38x04 - Dogs Decoded

[bunniefuu]

NARRATOR:
We are inseparable

We're best friends

MAN:
Anywhere you find humans

you will almost
certainly find dogs

NARRATOR:
And they are smarter
than we ever imagined

Astonishing new research
is revealing

that dogs are far more than
merely tamed wild animals

MAN:
What makes our relationships so
special is the dog's ability

to be able to read our emotions
so effectively

NARRATOR:
Have they evolved a new kind
of intelligence?

WOMAN:
Suddenly there were dogs doing

something that not even chimps
could do

NARRATOR:
Have dogs developed a language
to communicate complex emotions?

MAN:
Anger, fear, happiness, despair

MAN:
You can almost understand
what they're thinking

NARRATOR:
Why do we love an animal that
was once a fearsome predator?

How did dogs go from this

to this?

Is it in the genes
or the way we treat them?

And when did it all begin?

The bones tell one story

We start seeing the first things


NARRATOR:
The genes tell another



NARRATOR:
The answer is more important
than you might think

MAN:
Without dog domestication,

civilization just would not have
been possible

NARRATOR:
"Dogs Decoded,"
right now on NOVA.

Major funding for NOVA is
provided by the following

ExxonMobil, taking on

the world's toughest energy
challenges

And by:

And

And by the Corporation
for Public Broadcasting

and by contributions to your PBS
station from viewers like you

Corrie, come here

NARRATOR:
There are more pet dogs
than babies in the world...

Nearly half a billion

Good boy Sit

Come on

NARRATOR:
We treat them as if they are
fellow human beings

with all the thoughts, feelings

and emotions of a family member

Good girl

NARRATOR:
It's an incredibly close
relationship

We share our lives, our homes,
even our beds with them

We're very close;
we're best friends

Pippin sleeps with us

He loves being in the bed
with his head on the pillow

He just seems to fit in

She's there with my slippers
first thing in the morning

She's part of the family,
she is the family

NARRATOR:
For decades, science has
dismissed dogs

as being unworthy
of legitimate study

But all that has changed

Scientists are now attempting
to understand dogs

like never before

What kind of bond do we really
have with our dogs?

Can we read each other's
emotions?

Are they smarter than we think?

And how and when did this
unique relationship develop?

Dogs are all over the world,
they're everywhere

Anywhere you find humans, you
will almost certainly find dogs

We're now beginning to realize

that we can answer certain
questions in dogs

that we can't really answer
in any other species

JULIANE KAMINSKI:
There's been this expl*si*n
in dog research,

I think really because they are
specially tuned into humans

and this makes dogs extremely
interesting as a model

NARRATOR:
Here at England's
University of Lincoln,

Professor Daniel Mills
specializes

in veterinary behavioral
medicine

He's using eye tracking
technology

to probe how close our
relationship really is

MILLS:
What we're trying to do here

is see the world from
a dog's perspective

rather than just impose
our own views

as to how we think the dog sees
the world

NARRATOR:
He's attempting to discover

if dogs are as good at reading
our emotions

as their owners claim

WOMAN:
He'll know what I'm thinking

even before it's turned
into a thought bubble

WOMAN:
He is clearly an animal

I accept that he is
totally an animal

I am not under any illusions
that he isn't,

but he's more knowing than
I would expect an animal to be

He will look at me
with sorrowful eyes

and then give me one big lick
on the hand

as if to say, "It's all right"

It's this sixth sense
that dogs have

MILLS:
One of the things that a lot
of people comment on

is that dogs seem to be
naturally attuned to them

and be able to sense their moods
and whatever,

and part of our work here

is actually to look into
the scientific basis of that

NARRATOR:
The key to a dog's ability
to read our emotions

might lie in something we all do
without knowing it

MILLS:
When we express our emotions
in our faces,

we don't do it symmetrically

It's been shown that if you take
somebody's face

when they're expressing some
emotion, like happiness or anger

or something like that,

there is a difference between
the left and right side

NARRATOR:
Composite faces consisting
of two right or two left sides

look very different

MILLS:
One of the theories is that

maybe our emotions are more
faithfully presented

in the right side of our face,

and that's the side
that we tune into

And when we look at a face,

we have what's known
as a natural left gaze bias,

so you naturally look much more
towards the left,

i e, the right-hand side
of somebody's face

NARRATOR:
Eye-tracking software
demonstrates

that when presented
with a human face,

we nearly always look left first

Daniel Mills wants to find out
if dogs use the same trick

to read human faces

MILLS:
Shifting the direction
of your gaze

we thought was fairly unique
to people

until we started looking at dogs

[whistles]
Taz, Tazy!

NARRATOR:
To test the theory,

his team recreates this
experiment with dogs

Moose, what's that?

