The Compulsive Communicators Life on Earth

Why are you going that way?

You and I belong to the most widespread and dominant species of animal on Earth.

We live on the ice caps at the pole and the tropical jungles at the Equator.

We've climbed the highest mountain and dived deep into the seas.

We've even left the Earth and set foot on the moon.

And we're certainly the most numerous large animal.

There are something like 4,000 million of us today.

And we've reached this position with meteoric speed.

It's all happened within the last 2,000 years or so.

We seem to have broken loose from the restrictions

that have governed the activities and numbers of other animals.

Why should this be?

Well, the story starts back in Africa.

Ten million years ago, much of East and Central Africa was covered by wide open plains,

just as it is today, and living there were herds of grazing animals.

The ancestors of the antelope originally lived in the forest.

Other kinds of animals from there also ventured out into the open

in search of food.

Apes had come down from the trees.

Like the vervet monkeys of today,

those ancient apes probably stayed close to the fringes of the forest at first,

but regularly wandered out into the open to collect insects, seeds and other morsels.

The earliest of these ground-living apes were not much bigger than vervets,

but slowly, as they colonised the grasslands, they became better adapted to life in the open

and they grew somewhat in size.

About three million years ago, there were several species of them on the African plains,

and this is the reconstructed skull of one of them.

It has several characters which are an inheritance

from the tree-living, ape-like ancestors of this creature.

We can guess that its sense of smell, for example, wasn't very good.

The nasal cleft is quite small.

On the other hand, its vision was very good. It had two large, forward-facing eyes.

Its brain, while quite large, is only about half the size of that of modern man.

Although the teeth are missing in this specimen,

we know from others that they were remarkably even

and lacked the two long downward-pointing fangs which are sometimes present

and which lock the lower jaw in position.

So we can guess this animal could move its lower jaw from side to side

and was able to chew roots and nuts as well as eating flesh and maybe fruit.

Their fossilised bones are very rare.

We still don't know how many kinds there were or how they were related.

But on one thing, all who've studied their remains are agreed.

Those ancient apes included the ancestors of mankind.

They can be called, in fact, apemen.

And grasslands like these must have been the cradle of humanity.

Out on the grasslands, the talents the apemen's ancestors developed to cope with life in the trees

were put to other purposes.

Hands, once used for gripping branches,

were not much use for burrowing or tearing flesh.

But as time passed, they became more precise and dexterous in their grip

than any other primate's, and very like our own.

And these enabled the apemen to pluck not only leaves and fruit

but also to gather relatively fiddly morsels - nuts, seeds and insects.

The apemen were still quite small and largely defenceless.

This was a serious handicap,

for life on the open plain was dangerous.

As well as the harmless herds, there were hunters around.

LION GROWLS

The only way of escaping such enemies

was either to run fast, which the apemen weren't very good at,

or to climb a tree, of which there were not many.

So it obviously was of the greatest importance to get the earliest possible warning of danger.

Their ancestors' life in the trees led to a reduction in their sense of smell

but extremely good vision.

So the apemen must have reared up to get a good view of their surroundings.

And the vervets, faced with a similar problem, adopt just the same solution.

It's unlikely the apemen stood erect as a way of increasing speed,

for running on four feet is a much swifter way of getting around.

A vervet can outpace any two-legged primate.

But if you habitually rear on your hind legs, you can use hands for other things,

and one modern ape, the chimpanzee, does just that.

Chimps are the only animals that defend themselves with weapons like this.

ANGRY CHATTERING

There's every reason to suppose those early apemen could throw sticks and stones

just as modern chimps can.

Indeed, they would be in need of every form of defence they could get

because their teeth were small and they had no claws.

So, if threatened by a predator, they would pick up a stick

to try and defend themselves out on these African plains, as indeed I would.

And, what's more, with this in their hands,

they would stand some chance of driving off a predator from its kill

in order to claim the meat for themselves.

And eating meat has a lot to be said for it.

Getting all your sustenance from leaves is laborious and time-consuming.

They have comparatively little nourishment in proportion to their bulk.

So zebras are compelled to spend nearly half of their days grazing

in order to get all the food that they require.

The flesh-eaters, on the other hand, have a much lazier life.

