All language subtitles for Charles.Darwin.And.The.Tree.Of.Life.2009.720p.WEBRip.x264.AAC-[YTS.MX]

DAVID ATTENBOROUGH: Our Earth

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is the only known planet
that sustains life.

And it does so in abundance.

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I have been fortunate enough
over the years

to travel to some of the most
extraordinary and
remote places on Earth

to find and film animals.

This is the biggest
flower in the world.

The blue whale!

It's the biggest creature
that exists on the planet!

ATTENBOROUGH: The sheer number
and variety of
animals and plants

is astonishing.

Estimates of the number
of different species

vary from six million
to a hundred million.

Nobody knows exactly how
many different kinds
of animals there are here.

Wherever you look,
there's life.

There are often a multitude
of variations on
a single pattern.

Nearly 200
different kinds of monkeys,
for example.

And 315 humming birds,

nearly a thousand bats.

And beetles,
at least 350 thousand
species of them.

Not to mention a quarter
of a million different kinds
of flowering plants.

The variety is astounding.

(CHUCKLES)

(CHIRPING)

Even in this one
small English woodland,
you might see four or five

different kinds of finches.

Why should there be
such a dazzling variety?

And how can we make sense of
such a huge range
of living organisms?

Two hundred years ago,

a man was born who was
to explain this astonishing
diversity of life.

In doing so,
he revolutionised the way
in which we see the world

and our place in it.

His name was Charles Darwin.

This book, The Holy Bible,
explains how this wonderful
diversity came about.

On the third day, after
the creation of the world,
God created plants.

On the fifth day,
fish and birds,

and then, on the sixth day,
mammals and finally, man.

That explanation
was believed, literally,

by, pretty well, the whole of
Western Europe
for the best part

of 2,000 years.

And generations of painters
pictured it for the faithful.

This version was
painted in Italy
in the 16th century.

Here is God in
the Garden of Eden,

which is now filled
with all kinds of animals.

Here he is pulling Adam
out of the Earth

and here
creating the first woman
by putting Adam to sleep,

and then taking one of his
ribs and extracting
Eve from his side.

And she comes out assisted
by two angels.

And when God had finished,
he said to Adam and Eve,

"Be fruitful and multiply
and replenish
the Earth and subdue it,

"and have dominion over
the fish of the sea and over
the fowl of the air,

"and over every living thing
that moveth upon the Earth."

That made it clear
that according to the Bible

humanity could
exploit the natural world
as they wished.

This view of
mankind's superiority
still stood when, in 1831,

a British surveying ship,
the Beagle, set off on
a voyage around the world.

On board, as
a companion to the captain,

was the 22-year-old
Charles Darwin.

They crossed the Atlantic and
made landfall on
the coast of Brazil.

There, the sheer abundance
of tropical nature

astonishes the newcomer,

as I discovered
when I retraced
Darwin's steps, 30 years ago,

for a television series
about the diversity of nature.

Darwin, as a boy, had been
a fanatical
collector of insects.

And here, he was enthralled
almost to
the point of ecstasy.

In one day, in a small area,

he discovered
69 different
species of beetle.

As he wrote in his journal,
"It's enough to
disturb the composure

"of the entomologist's mind
to contemplate
the future dimension

"of a complete catalogue".

They went south,
rounded Cape Horn,
and so reached the Pacific.

And then, in September 1835,

after they had been away
for almost four years,

they landed on
the little-known islands
of the Galapagos.

Here, they found
creatures that existed
nowhere else in the world.

Cormorants that had lost
the power of flight.

Lizards that swam out
through the surf to graze on
the bottom of the sea.

Darwin, who had studied botany
and geology at
Cambridge university,

collected specimens
of the animals and plants.

And as usual,
when he went ashore
to investigate,

described what he
found in his journal.

"My servant and
self were landed
a few miles to the northeast,

"in order that I might examine
the district mentioned above

"as resembling chimneys."
Volcanic chimneys, presumably.

"The comparison
would have been
more exact if I had said

"the iron furnaces
near Wolverhampton."