NARRATOR:
They present a series of images
showing human faces,

dog faces and inanimate objects

and record the direction of a
dog's gaze with a video camera

ANAÏS RACCA:
We found that dogs,

when they are looking
at pictures of dog faces

or objects,

they will look randomly
on the left or the right

NARRATOR:
But when it comes
to human faces,

they make a remarkable discovery

RACCA:
So now we have Taz looking
at a human face,

so first she's looking
in the middle of the screen,

and here is the first eye
movements on the left

She's in the middle and
she's going on the left

Now this is Moose

And then we can see really well
that this is a left gaze

From here to here

We can see the white here

She's even moving her head

NARRATOR:
Does this mean dogs can read
human emotions?

As far as we know,
no other animal

has this relationship
with the human face

And dogs don't do this
with each other

This suggests that dogs have
acquired a new skill

enabling them to communicate
with us on an emotional level

Being able to detect
when somebody is angry

or potentially going to be
harmful to them,

you could understand that there
may be a biological advantage

in being able to read
people's emotions

and equally that it makes sense

for a dog to approach somebody
when they're smiling

If dogs can read human emotion,

and increasingly
the scientific evidence

is beginning to point
in that direction,

that's going to form the basis
of a very powerful bond

between human and dog

NARRATOR:
Evidence like this appears
to underpin

our conviction
that dogs understand us

in a way other animals cannot

But for many dog owners,

this unique relationship is much
more than a one-way street

I like to think
we can understand him

Yes, but he woofs and we talk

That's because he wants to be
part of the conversation

If he's bored, he'll take
a deep sigh and go

[imitates dog whine]

I think he's got a bark
when he wants to go out

Ruff!

And I think he's got a bark
when he hears strange noises

[growls]

Sometimes when he tells
the kittens off

he goes [barks and growls]
like that

If you're in a certain mindset,

you can almost understand
what they're thinking

NARRATOR:
The idea that we can understand
barking almost like a language

has always been dismissed
by scientists

But in Hungary,
an experiment is underway

looking for evidence to back up
the claims made by dog owners

Here in Budapest is one
of the world's first

research facilities dedicated
to the human/dog relationship

Dr Adam Miklosi wants to see

if humans really can understand
the barks of dogs

Today he's out on
a field expedition

collecting recordings

[barking]

ADAM MIKLOSI:
Scientists used to think that
barking is a random noise

without any specific
information or content

However, we have
a different idea

Dogs might tell us something
about their emotions...

Anger, fear, happiness, despair

So these are basic emotions

which I think humans might be
able to recognize

in the barking sound

NARRATOR:
To test this idea,

Adam and his team act out
a number of scenarios

provoking dogs to bark
in different ways

When other people listen
to these recordings,

will they be able to match
the bark to the emotion?

Alone bark

[whimpering]

That sounds like a dog asking
for attention

[whimpering yelp]

Aww, it's anxious

It's sad

Distressed

[high-pitched yelp]

Want to be let off a chain
or something like that

[barking]

I think that one's playful

[barks]

Excitement

MAN:
It seems as though

they're actually asking
their owner for something

[barking]

It sounds as if it may want
a ball or a toy or something

She could be playing with it

[barking]

Angry

This is a sound
that she would make

if she saw somebody behind
the fence walking along

[barking]

It's a stranger, I think

It's a stranger encroaching
on territory

[barking]

NARRATOR:
The results of Miklosi's
research are remarkable

It shows a strong agreement
between people

about the meaning
of different barks

[recording of barking]

MIKLOSI:
Overall in the study
you could say

that people can
discriminate six barks

and most of them were quite
successful in this

NARRATOR:
Dr Miklosi has created a system
to analyze the barks

It's helping him decode how dogs
communicate meaning

MIKLOSI:
I measure the three features
of this sound

One was the frequency,
the other was the tonality

and the third was the interval
between the barking sounds

And probably this is also what
the judgment of people is based

when they are describing
the bark

in terms of emotional content

NARRATOR:
But what's more surprising

is not our ability
to interpret the barks,

but what the barks
reveal about dogs

In the natural world,
dogs' wild relatives, wolves,

only bark as a warning

Amazingly, during the course
of domestication,

dogs may have evolved their
elaborate vocal repertoire

especially to communicate
with us

MIKLOSI:
At the basic level,
everyone can do it

and there is a good chance
that barking

is a very good means to
communicate with humans

NARRATOR:
The evidence from these
recent experiments

seems to confirm what dog owners
have asserted all along:

that dogs and people are
incredibly attuned to each other

in a way that no other
two species are

And new research techniques now
allow us to study more precisely

the nature of this bond

Some scientists believe
that our interaction

has a biochemical signature
that may be similar

to what happens between
a mother and a baby

It's really hard to describe

It's just an amazing feeling

NARRATOR: In Sweden,
Professor Kerstin Uvnäs-Moberg

has been studying the role
of the hormone oxytocin

in creating the bond between
mothers and their newborns

UVNÄS-MOBERG:
Oxytocin is a little, little
peptide hormone

It's just nine amino acids

It's produced in a very old
part of the brain

called the hypothalamus

And oxytocin helps the
mother quickly establish

the positive feelings
and the bond to the baby

NARRATOR:
Each time a mother breastfeeds,

she has a new release
of oxytocin,

which may reinforce the bond

UVNAS-MOBERG:
It's sort of in a way difficult
to understand

how you can be familiar
with somebody

who is actually a stranger
so quickly, don't you think?

Yeah

NARRATOR:
Professor Uvnäs-Moberg believes
oxytocin plays a similar role

in the bond between
dogs and their owners

To test the theory,

blood samples are taken
from dogs and their owners

before and during
a petting session

UVNAS-MOBERG:
We had a basal blood sample

and there was nothing,
and then we had the sample taken

at one minute and three minutes

and you could see this
beautiful peak of oxytocin

The fascinating thing
is, actually,

that the peak of oxytocin

is similar to the one we see
in breastfeeding mothers

NARRATOR:
Surprisingly, it's not just
the owners who are affected

Blood samples taken from dogs
reveal a similar burst

of oxytocin

It is a mutual kind of
interaction, you know

The owner touches with her hands

and they both smell,
hear and see each other

That is a very nice way of
triggering oxytocin release

in the two of them

NARRATOR:
Oxytocin has a powerful
physiological effect

It can lower the heart rate
and blood pressure

and may lead to reduced levels
of stress

Research indicates that owning a
dog could even extend your life

UVNAS-MOBERG:
If you have a dog,

you are much less likely
to have a heart attack

If you have a heart attack,

you are three to four times
more likely to survive it

if you have a dog
than if you don't

NARRATOR:
Our relationship with dogs
goes back thousands of years

So, how did it begin?

Where did the first dog
come from?

Darwin recognized our unique
relationship with dogs,

but even he couldn't
say for sure

which animal was the true
ancestor of today's dogs

It's a complex puzzle that both
archaeologists and geneticists

are working to solve

There's a huge amount of
variation in present-day dogs

Consider the difference between
a Pekinese and a Great Dane

Could they really
all be descended

from one wild ancestor?

GREGER LARSON:
It could have been a coyote

that may have intergressed
with a wolf

and then that may have been
slightly selected upon

to create one particular
breed of dog

Or jackals or African wild dogs

Any number of these other
dog-like species

that are out there must have
somehow come together,

and that's where that variation
must have come

NARRATOR:
Until the advent of genetics,

archaeology had few firm answers

LARSON:
All you have to play with
are the bones

and so when you look
at the bones,

if you don't have a very small,
flat-faced, round-headed pug

in the archaeological record,

you don't know where
that came from

Those are questions
that before genetics

you really couldn't answer

NARRATOR:
To unravel the evolutionary
origins of dogs,

geneticists compare
DNA from dogs

with that of their
wild relatives

Specifically they look at
mitochondrial DNA sequences

which pass unchanged
down the maternal line

Since mitochondrial DNA
changes little over time,

it can act as
a kind of signature

left by an animal's ancestors

Those markers in domestic dogs
show them to be

much more closely related
to gray wolves

than they are to any
other species

There's no admixture,

so we never see a mitochondrial
signature of, say,

an African wild dog or jackal
or coyote in a domestic dog

Of the thousands upon thousands
of mitochondrial DNA

that's been extracted
from domestic dogs,

every single one of them just
looks just like a gray wolf

[howling]

NARRATOR:
This controversy is settled

Dogs are domesticated wolves

But a mystery remains

When and how did this change
take place?

What is clearly a dog?

Clearly a dog is something
which is clearly not a wolf

Well, here's a wolf skull,

and as you can see,
it's a long, quite low skull

with a relatively flat top

The teeth are quite large and
the thing is quite narrow

Compare that with a domestic dog

This is a cairn terrier

And as you can see,
the process of domestication

has gone really quite a long way

The whole face is
very much shorter;