Meat is so nourishing that lions only need to eat every two days or so,

and then only for about half an hour.

Doubtless, leisure had its appeal to the apemen too.

Whereas lions simply sleep, maybe the inquisitive apemen

used their spare time to socialise, to play, to create.

A kill on the plains, no matter who makes it, attracts all kinds of flesh-eaters.

A whole pride of lions may find more than they need in a single zebra carcass.

One way or another, everything is consumed,

even the tail.

And when the biggest and most powerful have taken all they want,

there are plenty of scavengers to clear up the remains.

Well, I only had vultures to deal with that time, and I didn't even need a stick.

If there'd been hyenas, I guess I would have needed it, but I could have got rid of them.

And maybe if I'd had a few companions, I could have shifted a pride of lions.

But having got here, how could an apeman with small teeth

manage to get into a carcass like this?

Well, he could take a stone and...

And it's already cutting, and this is really a quite ordinary stone,

but one that has just been chipped here on either side to produce a cutting edge.

And just such stones have been found with the skeletons of the earliest apemen

of about two million years ago.

So, with a chipped stone, a stick and a pair of manipulative hands,

the apemen could have survived out on the plains as hunters.

This state of affairs lasted for several million years.

Slowly, the apeman became better at walking.

His legs lengthened to increase his stride,

and he grew to a height of about five and a half feet.

To mark his new stance, science has given him a new name.

Homo erectus - "upright man".

The foot acquired an arch to give a spring to his stride,

and his first toe grew to take the thrust of the foot.

The name "man" here has no sexist implications.

It's the scientific name for the genus to which these women, children and men belonged.

And a million years ago, they spread widely over the African plain.

Their fossilised remains are very rare,

for bodies lying out in the open are eaten by scavengers

and bones weather into dust.

But stone is much more durable, and in some places, the tools made by upright man

still litter the ground in huge numbers.

From them, we can see he was using his dexterous hands with increasing skill.

Almost every one of these stones, which have washed out from that bank over there,

have been worked by man in one way or another.

Some of them are far more elaborate than anything produced by the apemen.

Like this one, for example. Beautifully chipped.

This was probably a hand axe, used for digging up roots.

And then there are cleavers like this with a flat cutting edge.

They may have been used in butchering animals, cutting flesh and stripping skin.

These aren't the only tools.

This rounded stone has not been rounded by a stream, which would produce smooth surfaces,

but carefully chipped,

and it's probable that these rounded stones, of which huge numbers have been found here,

were used either for pounding vegetables of some kind

or as weapons.

And the reason we suppose they were used as weapons

is because also on this site have been found great numbers of animal bones.

This and most of the bones found on this site belonged to an extinct baboon

that was even bigger than the living baboon.

Most of these bones, like this fragment from the lower jaw, there are the teeth,

have actually been split open in order to get out the marrow.

This remarkable site provides a lot of evidence about the nature of upright man.

The stone from which tools are made, and there's around a ton of them,

doesn't occur naturally within 30km of here.

So all these stones must have been brought here deliberately by the people,

and that suggests foresight and planning.

For another thing, the baboon they hunted must have been a ferocious animal.

I don't imagine there are many men who would fancy the idea of going out

and trying to hunt a baboon armed with a few cobblestones.

And yet the extinct baboon was even bigger and presumably more ferocious.

So it seems likely that the early people hunted in teams.

Teamwork, foresight, planning.

That argues that they had some considerable skill in communicating among themselves.

SHOUTING

Letting others know how you feel is a basic part of communication.

No creature in the world does so more eloquently than man,

and no organ is more visually expressive than his face.

Even in repose, the human face sends a message, and one we tend to take for granted.

Each face proclaims individual identity.

In teams, recognition of other members is of great importance.

A hunting dog in a pack proclaims its identity by its own smell.

Primates, with their reduced sense of smell but very acute vision,

do it by the infinite variety of their faces.

We have more separate muscles in our faces than any other animal.

So we can move it in a variety of ways no other animal can equal.

And not only convey mood but send precise signals.

By the expression on our face, we can call people and send them away,

ask questions and return answers without a word being spoken.

Eyebrows are particularly eloquent.

