Attenborough: 60 Years in the Wild (2012) s01e02 Episode Script

Understanding the Natural World

1
When I first started making programmes,
the origin of life and the structure
of DNA was unknown.
The fact that continents might drift
across the surface of the planet
was ridiculed.
Then, science was something you did
in museums and laboratories.
Today, that's very different.
Today scientists travel
to the farthest ends of the Earth.
As a result of their discoveries,
we can now make sense of what
not so long ago
seemed baffling mysteries.
And for the last 60 years,
I've been travelling in their footsteps,
trying to translate
some of their insights into film.
Early in my television career,
I met the distinguished
Austrian scientist konrad Lorenz,
who was one of the first to try
and understand animal behaviour.
He worked with geese and he discovered
that if he was the first thing
young goslings saw when they hatched,
they would follow him wherever he went.
It was as if he had become their parent.
He called this process "imprinting"
and as a result of it,
the young continued to follow him
even as adults.
In 1952, Professor Lorenz
published a book
explaining how he could talk to animals
and in particular, to Greylag geese.
It was called king Solomon's Ring
and this is it.
And I was given the job
of interviewing him
on live television about it.
And I started by saying,
"Now, Professor Lorenz,
I understand you can speak
Greylag goose language,
and I've actually got a Greylag goose
here for you to have a few words with."
And the goose was very upset,
flapped its wings and went
like that, and Lorenz said,
"Oh, dear, all over the trousers!"
And very embarrassed,
took his handkerchief
and then blew his nose,
which produced a great smear
of goose droppings all down his cheek.
And I had to continue asking him
serious questions about animal behaviour
while he was covered in goose droppings.
But at least he saw the joke,
because after it was all over,
he took his book
and he drew a nice little cartoon
of the whole event in the front for me.
Today, filmmakers use
this imprinting technique
for their own purposes.
The first living creature these
young goslings saw was Rose Buck
and they stayed with her.
They even shared her bed with her.
Hi.
Off you go, then.
Good boys. Come on, then!
So now, they too
follow her everywhere. On foot
and eventually even in flight.
These are Greylag geese,
the same species
that Konrad Lorenz worked with.
And they are following me
because like his geese,
they've been imprinted on a human being.
And that human being,
of course, is Rose.
You see, they're all flying
straight in line behind one another
just as they do in the wild,
because there's a little turbulence
from the end of the wing there,
which makes it easier
for that one to get lift.
So they save energy
by flying in this way.
But who could have dreamt
that it would have been possible
to be sitting alongside one
as they do that?
Look at them! Isn't it wonderful?
The discovery of imprinting, of course,
was more than just a boon to filmmakers.
It threw a new light not only
on the behaviour of many birds,
but of animals of all kinds,
including mammals and indeed ourselves.
But back in the '50s,
other scientists were tackling some
even more mind-boggling problems.
For example, we knew next to nothing
about that great mystery of all,
the origin of life.
And then, in 1952, the year
I happened to join television,
a young post-graduate student
at the University of Chicago,
Stanley Miller, decided
to try and recreate
the conditions of the early Earth
in the laboratory.
It was a remarkably ambitious project
for a 22-year-old student.
He used apparatus like this.
In the bottom flask,
there's boiling water.
Steam from it rises up here
through these tubings
and goes to this flask here, which he
had filled with a mixture of gases,
methane, ammonia and hydrogen,
which are thought to have been present
in the early atmosphere.
And through that
he passed an electric discharge
from these two electrodes,
mimicking lightning.
Stanley Miller was working
against a deadline.
His professor had given him six months.
If by the end of that time
he had got no results,
he had to abandon his experiments
and return to working on his PhD,
which was about meteorites.
But his intuition proved correct.
A week later, he found a brown liquid
in the bottom of the flask.
It contained amino acids,
the building blocks of life.
Stanley Miller had demonstrated
that the first steps
on the path leading to life
could have happened spontaneously.
Conditions very similar to those
created by Miller in his laboratory
do actually exist in the natural world
today, in volcanic hot springs.
So, when in 1979 we came to make
a series called Life on Earth,
it seemed a good idea
to start our story
beside just such a hot spring
in Yellowstone National Park, Wyoming.
And in these springs, staining them
a whole variety of colours,
there flourish micro-organisms.
Micro-organisms that look to be
almost identical
with some of the earliest fossils
that we know.