(CHUCKLES)

The British
resident in the Galapagos
claimed that he knew

from the shape
of a giant tortoise's shell

which island it had come from.

If it had a rounded front,
it came from
a well-watered island

where it fed on
lush ground plants.

Whereas one
from a drier island
had a peak at the front,

which enabled it to reach up
to higher vegetation.

Were these tortoises,
each on their
separate islands,

different species?

And if so, was each one
a separate act of
divine creation?

The differences that Darwin
had noticed amongst these
Galapagos animals,

were, of course, all tiny.

But if they could develop,
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?

On his voyage home, Darwin
had time to
ponder on these things.

Could it be that species
were not fixed for all time,

but could,
in fact, slowly change?

On his return,
he sorted out his specimens

and sent them off
to relevant experts

so that each
could be
identified and classified.

Most of the mammal
bones and fossils
he sent to Richard Owen.

Owen was one of
the most brilliant
zoologists of his time.

He was the first to
recognise dinosaurs,

and indeed had
invented their very name.

And he would later become
the creator and first director

of the Natural
History Museum in London.

Many of the specimens
that Darwin collected

are still preserved
and treasured here

among the 70 million
other specimens housed in
the museum that Owen founded.

And here is one of them.

It's obviously the lower jaw
of some great animal,

and when Darwin discovered it,
it had bits of skin and
hair attached to it

so at first it was thought
to be the remains of some
unknown living species.

But now we know that it
is a species that was extinct
for some 10,000 years,

a giant ground sloth.

Owen examined it
in great detail

and eventually described
it and gave it the name
of Mylodon darwinii

in honour of its discoverer.

But that mutual respect
between two
great men of science

was not to last.

Soon after his
return from his voyage,

Darwin made his
home here in Down House
in Kent.

Here, he wrote
an account of his travels

and worked on detailed
scientific treatises

about corals and barnacles
and the geology and
fossils of South America.

But he also pondered deeply
on what he had
seen in the Galapagos

and elsewhere.

Maybe species were not fixed.

Every day, he took a walk
in this small spinney

that he had planted
at the end of his garden.

And it was here that he came
to ponder on the problems
of natural history

including that
mystery of mysteries:

how could one
species turn into another?

He noted that most,
if not all, animals
produce many more young

than live to breed themselves.

This female blue tit,
for example,

may well lay a dozen eggs
a year, perhaps 50 or so
in her lifetime.

Yet only two of
her chicks need to
survive and breed themselves

to maintain the numbers
of the blue tit population.

Those survivors, of course,
are likely to
be the healthiest

and best-suited
to their
particular environment.

Their characteristics
are then inherited

so perhaps over
many generations,

and particularly if there are
environmental changes,

species may well change.

Only the fittest survive.

And that was the key.

He called
the process natural selection.

(BIRDSONG)

That would explain
the differences that he had
noted in the finches

that he had brought back
from the Galapagos.

They were very similar
except for their beaks.

This one has a very thin,
delicate beak,

which it uses
to catch insects.

This one, on the other hand,
which came from an environment

where there
were a lot of nuts,
has a big, heavy beak,

which enables
it to crack them.

So maybe, over the vastness
of geological time,

and particularly
if species were
invading new environments,

those changes would amount
to very radical
changes indeed.

Darwin drew a sketch in one
of his notebooks to
illustrate his idea,

showing how
a single ancestral species

might give rise
to several different ones,

and then wrote
above it a tentative,
"I think".

Now he had to
prove his theory.

And he spent years gathering
abundant and
convincing evidence.

He was an extraordinary
letter writer.

He wrote as many as a dozen
letters a day

to scientists and naturalists
all over the world.

He also realised that when
people had first started
domesticating animals

they had been doing
experiments for him
for centuries.

All domestic dogs
are descended from a single
ancestral species, the wolf.

Dog breeders select those pups

that have the characteristics
that happen to please them.

Nature, of course,
selects those young animals

that are best suited
to a particular environment.

But the process is
essentially the same.

And in both cases,
it has produced
astonishing variety.