We can use them as question marks and as greetings.

But are our gestures recent conventions we've learned from one another?

Or are some inherited from our remote ancestors?

Did upright man formulate his hunting plans by pointing and nodding

and express his delight with a smile?

If we could meet modern men who have never been in contact with our world

and discover whether we had signals in common,

then we might find clues to the answer.

Ten years ago, I had the chance to do just that.

A patrol led by an Australian government officer

was going to cross one of the last patches of unexplored country in central New Guinea.

And I went with it.

The tribesmen who came with us said there were people living in these forests.

They saw them rarely and knew only one word of their language, their name.

Biame.

But no European had ever seen them.

Biame!

We walked for about a week without meeting anyone, and then one morning

the Biame quietly appeared.

Biame!

With gestures, they seemed to be saying we were in the middle of their territory.

They nodded in agreement, they smiled to give reassurance.

We wanted them to bring down other members of their group

and tried to convey this complicated message with gestures.

Although our two societies had never come into contact before this moment,

it seemed that many of our gestures did have the same meaning.

These nods and smiles, frowns and headshakes

were surely not mere conventions but deep in us.

It seemed they used the same name for their rivers as the tribesmen who were with us.

Their leader counted them for us.

To do that, he used a quite different gesture,

not a deep-seated one like a nod or a smile, but a conventional one, that has been learned,

and here, our cultural backgrounds divided us.

He used the fingers of one hand for numbers up to five.

Above five, the Biame clearly have their own individual code.

It's easy to follow it in sequence like this,

but the Biame also use these gestures individually, in bargaining, for example.

And then how would we know this gesture meant "eight"?

This one "nine"?

But before he got to 11 he used two of those facial expressions

that were immediately understandable to us.

Bafflement, because we got the names wrong,

and amusement at our stupidity.

Although we belonged to such different societies

and the only words we had in common were some names,

we had exchanged complicated messages using gestures inherited from our common past.

Gestures that may well have been used before the emergence of our own species

by our distant ancestors, upright man.

For a long time, upright man lived only in Africa,

as far as we can tell from evidence found so far.

But slowly his numbers increased and he began to extend his territories.

About a million years ago, he moved north into the Nile valley

and up into the Middle East.

His bones have been found in Asia dating from about the same time

in a hill near Peking.

Others have been dug up farther south, in Java.

And about 800,000 years ago, judging from fossil remains,

upright man was in Europe in some numbers.

Now the climate of Europe changed.

It got so cold, the ice caps on the mountains and in the north expanded,

locking up so much water that the sea level dropped,

exposing bridges of land across the Mediterranean

and making it easier for man to spread.

Then the weather warmed again.

Four times this happened.

The ice, even at its worst, never got as far as these valleys in central France

but at the peak of a glaciation, this land, now so verdant and fruitful,

must have been bitterly cold.

And in response to that changing climate,

men took to caves like this one.

There are literally hundreds of caves along this valley,

and there's scarcely one that doesn't have some sign of habitation.

Because of lots of excavations in them, we now have a clear picture

of the sort of lives these people led.

They wore clothes made out of skins

which they sewed with bone needles like these.

They went down and fished in the river with bone harpoons

and they hunted with spears and harpoons in the woods.

Their skill in working stone reached new heights

and they had a marvellous material to work on - flint.

Instead of making three or four blows,

some 400 to 500 precise actions were required to get the best out of a piece of flint.

It must have taken a lot of learning.

To chip an edge accurately, it has to be made even.

A razor-sharp knife made in about ten minutes.

And a deadly weapon in the hands of these people.

They were brave and skilful hunters,

and we know from blackened stones that they had control of fire,

which must have been a precious possession, not just to keep warm but to cook their meat.

This is the skull of a man

that was excavated from just near here.

You can see his teeth for chewing that meat are now relatively small,

so cooking was a very valuable technique.

But it's not just the teeth that have changed. So has the cranium.

The parts of the brain that control speech are fully developed,

so this man had probably a fluent and complex language.

In fact, there are virtually no significant differences

between this man's skeleton and skull and mine.

So anthropologists have called him, somewhat immodestly, Homo sapiens.

"Wise man".

