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Hello and welcome back to
Prehistoric Autopsy.

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We're at the University of Glasgow

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to continue our evolutionary
journey back into the past.

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Using the latest research,

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we're going to recreate in
extraordinary anatomical detail

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another of our prehistoric ancestors,

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one of the earliest humans -
homo erectus.

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For two months, we've been
rebuilding one individual

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from the bones up,

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using information gathered
from experts around the world.

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Recent discoveries are showing homo
erectus in a completely new light.

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That is a major breakthrough.

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It is, yes.

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Now, that is remarkable.
This is an old jaw. Yeah.

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This is a jaw which
has lost most of its teeth.

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And clues buried deep in the sea bed

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are revealing how their world
started to change.

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It's like being given a history book
of Earth's climate

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and no-one's ripped the pages out.

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Homo erectus was around for nearly
two million years,

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far longer than any other
human species.

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And at the end of the night,
we'll come face to face

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with one of these early ancestors.

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So let's get started.

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Welcome back!

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Well, last time,
we recreated a Neanderthal,

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known as La Ferrassie One.

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His kind were around for over
300,000 years.

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We found out that he had
a large brain,

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and he was a skilled hunter
and probably had language as well.

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Tonight, using these bones, we're
going to recreate an individual

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from one of the very first species
that we can comfortably call human,

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known as homo erectus.

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But first, let's just recap.

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We're here in 2012,
and this is us - homo sapiens.

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Last time, we discovered
we shared the planet

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with possibly four other species
including Neanderthals.

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And remember this little
hobbit down here - homo floresiensis,

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around until 12,000 years ago.

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But this is who we're looking at
tonight.

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Homo erectus lived
at the same time as us,

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but their story begins a way back
here - 1.8 million years ago.

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They were on the planet
far, far longer

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than any other single human species.

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So what is so special
about homo erectus?

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Well, to help us answer these
questions, we've got a lab up there

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where we'll be putting ourselves
and them to the test to find out

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how similar we were to them,
and they to us.

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And if you're wondering why
there's a man up there

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in his underpants
under a sun lamp,

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all will be revealed later.

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Over here, we've got experimental
archaeology

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and this is where we're hoping to
get inside our ancestors' brains.

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And where our experts
are looking for clues

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into how our ancestors lived.

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Back here, Palaeo-artist Viktor Deak

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and our team of model makers
have been working hard

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to create an incredibly
accurate reconstruction

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of one particular member
of this species -

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homo erectus.

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Someone who hasn't been seen
for a very, very long time.

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By rebuilding one of these
ancient ancestors,

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Viktor and the model making team
will help his game a unique insight

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into this remarkable species.

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'All our early ancestors
lived in Africa.'

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Homo erectus was the first
human species to leave,

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around 1.8 million years ago.

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They spread right across
the Middle East and Asia,

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getting as far as eastern China.

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So, how was Homo erectus
related to us?

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Intriguingly, many different
human species

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are believed to have
descended from them.

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One of these is Homo heidelbergensis,

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who in turn evolved into both
Neanderthals and us, Homo sapiens.

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They are also thought
to be the ancestor species

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of those tiny hobbits,
Homo floresiensis.

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All thought to have descended
from Homo erectus

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and all living at the same time.

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The individual that we're
interested in tonight

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was a young lad walking the earth
1.5 million years ago.

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He is known as Nariokotome boy.

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He lived near the Nariokotome River,

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which feeds into Lake Turkana,
in northern Kenya.

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When he died, l.5 million years ago,
his body sank into the silt

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and became fossilised.

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It was a revelation when his skeleton
was discovered in l984

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because it was still 90% intact.

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Tonight, to help us make one
of the most scientifically
accurate models we can,

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we're joined by palaeontologist
Professor Scott Simpson

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of Case Western Reserve University,
in Cleveland, Ohio.

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And Scott's been involved in some of
the key discoveries of Homo erectus.

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These bones are really wonderful,
they're an incredibly accurate cast.

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So Scott, introduce us
to Nariokotome Boy.

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Ah, well, this is one of the most
complete human ancestor skeletons

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that has been recovered, to date.

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He's probably aged about
eight years old when he died.

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But he looks like
he'd be older than that

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cos he's got both molars here
and I would normally say that

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looks, to me, like a 12-year-old
not an eight-year-old.

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He's very unusual - he has a mixture
of traits that show he's young

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and some mixtures of traits
that show he's old.

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So, if he was like a modern human
we'd say he's about 12 years old.

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But what we've done

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is we've looked at detailed studies
of the enamel of the teeth

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and we know, now, that he died
when he was eight years old.

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The one thing that immediately
strikes me

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is that...he seems very slight.

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There is a reason to suspect
that he was quite agile,

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even just looking at his skeleton
but nevertheless he is quite slim.

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Now Viktor, you've got Nariokotome
Boy's skeleton loaded up.

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Yes, I do.

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How are you filling
in the missing bits

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because again he's quite complete
but he's not all there.

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Well, what's really wonderful
about working like this

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is that I can mirror image
certain elements that exist

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and then fill in any gaps.

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So, can you mirror
that humerus, there,

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and stick it on the other side?

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Right, so, here we go, let's see.

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Actually, I've got the whole arm
set up, so there it is.

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Oh, fantastic.
And you've put the radii in as well.

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Now, we think he might have been
doing a fair bit of running,

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which we're going
to talk about later,

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but can you put him in a running
pose for us? Yeah, I can

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There he goes!

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This is still a virtual skeleton

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but a copy of Nariokotome
Boy's bones

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were delivered to our model makers

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and I went along to help
them put him together.

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Down at the workshop
Jez Gibson-Harris leads the team.

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'Another day, another hominin?'

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Yes!

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Finding such a complete skeleton
was a major breakthrough.

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Until Narikotome Boy was unearthed,

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only odd remains of Homo erectus
had been found.

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The missing parts of this cast
have been filled in

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using techniques like Viktor's
computer mirroring.

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The feet are thought to have
been similar to ours.

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An arched foot makes walking
and running more efficient.

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But the running pose
that we've chosen

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is a challenge for the model makers.

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So, this is our spine.

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And the idea is,
because he's running,

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we've got an angle
on the spine. Yeah.

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He's leaning forwards.

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Running is an exercise
in not falling over.

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So, I suppose, the challenge for you

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is going to be to make this as the
freestanding running Nariokotome Boy

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because he's going to want
to fall forwards. He is.

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Yes, the centre of balance
is quite far forward

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and we've only got him on one leg.

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That's nice and straight now.

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So looking at Viktor's picture,
then, this is his leg in stance,

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with the other leg about
to swing through, like that.

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That's going to be slightly
more tricky.

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Because that malleoli
should be right round here.
Right round the side.

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If you do that, if you bring that
tibia round so the patella,

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the kneecap's in the right place,

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I think we're pretty much there,
I mean, that looks really good.

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At the end of tonight's programme,

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we'll reveal our complete
reconstruction of Nariokotome Boy

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and discover what Homo erectus
may have looked like in flesh.

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'I think just getting those
elements assembled

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'means that you start
to see somebody.

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'He's not just a collection of bones
lying on the ground any more.'

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So what do you think
of the reconstructed skeleton?

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Well, I think he looks
absolutely fantastic.

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It's absolutely extraordinary.
Quite lifelike. Very agile.

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You get a real sense of movement.

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Yeah, and it's great

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because now we can see what his
skeleton might have looked like

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if he was complete.

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And there's lots of
anatomical features here,

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which have been described as being
something to do with running. Right.

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We talk about the nuchal ligament,

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which runs between a bump on the
back of the skull and neck.

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It's prevents our head
pitching forward.

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You can feel it on yourself,
or George.

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So, George, if you do exactly that
and tuck your neck down

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you can feel this quite thick band,
in the back of your neck,

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running all the way down here.
Oh, yeah! I can feel that, yeah.
That's the nuchal ligament.

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And he's got low shoulders as well.

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So we think he's probably swinging
his shoulders from side to side

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to counterbalance him
while he's running

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and a nice flexible
lumber spine too.

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Yes, so he could do the twist,
spin back and forth,

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which is also necessary
for walking and running.

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He had very strong back muscles.

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If we see, here, there are deep
gutters on either side -

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necessary for twisting your body
and holding you forward.

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It's anchoring the whole of your
trunk, down to your pelvis.

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And, then also, we think
Nariokotome Boy

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had quite big bottom
muscles as well.

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Quite big gluteus maximus.

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He looks really good.

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Well, the big gluteus
maximus muscles,

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we use the gluteus maximus when we
get out of a chair

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or walking up stairs.

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For an animal that's walking
and running in ancient Africa,

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you're going to need this muscle
for turning direction

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and slowing yourself down.

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Preventing your body from
pitching forward.

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So, are you convinced by these
adaptations to running
in Nariokotome Boy?

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There's a lot of information
out there

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suggesting perhaps he was
just a long distance walker.

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And because we see that many
humans are very well adapted
to long distance walking

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and walking, if you have
a large territory,

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is a very important adaptation
to living on the ancient
African landscape.

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but I think running is certainly
one explanation,

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explaining the anatomy
of Nariokotome.

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So, Nariokotome Boy evolved
to be good runner

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but the question is why?

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One of the things that drives
evolution is environmental change.

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So, what was happening to the world
Homo erectus lived in?

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For researchers at Columbia
University, in New York State,

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the answer to that question
lies in the sea bed.

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Professor Peter De Menocal
works on a technique

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that can reveal what our planet was
like millions of years ago.

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It measures climate change

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and it holds a clue
as to why Homo erectus

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may have been one of the first
long distance runners.

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By analysing earth cores,

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drilled from the seabed
off the coast of Africa,

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he can pinpoint key environmental
shifts in our ancestor's world.

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We use ocean sediment cores

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because the oceans are the ultimate
repository of all sediment.

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So the sediment just kind of gets
dumped into the ocean very slowly

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and continuously over time.

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So it's like being given
a history book of earth climate

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or earth history and no-one
has ripped the pages out.

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It's like a continuous
record of time.

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The accumulation rate
of this core is roughly,

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that would be equivalent
to about 1,000 years.

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So that's 1,000 years,
2,000, 3,000,

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4,000.

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00:12:09,626 --> 00:12:12,506
In this case, this core goes
back 10,000 years in time

237
00:12:12,506 --> 00:12:16,266
but we have another section that
actually fits in the bottom of this,

238
00:12:16,266 --> 00:12:18,586
goes back another 10,000.

239
00:12:18,586 --> 00:12:22,186
We have cores that go hundreds
of metres back below the sea floor

240
00:12:22,186 --> 00:12:24,946
and that takes us back millions
of years into the past.

241
00:12:27,666 --> 00:12:30,626
By looking at subtle colour
shifts in the cores,

242
00:12:30,626 --> 00:12:33,426
Peter can read periods
of dramatic climate change

243
00:12:33,426 --> 00:12:37,386
in the African landscape
across the millennia.

244
00:12:37,386 --> 00:12:39,946
You can see there's something
happening in this core,

245
00:12:39,946 --> 00:12:42,226
roughly right around this time,
a colour change.

246
00:12:42,226 --> 00:12:45,666
And this is between
five and 10,000 years ago.