In effect,
many of these different breeds

could be considered
different species,

because they do not, indeed,
they cannot interbreed.

For purely mechanical reasons,

there's no way in
which a Pekingese
can mate with a Great Dane.

Of course, it's true that,
if you used
artificial insemination,

you could get crosses between
almost any of these breeds.

but that's because
human beings have been
selecting between dogs

for only a few centuries.

Nature has been selecting
between animals for
millions of years,

tens of millions,
even hundreds of
millions of years.

So what might have started out
as we would
consider to be breeds,

have now become so different
they are species.

Darwin, sitting in Down House,

wrote to pigeon fanciers
and rabbit breeders

asking all kinds of detailed
questions about their
methods and results.

He himself,
being a country gentleman

and running an estate,
knew about breeding horses

and sheep and cattle.

He also conducted
careful experiments
with plants in his greenhouse.

But Darwin knew that the idea
that species could appear

without divine intervention
would appall
society in general.

And it was also
contrary to the beliefs
of his wife, Emma,

who was a devout Christian.

Perhaps for that reason,
he was keen to keep the focus
of his work scientific.

He made a point of not being
drawn in public about his
religious beliefs.

But in the latter part of his
life he withdrew from
attending church.

On Sundays,
he would escort Emma
and the children here

to the parish church in Down,

but while they
went into the service,
he remained outside

and went for a walk
in the country lanes.

Perhaps because he feared
his theory would cause
outrage in some quarters,

he delayed publishing it
year after year after year.

But he wrote
a long abstract of it.

And then, on July 5th 1844,
he wrote this
letter to his wife.

"My dear Emma, I have just
finished this sketch of my
species theory."

Some sketch.
It was 240 pages long.

"I therefore write this,
in case of my sudden death,

"that you will devote £400
to its publication."

He then goes on to list
his various
naturalist friends,

who would be asked to edit it
and check it,

and he ends the letter,
charmingly,

"My dear wife,
yours affectionately, C.
R. Darwin."

He continued to
accumulate evidence
and refine his theory

for the next 14 years.

But then his hand was forced.

In June 1858,
22 years after he got back
from the Galapagos,

here in his study in Down,
he received a package

from
a naturalist who was working
in what is now Indonesia.

His name was
Alfred Russel Wallace.

He had been
corresponding with Darwin
for some years.

But this
package was different.

It contained an essay
that set out exactly the same
idea as Darwin's:

of evolution by
natural selection.

The idea had come to Wallace
as he lay in his hut

semi-delirious in
a malarial fever.

But although his idea
of natural selection was
the same as Darwin's,

he had not spent 20 years
gathering the mountain of
evidence to support it,

as Darwin had done.

But whose idea was it?

In the end, the senior members
of the Linnean Society

decided that the fairest thing
was for a brief outline

of the theory from each
of them to be read out
one after the other,

at a meeting of the society
here in Burlington House,
in London.

The Linnean, then, as now,
was the place where
scientists studying

the natural world
held regular meetings

to present and discuss papers
about their
observations and thoughts.

The one held on July 1st 1858

was attended by
only about 30 people.

Neither of
the authors were present.

Wallace was 10,000 miles away
in the East Indies.

And Darwin was ill
and devastated by the death,
a few days earlier,

of his infant son.

So he was still at
his home in Kent.

As a consequence,
the two papers had to be read
by the secretary.

And as far as we can tell,
they made very little
impression on anyone.

Darwin spent the next year
writing out his
theory in detail.

Then he sent the manuscript
to his publisher, John Murray,

whose firm, then as now,
had offices in
Albermarle Street,

just off Piccadilly,
in London.

Murray was the great publisher
of his day,

and dealt with
the works of Jane Austen
and Lord Byron

whose first editions
still line these office walls.

Darwin regarded his work
as simply a summary,

but, even so, it's 400 pages.

It was published on
November 24th 1859.

This is not a first edition,
more's the pity.

First editions are worth,
literally, hundreds of
thousands of pounds.

This is a sixth edition.
My copy,
which I bought as a boy,

at 18, I notice,
and it cost me the princely
sum of one shilling.