The huge difference that separates this man

leaving such a cave as this and going down to fish in the river

and a smartly-dressed executive in Tokyo or London or New York stepping into his car

and driving off to his office to consult the latest computer printout

is not due to any change in the brain or the anatomy.

It's due to the emergence of a completely new evolutionary factor.

And the first dazzling signs of it are miraculously preserved right here.

From the back of many of these caves, tunnels lead down into the depths of the earth.

And into this blackness,

finding their way by lamps with a rush for a wick and animal fat for fuel, went early man.

They made these long and, surely for them, most important journeys

in order to do this, to paint.

This for me is one of the most moving of their paintings.

It represents a stylised horse, here its small black head with a long black mane.

And these spots on it, which appear to be dapples, probably have some other meaning

because they extend beyond the outline of the horse.

And here, perhaps most intimate and vivid of all,

a hand-print of one of those people.

Made probably by taking a mouthful of black paint

and blowing it over the hand like a stencil.

These early people were superlative artists

and drew the animals of their world with great sensitivity and such accuracy

that often we can identify the species they had in mind.

These are bison, no longer to be found in France but still surviving farther east.

Aurochs, a kind of giant cattle now totally extinct.

This gallery contains a procession of animals,

among them mammoths, shaggy with long hair.

The oldest of these paintings is thought to be about 30,000 years old.

The youngest maybe 10,000.

That's an immense span of time.

Five times the length of the entire history of western civilisation.

So it's unreasonable to suppose they all, throughout this time,

served exactly the same purpose.

Some, however, may well have been connected with a hunting magic.

By painting images of animals they sought, the hunters tried to control them.

Certainly, most of the images represent animals that were hunted for food.

It's tempting to interpret these signs as arrows or spears.

Perhaps they were drawn during a ritual when the men mimed the hunt they prayed for.

And among these sensitive and accurate drawings of animals,

there are much more mysterious designs.

This has been interpreted as a human figure, perhaps even a sacrifice

with spears in its flanks.

As well as these, and this is significant for what is to come,

there are geometrical symbols like these paired dots.

There are other odd shapes that occur again and again.

What these abstract symbols signify we have no idea,

but the fact they occur at all is significant for what is to come,

even though we don't know exactly what they mean.

In one place in the world, however,

we can discover why a nomadic hunting people paint on rock in caves

because here, in northern Australia, the aborigines still do so.

They too portray the animals they hunt for food.

Some are drawn as part of rituals to maintain the animals' fertility.

Others are made during ceremonies where people recount stories of their creation.

For this cave is a sacred place for them.

On the back of it, they've painted the image of one of their great creator spirits.

It lies on its side, its head to the left, its legs stretching out to the right.

And aborigines also draw abstract symbols.

These lines and dots are not aimless doodles.

They represent particular things.

Homo sapiens, "wise man", has made a huge step forward in his ability to communicate.

He's discovered how to represent objects not by their likeness

but by symbols.

In this great frieze, the educated eye of a man of the tribe

can read a sacred legend

telling how the great creator spirit moved across the land in the beginning of time

and showed men how to make spears and go hunting.

The ability to distinguish the edible from the poisonous,

to track and kill animals, to discover food in all but the most sterile of lands,

enabled "wise man" to spread throughout the world.

Many groups of people today still live entirely by these ancient skills.

The aborigines, by understanding their land with an intimacy that baffles outsiders,

can survive in desert country where strangers would die of starvation in days.

In the Kalahari desert, the bushmen too live in a similar way,

with the help of similar skills.

They are the most expert of hunters.

They know how to prepare poison to tip their arrows

and with them bring down big game, like a giraffe,

though the hunt may take many days and demand the greatest bravery and endurance.

Bushman women can recognise the characters of a leaf

that tells the knowledegable that this spindly stem

leads to a tuber in the ground that is loaded with water in the most severe of droughts.

As "wise man" spread through the world, so his body responded to his surroundings.

The rays of the sun in excess can be harmful

and many dwellers in the tropics acquired black pigment in their skins

which protected them from it.

But too little sunshine can also be bad for you.

The body needs it for vitamins,

so in northern lands, in Lapland, for instance, races possess fair skins.