247
00:12:45,666 --> 00:12:47,506
Sediments are green.

248
00:12:47,506 --> 00:12:48,946
Sediments are red.

249
00:12:48,946 --> 00:12:52,666
This redder sediment is the dust
that's blown off of west Africa.

250
00:12:52,666 --> 00:12:55,746
And then the absence of that
dust here is telling us

251
00:12:55,746 --> 00:12:58,306
that something in the African
climate changed.

252
00:12:58,306 --> 00:13:02,386
And this is when we know
that African climate was much
wetter than it is today.

253
00:13:02,386 --> 00:13:04,786
It was fully vegetated,
there were large lakes.

254
00:13:04,786 --> 00:13:08,026
So Africa was wet here
and it's dry here.

255
00:13:08,026 --> 00:13:11,306
Peter's team also analyse
the sediment

256
00:13:11,306 --> 00:13:14,706
for fossilised remnants
of plant matter.

257
00:13:14,706 --> 00:13:17,346
The types of plants that
were growing

258
00:13:17,346 --> 00:13:20,386
tell Peter when the climate
was warming up or cooling down.

259
00:13:21,946 --> 00:13:25,426
The swings between hot and wet
to cooler and drier

260
00:13:25,426 --> 00:13:30,386
have occurred many times throughout
the geological record

261
00:13:30,386 --> 00:13:33,306
but if we travel back
1.8 million years

262
00:13:33,306 --> 00:13:39,626
what can we discover about the time
that Homo erectus first appeared?

263
00:13:39,626 --> 00:13:43,666
There's this shift that happens
right around 1.8 million years ago,

264
00:13:43,666 --> 00:13:45,346
which is a really profound change.

265
00:13:45,346 --> 00:13:48,786
This is the first time that we see
modern Savannah grass extend.

266
00:13:48,786 --> 00:13:50,386
If you think of your
mind's eye image

267
00:13:50,386 --> 00:13:52,346
of what an African Savannah
looks like,

268
00:13:52,346 --> 00:13:53,666
that's when that appears.

269
00:13:53,666 --> 00:13:55,826
It's right around 1.8,
1.6 million years ago.

270
00:13:57,786 --> 00:14:02,146
So, right around the time
when Homo erectus appears
in the fossil record,

271
00:14:02,146 --> 00:14:05,626
east Africa experiences this really
tremendous change in vegetation

272
00:14:05,626 --> 00:14:09,386
from more closed habitats,
better watered habitats,

273
00:14:09,386 --> 00:14:11,186
toward much more open vegetation.

274
00:14:11,466 --> 00:14:14,386
With long legs
and a runner's physique,

275
00:14:14,386 --> 00:14:18,626
Homo erectus thrived in this
new environment.

276
00:14:18,626 --> 00:14:23,626
And they had another adaptation that
made them very effective runners.

277
00:14:23,626 --> 00:14:27,426
It's buried deep within the skeleton.

278
00:14:27,426 --> 00:14:29,146
But before we look at that,

279
00:14:29,146 --> 00:14:33,226
there's something I want to explain
about his anatomy.

280
00:14:33,226 --> 00:14:35,586
But I'd like you to try
something for yourself first.

281
00:14:35,586 --> 00:14:38,466
What I'd like you to do is
keep your head entirely still,

282
00:14:38,466 --> 00:14:40,186
and you can try this at home.

283
00:14:40,186 --> 00:14:43,226
First of all, I have to put my
glasses on. I have to read this.

284
00:14:43,226 --> 00:14:46,466
Get yourself a book or a piece
of paper with words on it.

285
00:14:46,466 --> 00:14:47,906
HE STARTS READING

286
00:14:47,906 --> 00:14:49,506
Start reading it.

287
00:14:49,506 --> 00:14:52,706
Move it from side to side very
quickly. Can you read it?

288
00:14:52,706 --> 00:14:54,466
No, it's gone.

289
00:14:54,466 --> 00:14:56,626
OK, let's try it the
other way round.

290
00:14:56,626 --> 00:14:58,386
Hold the piece of paper
entirely still

291
00:14:58,386 --> 00:15:00,786
and shake your head from
side to side.

292
00:15:00,786 --> 00:15:05,586
As shown in the two
drawings below the canals... OK.

293
00:15:05,586 --> 00:15:09,266
So you can still read it.
In three plains that are...

294
00:15:09,266 --> 00:15:12,146
So there's something
really clever going on

295
00:15:12,146 --> 00:15:14,146
and it's a really clever reflex

296
00:15:14,146 --> 00:15:17,546
which involves obviously your eyes
moving and that's the last thing

297
00:15:17,546 --> 00:15:21,186
but your ears are telling
your eyes effectively via a reflex

298
00:15:21,186 --> 00:15:25,386
how your head's moving and keeping
your eyes trained on one spot.

299
00:15:25,386 --> 00:15:28,106
Now why would that be
handy for this boy?

300
00:15:28,106 --> 00:15:30,066
It means you can
keep your eyes ahead

301
00:15:30,066 --> 00:15:32,946
and you can look at one spot
while you're running or jumping,

302
00:15:32,946 --> 00:15:34,546
whatever it is you're doing.

303
00:15:34,546 --> 00:15:38,466
So we have some
bits of anatomy over here.

304
00:15:38,466 --> 00:15:40,706
If I give that to you.

305
00:15:40,706 --> 00:15:44,266
And I'll bring this large
ear model over.

306
00:15:44,266 --> 00:15:46,186
The bit of anatomy that we're
interested in,

307
00:15:46,186 --> 00:15:48,066
which is allowing you to do this,

308
00:15:48,066 --> 00:15:51,826
is deep inside the skull
and this is a massive model of it.

309
00:15:51,826 --> 00:15:53,586
And here it is.

310
00:15:53,586 --> 00:15:57,026
So this is the vestibular
cochlea apparatus

311
00:15:57,026 --> 00:16:00,386
and here is your cochlea,
your organ of hearing,

312
00:16:00,386 --> 00:16:03,466
but here is part of the
organ of balance

313
00:16:03,466 --> 00:16:06,706
and also sensing direction changes
and accelerations.

314
00:16:06,706 --> 00:16:08,546
These are the semi-circular canals.

315
00:16:08,546 --> 00:16:11,466
Now, that's a really massive model
and Scott...

316
00:16:11,466 --> 00:16:13,986
That's not how big they are
in real life.

317
00:16:13,986 --> 00:16:15,826
That's the real thing?

318
00:16:15,826 --> 00:16:19,946
That is a real one.
So that's a human bony labyrinth.

319
00:16:19,946 --> 00:16:22,466
It is absolutely minute.
Isn't it beautiful?

320
00:16:22,466 --> 00:16:25,506
And we have this
anatomy for Homo erectus

321
00:16:25,506 --> 00:16:29,186
so we can get an idea of exactly
what this tiny, tiny bit

322
00:16:29,186 --> 00:16:32,066
of anatomy looks like in this
ancient ancestor.

323
00:16:32,066 --> 00:16:34,586
Now, in order to do this,

324
00:16:34,586 --> 00:16:38,226
the scientists did not
saw open the fossils,

325
00:16:38,226 --> 00:16:40,786
what they did instead
was to do that virtually,

326
00:16:40,786 --> 00:16:43,026
using a CT scanner.

327
00:16:43,026 --> 00:16:47,066
And then what they were able to do
is reconstruct

328
00:16:47,066 --> 00:16:51,146
what the membranous labyrinth of
Homo erectus would have looked like

329
00:16:51,146 --> 00:16:52,986
in three dimensions.

330
00:16:52,986 --> 00:16:57,506
The semi-circular canals
are a different shape and size

331
00:16:57,506 --> 00:17:01,906
from those of earlier ancestors
and other apes.

332
00:17:01,906 --> 00:17:04,386
And what's quite remarkable
about this is

333
00:17:04,386 --> 00:17:07,026
that it looks quite
similar to ours.

334
00:17:07,026 --> 00:17:10,946
So this suggests perhaps that
Homo erectus was very agile

335
00:17:10,946 --> 00:17:13,026
and probably running and jumping.

336
00:17:15,506 --> 00:17:18,186
And Homo erectus had to be agile.

337
00:17:18,186 --> 00:17:20,706
They weren't the only animals
out on the savannah.

338
00:17:22,066 --> 00:17:24,946
There were grazing
animals like rhinoceros.

339
00:17:24,946 --> 00:17:28,906
They have been around for nearly
17 million years.

340
00:17:28,906 --> 00:17:30,786
But in Homo erectus' world

341
00:17:30,786 --> 00:17:35,306
there were also predatory
mammals like this sabre-tooth cat.

342
00:17:35,306 --> 00:17:37,666
They would have been
a constant threat.

343
00:17:37,666 --> 00:17:41,306
Even with its smaller sabre teeth,
it would have been deadly.

344
00:17:43,146 --> 00:17:48,546
1.8 million years ago, Homo erectus
may have been the first human species

345
00:17:48,546 --> 00:17:52,066
to leave Africa and start to spread
around the world.

346
00:17:52,066 --> 00:17:55,906
But the ones that stayed behind
weren't alone.

347
00:17:55,906 --> 00:17:58,146
They shared their African environment

348
00:17:58,146 --> 00:18:03,346
with as many as four other
species of our early ancestors.

349
00:18:03,346 --> 00:18:05,906
So who else was around at the time
all this was happening?

350
00:18:05,906 --> 00:18:08,746
Once we go back over a million
years, there were some

351
00:18:08,746 --> 00:18:12,826
very different species living
alongside those early humans.

352
00:18:12,826 --> 00:18:16,186
Like this bruiser here,
Paranthropus boisei.

353
00:18:16,186 --> 00:18:19,306
And here he is.
He's such an odd-looking hominin.

354
00:18:19,306 --> 00:18:21,506
I can't believe he's
one of our relatives.

355
00:18:21,506 --> 00:18:23,226
Very strange. That's true.

356
00:18:23,226 --> 00:18:28,106
His whole anatomy seems to be taken
over by jaws and jaw musculature.

357
00:18:28,106 --> 00:18:30,306
He was a dedicated chewer.

358
00:18:30,306 --> 00:18:33,906
I mean, look at this, look at the
crest along the top of his head.

359
00:18:33,906 --> 00:18:35,386
So his temporalis muscles,

360
00:18:35,386 --> 00:18:38,346
which are the ones we can feel
if we're chewing,

361
00:18:38,346 --> 00:18:41,826
you can feel a muscle working
on the side of your head there.

362
00:18:41,826 --> 00:18:44,706
Well, his muscles went right up to
the top of his head.

363
00:18:44,706 --> 00:18:46,906
Ours stop about here, don't they?
That's right.

364
00:18:46,906 --> 00:18:49,826
Right about here, except
theirs, as they got older and older,

365
00:18:49,826 --> 00:18:53,106
grew to the midline and continued
growing, forming a sagittal crest.

366
00:18:53,106 --> 00:18:55,266
Something we don't
see in modern humans.

367
00:18:55,266 --> 00:18:59,226
Yeah. And then he's got incredibly
flared cheek bones.

368
00:18:59,226 --> 00:19:02,066
So that that muscle can get
through there, down to the jaw.