But even as we were filming
Life on Earth,
there was a momentous discovery,
one that suggested a different location
for the origin of life.
Roger. Alvin diving.
In 1979,
the deep water submersible Alvin,
working near the Galapagos Islands,
descended more than 2000 metres
to the floor of the Pacific Ocean.
Its mission was to film
volcanic activity.
But instead of a barren,
volcanic landscape,
its searchlights revealed
a whole community
of hitherto unknown animals
that were living in this blackness.
There were giant tubeworms
nearly a metre long
and among them, small fish and crabs.
But what were
all these creatures feeding on
so far from the energy of the sun?
Plumes of water,
superheated by the molten rock
deep in the Earth's crust
were spouting into the cold sea
and the chemical compounds they carried
were being deposited
as great rocky towers.
Some of the dissolved chemicals
were serving as food for bacteria.
The bacteria nourished the tubeworms
and they, in turn,
were food for crabs and fish.
More of these astonishing ecosystems
have now been discovered
elsewhere in the world's oceans,
each with its own unique inhabitants.
Clearly, events such as these
could have supported
the first micro-organisms
that appeared in the primeval seas
nearly four thousand million years ago.
But if so, how did
those early forms of life
give rise to the great diversity
of creatures that live today?
That problem has puzzled thinkers
since the very beginning of science.
In the 19th century,
zoology was still at the stage
of collecting and identifying species.
People went out to the wilder parts
of the world and shot an animal,
often the bigger the better,
and then brought them back
in order to be measured and identified.
And here in the storerooms
of London's Natural History Museum,
you can see some of the fruits
of their endeavours.
These specimens, carefully arranged
in groups of similar species,
together form a catalogue of life
on the planet.
It was Charles Darwin who made sense
of this vast catalogue
with his theory of evolution
by natural selection.
And in 1979, we used that theory
as the basis of that television series
surveying the whole of the natural
world, which we called Life on Earth.
There are some
four million different kinds
of animals and plants in the world.
Four million different solutions
to the problems of staying alive.
This is the story of how a few of them
came to be as they are.
Early on in the series,
I went to the Galapagos
to have a look at the animals
that had provided Darwin
with evidence for his theory,
the giant tortoises.
This one, for example,
with its deep, rounded shell,
comes from a well-watered island,
where it can feed mainly
on vegetation on the ground.
This one, on the other hand,
has a peak to the front of its shell
that enables it to stretch
its long neck upwards.
It comes from an arid island,
where the tortoises often have to crane
up to reach the only food available,
the branches of trees and cactus.
The suspicion grew in Darwin's mind
that species were not fixed forever.
Perhaps these tortoises were all
descended from common ancestors
and had changed to suit
their particular islands.
The differences that Darwin had noticed
amongst these Galapagos animals
were, of course, all tiny.
But if they could develop them,
wasn't it possible that
over the thousands or millions of years
a whole series of such differences might
add up to one revolutionary change?
He gave the idea irresistible force
by suggesting a mechanism which
might have brought that about.
He called the mechanism
natural selection.
So Darwin had explained
how different species evolved.
But he also proposed
that all life was inter-related,
having come from a common origin.
That, of course, implied
the existence of intermediate forms,
links between the great animal groups.
One living candidate
connecting fish to amphibians
had already been discovered in
the rivers of northern Australia.
The lungfish.
Although it lives in water
just like an ordinary fish,
it can also breathe air
through a pouch in its throat,
like a simple lung.
And it punts itself
along the river bottom
using two pairs of muscular fins
placed low on its body,
just like simple legs.
But the actual ancient creature
that linked fish
and the first land-living creatures
wasn't found until very recently.
Fossils of fish very like
these Australian lungfish
are known from rocks
that are some 400 million years old.
And we can be pretty sure that those
ancient fish could breathe air.
But could they manage to get out
of the water and up onto the land?
How could they have managed that?
Nobody could be sure.
There was a missing link.
And then, this turned up in 2004.
This was found in arctic Canada,
and was called Tiktaalik.
You see, it's about
the same size as a lungfish
but it's got a skull
which is flattened that way
and a row of formidable teeth.
But what about its limbs?
Well, a number of specimens
of its limbs have been found
and here's one of them.
It had a fleshy base,
just like a lungfish.
But it also had a joint
in the middle of that limb,
an elbow,
and at the end, a range of digits.
This almost certainly was the first limb
to move a creature up onto land.
