Original subtitles

Nature twisted horn narvalului

And shell snails and their relatives.

But what is the purpose of this action?

I met many fascinating animals,

but some seem particularly interesting.

Some are very familiar - we know them for centuries.

Others were discovered only recently.

All but raises interesting questions

And in this series, I try to find answers.

David Attenborough curiosities OF NATURE

Spirals are a commonplace in nature.

Rarely give them attention.

Practice, they have some great features

run many animals.

Some creatures, who developed a spiral

remodeled it in strange and wonderful ways.

In this episode, I try to find out why spiral

It is so important for two different animals.

A strange twist

Narvalul lives in the cold waters of the Arctic Sea.

It is rarely seen and they know very little about his life.

400 years ago, it was the source of myths and stories

which fooled many people, including the royal houses of Europe.

These are modern tapestries from Stirling Castle,

but exact copies of the originals are medieval.

They appear on some images

of a beautiful creature, the unicorn.

In the Middle Ages it was believed that the unicorn is a real animal

with magical powers.

King Scoþiei included the image of the stem,

and while it was inherited by the British on their coat of arms

And stands face to face with a lion English.

In the Middle Ages it was believed that the unicorn horn

detect and neutralize poison can.

So it is understandable that most kings of Europe

also wanted to have a wonderful and powerful object.

Such was hard earned treasure.

In the 16th century, an English sailor discovered incidentally one.

In 1576, Martin Frobisher sail in the North,

in search of a route linking the Atlantic to the Pacific,

And when he reached the shore of the frozen north of Canada

discovered seafront "unicorn horn".

When brought to England and quickly found a buyer -

Queen Elizabeth I.

It is the object

Sir Martin Frobisher who presented Queen Elizabeth I.

It is said that gave him 10,000 pounds.

To today, as over half a million.

"Horn of the Unicorn", worth more than its weight in gold.

Subject however, it was not what he believed Elizabeth I that is.

It was not a mythical animal horn,

Horn was a species of whale swimming in the Arctic Sea -

narvalul.

The first copies were brought south by the Vikings.

It seems they knew exactly to the origin,

but for 400 years they have maintained story

the origin of the mythical unicorn.

And further south in Europe, no one knew the narwhal,

And natural history books describe in detail the unicorn,

as if there really.

Unicorn Horn is hard to come by,

dishonest merchants meet demand for rhino horn grinding.

Basically, two types of corn are totally different.

It sees this narwhal skull

horn hole where he lives normally.

Increases the lip.

Rhino horn is basically Keratin,

the same material from which our nails done,

while narwhal horn is made of dentine.

Actually not a horn,

It is an enormous canine - a ivory.

Some women and they corner, but overall,

males have these long corner,

and which can reach three meters in length.

It was described as something between a tirbuºon

And a suliþã.

Savanþii true purpose puzzled for centuries.

Few creatures have ivory.

The best known are elefanþii.

Fildeºii Increase their incisors are actually.

The elephants, they have both sexes,

And they are being used in various ways, but especially to get food,

the hole in the ground, the grass torn or smashed trees.

Obvious difference between elephant and narwhal

narvalul is that only an ivory,

and the elephant has two,

but not always so.

This is a rarity.

Two ivory skull of a narwhal.

This rarity can open us a window into the past.

Maybe ancestors once had two corner narvalului,

and while they lost one.

What is their purpose?

One of the first supoziþii was that using fish caught,

Although he could not explain how transferring prey

capãtul colþului of the figure.

Someone else suggested that the animal

Uses corner to break through the ice.

Sympathetic, because narvalul spends most of his time under the ice,

but the mammal, and must emerge as breathing.

It is strange, however, that only males ivory.

And females must breathe.

Charles Darwin offered another explanation.

He likened ivory horns worn by male deer.

Deer antlers helps establish hierarchy in the mating season.

Deer with large antlers tighten the dominance states

sometimes waving them and battling with them.

Darwin said that Ivory's long narvalului

It works the same way -

a statement of domination and, if needed, and as a weapon.

That explains why males have these long corner.

That's why, when males meet, sometimes tighten încruciºeazã colþii,

in what can be considered a ritual battle.

Darwin's theory was accepted many times,

but recently, savanþii explored other possibilities.

Our teeth are a cover the thin layer of enamel

which protects the soft material underneath.

If it's damaged nerves are exposed

teeth, making them very sensitive to temperature.

Narvalului corner does not have this layer of enamel,

and high resolution images have revealed something unusual

linked to the external surface of the elongated tooth.

The surface is a

million holes called tubuleþe.

Each tubuleþ contains a fluid and is based on a nerve.

The fluid reacts to the environment,

so it is very sensitive ivory.

Tests have shown that narwhals can detect

the smallest changes in temperature and salinity of the water,

Key elements that determine the formation gheþii.

Their migration is related to narrowing

And widening of gheþã seasonal blanket.

So probably that corner aims to detect ice and open water.

His powers and sensors can be larger.

And probably can detect movement in the water,

or modiicãrile fertility in females.

There are theories to be verified.

If it is a sensor,

then duels males should be interpreted otherwise.

Perhaps they like to colþii and rub together.

A third explanation could be more practical.

Narvalilor Colþii elderly end up being înveliþi algae

which can block pores that lead to the nerves.

So males tighten colþii rub them together to clear a.

It could be a mutual care not fight?

Why only males have this tool touch not know.

Instead of being a weapon, this highly sensitive corner

helps males to find their partner.

More than likely that Ivory has several functions,

but why it must be twisted?

Twisting surface increases

And thus more exposed nerve terminaþii

thing that increases the sensitivity.

Another theory suggests there

that basically helps turning the corner to be right.

It seems counter-intuitive,

but fildeºii other large animals tend to flex up or down.