369
00:19:02,066 --> 00:19:03,786
But what are all those
muscles doing?

370
00:19:03,786 --> 00:19:07,506
Well, there's the jaw. Look
at that, those teeth are massive.

371
00:19:07,506 --> 00:19:10,066
Especially when we compare it to
the Homo erectus skeleton.

372
00:19:10,066 --> 00:19:12,786
Yeah, look at that.
They're almost two times as large.

373
00:19:12,786 --> 00:19:14,626
So these molars are absolutely huge,

374
00:19:14,626 --> 00:19:17,266
he must have been eating
really tough foods.

375
00:19:17,266 --> 00:19:20,226
Lots and lots of low quality foods.
Day in and day out.

376
00:19:20,226 --> 00:19:23,386
His nickname is Nut Cracker Man,
which kind of suggests that

377
00:19:23,386 --> 00:19:26,386
he's eating very hard foods but I
think recent analysis of his teeth

378
00:19:26,386 --> 00:19:29,146
suggested that he might
have been eating grasses as well.

379
00:19:29,146 --> 00:19:31,306
Absolutely. If we look
at the microwear,

380
00:19:31,306 --> 00:19:33,946
the small scratches on the teeth,
you can see that they ate

381
00:19:33,946 --> 00:19:37,386
lots and lots of grasses that were
covered in sand and phytoliths,

382
00:19:37,386 --> 00:19:39,626
which are little stones that
are found in grass,

383
00:19:39,626 --> 00:19:43,866
and together these wear
down the teeth very, very quickly.

384
00:19:43,866 --> 00:19:47,866
Boisei was a species perfectly
adapted to its environment.

385
00:19:47,866 --> 00:19:51,666
But when that environment started to
change, they were in trouble.

386
00:19:51,666 --> 00:19:54,426
The climate in Africa began
swinging between

387
00:19:54,426 --> 00:19:56,906
extremes of wet and dry.

388
00:19:56,906 --> 00:20:01,546
Unable to adapt, Boisei
couldn't cope and died out.

389
00:20:04,946 --> 00:20:07,226
But Homo erectus thrived.

390
00:20:08,626 --> 00:20:12,866
The key to their success
was their adaptablity.

391
00:20:12,866 --> 00:20:16,106
Some estimate that at their peak
there may have been

392
00:20:16,106 --> 00:20:20,066
as many as 125,000 of them living
across the world,

393
00:20:20,066 --> 00:20:24,346
from Africa, right across Asia,
to eastern China.

394
00:20:28,426 --> 00:20:31,666
This seems really bizarre
because we normally think of species

395
00:20:31,666 --> 00:20:34,386
adapting to one particular
type of environment

396
00:20:34,386 --> 00:20:36,746
but our ancestors
were having to get used to

397
00:20:36,746 --> 00:20:38,986
a rapidly changing environment.
That's right,

398
00:20:38,986 --> 00:20:42,386
It shows the complexity of necessary
adaptations for Homo erectus.

399
00:20:42,386 --> 00:20:44,226
Different habitats and environments

400
00:20:44,226 --> 00:20:46,346
require different types of
adaptations.

401
00:20:47,346 --> 00:20:52,706
In the heat of the African savannah,
keeping cool is crucial to survival.

402
00:20:54,706 --> 00:20:57,986
Many animals insulate themselves
against the harmful exposure

403
00:20:57,986 --> 00:21:01,746
of the sun with
a protective layer of hair.

404
00:21:03,586 --> 00:21:07,186
They rest at the hottest times
of the day, to avoid overheating.

405
00:21:07,186 --> 00:21:10,906
But that means they have less
time to travel and hunt.

406
00:21:10,906 --> 00:21:14,666
If Homo erectus was out running
in the heat of the day,

407
00:21:14,666 --> 00:21:17,626
what stopped him over-heating?

408
00:21:17,626 --> 00:21:21,906
Could this be the time that
our early ancestors lost their hair?

409
00:21:24,346 --> 00:21:28,146
I'm with Professor Peter Wheeler
from John Moores University.

410
00:21:28,146 --> 00:21:30,146
Would Homo erectus have been hairy?

411
00:21:30,146 --> 00:21:32,346
That's something we don't know,

412
00:21:32,346 --> 00:21:35,506
but what we can say is that there
are good reasons to think

413
00:21:35,506 --> 00:21:39,346
that it would have been advantageous
for Homo erectus not to be hairy.

414
00:21:39,346 --> 00:21:40,866
Tell me more, Peter.

415
00:21:40,866 --> 00:21:43,986
Yes. We've got these volunteers, who
aren't too dissimilar in physique

416
00:21:43,986 --> 00:21:46,666
to what the Nariokotome Boy might
have looked like

417
00:21:46,666 --> 00:21:48,626
had he survived to be an adult.

418
00:21:48,626 --> 00:21:50,506
And they're identical twins

419
00:21:50,506 --> 00:21:53,146
and they've trained to a similar
level of fitness.

420
00:21:53,146 --> 00:21:55,866
And we've had them
standing under these heat lamps,

421
00:21:55,866 --> 00:21:57,906
which emulate the African sun.

422
00:21:57,906 --> 00:22:00,706
One of the advantages of
retaining body hair

423
00:22:00,706 --> 00:22:02,506
is that it acts as a shield.

424
00:22:02,506 --> 00:22:05,586
It prevents a lot of the heat from
the sun getting through to the body.

425
00:22:05,586 --> 00:22:09,346
And we've selected clothes that are
similar in thermal properties

426
00:22:09,346 --> 00:22:11,746
to that of the hair of
living primates.

427
00:22:11,746 --> 00:22:15,946
So, in essence, we have a hairless
hominid and a hairy one.

428
00:22:15,946 --> 00:22:20,466
Yes. Now, although the surface of
the hair does get very hot,

429
00:22:20,466 --> 00:22:23,306
in this case clothing,
because it's insulating,

430
00:22:23,306 --> 00:22:26,506
most of it will be reflected and
reradiated back to the environment.

431
00:22:26,506 --> 00:22:29,706
It's the lighter colours
that are the warmest areas.

432
00:22:29,706 --> 00:22:34,946
The surfaces on the naked skinned
volunteer are hot.

433
00:22:34,946 --> 00:22:37,346
They are the skin being hot itself

434
00:22:37,346 --> 00:22:41,546
therefore the heat is being
absorbed directly by the body.

435
00:22:41,546 --> 00:22:43,826
So while animals are standing still

436
00:22:43,826 --> 00:22:48,946
their fur keeps them cool by
reflecting heat away from the body.

437
00:22:48,946 --> 00:22:52,906
But John's bare skin is absorbing
it so he is getting hotter.

438
00:22:52,906 --> 00:22:55,746
Well, let's see how you fare
when you start to run.

439
00:22:55,746 --> 00:22:58,426
We'll turn on fans to create
a similar airflow

440
00:22:58,426 --> 00:23:00,146
to when you're actually running.

441
00:23:00,146 --> 00:23:02,706
We have a health care
professional here.

442
00:23:02,706 --> 00:23:05,666
If you don't feel comfortable,
you stop at any time.

443
00:23:05,666 --> 00:23:08,026
OK. Start running.

444
00:23:16,426 --> 00:23:18,706
Well, Alice,
they're running away up here.

445
00:23:18,706 --> 00:23:21,746
Do we know why running would be
so important for Homo erectus?

446
00:23:21,746 --> 00:23:23,426
Scott, what do you think?

447
00:23:23,426 --> 00:23:26,346
Homo erectus probably lived
in very, very large home ranges.

448
00:23:26,346 --> 00:23:29,306
So that means
he had to meander around

449
00:23:29,306 --> 00:23:32,786
and run around or walk around these
large home ranges looking for food.

450
00:23:32,786 --> 00:23:35,266
Patrolling territories,
if that's appropriate,

451
00:23:35,266 --> 00:23:37,586
but they're really eating
high quality food

452
00:23:37,586 --> 00:23:40,426
whether it's meat or high quality
fruits and vegetables.

453
00:23:40,426 --> 00:23:42,626
But these are widely
dispersed across the savannah

454
00:23:42,626 --> 00:23:45,066
so you have to spend a lot of
time walking around,

455
00:23:45,066 --> 00:23:46,946
looking for these
high quality foods.

456
00:23:46,946 --> 00:23:50,186
So if he's looking for meat,
obviously, meat walks around

457
00:23:50,186 --> 00:23:53,186
and probably needs to be hunted,
so are we saying he was a hunter?

458
00:23:53,186 --> 00:23:56,826
You know, he probably was a hunter
although we often think of them

459
00:23:56,826 --> 00:23:59,146
hunting elephants and the largest
animals out there,

460
00:23:59,146 --> 00:24:01,346
they could have been hunting
some of those animals,

461
00:24:01,346 --> 00:24:04,306
although it's not likely, they're
probably eating smaller animals

462
00:24:04,306 --> 00:24:07,026
that are easy to trap or
surprise in the course of a day.

463
00:24:07,026 --> 00:24:08,666
So they were eating meat

464
00:24:08,666 --> 00:24:11,306
but they weren't the big hunters
that we see in Neanderthals.

465
00:24:11,306 --> 00:24:14,626
What about scavenging because
that's another way of getting meat?

466
00:24:14,626 --> 00:24:16,586
If he could walk and run
for long distances

467
00:24:16,586 --> 00:24:19,066
then presumably that would have
been an advantage to him.

468
00:24:19,066 --> 00:24:21,626
The problem with scavenged food,
though, is that there are

469
00:24:21,626 --> 00:24:24,426
a lot of other animals that are
also interested in scavenged food,

470
00:24:24,426 --> 00:24:27,106
like hyenas, lions,
jackals and birds of prey.

471
00:24:27,106 --> 00:24:30,146
But running would have been
useful in terms of getting away

472
00:24:30,146 --> 00:24:32,386
from other scavengers
and predators, I imagine.

473
00:24:32,386 --> 00:24:35,386
Only if you can run faster than the
other scavengers and predators.

474
00:24:35,386 --> 00:24:38,346
If we're talking about somebody
who's running around the savannah,

475
00:24:38,346 --> 00:24:39,906
we need to put some muscles on him.

476
00:24:39,906 --> 00:24:43,506
So let's go and see how Viktor's
getting on.

477
00:24:43,506 --> 00:24:46,706
Oh, look at this. That's lovely. So
you've got muscles on his body

478
00:24:46,706 --> 00:24:49,226
and muscles appearing on his
face as well.

479
00:24:49,226 --> 00:24:52,626
He's still looking quite lean
and I think that's right,

480
00:24:52,626 --> 00:24:55,186
he's got very slender bones,

481
00:24:55,186 --> 00:24:58,626
so we're not looking at great big
chunky musculature.

482
00:24:58,626 --> 00:25:01,186
He looks very lithe, doesn't he?

483
00:25:01,186 --> 00:25:03,346
Right, he would've had not
a lot of body fat,

484
00:25:03,346 --> 00:25:05,986
especially in that
environment and climate.

485
00:25:05,986 --> 00:25:08,106
As active as he was.

486
00:25:08,106 --> 00:25:11,186
All this information has been fed
to our model makers.