So Tiktaalik probably looked
a bit like present-day amphibians
such as salamanders.
The link between fish
and land-living animals
had now been found.
Another piece in the jigsaw of life
had been put in place.
But 60 years ago,
there was another baffling puzzle,
the odd way in which animals
are distributed on our planet.
For example, why is it
that closely related groups of animals
can occur on both sides of an ocean
in West Africa and South America,
for example?
Well, birds could fly
across the ocean, yes.
Mammals and reptiles, well, conceivably
they might have floated across
on rafts of vegetation.
But what about frogs?
Frogs like this one?
Frogs have permeable skins
and they're poisoned by saltwater.
So they couldn't have floated across.
But maybe it wasn't
the frogs that moved,
maybe it was the continents.
That was a suggestion
that was being debated
when I was a geology student
at Cambridge in 1945.
Could it be that the continents
of the Earth
were fragments
of a much larger supercontinent
that, over millions of years,
had drifted apart?
So I asked the professor of geology
here at Cambridge University
why he didn't tell us students
about that possibility.
And he replied, rather loftily,
"When you can demonstrate
that there is a force
that will move
a continent by a millimetre
I will consider it, but until then,
the idea is moonshine, dear boy."
But by the time I came
to make The Living Planet in 1984,
the answer had become clear.
And I thought that one of the most
dramatic ways to reveal it
would be to stand high up
in the greatest mountain range on Earth,
the Himalayas.
They were raised to their present height
about 65 million years ago,
from the bottom of the sea.
And what is the evidence
for that extraordinary statement?
Well it can be found
all over the place, just up here.
These slopes
are littered with fragments
like these.
This is obviously a shell
that's been turned to stone, a fossil.
But I'm about as far as possible
as it is to be from the sea.
Not only am I in the middle of Asia,
hundreds of miles from the sea,
but I'm over two vertical miles
above its level.
What forces could possibly have raised
the sea bed to these heights?
Well, we now know
that those forces are still in action.
These icelandic volcanoes erupt
from huge cracks, or fissures,
which regularly open up
in a line which runs right across
the width of the island.
But that line itself
is only the northern end
of a huge line of weakness
that runs for thousands of miles
southwards from Iceland
right round the side of the globe.
The sheer weight
of these molten ingots of rock
prevents them being swept away
from the vent by the gale,
so there's little danger of them
suddenly coming our way.
Well, there were pieces of lava
the size of a suitcase
landing with a thud
into the ash plain as we stood
and you could see them
glowing red hot and thumping down
into the ash. And the question is
just how close could you get?
Well, we got quite close enough
and when a lump of lava
did actually land
only about three or four feet behind me,
I thought the time had come to leave.
Now we know
that it was eruptions like these,
but at the bottom of the sea,
that explain the mystery.
Molten rock rises from the Earth's core.
Near the surface the rock spreads
in two directions and goes sideways.
It begins to lose heat.
Eventually, the much cooler rock
sinks back down.
Through this spreading process,
the Earth's crust
is very slowly dragged apart.
And it is this that ultimately
makes the continents move.
So what in my youth was no more
than a speculative theory
is now fully accepted.
Continents do drift.
The Indian subcontinent has moved north,
pushing up the sediments
that had accumulated on the sea floor
ahead of it to form the Himalayas.
Which is how my fossilised
seashell came to rest in mountains
over two miles high.
So, continental drift
explains why animals are distributed
in the way they are around the world.
But why do they behave
in the way they do?
Well, that has also been the subject
of investigation
in the last few decades.
In particular, how do they
communicate with one another?
Filming that gave me a chance
to join in those conversations.
A double knock on a tree is a statement
used by a Patagonian woodpecker to say,
"This patch of the forest is mine "
And if someone else claims it,
he'll certainly knock out a challenge
and come to investigate.
North American male cicadas
singing their deafening song
can be summoned by the noise
of a female's wing flick
that sounds like a finger snap.
Now can I bring you back?
And a male wants to investigate that.
How about coming this way?
Oh. The noise is awful.
In Minnesota,
it's not difficult to summon a wolf.
On Australia's Lord Howe Island,
there are other conversations to be had.
Nobody knows why it happens
but when you make strange noises here,
seabirds fall from the sky.
And in Florida, you can get
little lizards to reply to a mirror.
And there, that's it.
The full works.
All those signals are fairly simple,
but by the 1990s,
long-term studies were showing
that some monkeys
even have the beginnings
of a vocabulary.
