each with a purpose in an ordered universe over which our creator presided,

rewarding good deeds and punishing sin.

Charles Darwin's theory of evolution by natural selection

blew a hole in this comfortable explanation of life

and faced us with a blindingly obvious yet disturbing truth -

humans don't have dominion over animals.

We are animals.

We are the fifth ape.

But even Darwin hesitated to say this out loud.

It throws into question our trust in our fellow human beings.

Are our morals and manners just a veneer?

Since a struggle for existence drives evolution,

why don't we humans run an entirely dog-eat-dog world?

How about genocide and ethnic cleansing?

Are they some kind of survival strategy?

In this programme, I want to confront

the issue that Darwin skirted around in The Origin Of Species,

the evolution of human beings.

I want to ask what it means for us to be evolved.

The question is more urgent than ever.

Increasingly, religious people and others attack Darwinism for, in their view,

excusing selfishness and barbarism.

Throughout my career, I've wrestled with how to reconcile my liberal values

with what Darwin revealed to be the pitiless war of nature.

So now I'm going to take you into the Darwinian heart of darkness

and look for answers...

and for hope.

Natural selection is the driving force of our evolution,

but that doesn't mean that society ought to be run on Darwinian lines.

As a scientist, I'm thrilled by natural selection,

but as a human being, I abhor it as a principle for organising society.

Evolution by natural selection is a very simple idea.

Over thousands of generations, in a struggle for existence,

successful variations have survived to reproduce,

the process that gradually carves life into more and more specialised forms.

Life forms that include the apes -

gibbons, orang-utans, gorillas, chimps...and us.

Here, at London Zoo, back in the 1830s,

the arrival of the first apes outraged polite society.

Queen Victoria, for one, found them painfully and disagreeably human.

But another visitor was spellbound.

The young Charles Darwin saw the unmistakable truth

staring back at him from the other side of the cage.

The uncanny familiarity of ape hands

and the humanity we seem to glimpse in their eyes

was, for Darwin, further evidence to support the idea of evolution,

that all life was related.

The African apes, he realised, were our closest evolutionary cousins.

East Africa - my birthplace and, rather more importantly,

the birthplace of the human species itself.

Between five and six million years ago,

there lived in Africa an ape who had two children.

One of those children was destined to give rise to us,

the other was destined to give rise to the chimpanzees.

If I stood here and held my mother's hand,

and she held her mother's hand,

and she held her mother's hand, and so on,

back to the grand ancestor of all humans and all chimpanzees,

how far would the line stretch?

The answer is about 300 miles.

Over that surprisingly short distance,

the fossil record shows evidence of extraordinary changes.

The palaeontologist Richard Leakey and his family

have uncovered the hard evidence in Kenya's Rift Valley,

evidence that charts the evolution of our ancient human ancestors.

About 1.9 million years ago,

you have skulls like this turning up.

This is what they were calling Homo habilis.

Largish brains, still got a flat, big face,

and probably ancestral to Homo erectus, which turns up in Africa

at about 1.8 million years.

This, then, is the ancestor to Homo sapiens.

This persists for almost a million years, this condition,

and then it gives way to something with an even larger brain -

things that are much more like ourselves.

These whopping great vaults.

The brain has really expanded.

It's much more like a modern human brain in terms of size

and in terms of shape,

and by the time you get to this,

all of these others have disappeared from the fossil record.

So all the major steps in the human story are, in fact, told in Africa.

I often meet people who say to me, "Nobody's going to tell me I'm an ape."

Is there a kind of visceral revulsion? Do you meet that, as well?

Yes, I do, but it seems to be so misplaced

because, as you know, we are the fifth ape.

We never separated from the apes, we just do things differently.

I've often found it fun to go to an ape exhibit in one of the big zoos

and you can watch people looking at a group of chimpanzees,

and what is very clear, if you watch their facial expression,

you can see that they're not so sure that that ape's like them

but they can look around and say, "There's a similarity

"between the person on the other side of the cage."

We're closer to chimps, African chimps,

than a horse is to an ass.

Horses and asses put together produce offspring.

"Wow!" says everybody. "Are you...?"

"Yeah, I am."

It's an unsettling thought.

In evolutionary terms, we're so closely related to chimps

that it's not ridiculous to ask

whether we might still be able to breed with them.

We're the human animal,

upright, big-brained ape cousins who evolved to out-think the competition.

As a biologist, I've wondered at the challenging implications of this,

what it tells us about human society now.

But over half the people on Earth

are so horrified by what Darwinism reveals about our origins,

they just refuse to believe it.

I'm an ape. Are you an ape?

No, I'm not, I'm a human being.

I'm on a journey exploring the dark side of Darwinism.

I want to confront what it means for us

to have evolved in nature's brutal struggle.

Why should the fifth ape love thy neighbour?

The thought of our animal origins can upset people.

Read The Origin Of Species, Darwin's masterpiece

that set out his theory of evolution,

and you will find only a handful of passing references to human origins.

That man was made in God's image,

having dominion over the animals,

defined what it meant to be human,

so discussing human evolution was just too risky.

Darwin shied away from it

and simply wrote near the end,

"Light will be thrown on the origin of man and his history."

But when the book came to be published in 1859,

the buzz was all about the extraordinary implications for mankind.

Were we just beasts in fancy dress?

Evolution become known as "the monkey theory".

The row has not gone away.

In Kenya, the cradle of mankind,

religious groups are trying to block the opening

of the National Museum's exhibit of human fossils.

The fossil record of human ancestry has a particular fascination.

To me, these are far more precious than the Crown Jewels.

This is the Turkana Boy.

Homo erectus, 1.5 million years old.

The most complete ancient human skeleton ever found.

It's one of the most precious relics in any museum

anywhere in the world.

It would be an enormous pity if there were any pressure

not to allow it to be seen.

CHOIR SINGS A PRAISE SONG

The ten-million-strong Evangelical movement in Kenya

has run a hide-the-bones campaign.

By coincidence, I was born right next door to the church

where the protest is being led by Bishop Bonifes Adoyo.

Bishop, how do you do? Very nice of you to agree to this meeting.

Same here to meet the great professor.

Let's go in, shall we?

I was born just over the road, there.

No, I'm told over the other side.

Well, we'll have to work that out.

Yeah, yeah.

'It was clear that we weren't going to see eye-to-eye from the beginning.'

I'm an ape. Are you, Bishop?

I'm not. I definitely am not.

(LAUGHS)

I'm special.

Made in the image of God, in the creative mind of God,

creative as God is, who made me.

That's the difference between the ape and me.

Well, I'm an ape. I'm an African ape.

I'm very proud to be an African ape, and so should you be.

Don't you think the evidence should be displayed

for all to see and make up their own minds?

Sure.

You are against displaying it.

Everybody should make up their own mind.

No, I am not against the display,