487
00:25:11,186 --> 00:25:13,786
Once the muscles have been put on
the skeleton,

488
00:25:13,786 --> 00:25:16,866
Narikotome Boy really does start
to look more human.

489
00:25:23,066 --> 00:25:26,866
The team use modelling clay to form
muscles around the skeleton.

490
00:25:26,866 --> 00:25:32,306
For sculptor Reza, making sure
they are accurate is tricky work.

491
00:25:32,306 --> 00:25:34,626
Reza, you look a bit nervous.

492
00:25:34,626 --> 00:25:36,586
Well, this is my baby.

493
00:25:38,546 --> 00:25:40,666
Wow, that looks a bit different.

494
00:25:43,026 --> 00:25:46,506
Let me just unwrap the
arms and legs.

495
00:25:46,506 --> 00:25:48,866
Well, he's got a very lovely
serratus anterior,

496
00:25:48,866 --> 00:25:50,066
I can say that right now.

497
00:25:50,066 --> 00:25:52,026
Look at this lovely muscle
right here,

498
00:25:52,026 --> 00:25:55,666
this is the muscle that holds the
scapula onto the back of the thorax.

499
00:25:55,666 --> 00:25:59,186
So this is all looking anatomically
beautiful. Very accurate.

500
00:25:59,186 --> 00:26:01,106
Thank you.

501
00:26:01,106 --> 00:26:05,386
'Considering Narikotome Boy
was around 1.5 million years ago,

502
00:26:05,386 --> 00:26:09,546
'his body is surprisingly
similar to ours.'

503
00:26:09,546 --> 00:26:14,226
We're seeing all of the muscles
that we'd see in us.

504
00:26:14,226 --> 00:26:17,266
These are the same muscles.
Yes, exactly.

505
00:26:17,266 --> 00:26:19,186
They're in the same places.

506
00:26:19,186 --> 00:26:22,066
I quite like him without a head.

507
00:26:22,066 --> 00:26:23,866
THEY LAUGH

508
00:26:23,866 --> 00:26:26,066
Now we haven't got hands
or feet on him,

509
00:26:26,066 --> 00:26:28,906
but at the moment
he does look very human, doesn't he?

510
00:26:28,906 --> 00:26:32,146
Yeah, it does. I think that's going
to change when we put the head on.

511
00:26:32,146 --> 00:26:35,826
Cos it really is the head which
is so different.

512
00:26:35,826 --> 00:26:37,026
Right, yes.

513
00:26:37,026 --> 00:26:41,026
He's got quite a small brain, and
quite a distinctive face as well.

514
00:26:41,026 --> 00:26:46,226
There's a couple of tweaks that
I think would really help.

515
00:26:46,226 --> 00:26:49,906
He's running and actually we need to
get a bit of a twist going on.

516
00:26:49,906 --> 00:26:52,506
So when you're running along...

517
00:26:52,506 --> 00:26:54,386
So you're swinging your...

518
00:26:54,386 --> 00:26:57,826
You swing your chest the other way
to kind of... Right, yes.

519
00:26:57,826 --> 00:27:00,546
To counterbalance because your
leg's trying to spin you off

520
00:27:00,546 --> 00:27:02,306
in that direction.

521
00:27:02,306 --> 00:27:04,386
Yeah, we can do some
adjustments there.

522
00:27:04,386 --> 00:27:08,346
He's coming on really nicely.
Thank you.

523
00:27:09,666 --> 00:27:11,866
He's really starting to take shape.

524
00:27:11,866 --> 00:27:13,946
Now, our volunteers have really been

525
00:27:13,946 --> 00:27:16,066
working up a sweat on these
treadmills

526
00:27:16,066 --> 00:27:18,706
so now I want to see
who's keeping their cool.

527
00:27:18,706 --> 00:27:22,546
How are you feeling? Tough.
Tough? Yeah.

528
00:27:22,546 --> 00:27:26,666
And our naked skinned human? OK.

529
00:27:26,666 --> 00:27:28,626
He feels he can keep going.

530
00:27:28,626 --> 00:27:31,306
He's dissipating the heat load
that his muscles are producing

531
00:27:31,306 --> 00:27:33,346
much more easily.

532
00:27:33,346 --> 00:27:35,986
And there are two distinct reasons
why he is able to do this.

533
00:27:35,986 --> 00:27:39,426
The loss of his body hair means
that heat can flow from his body

534
00:27:39,426 --> 00:27:42,106
more easily
out into the environment.

535
00:27:42,106 --> 00:27:44,546
The second advantage is the
loss of body hair

536
00:27:44,546 --> 00:27:47,026
makes sweating much
more effective.

537
00:27:47,026 --> 00:27:50,306
When the sweat is secreted onto
the skin surface,

538
00:27:50,306 --> 00:27:52,626
the increased air flow
over the skin means

539
00:27:52,626 --> 00:27:54,786
that sweat is evaporated
at a greater rate.

540
00:27:54,786 --> 00:27:57,586
I think you can switch
the machines off now

541
00:27:57,586 --> 00:28:01,786
cos I'm worried you're about
to have heatstroke.

542
00:28:01,786 --> 00:28:05,666
Now, haul up your shirt there.
Look at that.

543
00:28:05,666 --> 00:28:08,746
Now, all that heat
has been trapped inside,

544
00:28:08,746 --> 00:28:11,946
his core, his insides,
are really heating up.

545
00:28:11,946 --> 00:28:17,506
John on the left there is not
nearly as hot underneath,

546
00:28:17,506 --> 00:28:20,746
so the advantages are quite clear.

547
00:28:20,746 --> 00:28:23,986
The advantages are very clear,
particularly during activity

548
00:28:23,986 --> 00:28:27,026
either through long distance
persistence walking,

549
00:28:27,026 --> 00:28:30,586
through the heat of the tropical day
or short bursts of intense activity

550
00:28:30,586 --> 00:28:32,346
such as our volunteers
have done here.

551
00:28:32,346 --> 00:28:34,786
There's one other problem with
exposed skin in the sun is

552
00:28:34,786 --> 00:28:38,186
that you would have to have dark
skin protected by melanin.

553
00:28:38,186 --> 00:28:39,906
What about hair on the head?

554
00:28:39,906 --> 00:28:42,466
One of the reasons that we
think hair is retained on the head

555
00:28:42,466 --> 00:28:45,786
is that it's actually shielding
those areas of the body in a biped

556
00:28:45,786 --> 00:28:49,226
which are most exposed to the
strongest fluxes of solar radiation.

557
00:28:49,226 --> 00:28:51,506
It protects the brain?
When the sun is overhead.

558
00:28:51,506 --> 00:28:54,146
It's shielding
the brain from overheating.

559
00:28:54,146 --> 00:28:55,426
Steven, how do you feel?

560
00:28:55,426 --> 00:28:57,346
That was really hard.
That was really hard.

561
00:28:57,346 --> 00:29:00,426
Good. You could have kept going,
I reckon. Yeah.

562
00:29:01,826 --> 00:29:05,026
Under the searing savannah
sun, Nariokotome Boy

563
00:29:05,026 --> 00:29:08,306
could only run during the day
if he could keep cool.

564
00:29:08,306 --> 00:29:12,946
Sweating is the most efficient
way of losing heat and to do that

565
00:29:12,946 --> 00:29:15,666
he would have needed
very little body hair.

566
00:29:15,666 --> 00:29:17,746
This is really interesting

567
00:29:17,746 --> 00:29:20,226
and I find it really intriguing
that we could be looking at

568
00:29:20,226 --> 00:29:23,266
the point in our story
where our ancestors lost their fur.

569
00:29:23,266 --> 00:29:25,266
That's right. This is very unusual.

570
00:29:25,266 --> 00:29:28,146
Humans are unique among primates
because we are naked.

571
00:29:28,146 --> 00:29:30,626
We just don't have the hair that
the other primates have.

572
00:29:30,626 --> 00:29:33,386
Perhaps the most compelling reason
that we've lost the hair

573
00:29:33,386 --> 00:29:34,986
is that we wanted to shed heat.

574
00:29:34,986 --> 00:29:38,266
That allows us to be active
throughout the course of the day,

575
00:29:38,266 --> 00:29:41,346
as apposed to...most mammals
rest at noon time.

576
00:29:41,346 --> 00:29:43,506
And this is exactly what the
experiment showed.

577
00:29:43,506 --> 00:29:44,546
Very clearly.

578
00:29:44,546 --> 00:29:49,666
Hairlessness could mean that we can
keep cool in a hot environment.

579
00:29:49,666 --> 00:29:52,786
Perhaps that does mean that
our ancestors could have gone out

580
00:29:52,786 --> 00:29:55,706
and perhaps scavenged meat, perhaps
hunted meat, in a period of time

581
00:29:55,706 --> 00:29:58,626
when other predators might have
been resting in the shade.

582
00:29:58,626 --> 00:30:00,706
That's right.
And it's interesting that,

583
00:30:00,706 --> 00:30:03,866
if meat were a more important
part of these ancestors' diets,

584
00:30:03,866 --> 00:30:07,146
it's interesting to see that the
teeth are getting smaller

585
00:30:07,146 --> 00:30:10,986
and also to see that Nariokotome Boy
has a very different shaped thorax,

586
00:30:10,986 --> 00:30:14,986
rib cage, and it's been suggested
that he's got a shorter gut.

587
00:30:14,986 --> 00:30:18,226
It could very well be, because if we
look at the shape of the rib cage,

588
00:30:18,226 --> 00:30:22,146
the rib cage is not as broad,
wide or flared out as some of our
earlier ancestors.

589
00:30:22,146 --> 00:30:25,746
That means that the space in between
the pelvis and the diaphragm,

590
00:30:25,746 --> 00:30:29,186
where our guts live,
seems to be a smaller volume.

591
00:30:29,186 --> 00:30:30,906
We have smaller guts.

592
00:30:30,906 --> 00:30:33,946
Which suggest that he was eating
better quality foods.

593
00:30:33,946 --> 00:30:36,466
The shorter the gut,
the better quality the food.

594
00:30:36,466 --> 00:30:39,586
So meat could be an explanation
for that but there could be

595
00:30:39,586 --> 00:30:43,386
another explanation as well why guts
and teeth are getting smaller.

596
00:30:43,386 --> 00:30:47,346
It could have been that these guys
were cooking their food.

597
00:30:47,346 --> 00:30:50,826
It's controversial because
until recently, it was thought humans

598
00:30:50,826 --> 00:30:54,106
didn't control fire
until around 400,000 years ago.

599
00:30:54,106 --> 00:30:56,066
But new chemical analysis techniques

600
00:30:56,066 --> 00:30:58,906
may just have put
a match to all that.

601
00:31:02,266 --> 00:31:05,586
Cooking with fire is a uniquely
human behaviour.

602
00:31:05,586 --> 00:31:08,746
Today, Homo sapiens are the only
species to do it,

603
00:31:08,746 --> 00:31:11,346
but that hasn't always
been the case.

604
00:31:14,346 --> 00:31:18,506
In Williamstown, Massachusetts,
Dr Anne Skinner has been analysing

605
00:31:18,506 --> 00:31:22,706
tiny fragments of ancient animal
bones that have been burned.