In Asia, there developed a race with olive skins and slanting eyes.

Some of them migrated across the Bering Strait into the New World

and down to the rainforests of South America, where they still live.

They too are skilled hunters, and some still find all they need

from the wild animals and plants of their forests.

This was the way all human beings in the world existed until comparatively recently.

Nowhere were they numerous.

Their expectation of life was short.

Their birth rate and the survival of their children

kept in check by the scarcity of food and the hazards of their lives.

But then came a revolution, one that was to start that explosion of man's population.

And the trigger was this.

A wild form of wheat or barley

that grew then as now on the fertile deltas of the Middle East.

It's got a lot of seeds, easily separated from the husks and full of nourishment.

About 10,000 years ago, man realised

he no longer need go searching for the wild plant.

He could take these seeds and plant them.

And then he would no longer be compelled to follow the wandering life.

He could settle down.

Some animals too could be domesticated and kept permanently around his settlements,

to be slaughtered when he wanted meat.

So human beings were able to build permanent homes in groups close by one another.

And around the eastern end of the Mediterranean,

in the Middle East and India, small villages appeared.

The villages grew into towns,

and by 5,000 years ago, there were great cities like this one, Uruk,

whose ruins have been excavated from the sands of Iraq.

It held several thousand people. Its citizens built walls around it for protection,

ordered their streets, dug canals to protect from floods.

And in the centre of their city, they built their temple, the ziggurat,

an artificial mountain made out of brick,

bonded together with layers of reeds.

Clearly, to build such a carefully designed monument as this on such a scale,

the people had to have real organisation.

And they must have led complicated lives too,

for not only were they skilled architects, but they were farmers,

they made pottery, fragments of it are all over this site,

they were traders and they probably also paid taxes.

At all events, they found it necessary

to have some way of recording their affairs and transactions,

because in this very site has been found this.

The earliest known piece of writing.

It's thought to be some sort of tally recording the issue of rations

over a five-day period.

Each column represents one day, and, incidentally, reads vertically.

The symbols are a mixture of pictorial representations

and abstract designs.

This triangular one is purely abstract and is believed to mean "bread".

Whereas this sign looks like and may mean a wheatsheaf.

The different-shaped dots in front refer to the quantities of each commodity.

This tablet was baked over 5,000 years ago.

But that, in the timescale that we've been thinking on,

is comparatively recently, a mere 100 or so generations.

When he marked and baked this,

man turned the surge of evolution into a new course.

Now, for the first time, it was possible for a person

to transmit information quite independent of his own existence or presence.

And so an individual man was able to pass on information

about his failures and successes, his insights, his strokes of genius,

his accumulation of humdrum facts,

from one individual to the community,

from a community to a generation, and for generations beyond.

The discovery of writing was made independently by many people worldwide.

So the question inevitably arises -

are we fundamentally and crucially different from all other living organisms?

Or is there an overall pattern into which we and all other animals naturally fit?

All living things are continually influenced by information from the past.

And the more information they get, the better they can solve their problems.

Every animal receives that information inherited from its parents,

and coded not in letters but in chemicals - DNA.

These are models of just one section of that giant molecule of DNA,

vastly enlarged.

Many molecules go to make genes,

and genes together can be regarded as a library of instructions to an animal

on how to solve the problems of survival.

Clusters of genes in the primordial seas

began to reproduce some 3,500 million years ago. Bacteria.

If we represent the immense period of time between then and now by one year,

and this stage is its first moment,

then more complex micro-organisms like these

didn't develop until the middle of August, over 1,000 million years later.

As time passed, organisms accumulated more genes that could carry the instructions

necessary for building bigger and more complex bodies,

which in turn could solve more difficult problems of survival.

And so animals found new ways of living in the seas.

At the beginning of November, the first backboned creatures appeared.

Towards the end of that month, the first animals left the water

and colonised the land.

And now the pace quickened.

The backboned animals also invaded the land.

By the beginning of December, some had acquired waterproof skins

and broken their dependence on water.

During the middle of December, one group could generate heat in their bodies,

and had elaborated their scales into feathers.

The first furry warm-blooded creatures appeared around the same time,

but it wasn't until 25th December that the dinosaurs disappeared

and the mammals came into their own.