The first edition,
of 1,250 copies
sold out immediately.

and it went for a reprint,
and then another reprint
and another reprint.

It's a book that
contains very few
technical terms.

It's easily
understood by anybody.

And, predictably,
it caused an outrage,

not only throughout
this country, but indeed all
the civilised world.

What scandalised
people most, it seems,

was the implication
that human beings were not
specially created by God

as the book of Genesis stated,
but were descended from
ape-like ancestors.

A notion that
provided a lot of scope
for cartoonists.

The leaders of the Church,
headed by Samuel Wilberforce,

the Bishop of Oxford,
attacked it on the grounds
that it demoted God

and contradicted
the story of creation
as told by the Bible.

"That Mr Darwin
should have wandered

"from this broad highway
of Nature's works

"into the jungle of
fanciful assumption
is no small evil."

"I have read your book
with more pain than pleasure.

"It is the frenzied
inspiration of the inhaler
of mephitic gas."

"Fails utterly."

Darwin's theory
implied that life
had originated in simple forms

and had then become
more and more complex.

He knew perfectly well
that the whole
idea of evolution

raised a lot of questions.

In fact,
some of those questions
would not be answered

until comparatively recently.

But in his own time, many
distinguished scientists
raised what seemed to be

insuperable difficulties.

And foremost among them
was Richard Owen,

the man who, 20 years earlier,
had named
the extinct ground sloth

in honour of Darwin.

Over the years, the two men
had developed
a deep personal dislike

of one another,
and had quarrelled frequently.

It wasn't that Owen thought
that the story of
the Garden of Eden

was literally correct,
but nonetheless
he was a deeply religious man.

He had, after all,
ensured that his museum,

which would display
the wonders of creation,

echoed, in its design,
the great Christian cathedrals

of mediaeval Europe.

And Owen knew about
the diversity of life.

Indeed, he had spent
his whole career
cataloguing it.

But even so, he refused
to believe that a species
could change over time.

He, and other pioneer
Victorian geologists,

as they established
their
comparatively new science,

recognised that the outlines
of the history of life

could be deduced by examining
the land around them.

Look at these rocks
in Northern Scotland.

We know from fossils that were
associated with them

that they are very ancient.

And they are sandstones.

Compacted sand
that was laid down
at the bottom of the sea

layer upon layer upon layer.

But look how many
layers there are.

Clearly, those at the top
must have been laid down after
those beneath them.

So, as you descend
from layer to layer,

you are, in effect,
going back in time.

So a fossil species,
if it comes from
a particular layer,

is of a particular age.

And if you can recognise
each one, then you can begin
to piece together

the outlines of
life's history.

My krafta.

The ability to identify
fossils and place them
in their geological time zone

was still an essential skill
when I was at
university a century later.

We worked our way
through drawers,
like these,

which are full of fossils
of one sort or another.

But none of them had labels.

Only numbers.

So you were
expected to be able
to pick up one

and say,
"Yes, that's a belemnite".

Actually which
belemnite it is,
I can't remember now.

And when you came to
your practical exam,

your examiners would produce
one of these and say,

"Okay, what's that?"

And you either
knew or you didn't.

And the way you knew was
because of all the work you
did in drawers like these,

hour after hour.

Owen did not deny the
sequence in which all these
different species appeared,

but he believed
that each was separate,
each divinely created.

Darwin's theory, however,
required that there
should be connections,

not just between
similar species, but between
the great animal groups.

If fishes and reptiles
and birds and mammals

had all evolved from
one another, then surely there
must be intermediate forms

between those great groups.

And they were missing.

And then, just two years after
the publication of
The Origin of Species,

Richard Owen himself purchased
the most astonishing
fossil for his museum.

It had been found
in this limestone
quarry in Bavaria.

The stone here
splits into flat,
smooth leaves

that have been
used as roofing tiles
since Roman times.

Most are blank,
but occasionally,
when you split them apart,

they reveal
a shrimp or a fish.