606
00:31:22,706 --> 00:31:26,706
They were found at a site used by
Homo erectus.

607
00:31:26,706 --> 00:31:30,306
And Anne made
an extraordinary discovery.

608
00:31:33,106 --> 00:31:37,186
What elements within the bone are you
particularly interested in?

609
00:31:37,186 --> 00:31:39,626
The part I'm interested in
is the proteins.

610
00:31:39,626 --> 00:31:41,786
And how does the fire affect them?

611
00:31:41,786 --> 00:31:47,226
It breaks down the protein and
leaves behind just these small bits

612
00:31:47,226 --> 00:31:52,386
that can be seen even a million
to 1.5 million years later.

613
00:31:54,706 --> 00:31:58,226
Using a technique
known as electron spin resonance,

614
00:31:58,226 --> 00:32:02,306
she can analyse
changes in bone protein.

615
00:32:02,306 --> 00:32:07,026
These reveal what temperature
the bones were burned at.

616
00:32:07,026 --> 00:32:12,106
Natural fires from the time of Homo
erectus would have been

617
00:32:12,106 --> 00:32:15,706
grassfires that burn at
300 degrees Celsius.

618
00:32:16,946 --> 00:32:19,626
But man-made fires,
created in a hearth,

619
00:32:19,626 --> 00:32:22,986
reach much higher temperatures.

620
00:32:22,986 --> 00:32:26,946
So if I have bones
that are heated above 300,

621
00:32:26,946 --> 00:32:30,786
and especially above 400, to
give us a little leeway here,

622
00:32:30,786 --> 00:32:34,706
then I can be sure that they were
not heated in a grassfire,

623
00:32:34,706 --> 00:32:37,626
and hence they have to
have been heated

624
00:32:37,626 --> 00:32:41,106
in a fire constructed by hominids.

625
00:32:42,946 --> 00:32:47,666
Anne used her technique to analyse
burnt fragments of antelope bones

626
00:32:47,666 --> 00:32:51,586
found in Swartkrans cave
in South Africa.

627
00:32:51,586 --> 00:32:55,906
This was a cave where Homo erectus
remains had also been found.

628
00:32:55,906 --> 00:33:01,226
Remarkably, she found that the bones
had burned at 350 degrees Celsius,

629
00:33:01,226 --> 00:33:05,986
and believes this shows they must
have been burnt in a hearth.

630
00:33:07,186 --> 00:33:11,106
I can show that these bones were
burned in a fire

631
00:33:11,106 --> 00:33:14,586
that must have been created
and controlled at the cave

632
00:33:14,586 --> 00:33:17,986
and that dates to somewhere
between 1 and 1.5 million years,

633
00:33:17,986 --> 00:33:21,226
which is older than any other site
that has ever been found.

634
00:33:21,226 --> 00:33:24,866
That is a major breakthrough.
It is. Yes.

635
00:33:25,866 --> 00:33:29,906
Scientists believe that the only
species to have the mental ability

636
00:33:29,906 --> 00:33:33,826
to use fire at this time
was Homo erectus.

637
00:33:33,826 --> 00:33:37,226
So from your work
at Swartkrans cave,

638
00:33:37,226 --> 00:33:42,346
what are you able to
tell about Homo erectus and fire?

639
00:33:42,346 --> 00:33:44,786
Well, the fire itself
is interesting.

640
00:33:44,786 --> 00:33:49,946
But the idea that these entities
had the ability to even conceive

641
00:33:49,946 --> 00:33:52,666
that they might
control their own environment

642
00:33:52,666 --> 00:33:55,586
rather than just letting the
environment control them.

643
00:33:55,586 --> 00:33:59,146
Instead of seeing a burning bush
and running in the other direction,

644
00:33:59,146 --> 00:34:02,346
to conceptually say,
"Hey, we could use that.

645
00:34:02,346 --> 00:34:06,066
"Even if we weren't cooking, we
could use it to scare away leopards.

646
00:34:06,066 --> 00:34:08,106
"We could use it to keep warm".

647
00:34:08,106 --> 00:34:11,306
Just thinking that there's
something that you could use

648
00:34:11,306 --> 00:34:15,466
in your environment is...takes
more effort than you might think.

649
00:34:19,066 --> 00:34:22,066
Anne's findings
have rewritten the timeline

650
00:34:22,066 --> 00:34:25,706
on Homo erectus' ability
to harness fire.

651
00:34:26,826 --> 00:34:32,066
Evolutionary biologist Dr Rachel
Carmody has studied the research.

652
00:34:32,066 --> 00:34:35,026
She believes that the early
use of fire could even have

653
00:34:35,026 --> 00:34:37,746
accelerated their development.

654
00:34:38,826 --> 00:34:41,146
This kind of work is
really showing us

655
00:34:41,146 --> 00:34:45,906
that humans were controlling fire
and were possibly using it

656
00:34:45,906 --> 00:34:50,066
for things like cooking very
early on in human evolution.

657
00:34:51,266 --> 00:34:55,026
Cooked food means a more varied,
higher energy diet.

658
00:34:55,026 --> 00:34:57,986
This reduces
the workload for the gut

659
00:34:57,986 --> 00:35:01,266
and leaves calories
spare for the rest of the body.

660
00:35:01,266 --> 00:35:05,386
A fifth of the calories we consume
are used to fuel our brains.

661
00:35:05,386 --> 00:35:08,626
There's a theory that a switch
to cooked food is

662
00:35:08,626 --> 00:35:12,186
one of the things that encouraged
an increase in brain size.

663
00:35:13,546 --> 00:35:16,066
What we see at this
point in human evolution

664
00:35:16,066 --> 00:35:19,986
is the beginning of a trade-off,
where gut size gets smaller

665
00:35:19,986 --> 00:35:23,146
and so you save energy by
having a smaller gut.

666
00:35:23,146 --> 00:35:26,346
But humans seem to have been able
to reallocate that saved energy

667
00:35:26,346 --> 00:35:28,346
towards fuelling a larger brain.

668
00:35:28,346 --> 00:35:33,586
So is there a link between a better
diet and growing bigger brains?

669
00:35:34,906 --> 00:35:37,506
I find this intriguing and
slightly unsettling

670
00:35:37,506 --> 00:35:40,666
because for me this is evolution
turned on its head.

671
00:35:40,666 --> 00:35:43,746
Because we're saying that we are
saving some energy somewhere

672
00:35:43,746 --> 00:35:47,066
so that means we can grow
a bit of ourselves bigger.

673
00:35:47,066 --> 00:35:50,306
George, what do you think?
A chimpanzee spends 47% of its time

674
00:35:50,306 --> 00:35:52,506
chewing and eating and
processing food,

675
00:35:52,506 --> 00:35:54,786
whereas humans only spend 4.7%

676
00:35:54,786 --> 00:35:58,666
so you've got all this extra time
and energy to do something with it.

677
00:35:58,666 --> 00:36:00,346
Why not cooking?

678
00:36:00,346 --> 00:36:03,666
While we are looking at size of
brains, I've got a very graphic way

679
00:36:03,666 --> 00:36:06,026
of demonstrating how
brains are getting bigger

680
00:36:06,026 --> 00:36:09,506
through human evolution
and that's through over here.

681
00:36:09,506 --> 00:36:11,546
Thank you, Scott.

682
00:36:11,546 --> 00:36:14,506
Stick Nariokotome Boy's
skull in there.

683
00:36:14,506 --> 00:36:17,546
We've got a range of different
humans here from different times

684
00:36:17,546 --> 00:36:20,546
in our story, in fact these
ones aren't even human,

685
00:36:20,546 --> 00:36:23,946
they're ancestors
but they're not quite human yet.

686
00:36:23,946 --> 00:36:27,426
This is perhaps the earliest fossil
that we have

687
00:36:27,426 --> 00:36:31,386
which we might be able to call a
human ancestor, this is Toumai,

688
00:36:31,386 --> 00:36:34,786
Sahelanthropus tchadensis,
from about 6 or 7 million years ago.

689
00:36:34,786 --> 00:36:36,666
That's right.

690
00:36:36,666 --> 00:36:41,666
And these beads represent the volume
of the brain. Of the inside.

691
00:36:41,666 --> 00:36:44,306
And this is a pretty tiny brain,
isn't it, Scott?

692
00:36:44,306 --> 00:36:46,866
It's just a little bit larger
than a chimpanzee

693
00:36:46,866 --> 00:36:50,826
or maybe chimpanzee average size.
So it's not very smart.

694
00:36:50,826 --> 00:36:53,986
And then this one is
Australopithecus africanus.

695
00:36:53,986 --> 00:36:57,906
Yes, she's from South Africa from
2.5 to 2.8 million years ago.

696
00:36:57,906 --> 00:37:02,026
Also walked upright on two legs like
we do and perhaps Sahelanthropus.

697
00:37:02,026 --> 00:37:05,426
And this is the average
size of this species' brain.

698
00:37:05,426 --> 00:37:07,786
So there you go,
a little bit bigger.

699
00:37:07,786 --> 00:37:10,626
And now we come to Nariokotome Boy
and his kind.

700
00:37:10,626 --> 00:37:12,746
So Homo erectus.

701
00:37:12,746 --> 00:37:15,306
Now that volume
that you're pouring in there

702
00:37:15,306 --> 00:37:18,426
actually represents an adult
of that species.

703
00:37:18,426 --> 00:37:20,146
It does, yes.

704
00:37:20,146 --> 00:37:23,666
His brain is a bit smaller than that
but had he grown to be an adult

705
00:37:23,666 --> 00:37:26,026
then he would have achieved
something like that.

706
00:37:26,026 --> 00:37:28,706
It's kind of average
for the species as well, isn't it?

707
00:37:28,706 --> 00:37:31,626
That's right, although there's quite
a large range of brain size

708
00:37:31,626 --> 00:37:34,706
in Homo erectus because it spans
such a very long period of time.

709
00:37:34,706 --> 00:37:37,306
And I recognise that skull.
That's your skull.

710
00:37:37,306 --> 00:37:39,946
That's me, that's my skull.

711
00:37:39,946 --> 00:37:42,306
Oh, it's tiny, look.

712
00:37:42,306 --> 00:37:45,186
Absolutely tiny. Hang on a minute.
Smaller than Homo erectus.

713
00:37:45,186 --> 00:37:46,346
Hang on a minute!

714
00:37:47,746 --> 00:37:51,306
So this really is the weirdest
things about us

715
00:37:51,306 --> 00:37:53,626
is the huge brains that we have.

716
00:37:53,626 --> 00:37:57,466
And our brains have been growing
throughout human evolution.

717
00:37:57,466 --> 00:37:59,626
But it's not all about the size of
the brains,

718
00:37:59,626 --> 00:38:04,826
it's actually what's going
on with those brains and what we're
doing with them that's important.

719
00:38:04,826 --> 00:38:08,466
And here's where we turn from fossil
bones to archaeology.

720
00:38:08,466 --> 00:38:11,226
We've got Professor Bruce Bradley
of Exeter University here,

721
00:38:11,226 --> 00:38:16,266
to tell us about what they're
doing with these big brains.