it's been contracted
towards the brain case

The brain case itself has
a much steeper front

and a much more bowed
upper surface

So if you found that,

you'd be in no doubt you were
dealing with a domestic dog

But this is a domestic Alsatian,

and telling these apart

really would be
substantially difficult

NARRATOR:
And since early dogs were
probably very wolf-like,

it's hard to pinpoint when
domestication happened

by looking at the shape
of the bones

ROWLEY-CONWY:
The best I can give you
is around



We start seeing the first things
that everybody would accept

as being domestic dogs

NARRATOR:
But mitochondrial DNA offers
a different set of clues

LARSON:
The original genetic dates that
were coming out

seemed to suggest that
domestication was happening

on a far earlier timescale
than was suggested

by anything in the
archaeological record

The first dates that were coming
out were on the order

of a hundred thousand years
or more,

which a lot of archaeologists
raised their eyebrows at

NARRATOR:
It's hotly debated exactly when
dogs were domesticated,

but geneticists and
archaeologists agree

on one thing: our relationship
with dogs goes back

thousands of years,
further than with any other pet

It was a time when we were still
hunter-gatherers

ROWLEY:
Dogs were certainly the first
animal to be domesticated

and they fit into hunting
and gathering societies

better than any other species
out there

LARSON:
At this stage,
when we're hunting and gathering

and k*lling wild animals,

after you finish with them

you're creating a relatively
large pile

of bone and leftover meat,

things that these wolves would
have been very attracted to

Those wolves that were able to
take advantage of that resource

and were a little bit
less afraid

and could approach
the human camp

were then setting themselves up

into a closer relationship
with humans

We are carnivores,
we are social carnivores,

we hunt in groups
and we hunt in daylight

There are not many other species
that do that

The wolf is a social carnivore
that hunts by daylight

And therefore I think there's
natural potential for teamwork

between those two species

LARSON:
We became much better hunters
with dogs

We are more successfully
taking down large game,

which means we have
more food to eat,

which means we can have
more offspring,

which means the overall
populations of humans grow

NARRATOR:
Dog domestication may have
helped pave the way

for a fundamental change
in human lifestyle

ROWLEY-CONWY:
It's hard to see
how early herders

would have moved and protected
and guarded their flocks

without domestic dogs
being in place

And one has to wonder

whether agriculture would ever
really have made it

as a viable alternative
to hunting and gathering

NARRATOR:
Some believe that the influence
of dogs on our development

was not just important
but pivotal

LARSON:
Dogs absolutely turn the tables

Without dogs, humans would still
be hunter-gatherers

Without that initial starting
phase of dog domestication,

civilization just would not have
been possible

NARRATOR:
We look at our dogs
and we see an intelligence,

an ability to interact with us

unlike any other
domesticated animal

But are dogs really that clever,

or are they just dumb animals
taught to perform tricks

that mimic human behavior?

I think she's very smart

She learns tricks fairly quickly

If I'm packing a suitcase,

they will go and sit
in the suitcase

because they know that suitcase
is going to go somewhere

When I'm talking to him,

most of the time his little head
usually jilts to the side

as if he knows what I'm saying

I do talk to her and she picks
up on what I say to her

I know it sounds stupid,
but I do actually have

a conversation with my dog

NARRATOR:
So how does the intelligence
of a dog

compare in the animal kingdom?

New research is discovering
that in certain ways,

dogs may actually think
more like us

than any other animal,

including our nearest relative,
the chimpanzee

KAMINSKI:
Of all the questions

around the evolution
of human cognition,

of course people would focus in
on chimps quite naturally

And suddenly there were
dogs doing something

that not even chimps could do

NARRATOR:
Cognitive psychologist
Juliane Kaminski compares chimps

with dogs in a series
of revealing experiments

At Leipzig Zoo,
Kaminski is testing chimps

to see if they can understand
human gestures, like pointing,

to find a hidden treat

As simple as it seems to us,

even our nearest
primate relatives

fail the task miserably

KAMINSKI:
She's not really focusing on me

and she's simply
making her own choice

Most of the time you can see
that she makes a decision

long before I give my gesture

She doesn't even wait
for my information

It's such a cooperative
interaction,

so it's like really I'm
providing information for her

to find food, which is just
simply something

which would never happen
in a chimp group, really

I mean a chimp wouldn't go like,
"Oh, look, there's the banana,"

and then another chimp could go
and get it

NARRATOR:
Since we're the only species
that makes this gesture,

it would be remarkable if any
animal could understand it

Good boy

NARRATOR:
But dog owners
take it for granted

that their dogs respond
to pointing

Good boy!