At dawn,
Vervet monkeys come down from the trees
to search for food on the ground.
Down here, of course,
they're much more vulnerable
than they were up in the trees,
but there's always a sentinel on watch.
A python!
The sentinel gives a call
which means "snake".
The meaning is very precise,
and is only made when a snake appears.
It could be called a word,
and when other Vervets hear it,
they know exactly what the danger is.
Calls with such specific meanings
are very rare in the animal world,
but Vervets have developed
several of them.
A call that means "danger from the air".
And the Vervets run into
the denser branches,
where the eagle won't pursue them
for fear of damaging its wings.
From the safety of the thorny branches,
the Vervets scream furiously,
and one is even brave enough
to launch a lightning attack.
Communication between
males and females of a species,
not only by sound
but by visual signals, has of course
long fascinated naturalists,
particularly in the 19th century.
When I was a boy of about nine,
I read a book
that thrilled me to the core.
This is it.
It's called The Malay Archipelago.
The land of the orang-utan
and the bird of paradise,
by Alfred Russel Wallace.
And it contained one
particularly exciting illustration.
This is it. It shows
native tribespeople
hunting birds of paradise,
which are displaying in the tree.
And I dreamt that sometime
I might get there to see it for myself.
Well, in 1957, I did.
From the capital
of New Guinea, Port Moresby,
we chartered a plane and flew inland,
heading for territory that was
still regarded as being pretty wild.
After an hour's flight,
we were nearing the middle
of the mountains,
when suddenly we saw a wide,
fertile valley ringed with mountains.
This was our destination,
the place in which we planned to work
for the next few months.
The valley of the Wahgi river.
The Wahgi people knew
about birds of paradise, all right.
They used their plumes as money,
and they were essential elements
in all important transactions.
I watched a ceremonial dance in which
each man had decorated himself
with the plumes of at least
30 birds of paradise.
Here I was looking at the remains
of 20,000 dead birds.
They were clearly so keenly hunted,
we stood little chance
of finding them here.
So cameraman Charles Lagus and I
decided to go
into wilder country to the north.
It was hard walking,
but when we reached the top of the ridge
that formed the wall of the valley,
we ran into trouble.
I found, to my horror,
that the men were refusing
to go any further.
They told me very firmly that this
was the end of their tribal frontier.
I thought for a bit
that we weren't paying them enough,
so I thought, well, you know
another cake of salt all round,
that'll be all right. But no, the
It turned out that they said
that the people who lived beyond there
were bad men.
"They eat people," they said.
"We won't go there."
And I was saying, "Now, come along,
lads, we We can manage this."
When suddenly I noticed a white feather
flickering behind a boulder
and I looked round
and there was another one behind a tree,
and while I was wondering
what this meant,
suddenly, these men leapt out of hiding
and came charging
down the path towards us
waving stone axes and spears.
And I simply couldn't think of what
to do except to go towards them
and stick out my hand
and said, "Good afternoon."
And to my astonishment,
they seized my hand,
pumped it up and down and said,
"Good afternoon, good afternoon."
And it turned out that the reason was
that this tribal frontier was where
when two people met, they made sure
that the other person thought
they were still warlike and tough.
Because if they didn't,
and appeared to be soft and peaceable,
then obviously they were ready
for a bit of rape and pillage,
so whenever the two people met,
they always looked ferocious.
It certainly convinced me.
Much relieved, we carried on.
We heard calls of birds of paradise,
but we just couldn't find a place
where we could film them.
And then, after three weeks,
one morning at dawn, our luck changed.
Low down in a tree,
a plumed bird of paradise
and there, his unplumed female.
As far as I knew,
this was the first film ever taken
of a bird of paradise
displaying in the wild.
The pictures were okay
as far as they went,
but Charles's camera
was an old clockwork one
and it made a noise like a cement mixer,
so I couldn't record the sound
while he was filming.
But when he had finished,
I turned on the recorder
and I got two sets of calls,
one which went
with two and one
with three.
When we came back,
I joined the two together so they ran,
and we could play it
throughout the display.
And after the show had gone out,
I got a letter from my old professor
of zoology and he said,
"Many congratulations
on this wonderful documentation
of bird of paradise displays"
but had I noticed
that in fact this bird
did its two-note call and then
its three-note call alternating,
never two together and three together?
Would I perhaps write a learned paper
about this strange phenomenon?