It's almost
impossible to resist
the temptation of pulling down

almost every boulder you see
and then opening
it like a book.

to look at each unopened page
to see whether, maybe,

it contains yet
another fossil.

But this fossil
was something unprecedented.

It is still one of the
greatest of the treasures
that are stored

in the Natural History Museum.

And this is it.

It's called Archaeopteryx.

It has unmistakable feathers
on its wings

and down its tail.

So Owen had no hesitation
in calling it a bird.

But it was
unlike any other bird
that anyone knew of,

because it had claws
on the front of its wings,

and as was later discovered,
it didn't have a beak but
jaws with teeth in it,

and a line of bones
supporting its tail.

So it was part reptile,
part bird.

Here was the link between
those two great groups that
was no longer missing.

Gosh, you really can see
the filaments there.

Other examples of the same
creature show its feathers
even more clearly.

We know from the bones
of the Archaeopteryx

that it was at best
a very poor flyer.

So, it's not surprising
that eventually
it was superseded

by more modern,
more efficient birds.

And that's
the fate of these links
between great groups.

Eventually,
they become extinct.

And the only way
we know they existed

is from their
fossilized remains.

Even so,
there is a bird alive today
that illustrates the link

between modern
birds and reptiles.

The hoatzin
nests in the swamps
of tropical South America.

There are caiman in
the water beneath,
ready to snap up any chick

that might fall from its nest.

So,
an ability to hold on tight
is very valuable.

And the nestlings have
a very interesting
way of doing that.

The young still have claws
on the front of their wings as
Archaeopteryx did.

Here is vivid
evidence that the wings
of birds are modified forelegs

and once had toes
with claws on them.

There's another
creature alive today
that represents a link

between
the great animal groups.

A descendant of
a group of reptiles

that took a different
evolutionary course

and evolved not
feathers but fur,
the platypus.

When specimens
of this creature first reached
Europe from Australia

at the very end of the
18th century, people refused
to believe their eyes.

They said it was a hoax.

Bits and pieces of
different creatures
rather crudely sewn together.

And, yet, in a way,
those early
sceptics were right.

The platypus is
the most extraordinary
mixture of different animals.

It's part mammal
and part reptile.

And so it can give us
some idea of how the first
mammals developed.

When it comes to breed,

it does something
that separates it from all
other mammals except one.

In its nest,
deep in the burrow,
it lays eggs.

It's this that
links the platypus
with the reptiles.

This that entitles it to be
regarded as the most
primitive living mammal.

So, the links between
the great animal groups

are not, in fact, missing,
but exist both as fossils and
as living animals.

Although the fossil record
provides an answer

to the problem
of missing links,
it also posed a major problem.

It started very abruptly.

The earliest known fossils
in Darwin's time

came from a formation
called the Cambrian.

And there were two main kinds.

These, which look
like fretsaw blades
and are called graptolite,

and these,
like giant wood lice,
which are called trilobites.

Could it really be
that life on Earth started

with creatures as
complex as these?

As a boy,
I was a passionate
collector of fossils.

I grew up in
the city of Leicester,

and I knew that in this area,
not far from the city,

called Charnwood forest,

there were the oldest rocks
in the world.

Older even than the Cambrian.

So, therefore, by definition,
they would be without fossils.

There was no point in me
looking for fossils in
these ancient rocks.

There were, it's true,

very rarely, some rather odd
shapes in these rocks,
like this one here.

But they were dismissed
as being some kind of
mechanical aberration.

I mean, after all,
how could there
be anything living

in these
extremely ancient rocks?

And then, in 1957,

a schoolboy with
rather more patience
and perspicacity than I had

found something
really remarkable.

And undeniably
the remains of
a living creature.

And here it is in
Leicester museum,

where it's been brought
for safe-keeping.

It's called Charnia.

Who could doubt that this
is the impression
of a living organism?

It has a central stem,
branches on either side.

In fact, it seems to have been
something like the sea pens

that today grow
on coral reefs.

Since its discovery,
a whole range of organisms

have been found in rocks
of this extreme age.

Not only here in
the Charnwood forest

but in many other
different parts of the world.