722
00:38:16,266 --> 00:38:20,066
Very interestingly, when we see
the beginning of Homo erectus,

723
00:38:20,066 --> 00:38:23,786
we see a quantum change in the way
they're making stone tools.

724
00:38:23,786 --> 00:38:26,546
And they're going from very simple
stone tools where

725
00:38:26,546 --> 00:38:30,266
a piece of stone would be picked up
and just the end would be

726
00:38:30,266 --> 00:38:33,226
knocked off... Now, we need to
put on some safety glasses.

727
00:38:33,226 --> 00:38:37,826
Because this can be dangerous.
Sharp things flying around.

728
00:38:37,826 --> 00:38:42,466
And so it's very simply the earliest
stone tools, are taking

729
00:38:42,466 --> 00:38:46,226
a piece and just knocking the end
off of it to get a sharp edge.

730
00:38:46,226 --> 00:38:51,306
Yeah, that's sharp.
Yeah. You know, it's not a brilliant
tool. It's pretty basic, though.

731
00:38:51,306 --> 00:38:53,786
It's pretty basic, and you're
just taking the form

732
00:38:53,786 --> 00:38:56,346
that you have naturally, and just
knocking the end off of it.

733
00:38:56,346 --> 00:38:59,506
So what do we see
when we get to Homo erectus?

734
00:38:59,506 --> 00:39:03,066
Think about that,
and then think about doing this.

735
00:39:03,066 --> 00:39:07,106
They're shaping the whole piece,
and they're not only doing that,

736
00:39:07,106 --> 00:39:10,506
they're turning it into something
much more complex.

737
00:39:10,506 --> 00:39:13,826
There's flaking on two sides, with a
straight edge that goes all around.

738
00:39:13,826 --> 00:39:16,306
In order to do that,
they must have an idea

739
00:39:16,306 --> 00:39:18,346
of what they're going
to end up with.

740
00:39:18,346 --> 00:39:20,106
It isn't just random bashing.

741
00:39:20,106 --> 00:39:23,626
They have a plan in their head
to make that shape.

742
00:39:23,626 --> 00:39:26,586
This is a real planned object,
and it takes a really different

743
00:39:26,586 --> 00:39:29,266
kind of technique.

744
00:39:29,266 --> 00:39:32,306
So instead
of just sort of hitting it with

745
00:39:32,306 --> 00:39:37,306
a stone, what I'm going to be doing
is working on this edge here.

746
00:39:37,306 --> 00:39:42,066
And then as I strike pieces, you
can see they run across the surface.

747
00:39:42,066 --> 00:39:43,546
So I'm not only shaping an edge,

748
00:39:43,546 --> 00:39:46,746
I'm shaping the whole thing
three-dimensionally.

749
00:39:46,746 --> 00:39:50,186
This takes an incredibly different
mindset,

750
00:39:50,186 --> 00:39:53,146
a cognition,
a way of thinking and seeing things.

751
00:39:53,146 --> 00:39:56,226
So, what we're looking at is
like you said - planning.

752
00:39:56,226 --> 00:39:58,826
But what's more interesting is not
just that they made these

753
00:39:58,826 --> 00:40:02,066
hand axes,
but to get to these hand axes,

754
00:40:02,066 --> 00:40:05,786
particularly in parts of Africa,
they had very large pieces of stone.

755
00:40:05,786 --> 00:40:09,506
I wondered why that was there.
How do you get this, from this?

756
00:40:09,506 --> 00:40:11,586
What Homo erectus was doing is
they were taking

757
00:40:11,586 --> 00:40:15,386
and making these big things,
which we call blanks.

758
00:40:15,386 --> 00:40:19,306
And then THESE were being
turned into the hand axes.

759
00:40:19,306 --> 00:40:23,066
So they're making their own
form. Free-form.

760
00:40:23,066 --> 00:40:27,026
So can you get a blank out of there?
Well, we're going to see...

761
00:40:28,106 --> 00:40:32,346
Oh! So... Wow.

762
00:40:32,346 --> 00:40:36,866
So this to me is like Michelangelo
looking at a block of marble,

763
00:40:36,866 --> 00:40:39,426
and saying
"I can see David inside it."

764
00:40:39,426 --> 00:40:41,706
I see three or four
Davids in this one.

765
00:40:44,266 --> 00:40:48,466
So Homo erectus had bigger brains
and better tools.

766
00:40:48,466 --> 00:40:52,226
They could cover
large distances, and it seems
they may even have had fire.

767
00:40:54,226 --> 00:41:00,106
With these skills,
they were well equipped to explore
territories outside Africa.

768
00:41:00,106 --> 00:41:02,466
But what did they look like?

769
00:41:02,466 --> 00:41:05,866
Right, I'm off to see how Viktor's
getting on over here.

770
00:41:05,866 --> 00:41:08,426
Because our Nariokotome Boy

771
00:41:08,426 --> 00:41:12,666
should be starting to look almost
finished now.

772
00:41:12,666 --> 00:41:17,106
I'm just working out the hair...
You're not revealing the face yet!

773
00:41:17,106 --> 00:41:19,466
No. I've got to keep it
a secret for you.

774
00:41:19,466 --> 00:41:23,546
So you're not putting that much
hair on the rest of his body.

775
00:41:23,546 --> 00:41:25,666
No. Because of thermo-regulation

776
00:41:25,666 --> 00:41:29,106
his hair covering would have been
less.

777
00:41:29,106 --> 00:41:31,266
He's still going to be
retaining a bit of furriness

778
00:41:31,266 --> 00:41:34,106
from his ancestors,
he's not THAT far removed yet...

779
00:41:34,106 --> 00:41:38,266
And he's got dark skin.
Dark skin to help against the sun.

780
00:41:38,266 --> 00:41:40,746
But looking more like us, actually.
Definitely.

781
00:41:40,746 --> 00:41:43,746
So it's time to join our model
makers in their studio,

782
00:41:43,746 --> 00:41:48,706
where they're going to need
a lot of patience to finish off
Nariokotome Boy.

783
00:41:52,026 --> 00:41:55,146
The modellers have finished
sculpting Nariokotome Boy's body,

784
00:41:55,146 --> 00:41:58,626
and now it's time
to cast the model.

785
00:41:58,626 --> 00:42:02,266
First he's carefully wrapped
in fibreglass to make a mould.

786
00:42:03,986 --> 00:42:09,906
Liquid silicone is poured into the
mould to create a model with
a lifelike skin texture.

787
00:42:11,426 --> 00:42:14,626
The next challenge is to decide how
hairless he should be

788
00:42:14,626 --> 00:42:16,386
to allow effective sweating,

789
00:42:16,386 --> 00:42:19,986
and to choose a skin tone
which would have given him

790
00:42:19,986 --> 00:42:22,626
adequate protection from the
African sun.

791
00:42:23,826 --> 00:42:27,866
The researchers have given us advice
on which way to go with the colour
of this figure,

792
00:42:27,866 --> 00:42:32,626
and the feedback is we've got this
darker brown colour,

793
00:42:32,626 --> 00:42:34,706
and now we've come to
the painting stage,

794
00:42:34,706 --> 00:42:38,866
whereby
we mix up washes of silicone fluid

795
00:42:38,866 --> 00:42:42,746
and we put in different pigments,
create the different washes

796
00:42:42,746 --> 00:42:47,666
that are applied layer upon layer,
and these will bring up the
skin tones.

797
00:42:47,666 --> 00:42:48,986
But it's quite a long process.

798
00:42:48,986 --> 00:42:51,546
One of the challenges is to get
the lighter skin tones

799
00:42:51,546 --> 00:42:55,546
around the feet
and around the palms of the hands.

800
00:42:55,546 --> 00:42:59,546
It's looking very shiny at the
moment, but once it's complete we'll

801
00:42:59,546 --> 00:43:03,626
put a matting agent on and that'll
give it a much more natural look.

802
00:43:03,626 --> 00:43:07,386
With their dark, hairless skin
and lean physique,

803
00:43:07,386 --> 00:43:10,546
Homo erectus may have left Africa
and spread

804
00:43:10,546 --> 00:43:15,426
right across Asia...
but they didn't go far north.

805
00:43:15,426 --> 00:43:17,746
And the reason for this may have had

806
00:43:17,746 --> 00:43:20,786
something to do with
the colour of their skin.

807
00:43:20,786 --> 00:43:23,506
Well, this is
Professor Barbara Boucher

808
00:43:23,506 --> 00:43:26,506
of Queen Mary University of London,
who has spent decades

809
00:43:26,506 --> 00:43:30,626
looking into the relationship
between skin colour and health.

810
00:43:30,626 --> 00:43:32,946
I mean, he's living in a tropical
environment

811
00:43:32,946 --> 00:43:36,826
so presumably we would expect him
to have dark skin to protect his...
You certainly would.

812
00:43:36,826 --> 00:43:40,026
He'd be in quite a deal of trouble
with sunburn

813
00:43:40,026 --> 00:43:42,866
and skin cancers,
and generally uncomfortable.

814
00:43:42,866 --> 00:43:47,386
The trouble is as you move north a
lot less ultraviolet gets through,

815
00:43:47,386 --> 00:43:50,346
and we need ultraviolet
to make Vitamin D

816
00:43:50,346 --> 00:43:52,786
because it's one of
our essential hormones

817
00:43:52,786 --> 00:43:55,626
and we depend on sunlight
to make it.

818
00:43:55,626 --> 00:43:58,826
If you are in the north
and you've got very dark skin,

819
00:43:58,826 --> 00:44:01,466
you tend to run out of vitamin D.
You just don't make enough.

820
00:44:01,466 --> 00:44:03,146
You're a clinician
and a scientist,

821
00:44:03,146 --> 00:44:08,346
so clinically, what is the problem
if people are vitamin D deficient?

822
00:44:08,346 --> 00:44:10,946
The first thing you would expect
to get is bone disease.

823
00:44:10,946 --> 00:44:13,866
Children as we well know
get rickets,

824
00:44:13,866 --> 00:44:16,346
and women in pregnancy
tend to get soft bones.

825
00:44:16,346 --> 00:44:18,026
If you have a soft bone,

826
00:44:18,026 --> 00:44:21,186
walking about you tend to squash
your pelvis in,

827
00:44:21,186 --> 00:44:24,546
and your pelvis gets narrowed and
you can't deliver babies,

828
00:44:24,546 --> 00:44:25,866
so mother and baby die.

829
00:44:25,866 --> 00:44:28,746
So we've talked about effects
on bone. What about immunity?

830
00:44:28,746 --> 00:44:31,266
Is vitamin D important
for that as well?

831
00:44:31,266 --> 00:44:32,826
Very important for that.

832
00:44:32,826 --> 00:44:36,306
You need vitamin D to make various
compounds that destroy bacteria.

833
00:44:36,306 --> 00:44:39,106
You can reduce the dangers
of bad infections

834
00:44:39,106 --> 00:44:41,106
and the risks of viral illness

835
00:44:41,106 --> 00:44:43,986
and perhaps rather reduce
the hazards of TB.

836
00:44:43,986 --> 00:44:45,066
This is fascinating.

837
00:44:45,066 --> 00:44:49,106
I think it shows that disease
can have a very powerful influence

838
00:44:49,106 --> 00:44:51,186
on how populations
grow and spread.