And I had to explain to him
that actually, it was the limitation
of early natural history photography.
But the pictures produced
by our primitive equipment
were black and white and fuzzy.
So, 40 years later, I made
another attempt to film the birds
that Wallace had described so vividly.
As far as I know,
Wallace wasn't able to climb the tree
to get a closer view of the birds,
but these days we've got ways
of doing so relatively simply.
You fire a thin line with a catapult
over one of those high branches,
haul up a thicker rope,
attach a system of counterweights,
now all you have to do
is to clip yourself on and up you go.
And here's the top.
The birds are in another emergent tree,
just like this one,
and I've got I've got
an absolutely clear view of them.
This, at last,
is Wallace's picture come to life.
He was the first European to glimpse
this extraordinary spectacle,
and he knew well, in general terms,
what was happening.
This is a female,
and she's come to pick a mate
from among the gorgeous males
who are displaying.
The female has hopped onto the perch
of the male of her choice,
that's a straight invitation to mate.
This is all he does as a father.
Now she'll fly away
and raise her young unaided.
The females are comparatively drab.
It's only the males
that have extravagant plumes.
Each of the 40-odd species
has its own kind.
Growing them and displaying them
must take a huge amount
of a male's energy.
Can it really be worth all this,
just to mate with a female?
Well, it seems that it is,
at least for the male who puts on
the most impressive performance,
for he will mate with virtually
all the females in the area.
So, generation after generation,
it's only the winner
whose genes are passed on,
and it is this, over many generations,
that produces such great extravagance
of plumage and display.
It's a process known
as "sexual selection".
The males of another family
of New Guinea birds
impress their females not with feathers
but with brightly coloured objects,
which they collect
and display in bowers.
And this is the work
of the master builder among bower birds.
I'm in the Vogelkop,
on the far western tip of New Guinea,
and this is the bower
of the Vogelkop bower bird.
And what an astonishment it is,
surely one of the wonders
of the natural world.
The bower has been
completely roofed over.
There are orange fruit, there are these
glowing orange dead leaves,
behind me there are black fruits,
all of which has been brought
specially by the bird.
A further step in our understanding
of such spectacular behaviour
came in 1976 when Richard Dawkins
published this book, The Selfish Gene.
In it, he brings together evolution,
genetics and animal behaviour
and argues that it is the gene
that drives evolution.
The survival of an individual animal
is of less importance
than the survival of its genes.
And thinking about selection
at the level of the gene
also enables us to understand
why it is that some animals sometimes
behave in an unselfish way.
These ants are all female,
and they're prepared Ow!
They're prepared to They're prepared
to attack me in defence of their colony
and to die in the process,
because the genes they carry
are the same as their sister workers
and indeed their mothers.
So in attacking me, they are, in fact,
doing their best to help ensure
that their genes are passed
to the next generation,
you don't have to breed yourself
to pass on your own genes.
All the female worker and soldier ants
in this nest are sisters
and the share 75% of their genes.
So the colony acts as a kind
of single super-organism.
And amazingly,
it was discovered that some mammals
live in a similar kind of community.
Meerkats in the Kalahari Desert.
They spend the night in burrows,
they find all the food
they need on the ground,
they're swift and expert runners.
But oddly enough, they also climb
and they have very good reasons
for doing so.
But first of all they have to
warm up in the early morning sun.
They live in groups
in which the only dominant pair breeds
and some of their offspring,
even when adult,
do not breed but stay around
to help rear the young.
While one helper watches out for danger,
another catches a scorpion
and encourages
one of the youngsters to eat it.
These helpers appear
to be very unselfish,
but they're acting in this way
probably because they share
the same genes as their charges,
and by helping them, they're ensuring
the transmission of those genes
to the next generation.
The first meerkat film we made
turned these animals into stars,
not, I must admit,
because of their selfish genes
but because of their
enchanting personalities.
The factors that make these animals
behave in the way they do
are transmitted in their genes.
But what kind of physical structure
could carry all this information?
That was one of the great puzzles
that had intrigued geneticists
ever since the beginnings
of their science a century ago.
But that mystery too
was about to be solved.
In 1953, here
in the Cavendish Laboratories,
two young researchers,
Francis Crick and James Watson,
were building models like this.
It was their way
of thinking about and investigating
the structure of a complex molecule
that's found in the genes
of all animals, DNA.
The crucial bit are these chains
which encircle the rod, one,
and here is a second, and entwine.