Fossil hunters searching
these rocks in the Ediacara
Hills of Australia

had also been discovering
other strange shapes.

At first, many scientists
refused to believe that
these faint impressions

were the remains of jellyfish.

But, by now, enough specimens
have been discovered

to make quite sure that,
that indeed is what they are.

So, now we know
that life did
not begin suddenly

with those complex animals
of the Cambrian.

It started much, much earlier,
first with simple
microscopic forms,

which eventually became
bigger, but which were still
so soft and delicate

that they only very rarely
left any mark in the rocks.

The question of
the age of the Earth

posed another problem
for Darwin's theory.

In the 17th century,
an Irish bishop
had used the genealogies

recorded in the Bible
that lead back to Adam

to work out that
the week of Creation

must have taken place
in the year 4004 B.C.

That may seem to us to be
a very naive way
of doing things,

but what other
method was there anyway?

The Victorian geologists
had already concluded

that the Earth must be
millions of years old.

But how many millions,
no one could say.

Then, less than 50 years
after
the publication of The Origin,

a discovery was made in what
seemed a totally
disconnected branch of science

that would ultimately
provide the answer.

A Polish woman
working in Paris,
Marie Curie,

discovered that some rocks
contained
an element called uranium

that decays over time at a
steady rate through a process
called radiation.

Today,
a century after she made
her extraordinary discovery,

the method of dating
by measuring
changes in radioactivity

has become greatly refined.

This is a sample taken from
those very ancient rocks
in Charnwood forest.

And these tiny crystals
are revealed to be

562 million years old.

That provides
more than enough time
for natural selection

to produce
the procession of fossils

that eventually leads to the
living animals and
plants we know today.

But there was
another objection.

If all animals within a group
have a common origin,

how is it that
some kinds of animals
are distributed

throughout
the continents of the world
except for Antarctica?

How is it that, for example,
frogs in Europe and Africa

are also found here in
South America on the other
side of the Atlantic Ocean?

Bearing in mind
that frogs have
permeable skins

and can't
survive in sea water.

Darwin himself had
a couple of suggestions.

One was that they might
have floated
across accidentally

on rafts of vegetation.

And the other is that maybe
there were land bridges
between the continents.

But even he was not convinced
by either explanation.

Even as late as 1947,

when I was a geology student
here at Cambridge,

there was no
convincing explanation.

It's true that back in 1912,
a German
geologist had suggested

that at one time
in the very
remote distant past,

all
the continents of the Earth
that we know today

were grouped together
to form one huge
supercontinent.

And that over
time this broke up
and the pieces drifted apart.

That would have
provided an answer.

But when I asked the professor
of geology here,
who was lecturing to us,

why he didn't
tell us about that
in his lectures,

he replied rather loftily,
I must say,

"When you can
demonstrate to me
that there is a force on Earth

"that can move the continents
by a millimetre,
I will consider it.

"But until then, the idea
is sheer moonshine, dear boy."

But then in the 1960s,
it became possible to map
the seafloor in detail

and it was discovered not only
that
the continents have shifted

in just the way that
the German
geologist had suggested

but that they
were still moving.

New rock wells up from
deep below the Earth's crust

and flows away on either side
of the mid-ocean ridges,

carrying
the continents with it.

Amphibians had
originally evolved
on this supercontinent

and had then travelled on each
of its various fragments

as they drifted apart.
Problem solved.

Perhaps,
the biggest problem of all
for most people

was the argument put forward
for the existence of God

at the beginning
of the 19th century

by an Anglican clergyman
called William Paley.

He said,
supposing you were walking
in the countryside

and you picked up
something like this.

You would know from looking at
it that it had been
designed to tell the time.

There must,
therefore, be a designer.

And the same argument
would apply if you looked

at one of the intricate
structures found in nature,
such as the human eye.

And the only
designer of the human eye
could be God.

Anti-evolutionists maintain
that the eye would only work

if it was complete
in all its details.

Darwin, on the other hand,
argued that
the eye had developed

becoming increasingly complex
over a long period of time.

That would only work
if each stage of development

was an improvement
on the previous one.