NARRATOR:
For Kaminski, it's proof

of their extraordinary
social intelligence

KAMINSKI:
If you really
look at that gesture,

it's an informative gesture,

so it's, in its essence,
a very cooperative interaction

So I'm really helping you
to find something

And for dogs,

following pointing seems
to be very natural

and it makes dogs
extremely interesting

NARRATOR:
In fact, dogs are so tuned
into our social cues,

they can even pick up
on something as subtle

as the direction of our gaze

[speaking German]

Humans have unique
almond-shaped eyes

with exposed white sclera
visible on each side

KAMINSKI:
One hypothesis is that we have
evolved those eyes

because we use it
for communication,

so you can

really with human eyes
you can really tell easily

which direction I'm looking

NARRATOR:
But these aren't skills dogs use
with each other

They are abilities
dogs only use with us

KAMINSKI:
I think it's very easy
to imagine

that they develop special skills
in interacting with humans

because that's
their new social partner

So they kind of learn to
interpret human communication,

which is different
from dog communication

So they kind of learned
a second language

So you could probably say
they are bilingual, yes

NARRATOR:
Even puppies as young
as six weeks old

seem to respond
to human gestures

At least some of the time

KAMINSKI:
If they learn it,
they learn it very quickly,

and it's obvious that they are
ready to do it

So from the very beginning,

they are ready to receive
human communication

NARRATOR:
Dogs are primed to communicate
with us,

but just how smart are they?

New research reveals
their abilities extend

way beyond what anyone thought

Professor Kaminski
has discovered

a remarkable border collie
living in Austria

just outside Vienna

She's conducted a series
of experiments

and is amazed at the dog's
intelligence

She can distinguish objects
by name,

which is really amazing

And she has, like,
many, many words

Käse.

Das Zebra.

NARRATOR:
With a vocabulary
of over 340 words,

Betsy is pushing the boundaries

of what we think dogs
are capable of

Karotte.

Sandwich.

NARRATOR:
Betsy's owner, who prefers
to remain anonymous,

explains how this all started

OWNER:
I think it was when she was
four or five months old,

when she spontaneously started
to connect human words to items

When we were discussing

"shall we play with the rope
or with the ball?"

she immediately started to bring
those items,

so it was actually her idea
and from this time on,

we started to really train her
on different words

It was maybe one toy per week
and it worked

KAMINSKI:
I think on average
a well-trained dog maybe knows

like 15 commands or something

There are just a very few
individuals who can do

what she does

I can tell you that I tried it
with my own dog

and it didn't work at all

So he could maybe distinguish
two objects

after a while and after
extensive training

But she is really able to learn
this easily

More than 300 objects...
That's pretty amazing

NARRATOR:
Betsy's understanding
of vocabulary

rivals that of a two-year-old,

so Kaminski wants to test
her comprehension

on other skills as well

Can you go find me one
of them over there? Yeah?

NARRATOR:
Two-year-olds are just beginning
to understand

how to use symbols
such as scale models

to represent something else

Though it looks easy,
it requires abstract thinking

way beyond the capacity
of almost all animals

But would Betsy be able
to do this, too?

[giving instructions in German]

Ja...!

[speaking encouragingly
in German]

KAMINSKI:
This was something the owners
had never tried before

so when I came and I said,
"I want to do this,"

they were really, like, "Oh, no
way, that's not going to work"

I was the first one doing
that with her

and she had no problem doing it
right from the beginning

This is surprising because
in its essence,

if I hold out an object,

she turns it into
something communicative

and that's so interesting

NARRATOR:
Children also begin to grasp

that a drawing or photograph can
depict a real object

Thank you very much, well done

KAMINSKI:
In its essence, the picture is

something very different
as the object

so it's a it's a piece
of paper, but

and it's two-dimensional
but it's representing something,

so she obviously interprets that
as representing an object,

a three-dimensional object,
and that's so interesting

that she does this

"I know exactly what you want

This is the one you want and I'm
going to go and get it for you"

Ja, gut, super!

Braves Madchen,
gut gemacht, super.

NARRATOR:
Kaminski is unsure how many dogs
might have similar abilities,

but Betsy has shown that certain
dogs may have the potential

to be more intelligent than
we ever thought possible

So how did dogs acquire
these unique abilities?

Did these evolve
over thousands of years,

or is it rather the way dogs
have been raised

in a human environment?

[howling]

Dogs and wolves are still
the same species today

They can easily interbreed

Overall, wolves and dogs are


Given that they're
biologically so similar,

is it the way we raise them
in our homes that makes a dog?

Researchers in Hungary set out
to answer this question

KUBINYI ENIKÖ:
We wanted to see

whether the special relationship
between humans and dogs

are due to nature or nurture

So we wanted to see what happens

if a wolf is raised in a human
environment, in a home,

whether it would act
like a dog or not

NARRATOR:
A litter of five-day-old cubs

is taken from a wolf sanctuary
outside Budapest

Several young researchers are
their adoptive parents,

caring for them 24 hours a day

As a control for the experiment,
they already raised puppies

Now they aim to raise the wolf
cubs in the same way

So we were especially nice
with our cubs

because we wanted to maintain

a very good relationship
with them

They were really cute,
so it was not very difficult

to carry them everywhere
we were going

and we also slept together
with the cubs

So the bonding, it was good

I mean, I really liked my cubs

and there was a strong, really
strong relationship between us

NARRATOR:
Then something changed

Despite raising the cubs
in the same way as the puppies,

at eight weeks,
differences start showing up

ENIKÖ:
Dog puppies were always
interested in what I was doing

There is a very strong
cooperative tendency in dogs

and this was missing in wolves

They had their own ideas

They were not much interested
in my activities

NARRATOR:
The researchers want to find out
exactly what is going on

and decide to run a series of
tests comparing the wolf cubs

with puppies of the same age

[toy yipping]