839
00:44:53,266 --> 00:44:57,706
Many diseases leave very little
mark on our skeletons,

840
00:44:57,706 --> 00:45:00,346
but when they do, that evidence
in ancient bones

841
00:45:00,346 --> 00:45:05,826
can tell us something more about
our ancestors and their way of life.

842
00:45:08,266 --> 00:45:12,426
I've been to Germany to look at some
controversial new evidence.

843
00:45:13,626 --> 00:45:18,546
In 2007, at the University of
Gottingen's School of Anatomy,

844
00:45:18,546 --> 00:45:21,946
Professor Michael Schultz
was asked to examine a fragment

845
00:45:21,946 --> 00:45:23,826
of a Homo erectus skull.

846
00:45:28,226 --> 00:45:32,986
Found in a quarry in Turkey,
it had a remarkable story to tell.

847
00:45:34,266 --> 00:45:38,426
That's a part of a frontal bone
found in Turkey

848
00:45:38,426 --> 00:45:41,666
where they were sawing blocks
and making tiles,

849
00:45:41,666 --> 00:45:45,706
and very probably we must have
blocks with the rest of the skull

850
00:45:45,706 --> 00:45:47,746
or even the whole skeleton.

851
00:45:47,746 --> 00:45:50,106
So this means that in fact
the rest of this skull

852
00:45:50,106 --> 00:45:53,786
could be in tiles like this
on somebody's bathroom wall?

853
00:45:53,786 --> 00:45:55,826
That's possible but I doubt it.

854
00:45:55,826 --> 00:45:59,266
Everyone's going to be looking
at their bathroom walls now.

855
00:45:59,266 --> 00:46:01,586
And how old is this skull?

856
00:46:01,586 --> 00:46:05,506
It was dated approximately
500,000 years.

857
00:46:07,706 --> 00:46:10,866
When Michael looked
at the inside of the skull,

858
00:46:10,866 --> 00:46:13,346
he saw tiny marks
which shouldn't be there.

859
00:46:15,106 --> 00:46:19,026
We have very small
granular impressions.

860
00:46:19,026 --> 00:46:22,666
We have also impressions
of very small blood vessels,

861
00:46:22,666 --> 00:46:25,146
probably arteries.

862
00:46:25,146 --> 00:46:27,706
Normally you'd expect the surface
of that to be quite smooth

863
00:46:27,706 --> 00:46:29,946
and you wouldn't see
so many blood vessels?

864
00:46:29,946 --> 00:46:34,346
That's right. We have maybe here
new formations of bone.

865
00:46:37,026 --> 00:46:40,026
Something had put pressure
on the inside of the skull,

866
00:46:40,026 --> 00:46:41,546
causing pits in the bone.

867
00:46:44,946 --> 00:46:49,026
OK, so we've got pits,
and we've got new bone growth,

868
00:46:49,026 --> 00:46:52,746
and also grooves from unusual
blood vessels here.

869
00:46:52,746 --> 00:46:54,466
What do you think that means?

870
00:46:54,466 --> 00:46:55,866
We have to be very careful,

871
00:46:55,866 --> 00:47:00,466
but I am convinced that this
very probably is caused by TB.

872
00:47:02,746 --> 00:47:06,186
It's remarkable to have
this diagnosis of TB, Tuberculosis,

873
00:47:06,186 --> 00:47:07,866
in Homo erectus.

874
00:47:09,666 --> 00:47:13,306
This is a disease which was thought
to have emerged

875
00:47:13,306 --> 00:47:14,986
just 10,000 years ago,

876
00:47:14,986 --> 00:47:19,706
yet this skull is 500,000 years old.

877
00:47:21,106 --> 00:47:25,186
When the skull is compared to a
modern human skull from a TB victim,

878
00:47:25,186 --> 00:47:27,306
the similarities are startling.

879
00:47:28,866 --> 00:47:30,146
This is really interesting

880
00:47:30,146 --> 00:47:32,586
because we're seeing
exactly the same changes.

881
00:47:32,586 --> 00:47:35,026
We can see the pits there
and new bone formation.

882
00:47:35,026 --> 00:47:37,466
So we've got a skull from the
19th century that's showing

883
00:47:37,466 --> 00:47:40,306
precisely the same changes
as the 500,000-year-old skull.

884
00:47:40,306 --> 00:47:44,506
And we know exactly that this skull
is from a young adult

885
00:47:44,506 --> 00:47:48,266
and we know that he died from TB.

886
00:47:48,266 --> 00:47:51,826
So in fact what we're looking at
in that much more ancient piece

887
00:47:51,826 --> 00:47:56,106
of skull are the tiny lumps which
give TB its name, the tubercles,

888
00:47:56,106 --> 00:47:59,066
making an impression
on the skull here.

889
00:47:59,066 --> 00:48:01,786
Finding evidence of a disease
like TB

890
00:48:01,786 --> 00:48:08,106
among simple hunter-gatherers
like Homo erectus is revolutionary.

891
00:48:08,106 --> 00:48:12,186
At first sight, I couldn't
accept that this might be TB

892
00:48:12,186 --> 00:48:14,106
from 500,000 years ago!

893
00:48:14,106 --> 00:48:16,266
I have to say, Michael,
that I was quite sceptical.

894
00:48:16,266 --> 00:48:20,586
But now, with you showing me
the signs on this very good cast,

895
00:48:20,586 --> 00:48:23,426
I have to say I'm convinced.

896
00:48:23,426 --> 00:48:27,106
What do you think, Scott? I thought
it was fairly convincing evidence

897
00:48:27,106 --> 00:48:28,386
of TB inside that skull.

898
00:48:28,386 --> 00:48:32,706
We have to be cautious perhaps on
the identification of tuberculosis.

899
00:48:32,706 --> 00:48:36,306
Given that this could potentially
be TB, this is fascinating

900
00:48:36,306 --> 00:48:40,266
because it pushes the origins
of TB in humans

901
00:48:40,266 --> 00:48:43,106
back much further
than previously thought.

902
00:48:43,106 --> 00:48:45,586
Even quite recently we thought
we didn't get TB

903
00:48:45,586 --> 00:48:47,186
until we started farming cattle.

904
00:48:47,186 --> 00:48:49,786
What's interesting is the
disease process tells us a lot

905
00:48:49,786 --> 00:48:53,266
about the behaviour and the
adaptations of extinct ancestors.

906
00:48:53,266 --> 00:48:55,786
It says something about
the way humans are interacting,

907
00:48:55,786 --> 00:48:57,786
populations are interacting
across Eurasia.

908
00:48:57,786 --> 00:49:00,426
It's also saying something
about how humans are interacting

909
00:49:00,426 --> 00:49:02,626
with other animals on the landscape,
like cattle.

910
00:49:02,626 --> 00:49:06,506
Tuberculosis is a pathogen that
lives in cattle and other bovids.

911
00:49:06,506 --> 00:49:10,506
It's amazing how much pathology,
disease in ancient human remains,

912
00:49:10,506 --> 00:49:12,186
can reveal about our ancestors,

913
00:49:12,186 --> 00:49:16,666
but could it even provide us
with an insight into their feelings?

914
00:49:22,306 --> 00:49:25,466
One trait that we think
marks us out as human

915
00:49:25,466 --> 00:49:27,506
is the sophistication
of our emotions,

916
00:49:27,506 --> 00:49:30,386
like sympathy and compassion.

917
00:49:31,866 --> 00:49:33,826
But can fossilised bones

918
00:49:33,826 --> 00:49:36,346
tell us anything about
our ancestors' feelings?

919
00:49:36,346 --> 00:49:39,706
I've been to
the Republic of Georgia,

920
00:49:39,706 --> 00:49:42,746
to the small medieval
town of Dmanisi.

921
00:49:44,106 --> 00:49:48,386
Here, archaeologists have found
remains of Homo erectus

922
00:49:48,386 --> 00:49:50,466
that they believe may do just that.

923
00:49:54,546 --> 00:49:57,746
Professor David Lordkipanidze
is leading the excavations.

924
00:49:57,746 --> 00:50:01,866
David, what's that over there?
Some kind of animal fossil.

925
00:50:01,866 --> 00:50:04,466
Is that as old as the human fossils
you've been finding here?

926
00:50:04,466 --> 00:50:08,946
Yeah, it's 1.8 million years old.
It belongs to a deer.

927
00:50:08,946 --> 00:50:11,826
It's a fantastic preservation
of bones.

928
00:50:11,826 --> 00:50:17,186
1.8 million years ago, environment
was more Africa-like in some ways.

929
00:50:17,186 --> 00:50:22,466
Here was definitely environment
more savannah-type on one hand,

930
00:50:22,466 --> 00:50:26,426
but it had also forest elements,
it had a wood.

931
00:50:26,426 --> 00:50:31,066
It shows that climate
was not as hot as in Africa,

932
00:50:31,066 --> 00:50:34,466
and they had much
colder winters here.

933
00:50:34,466 --> 00:50:37,426
These are some of the earliest signs
we have

934
00:50:37,426 --> 00:50:41,746
of our ancient ancestors
outside Africa.

935
00:50:41,746 --> 00:50:45,946
Surviving in this challenging
climate would have been tough.

936
00:50:45,946 --> 00:50:48,546
Professor Lordkipanidze
has found a skull

937
00:50:48,546 --> 00:50:51,066
that raises
some interesting questions

938
00:50:51,066 --> 00:50:54,346
about how some of them
survived at all.

939
00:50:54,346 --> 00:50:57,986
Look at that, that's just beautiful!

940
00:50:57,986 --> 00:51:01,826
Yeah, it's a cast
of the Dmanisi hominid.

941
00:51:01,826 --> 00:51:04,426
And it was that complete,
it wasn't in pieces?

942
00:51:04,426 --> 00:51:09,306
It was not in pieces.
There were some small breaks.

943
00:51:09,306 --> 00:51:11,706
But generally we could...

944
00:51:11,706 --> 00:51:13,266
Isn't that wonderful?

945
00:51:13,266 --> 00:51:15,906
So you know the brain size
of this individual,

946
00:51:15,906 --> 00:51:17,586
you know what his face looked like.

947
00:51:17,586 --> 00:51:20,346
Absolutely, and also we have a jaw.

948
00:51:21,786 --> 00:51:27,266
1.8 million years ago, Homo erectus
had made it here to Georgia.

949
00:51:27,266 --> 00:51:30,586
That in itself is astonishing.

950
00:51:30,586 --> 00:51:36,466
But what's even more surprising
is that this person was toothless.

951
00:51:36,466 --> 00:51:38,706
Now that is remarkable.
This is an old jaw.

952
00:51:38,706 --> 00:51:40,706
This is a jaw
that's lost most of its teeth.

953
00:51:40,706 --> 00:51:43,506
It looks like the only tooth that
could possibly have still been

954
00:51:43,506 --> 00:51:46,346
in the mouth is that one there.
Is that a canine?

955
00:51:46,346 --> 00:51:47,626
Yes, it was just one canine.

956
00:51:47,626 --> 00:51:51,266
And we can tell that all of these
were lost a long time before death

957
00:51:51,266 --> 00:51:54,466
because the bone
of the jaw has shrunk right down.

