,

and it's designed

to be able to delicately pull up

little tufts of newly-sprouted grass

and shrubs.

Because Lyuba is so well-preserved,

new scientific techniques have enabled

us to examine her internal organs,

revealing startling adaptations

to the extremes of the Ice Age.

Recent CT scans show her kidneys are far larger

than you'd expect in an animal of her size.

This type of oversized kidney is

also seen in desert-adapted camels

suggesting that mammoths'

internal structure was also changing

to cope with the dry conditions

of the Mammoth Steppe,

where there was plenty of food,

but little water.

Frozen carcasses like Lyuba

are revered by scientists

as windows into the past.

She was found on the banks

of the Uribei River,

on Siberia's Yamal Peninsula.

She was brought in from the cold by

the French explorer Bernard Buigues.

He's hunted mammoth remains for over

which he shares with scientists

around the world.

Here we have approximately 400, 450

remains of different mammoths, yeah?

But, of course, not 450 full carcass.

But each bone can tell you

the story of the animal

so we can say that, here,

we store around 450 mammoth.

Bernard works closely with a large

network of indigenous Arctic people.

They contact him when they stumble

upon mammoth remains.

He now gets more calls than ever

as the permafrost is melting

at an unprecedented rate,

exposing potential new finds.

A brief window of fine weather

bathes the Arctic

in round-the-clock sunlight

each summer.

It's the perfect time for me

to join him as he makes camp

and starts a new expedition following

reports of a mammoth discovery.

If true, it will further our

understanding of these Ice Age titans.

We're deep in the tundra here, about

and it's beautiful sunny weather

at the moment,

but it could turn at any point

and the snow could return.

This is such a dynamic time.

Things are on the move,

and things are being eroded as well.

The river banks are literally falling

into the rivers as the water levels rise

and so it's precisely now that

ancient remains start to come to light.

Bernard's a member of the

International Mammoth Committee...

.. a team which includes

palaeontologists...

.. geophysicists

with ground-penetrating radar...

.. and even an ex-KGB officer.

Professor Dan Fisher

of Michigan University

is the world's leading

mammoth tusk expert.

He visits the Arctic each year,

and, through analysing

hundreds of tusks,

he's developed an unrivalled understanding of

the mammoth populations that once roamed here.

So did tusks grow throughout

the life of a mammoth?

Do they actually represent

a record of an entire lifetime?

They do.

That's one of the,

I mean just thinking of it

sort of aesthetically,

it's almost magical,

but here these things are that do

grow throughout life,

that are virtual diaries.

There are days represented,

each day as a thin layer of dentine,

days, weeks, years

are all recorded structurally

and in patterns of

compositional variation

and of course they didn't do

it for our benefit!

But what insights it gives us

in the lives of these animals.

'Although each tusk is a valuable

source of information,

'it's only when multiple finds are

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