The puppies engage

The wolves don't

Unlike dogs, the wolf cubs do
not respond to pointing

In fact, they hardly make eye
contact with humans at all

The cubs behave the same
as they would in the wild

[cub growling]

ENIKÖ:
She was really possessive

If she wanted to grab an object,

it was really difficult
to get it back,

and if we wanted to open the
refrigerator and have breakfast,

the pup was immediately in
the middle of the refrigerator

and grabbed something

It is not like with a dog that
you say, "No, you shouldn't"

It just didn't care

[growling]

NARRATOR:
The battles worsened

ENIKÖ:
After the second month,

we started to have
more and more conflicts

and the wolves wanted
to destroy everything

And of course when the cub is
a small cub, it's nothing,

but when they reach 40 or 50
kilograms, you know,

it starts to be really dangerous

We just could not keep them
in the house anymore

Hoo!

NARRATOR:
After four months, the cubs had
to be returned to the reserve

The experiment shows that
upbringing has little impact

It's impossible to turn a wolf
into a dog,

no matter how much it is loved
and nurtured

ENIKÖ:
So according to our experiences,

the dog is not
a socialized wolf at all

These differences we experienced

in the communicative ability and
in the social behavior of dogs,

this is the effect
of domestication

NARRATOR:
The differences must lie

in the way dogs have been bred
by humans

over thousands of years

Their unique abilities are
now part of their nature

But how did dogs evolve
these innate attributes?

Can we figure out
what made them tame?

A remarkable experiment
in Siberia may hold the key

to understanding how wolves
evolved into domesticated dogs

[horn honks]

Half a century ago,

Soviet scientists set up
a breeding program

to see if they could domesticate
silver foxes

Foxes are closely related
to wolves

The project, which has attracted
the attention

of scientists across the world,

is opening a remarkable window
on the process of domestication

Here on a farm outside
the city of Novosibirsk,

the experiment still
continues today,

overseen by Dr Lyudmila Trut

The breeding program
began in 1959

when the first foxes were
selected from local fur farms

[Trut speaking Russian]

[translated]:
We approached the animals
in the cages

and recorded their reaction
to us

We could see

that some of the foxes showed
aggressive behavior

Others were frightened

But only one percent of them
showed neither signs of fear

or aggression

NARRATOR:
This one percent is selected to
become the founding generation

of a new population of foxes

At every generation, the
selection process is repeated

Only the tamest foxes are
allowed to breed

Within just three generations,

the aggressive behavior
begins to disappear

The radical changes came through
in the eighth generation,

when foxes started to seek
contact with humans

and show affection to them

The amazing thing was that cubs
who had just started to crawl

opened their eyes and started
showing affection to humans

by breathing heavily, wagging
their tails and howling

This kind of response was
a big surprise to us

NARRATOR:
Half a century and nearly


the foxes are tamer than ever

It's an accelerated model

of how dogs might have been
domesticated from wolves

In order to understand the role
that genetics plays

in the taming process,

the scientists also bred a group
of foxes to be more aggressive

[foxes yipping]

[speaking Russian]

[translated]:
It just bit my hand

I didn't even open the cage

I just put my hand out

and it managed to bite me
through the bars

This isn't a fox, it's a dragon

[fox shrieking]

NARRATOR:
This experiment allows
researchers

to make unique comparisons

between tame
and aggressive foxes

[translated]:
We did an experiment
with cross-fostering,

where we gave aggressive cubs
to tame mothers and vice versa

We found out that the mother's
behavior does not influence

that of the cub

This cub was brought up
by a tame mother

NARRATOR:
The results are clear

The difference between tame
and aggressive foxes

is almost entirely genetic

We even took the experiment
one stage further

and transplanted embryos
from aggressive mothers

into tame mothers,
but the results were the same

It proved that you can't change
the gene of aggressiveness

and it will be kept
and preserved

for the next generation

NARRATOR:
Geneticists have already located

several regions on the fox
genome responsible for tameness

They're now taking blood samples
from tame and aggressive foxes

in an attempt to pinpoint
the specific genes

Dr Anna Kukekova, the scientist
leading this research team,

makes the 5,000-mile journey
to Siberia to study the foxes

KUKEKOVA:
Behavior is complex

We're pretty sure there will be
not a single gene,

definitely the orchestra
of genes,

which is responsible
for this behavior

NARRATOR:
One fascinating result
to come out of this experiment

is the fact that tamer foxes
are producing less adrenaline

With lower adrenaline levels,

the foxes experience less fear
and are less aggressive

He is like a doggy, you know,
like the puppy who's very happy

when somebody picks him up
from the floor

[fox panting excitedly]