This is the double helix.
An extraordinary feat
of intellectual deduction
and it led to a whole new
branch of science,
molecular genetics.
More recently,
DNA has given us new insights
into the family relationships
of animals,
using a technique
called DNA fingerprinting.
It was developed by Sir Alec Jefferies
of Leicester University in 1984,
and using just a simple smear of blood,
it's possible
not only to the identify
one particular individual,
but to establish whether or not
it's closely related to another.
For example, we used to think
that most birds lived
in straightforward pairs.
We watched them courting
and mating and rearing their young,
and so we assumed
that they were faithful to one another.
But DNA fingerprinting showed us
how wrong we were,
as I explained in The Life of Birds.
Perhaps the most bizarre
behaviour of all
takes place in the suburban gardens
of England.
And it seems that until very recently,
nobody even noticed.
A young female hedge sparrow,
a Dunnock, ready to lay.
This is her mate Alpha,
singing lustily,
declaring his ownership of the nest
and the territory around it
from which he gathers food.
The pair often feed together,
a devoted couple if ever you saw one.
He seldom lets her out of his sight,
for she is not as faithful
as she might be.
There's a third bird around, Beta,
another younger male.
He's not popular with Alpha
and they're continually squabbling.
Sometimes the fights can get
quite vicious and feathers fly.
But in spite of that, Beta stays around,
skulking in the hedge.
Alpha, it seems, has the female
to himself once more,
but she has got her eye cocked.
Beta is still in the hedge,
calling quietly to her.
She joins him.
And now, while Alpha
is preoccupied with feeding,
she and Beta get together.
Twirling her tail is an invitation
and in a split second, they mate.
Beta flies away.
But now, out in the open,
she is courting Alpha
with that same old tail-twirling.
And now, he mates with her.
She has kept two males happy,
both of whom will help to feed
the young when they hatch.
DNA fingerprinting has now revealed
that only about a fifth
of the apparently monogamous birds
are actually genuinely faithful
to one another.
Molecular genetics,
combined with long-term studies
of animals in the wild,
have challenged our preconceptions
about how animals live their lives.
And there are also long-term studies
that have shed light
on our own evolution and ancestry.
In particular, those by Jane Goodall,
who started her work in 1960,
in Tanzania, on chimps.
The 26-year-old Jane Goodall
arrived in Africa
with no scientific training
and had to patiently
follow the chimps for two years
before they allowed her
to get close to them.
In order to identify them,
she gave them the sort of names
we use for one another,
which got her into a lot of trouble
with more conventional scientists,
who accused her of crediting
her animals with human characteristics
for which there was no evidence.
But she made some
revolutionary discoveries,
including proving that chimps use tools
and even modify them
for particular purposes.
They fish for termites with twigs
which they make more effective
by stripping off the leaves.
Manufacturing tools in such a way
had until then
been thought to be something
that only human beings could do.
But in the late 1970s,
chimps on the other side
of the continent, in West Africa,
were discovered using different tools
in a different way.
Placing the nuts in a hole in a root,
they crack them open
with specially selected hammers.
Repeated use has deepened the hole
and produced an anvil
that holds the nut in place.
Using these tools, experienced chimps
can crack two nuts a minute.
For the hardest nuts, they keep
and transport rare stone hammers.
Cracking is not easy,
you have to choose both a good anvil
and a good hammer.
Only West African chimpanzees
have developed
this nut-cracking ability.
And it takes more than 10 years
to learn the technique.
It's now known that chimps
use up to 20 different types of tools.
Nut-cracking was first discovered
by Christophe Boesch,
who had been studying
these chimps since 1976.
And in 1989, I went out
to the Ivory Coast to visit him.
How did you manage to get
these animals so accustomed to you,
so that we could stand
as close to them as this?
Oh, just patience, took us five years.
- Five years?
- Five years,
just following them, being always
very quiet, never aggressive.
Always the same colours
in clothes and patience, patience.
But Christophe
wasn't entirely sure
that he wanted a 63-year-old
with him in the forest.
"Who is this old man?" he said
"Who is this old man who wants to come?"
"Is he fit can he run?"
The answer to those was "no"
on both but nonetheless,
I managed to get there.
And his technique was that
he would travel with them all day,
wherever they went,
and when they moved, he moved,
and he didn't leave them until they
had made their nests at night.
And only then would he go back
to his camp,
but then get up at 4:00 the next morning
in order to run back there,
to catch them
before they went off again.