Increasing ivory spiral helps to maintain law

And thus reduce Traction in water.

There are also another way that helps turning the swimmer.

While the animal forward,

Remove the water around the corner from him, spiral, reducing Traction.

Today We know the true identity of animals

producing these spectacular suliþe of ivory.

The myth that came from unicorns was shattered in 1638

a Danish scientist, Ole Wurm, a press release

which clearly reieºea be from narwhal.

Then, of course, its value dropped.

Today not think it has magical properties,

but still do not understand many things about him.

Further dscoperim nautilus shell and the snail as

They differ in how they are twisted.

Narvalul is unique in its own way.

No other animal has a tooth as a suliþã,

So how I think they unicorns.

The second topic belongs to a group of animals

who took spiral and adapted it in a variety of ways -

snails.

When the first snails crawled out of the sea on dry land

They took and shell

which will prove crucial element in their survival out of the water.

They were distant relatives of the other creatures with shells

that dominated the seas millions of years.

It's amoniþi.

Here's one of them old almost 160 million years.

Although to a point they experienced shell shape,

nearly all looks so -

turtiþi, spiralaþi and symmetrical.

While, amoniþii disappeared

but since then, other creatures have developed shell

in a variety of shapes and sizes.

This variety has shown success enjoyed spiral

basic design as the shell ...

... And how can be designed and decorated.

Snail shell, the shell eggs and poultry,

It is made of calcium carbonate.

It appears at the beginning of life snails

not ever deny it, but simply increases while the animal is higher.

Regardless of shapes and sizes, they are always spiral.

Spirals are used by animals for a long time.

We can trace back in time to a group of marine creatures

which first appeared about 500 million years ago,

and there are also some today.

Here's one - nautilus.

Today, is found only deep in the Indo-Pacific ocean,

but millions of years ago, these animals were widespread.

Their ancestors however, had a different form.

There is evidence that nautiloizii were originally righteous,

it just a little curbaþi to the top

And then they were righteous, so,

with separate chambers along their length.

As they past million years started to twist,

So until they arrived.

Then, after millions of years,

Another group adopted turning the symmetry.

These are the amoniþii.

Why these animals and twisted cochior?

If cochior remain straight while high,

will inevitably be somewhat burdensome.

Twisting made them more compact and perhaps more mobile.

Whatever the reason, changing the shape of the shell was a success.

They appeared thousands of new species, all twisted shell.

These fossilized shells tell us

something about soft bodies inside,

but living nautilus can tell us more.

At first only the shell is made up of several rooms,

but can reach maturity and 30.

Richard Owen, the founding director of the Museum of Natural History in London

He made the first complete description of the nautilus.

This is Owen's personal copy and is full of drafts.

His drawings show how the animal is placed inside the shell.

Almost the entire soft tissue and tentacles

is in the outer room,

And a long tube called sifunclu through all rooms

And through it the animal can pump water in or can remove,

And thus regulates buoyancy tighten.

Nautilus spiral not only protects the soft body of enemies,

but it allows them to move and,

And it is so resistant that Nautilus can dive up to 700 m,

where the pressure would kill a human.

At the height of their success,

There are hundreds of species of nautiloizi,

and their cousins ​​were even more diversificaþi amoniþii and variation.

Their shell floats allowed some of these creatures

to reach huge sizes.

Some were as a man.

But it was impossible for such creatures

to leave the water with such a shell.

It would have been too heavy and cumbersome.

However, something happened moluºtele,

They could leave the water and moved on land.

Amoniþilor Dynasty has developed various types of shells,

and coiled same chip.

Some of these new forms feed on seabed

And therefore they did not need to be too mobile.

Other relatives of amoniþilor shell went further,

And they changed shape and twisted shell and their soft bodies.

These are the descendants of them - snails.

The problem symmetric shell

whorl is that each should grow outside another,

so it quickly get very large shell.

Becoming asymmetrical and compensating each whorl on the side,

shell remains more compact, more rounded and easier to handle.

Changing symmetry snails

It seems to be triggered by the action of a single gene.

This change can bring complications.

Due to the asymmetrical shape of the shell,

snails must be positioned carefully when they mate.

In most snails, that's not a problem,

because their body's basic plan is the same.

But not all.

Just like people who are right-handed or left-handed,

shell snails can twist left ...

or right.

The vast majority of snail shells, turned right,

but in an area of ​​Japan

left turning the clear benefits of this species.

Because of this creature - a snake that eats snails.

ªarpele is so specialized and developed jaws

asymmetric shape to become prey.

The right side of the lower jaw has several teeth than the left.

Recently, Japanese savanþii filmed hunting behavior of this snake.

When attacking a snail with shell turns to the right,

extra row of teeth penetrate the snail meat

And by moving forward and backward jaw,

snail shell separates body.

But when attacking a snail with shell turning to the left

things are not so simple.

Position shell means

that the snake can not use its specialized jaws as efficiently and quit.

Tereºtri snails shell helps conserve moisture and to-

And protect them from enemies.

Soft body of the snail,

it is a mass welcome for any predator can break the shell.

Some snails and shells have hardened.

Some are protected Thep.

Others are very thick, almost can not be broken.

Some savanþi I think this is the golden age of snails

It never was so that species on various

or variety of shells.

While snails are variations,

nautilus not.

The oceans were once dominated by creatures like this,

while today there are only a small number of species.

While snails took a shell and changed continuously,

modern nautilus spiral remained symmetrical block

which has changed little for hundreds of millions of years.

It is fair to say that nautilus shell

It is a window into the past, back when

a simple spiral, but symmetrical dominate the seas.

Both whales and snails advantage as twisting,

a pattern that emerged 500 million years ago,

And which is still widespread today.