It's unbelievable how they
trust, how they trust people

and I just really admire
these animals

TRUT:
So within 50 years

of our intensive selection
process,

this fire-breathing dragon has
turned into a human friend

If foxes were brought up
in a domestic environment,

interacting with other animals
and humans,

they would make fantastic pets

They are as independent as cats

but at the same time as devoted
as any dog could be

NARRATOR:
One surprising result
of this experiment

is that as
the foxes' behavior changes,

so does their physical
appearance

Just a few generations
into the experiment,

scientists noticed
a curious phenomenon

The normal pattern
and silver color of the coat

changed dramatically
in some of the tame foxes

Their tails often became curly
instead of straight

Some young foxes kept
their floppy ears

for much longer than usual,

and their limbs and tails
generally became shorter

than their wild counterparts'

In effect, the tame silver foxes

were beginning to look
more like dogs

BRIAN HARE:
What this shows is that when you
select against aggression,

you get almost all the same
suite of changes that you see

when you compare dogs to wolves

NARRATOR:
Evolutionary anthropologist
Brian Hare

is visiting the breeding program
in Siberia

He believes once you select
for tameness,

changes in appearance
will naturally follow

HARE:
I think the surprise when
thinking about dog origins

is that there are so many ways

that dogs are different
from wolves,

so is it that you had to select

for each of these traits
individually?

Well, the answer
from the fox work is no

If you just select for behavior,

a lot of the morphological
and physiological changes

that we see
between wolves and dogs,

they just get dragged along

You end up with this crazy
variance, you know...

Floppy ears, curly tails
you know, all these other things

that are really cute
to talk about

so you get a lot of stuff
for free

when you select
against aggression

NARRATOR:
For Hare, this wide variety
of physical traits

reveals something fundamental
about domestication

HARE:
When you're selecting against
aggression, what you're doing

is you're favoring
juvenile traits

Juveniles and infants show much
less aggression than adults,

and so basically
you've frozen development

at a much earlier stage,

and so you have an animal as
an adult that looks and behaves

much more like a juvenile

It's amazing that you get

all this variance that's hidden
under the surface

It starts to express itself,

and then, of course, later
people can directly decide,

"I really like the one
with the curly tail

"and I'm going to take
two of them

and I'm going to put them
together"

And then you can end up having
dogs that sort of shift

in ways that people
want them to go

NARRATOR:
In the past few hundred years,

we've taken dogs'
infantile features

and emphasized them even further
through selective breeding

We've created hundreds of breeds
to fulfill different roles,

but some of them have been bred
purely for their looks

MORTEN KRINGLEBACH:
I think this kind of breeding

really tells us a lot about
what kind of people we are,

what it is
that we like about dogs

How would you describe Nelly?

One word

Uh,

Cute

GIRL:
Cute, adorable

and funny

I just look at her and I
I just smile

Particularly when she's sleeping

She's very, very cute

NARRATOR:
We all know we find them cute,

but what is it exactly

that makes us respond to dogs
so powerfully?

Psychiatrist Morten Kringlebach
has a theory

as to why the way dogs look has
such a profound impact on us

The need to nurture I think is
something that is so deep in us

that we find it very difficult
to resist

Dogs, puppies have
very infant-like features,

and maybe that's
one of the reasons

why we think they are,
you know, so cute

is that they remind us
of the infants

that we are, so to speak,
programmed to like

There's something about the way

that the facial features
are organized

that makes us want
to care for them,

and it's about having
a large forehead,

it's about having large eyes,
big ears,

and there's something about that

that almost unconsciously
we cannot help ourselves

but actually like

How are you feeling in there?

WOMAN:
Good

We're just going to go
one more scan

NARRATOR:
Dr Kringlebach is exploring

how strongly we respond
to these infantile features

He uses an extremely powerful
machine called a MEG scanner

that allows him to measure
in real time

the brain's response to pictures
of baby and adult faces

KRINGLEBACH:
What we found was that
within a seventh of a second,

there was activity in the
frontal part of the brain,

just over the eyebrows,
in the orbitofrontal cortex,

that was present when you were
looking at the infant faces

but not when you were looking
at the adult faces

This part of the brain is
very much involved

in emotional responses,

and so what we think we may have
stumbled across here

is really in many ways
the brain equivalent

of the parental instinct

There's almost like
a wired-in automatic reaction

Just as with the infant,
when you are looking at dogs,

you find it very hard
to control your emotions

You find it very hard not to get
that need to nurture

Wow, look at that...
What a nice belly

Mushu, mushu hey [laughing]

[in baby-talk voice]:
Oh, Boo, you're so cute,
yes, you are

Oh, yes

NARRATOR:
But when we treat dogs
as if they were children,

do we sometimes allow them
to replace our children?