And he was quite
Christophe was quite right.
I mean, it's hugely demanding.
I've never been so tired in all my life.
But Christophe had also discovered
a darker side to chimps' personalities.
You don't normally
think of them as hunters,
more as gentle vegetarians,
munching fruit and picking leaves.
But if you follow them for any length
of time in their true home,
these forests in West Africa,
you discover that they are hunters.
What's more, they hunt in teams
and have a more complex strategy
than any other hunting animal except
Except, of course, man.
The technique
they'll almost certainly use
is that one of them will be driving
the Colobus ahead of him.
Then there will be others that go up
on either side who are the blockers,
who won't make any attempt
to catch the monkeys.
And then there are chasers who go
and grab at the monkey if they can,
and finally, there's one male
who will go up ahead and ambush it,
so bringing the whole trap closed.
The monkeys are now getting alarmed.
A driver's going up to prevent the group
from settling and to drive them
towards an area
where they're more easily trapped.
Now it looks as though
they're all in position.
The drivers have gone up,
the blockers have gone up.
And now, the one
who's going to make the ambush
and close the ring, he's gone up, too.
The Colobus will be very lucky
if they escape now.
They've got one.
And now the kill is brought down,
so that the females
and others can share it.
And there's the reward
for that long chase,
the divided body of a Colobus monkey.
These blood-stained faces
may well horrify us,
but we might also see in them
the face of our long distant,
hunting ancestors.
And if we are appalled
by that mob violence and blood lust,
we might also see in that, too, perhaps
the origins of the teamwork
that has, in the end,
brought human beings
many of their greatest triumphs.
But the studies of chimpanzees
started by Jane Goodall,
continued by Christophe Boesch
and others,
have shown us something else.
It's not just that chimpanzees
are capable of developing
their own techniques
for hunting or tool-making,
but that each community of chimps
is capable of developing
its own version.
In other words,
chimpanzees' communities
have their own cultures.
And that was thought to be something
that was uniquely human.
Everyone knew, of course,
that chimps are our biological cousins,
but it's only in the last 20 years
that we've discovered
that we share
about 95% of our DNA with them,
and that's because
we now have the tools to find out
exactly how closely we are all related.
In 1990, scientists in 20 labs
around the world
set out to identify
all the 3,000 million
separate chemical units
that make up the human genetic code.
It took nearly 13 years,
and then exactly 50 years
after Crick and Watson
had worked out the structure of DNA,
the human genome was cracked.
And this is it.
In these volumes
is all the information needed
to define the genetic structure
of the human species.
Each number refers
to one of our 23 chromosomes.
If I open it up, you can see
that the text consists
of just one very, very, very long list
of just four letters: A, C, T, G.
Each combination represents instructions
for one element in the human design.
This is the secret language of DNA.
This is the book of life.
And each one of us has our own edition.
When I first heard back in 1953
that the structure of DNA
had been worked out,
I could scarcely have imagined
that it would ever be possible
to print out the whole
of one genome in a book.
But today the process has been
so speeded up that it's possible
for anyone to have it done
in half a day.
And the comparison between the genome
of one species and another
has proved very revealing.
The hot chemical springs of Yellowstone
contain the very simplest form of life,
single-celled bacteria,
about as far removed
from our complex selves
as any organism could be.
But we share some 200 of our genes
with those very early life forms.
Indeed, there are some genes
that are common to every single species
of life on the planet.
Our DNA extends in an unbroken chain
right to the beginning of life
four thousand million years ago.
So now, we can trace
our evolutionary heritage
back through geological time.
Back to the age of dinosaurs.
And further still,
to the early amphibians.
Back to the fish
and the first back-boned animals.
And further still,
to the single-celled organisms
that were the very earliest form of life
to appear on this planet.
So in my lifetime,
science has solved many of the riddles
which 60 years ago seemed so baffling.
How mountain ranges are formed.
Why animals are distributed
in the way they are
and how they communicate
with one another.
How a complex chemical molecule
can transfer the characteristics
of one generation to the next.
It's even shed some light
on that deepest of mysteries,
the very origin of life.
So now the natural world
makes more sense than it ever did,
which is why studying it
is so rewarding and so delightful.
I've lived through an era
of extraordinary scientific discoveries.
But we've also in that time
profoundly changed the way
we view the natural world.
And that will be the subject
of next week's programme.
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