958
00:51:54,466 --> 00:51:56,346
So we know that must have
happened

959
00:51:56,346 --> 00:51:59,586
months or even years
before this person died.

960
00:51:59,586 --> 00:52:05,386
This person survived at least
a few years without teeth.

961
00:52:07,466 --> 00:52:12,226
Somehow, this toothless person
survived against the odds.

962
00:52:13,626 --> 00:52:16,746
The evidence suggests that they
were living here

963
00:52:16,746 --> 00:52:19,186
long before our ancestors
learned to control fire.

964
00:52:20,626 --> 00:52:25,266
So in the harsh winters, they may
only have had raw meat to live on.

965
00:52:26,546 --> 00:52:30,506
These people were depending
mostly on meat,

966
00:52:30,506 --> 00:52:35,066
and without teeth it's very
difficult to get meat.

967
00:52:35,066 --> 00:52:40,146
So how does this person
survive, as a hunter-gatherer,

968
00:52:40,146 --> 00:52:42,346
and with fairly basic technology,

969
00:52:42,346 --> 00:52:45,506
in this environment - with no teeth?

970
00:52:45,506 --> 00:52:49,866
I think this is indirect
evidence of the

971
00:52:49,866 --> 00:52:53,186
altruism or compassion.

972
00:52:53,186 --> 00:52:57,026
I'm sure somebody was taking
care of this individual.

973
00:52:57,026 --> 00:53:00,906
It's lovely to say, OK, we've
potentially got evidence of altruism

974
00:53:00,906 --> 00:53:03,146
and compassion here, but

975
00:53:03,146 --> 00:53:08,066
just to be quite kind of
harsh and economical about it,

976
00:53:08,066 --> 00:53:11,746
what kind of advantage could that
have brought, in evolutionary terms?

977
00:53:11,746 --> 00:53:15,506
Maybe this person had knowledge
which others needed still.

978
00:53:16,826 --> 00:53:19,706
So it was maybe very pragmatic also.

979
00:53:19,706 --> 00:53:25,506
Could it be that compassion
contributed to the success
of Homo erectus?

980
00:53:28,386 --> 00:53:30,866
I think it's quite
interesting to think that

981
00:53:30,866 --> 00:53:35,946
compassion could have been an
important feature of our evolution.

982
00:53:35,946 --> 00:53:40,066
It certainly characterises humans,
because our human social
relationships are so strong,

983
00:53:40,066 --> 00:53:43,586
and many of the relationships
we build are built on friendship
and compassion

984
00:53:43,586 --> 00:53:46,346
as opposed to some
strict evolutionary need.

985
00:53:46,346 --> 00:53:50,066
Well, there is a chimpanzee
skull in a museum in Kent

986
00:53:50,066 --> 00:53:55,386
that clearly hasn't got any teeth,
and has obviously had his teeth lost

987
00:53:55,386 --> 00:53:59,586
before he died, so he or she was
clearly being looked after
in some way.

988
00:53:59,586 --> 00:54:01,706
It's interesting, isn't it,
because I think that

989
00:54:01,706 --> 00:54:04,866
when we see that in another species
we don't immediately jump in and say

990
00:54:04,866 --> 00:54:08,026
there must be some kind of
compassion, some kind of altruism
going on here.

991
00:54:08,026 --> 00:54:11,866
But of course altruism isn't
something which is limited to
humans anyway.

992
00:54:11,866 --> 00:54:16,186
No, that's right. It's a
characteristic of all evolving
organisms, social organisms.

993
00:54:16,186 --> 00:54:19,266
So even though we don't know why
we're doing it,

994
00:54:19,266 --> 00:54:23,146
altruism may not be entirely
unselfish!

995
00:54:23,146 --> 00:54:25,306
No, because humans are
so behaviourally plastic,

996
00:54:25,306 --> 00:54:28,186
we can change our behaviour
throughout our entire lifetime,

997
00:54:28,186 --> 00:54:30,546
that what we want to do is
we want someone who's had a rich

998
00:54:30,546 --> 00:54:33,626
experience, and understands where
the resources are in tough times.

999
00:54:33,626 --> 00:54:37,906
And understands, can decipher
complex social relationships.

1000
00:54:37,906 --> 00:54:41,266
So compassion and altruism are
useful evolutionarily.

1001
00:54:41,266 --> 00:54:43,386
Well, we're nearly at the end
of our quest,

1002
00:54:43,386 --> 00:54:45,626
but there's one last question.

1003
00:54:45,626 --> 00:54:49,266
Are there any clues as to how
Nariokotome Boy died?

1004
00:54:49,266 --> 00:54:51,906
Well, there's nothing that
completely hits you

1005
00:54:51,906 --> 00:54:55,266
between the eyes, but there might be
something going on with his teeth.

1006
00:54:55,266 --> 00:54:57,946
If we look right here on the right
side of his jaw,

1007
00:54:57,946 --> 00:54:59,746
we see that there's an area of
erosion.

1008
00:54:59,746 --> 00:55:03,106
Right here between his premolar
and molar. It's always the teeth,
isn't it?!

1009
00:55:03,106 --> 00:55:08,506
Is that an abscess? Well, it's some
type of inflammatory response, so he
probably has an infection going on.

1010
00:55:08,506 --> 00:55:12,466
Well, I had a bad abscess in my jaw
a week ago,

1011
00:55:12,466 --> 00:55:14,346
and it was so painful.

1012
00:55:14,346 --> 00:55:18,546
I think it's interesting to
think about how infection might
have affected our ancestors as well,

1013
00:55:18,546 --> 00:55:21,586
because if you had an abscess in
your jaw, what happened after that?

1014
00:55:21,586 --> 00:55:25,266
Well, I removed part of it and
then I got antibiotics!

1015
00:55:25,266 --> 00:55:27,266
Otherwise I don't know
what I'd have done.

1016
00:55:27,266 --> 00:55:30,746
You know, this is really subtle,
it may not have been the thing
which killed him -

1017
00:55:30,746 --> 00:55:32,626
but it could have been.

1018
00:55:32,626 --> 00:55:38,106
Yet again it's amazing the amount
of detail we've been able to
glean from just a handful of bones.

1019
00:55:40,706 --> 00:55:44,426
Over six months, Viktor and our
model makers have pieced together

1020
00:55:44,426 --> 00:55:47,226
the skeleton of this tall and agile
runner.

1021
00:55:48,546 --> 00:55:53,706
Carefully sculpting
muscles to reflect a physique
fuelled by meat eating,

1022
00:55:53,706 --> 00:55:57,026
and adding the finishing touch
of a hairless sweating skin,

1023
00:55:57,026 --> 00:55:59,066
that made him so well adapted

1024
00:55:59,066 --> 00:56:01,786
for hunting and scavenging
on the savannah.

1025
00:56:03,226 --> 00:56:04,546
And now he's finished.

1026
00:56:05,746 --> 00:56:07,346
None of us have seen him yet,

1027
00:56:07,346 --> 00:56:10,586
but we're finally about to meet him
in the flesh.

1028
00:56:12,106 --> 00:56:14,106
Shall we go and have a look?
Absolutely.

1029
00:56:14,106 --> 00:56:17,506
Do you want to come and have a look,
everybody? This is it, this is it.

1030
00:56:17,506 --> 00:56:21,026
VIKTOR: Can't wait to show you.
I'm pretty excited about it.

1031
00:56:21,026 --> 00:56:23,786
You all ready? Right then, Viktor...

1032
00:56:23,786 --> 00:56:26,506
One, two, three!
The real Nariokotome.

1033
00:56:26,506 --> 00:56:28,666
Wow!

1034
00:56:28,666 --> 00:56:32,706
He looks a bit different
from the last time I saw him.

1035
00:56:32,706 --> 00:56:36,226
A face from one
and a half million years ago.

1036
00:56:36,226 --> 00:56:39,346
The face, I'm really happy with.

1037
00:56:39,346 --> 00:56:42,826
This is an eight-year-old.
Yeah, that's quite shocking.

1038
00:56:42,826 --> 00:56:46,106
That blows me away, because my
eight-year-olds were like,
this tall.

1039
00:56:46,106 --> 00:56:48,066
He's a big eight-year-old.

1040
00:56:48,066 --> 00:56:50,426
The hair he HAS retained is
totally credible,

1041
00:56:50,426 --> 00:56:53,826
that would be a very good protective
barrier against the radiation
from the sun.

1042
00:56:53,826 --> 00:56:56,706
And then he's lost
hair on the rest of his body.

1043
00:56:56,706 --> 00:57:00,226
So he would have been able to sweat,
cool down.

1044
00:57:00,226 --> 00:57:02,746
Yes, so he's got quite a large
surface area

1045
00:57:02,746 --> 00:57:06,466
but that surface area isn't
absorbing rays from the sun.

1046
00:57:06,466 --> 00:57:09,986
What would he think if he saw us
now? What would he make of us?

1047
00:57:09,986 --> 00:57:12,186
I'm really quite moved by it.

1048
00:57:12,186 --> 00:57:14,906
I've only ever seen Nariokotome
Boy's bones before,

1049
00:57:14,906 --> 00:57:18,146
and suddenly here he is amongst us.
He's lovely.

1050
00:57:19,226 --> 00:57:22,666
Well, with the help of experts
around the world and the people

1051
00:57:22,666 --> 00:57:27,746
in this room, we've been able to
create our very own Nariokotome Boy.

1052
00:57:27,746 --> 00:57:32,746
In our last programme, tomorrow,
we'll be travelling back
3.2 million years

1053
00:57:32,746 --> 00:57:35,986
to meet one of our very earliest
ancestors...

1054
00:57:35,986 --> 00:57:39,986
a female who walked on two legs.
Called Lucy.

1055
00:57:39,986 --> 00:57:43,666
I've been to the States to
see what the fossilised remains

1056
00:57:43,666 --> 00:57:47,546
of the world's oldest
child are revealing about

1057
00:57:47,546 --> 00:57:52,466
how Lucy's species moved,
and about the origins of childhood.

1058
00:57:52,466 --> 00:57:56,666
Here is an individual,
still growing its brain,

1059
00:57:56,666 --> 00:57:58,786
and still learning from the parents.

1060
00:57:59,826 --> 00:58:02,066
Alice has been learning how
techniques

1061
00:58:02,066 --> 00:58:05,506
borrowed from the aeronautical
industry can cast light

1062
00:58:05,506 --> 00:58:08,426
on when our early ancestors
left the trees.

1063
00:58:09,506 --> 00:58:12,786
We've got a very, very different
pattern in the way

1064
00:58:12,786 --> 00:58:15,666
the forces are spreading
throughout the bone.

1065
00:58:15,666 --> 00:58:18,746
And I caught up with some
of our closest living relatives,

1066
00:58:18,746 --> 00:58:22,346
to find out if they can give us
any clues as to how Lucy

1067
00:58:22,346 --> 00:58:24,746
and her species might have
communicated.

1068
00:58:27,626 --> 00:58:32,226
And we'll be finding out the price
she had to pay to walk upright.

1069
00:58:32,226 --> 00:58:35,746
Join us back here, next time.
Goodnight. Goodnight.

1070
00:58:38,186 --> 00:58:41,426
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