And today, we know enough
about the animal kingdom

to know that is
indeed the case.

Some very simple animals
have nothing more than
light-sensitive spots

that enable them to
tell the difference
between light and dark.

But if a patch of
such spots formed
even the shallowest of pits,

one edge of the pit would
throw a shadow and so reveal
the direction of light.

If the pit got deeper
and started to close,

then light would
form a blurred image.

Mucus secreted by the cells
would bend
the light and focus it.

If this mucus hardened,
it would form a proper lens

and transmit a brighter
and clearer image.

All these different
fully functional stages

at different levels
of complexity are found in
living animals today.

This single-celled creature
has one of those
light-sensitive spots.

Flatworms have a small pit
containing light spots

so they can detect the shadow
of a predator.

A snail's blurry vision is
good enough to enable it to
find its way to food.

And the octopus has an eye
with a proper lens

and can see as
much detail as we can.

So the structure
of the human eye
does not demand the assistance

of a supernatural designer.

It can have evolved gradually,

with each stage
bringing a real advantage

as Darwin's theory demands.

Natural selection, of course,
requires that an animal's
characteristics

are handed from one generation
to the next.

It's obvious that children
resemble their parents.

Anyone knows that.

But when you
come to think of it,
how does that come about?

In Darwin's time,
nobody had the faintest idea

about
the mechanism or the rules
that govern that process.

Except, perhaps, for one man,

who was working in the city of
Brno in what is now
the Czech Republic

at exactly
the same time that Darwin
was writing his book in Kent.

That man's name
was Gregor Mendel.

He discovered the laws of
inheritance by breeding
thousands of pea plants

and observing how they changed
from one
generation to the next.

He found that while
many characteristics
were passed down directly

from one generation to
another, others could
actually skip a generation.

How could that happen?

Mendel explained this
by suggesting that each plant,
each organism,

contained within it
factors which were responsible

for creating
those particular
characteristics.

Today we call
those things genes.

But nobody had any
idea how they worked

until a hundred years
after Mendel's time.

And then the answer
was discovered in Cambridge.

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 is
found in the genes of
all animals, DNA.

The crucial bit
are these chains
which encircle the rod.

And here is
a second and entwined.

This is the double helix.

The workings of the DNA
molecule are now
understood in such detail

that we can
demonstrate something
that is truly astounding.

A gene taken from one animal
can function in another.

The gene that
causes a jellyfish
to be luminous, for example,

transplanted into a mouse,
will make that mouse luminous.

The genetic code
can also reveal relationships.

Even our law courts accept
that DNA fingerprinting

can establish whether a man
is the father of
a particular child.

And it can also reveal
whether one kind of animal

is related to another.

It proves,
for example, that kangaroos,
ground-living animals

that run with great leaps
are closely related to koalas,

that have taken
to climbing trees.

That insect-eating shrews

have cousins
that took to the air
in search of insects, bats.

And that one branch of the
elephant family, way back in
geological history,

took to the water
and became sea cows.

So, 150 years after the
publication of Darwin's
revolutionary book,

modern genetics has confirmed
its fundamental truth.

All life is related.

And it enables us to construct
with confidence
the complex tree

that represents
the history of life.

It began in the sea,
some 3,000 million years ago.

Complex chemical molecules
began to clump together

to form
microscopic blobs, cells.

These were
the seeds from which
the tree of life developed.

They were able to split,
replicating
themselves as bacteria do.

And as time passed,
they diversified
into different groups.

Some remained
attached to one another,
so that they formed chains.

We know them today as algae.

Others formed hollow balls,
which collapsed
upon themselves,

creating a body with
an internal cavity.

They were the first
multi-celled organisms.

Sponges are their
direct descendants.

As more variations appeared,
the tree of life grew and
became more diverse.

Some organisms
became more mobile

and developed a mouth
that opened into a gut.

Others had bodies stiffened
by an internal rod.

They, understandably,
developed sense organs
around their front end.

A related group
had bodies that were
divided into segments,

with little
projections on either side

that helped
them to move around
on the sea floor.