The information and instructions carried by the DNA in the sex cells was supplemented.

The young mammal, dependent on its mother for milk and protected by her,

begins to learn from her how to deal with the world around it.

So animal communities developed traditions, cultures,

and were able to transmit them from one generation to another.

Now the skills acquired during an individual's lifetime

need no longer die with it.

Some at least could be handed on, supplementing the inborn genetically programmed skills.

In the early morning of December 31st,

apes and apemen appeared.

And we arrived about two minutes before the end of that last day.

No creature is so dependent upon its mother for such a large proportion of its life

as is the human baby.

And through language, none learns so much from her or so quickly.

Come on. You're not very awake, are you?

Our spoken language is enormously more subtle and informative

than any other system of communication in the animal world.

It's almost impossible to prevent a baby from acquiring it.

Are you going to open that?

By the age of five, every child will have mastered the meaning of 6,000 words

and is able to operate 1,000 rules of grammar, an astonishing feat of learning.

As their world expands, they learn not only from their parents

but other children and adults,

so that the whole accumulated experience of the community can become theirs.

By means of words, skills can be rapidly taught and problems quickly explained and solved.

Make sure it's nice...and strong

and helps the pot.

Nitrogen...dioxide.

And they learn, too, to comprehend symbols that not only represent spoken words

but completely new concepts.

Di-nitrogen oxide.

Now, as in our previous experiment, we're going to heat lead nitrate here.

We're getting a nice flow of colourless gas in the gas jar.

Notice the residue...

..Specimen to get this orientation, and this is achieved by

this here, this control here.

Over the past 1,000 years,

cultures have devised ways of duplicating those symbols

so that one individual could communicate with thousands.

Printing.

A great library can be seen as an extension of the human brain.

But it contains far more information than any single human memory could do.

Here are stored the insight, the experience, the wisdom of past generations

so that we can consult it, benefit from it and, in turn, contribute to it.

So we're no longer dependent on the very slow processes of physical evolution.

If we need to fly, we don't have to wait millions of years

while our arms turn into wings.

Over a few generations, we can study the problems of physics and metallurgy

and mathematics and aerodynamics,

and build ourselves aeroplanes.

As this information increases with growing speed,

so we've developed radically new methods of storing and retrieving it all.

The computer, the transistor, the microprocessor and the silicon chip,

all developed within the last decade or so,

now give us greater power to sort our knowledge, to link fact to fact

so that our understanding of the nature of the world we inhabit

becomes ever more detailed and subtle.

With the help of electronics, we can recall information

from data banks, no matter where they are,

and we can communicate directly and instantaneously with one another

right round the globe.

We can predict the behaviour of our machines

and make calculations which were once quite beyond the human brain.

And with the existence of worldwide communications

and the use of powerful computers,

we can forecast with greater precision that most unpredictable of events on our planet,

its daily weather.

20,000 years ago, man drew messages for the gods in caves.

Now he sends them to extraterrestrial beings in the sky.

In his rockets, he puts images to greet other beings in other galaxies

in case they exist.

Images of himself in the gesture of welcome.

Details of his discoveries.

And photographs that he hopes may give other intelligences elsewhere

some impression of what life is like on Earth.

This is the last programme in this natural history,

and it's very different from the others

because it's been devoted to just one animal - ourselves.

And that may have been a misleading thing to have done.

It may have given the impression that man was the ultimate triumph of evolution,

that all those thousands of millions of years of development

had no purpose other than to put man on Earth.

There is no scientific evidence whatsoever for such a belief.

No reason to suppose that man's stay on Earth should be any longer than that of the dinosaurs.

He may have learned to control his environment,

to pass on information from one generation to another,

but the forces of evolution that brought him into existence here on these African plains

are still at work elsewhere in the world

and if man were to disappear, for whatever reason,

there is doubtless somewhere some small, unobtrusive creature

that would seize the opportunity and, with a spurt of evolution, take man's place.

But although denying a special place in the world may be becomingly modest,

the fact remains that man has an unprecedented control over the world and everything in it.

And so, whether he likes it or not,

what happens next is very largely up to him.

Subtitles by Red Bee Media Ltd