Some of these segmented
creatures developed hard,
protective skins

which gave their
body some rigidity.

So now the seas were filled
with a great
variety of animals.

And then, around 450 million
years ago, some of these
armoured creatures

crawled up out of the water
and ventured onto land.

And here, the tree of life
branched into a multitude of
different species

that exploited
this new environment
in all kinds of ways.

One group of them developed
elongated flaps on their backs

which, over many generations,
eventually
developed into wings.

The insects had arrived.

Life moved into the air

and diversified
into myriad forms.

Meanwhile, back in the seas,

those creatures
with the stiffening rod
in their bodies

had strengthened it
by encasing it in bone.

A skull developed,
with a hinged jaw that could
grab and hold onto prey.

They grew bigger
and developed fins
equipped with muscles

that enabled them to swim
with speed and power.

So fish now dominated
the waters of the world.

One group of them developed
the ability to gulp air from
the water surface.

Their fleshy fins became
weight-supporting legs,

and 375 million years ago,
a few of these
backboned creatures

followed
the insects onto the land.

They were amphibians,
with wet skins,

and they had to
return to water
to lay their eggs.

But some of their descendants
evolved dry, scaly skins,

and broke their link with
water by laying eggs with
watertight shells.

These creatures, the reptiles,
were the ancestors of today's

tortoises, snakes,
lizards and crocodiles.

And, of course,
they included the group
that, back then,

came to dominate the land:
the dinosaurs.

But 65 million years ago,
a great disaster
overtook the Earth.

Whatever its cause,
a great proportion
of animals were exterminated.

All the dinosaurs disappeared,
except for one branch

whose scales had become
modified into feathers.

They were the birds.

While they spread through
the skies, a small,
seemingly insignificant,

group of survivors began to
increase in numbers on
the ground beneath.

These creatures differed
from their competitors

in that their bodies were warm
and insulated
with coats of fur.

They were the first mammals.

With much of
the land left vacant
after the great catastrophe,

they now had their chance.

Their warm, insulated bodies
enabled them to be
active at all times,

at night as well
as during the day.

And in all places,
from the Arctic
to the tropics,

in water as well as on land,

on grassy plains
and up in the trees.

There can be no doubt about
our close relationship

to these chimpanzees.

Our bodies are so similar.

The proportions of our limbs
or our faces may differ,

but otherwise we are
very, very similar.

The arrangement of
our internal organs,

the chemistry of our blood,

the way our bodies work,

all these are
almost identical.

And DNA confirms that.

Indeed,
we are as closely related
to chimpanzees

and the rest of
the apes and monkeys,

as say, lions are to tigers
and to the rest
of the cat family.

Suddenly,
an image from our remote past
comes vividly to light,

the time when our
distant ancestors,

in order to keep up
with the changing environment,

had to wade and keep
their heads above water in
order to find food.

That crucial moment
when our far distant ancestors

took the step
away from being apes

and a step towards humanity.

The Natural History Museum
is one of the most important
museums of its kind

in the world.

Richard Owen
brought it into existence,
but, over a century later,

discoveries from
many branches of science

have shown that his belief
that species can never change

but always remain
exactly the same
was mistaken.

It was Charles Darwin's
profound insights that have
proved to be true.

And now, to mark
the 200th
anniversary of his birth,

his statue is being taken
from its
out-of-the-way location

to be placed centre stage
in the main hall.

Darwin's great insight
revolutionised the way in
which we see the world.

We now understand
why there are so
many different species.

Why they are distributed
in the way they
are around the world.

And why their bodies and our
bodies are shaped in
the way that they are.

Because we understand
that bacteria evolve,

we can devise
methods of dealing
with the diseases they cause.

And because we can disentangle
the complex relationships

between animals and plants
in a natural community,

we can foresee some
of the consequences
when we start to interfere

with those communities.

But above all,
Darwin has shown us
that we are not apart

from the natural world.

We do not have
dominion over it.

We are subject to
its laws and processes

as are all other
animals on Earth

to which indeed
we are related.

(LAUGHING)