They are essentially moving our
focus away from having children

on to having pets

ROWLEY-CONWY:
I think we can think
of little puppies brought home

as parasites

They don't do anything useful

They're not perceived
as a food source

They're not perceived
as a guard dog

They are simply brought home
for fun

The cuckoo is perhaps
quite a good analogy,

because the baby cuckoo,
of course,

being planted
in somebody else's nest,

prompts mother bird to look
after baby cuckoo,

even though there's nothing in
it for the mother bird at all

KRINGLEBACH:
I think it's safe to say

that dogs have evolutionarily
been very successful

If you compare them to wolves,

you will see that wolves are now
an endangered species,

while dogs, of course,
are all around the world

NARRATOR:
Whether they are viewed as
parasites or beloved companions,

no one can deny
the evolutionary success

of the domesticated dog

In fact, there are
over 400 million worldwide

And humans have created over 400
genetically distinct breeds

Research on dogs is heading
in exciting new directions

Geneticists have already mapped
the genome of one breed...

The boxer

Studying this genome, scientists
now realize that it offers

tremendous promise
in curing human disease

Dr Elinor Karlsson,
of the Broad Institute,

was part of the team that mapped
the boxer genome in 2005

KARLSSON:
If you looked in,

you know,
a population of humans,

you'd have quite a lot of
genetic variation across them

People would be quite different
from one another

But within a breed, dogs are
very similar to each other

NARRATOR:
Dr Karlsson believes that
she can use that similarity

to understand the genetics
of human disease

KARLSSON:
I think there's hundreds of
diseases that are in common

between dogs and humans

There's diabetes, there's
various cardiac diseases,

there's epilepsy,

there's a lot of different
cancers...

Bone cancers, breast cancers,
brain tumors

NARRATOR:
Today the team is taking
blood samples from boxers,

which are susceptible
to a fatal heart disease

called cardiomyopathy

The DNA in their blood could
hold vital clues

to the causes of the disease

KARLSSON:
Once we had the dog genome
sequenced,

we could design a gene chip
which would allow us to compare

all of our sick dogs
and our healthy dogs

and find the genes that are
causing diseases

NARRATOR:
Using a genotyping machine, Dr
Karlsson simultaneously analyzes

thousands of regions of DNA

from boxers with and without
this disease

KARLSSON:
So what you see

when you compare the sick dogs
to the healthy dogs

and go across the genome from
chromosome 1 to chromosome 2

and across, is that most of the
points are right near zero

and there's not a lot
of differences

between the healthy dogs
and the sick dogs

until you get to chromosome 17
and there, all of a sudden,

you have a huge number
of differences,

and this is really exciting
because this means that this is

the region of the genome

that holds the gene
that's causing our disease

NARRATOR:
Now, with the mutation's
identity known,

the team is able to locate the
corresponding gene in humans

It's accelerated a process
that, without dogs,

could have taken decades

KARLSSON:
I think that there's probably
a lot of diseases

that are so complicated
in humans,

that dogs basically give us
a huge head start on that

We can really say that dogs
are good for our health

NARRATOR:
For a pet that has
been around so long,

dog research is a surprisingly
new area of science

Experiments have shown what dog
owners have always suspected...

After thousands of years
of living together,

dogs are attuned to us
like no other animal

It's a very important part
of life to actually know a dog

and especially a dog that adores
you like this

It's got to be good
for your self

It's kind of impossible
to have a bad day

when you're coming home

to a wet nose and a waggy tail,
I think

I can't imagine life without her

WOMAN:
It's quite strange

We weren't lacking anything
before we had him,

and yet now we would feel we
were lacking if he wasn't here

They just enrich your life;
they are the best thing ever

They keep you young

NARRATOR:
New research has taken
our understanding

of how dogs evolved
to a whole new level,

getting us closer
to what it means to be tame

MILLS:
While we can have
good relationships

with a wide variety of animals,

historically our relationship
with dogs seems to have been

the longest one
with any domestic animal

LARSON:
I think one reason

that there are almost seven
billion people on earth

is in large part due to the role
that dogs have played

in our evolutionary existence

Personally I don't think
it's any coincidence

that the dog is referred to
as man's best friend

The exploration continues
on NOVA's website,

where you can stream
"Dogs Decoded" online.

Hear how dogs compare
to other smart animals

and vote for your favorite.

And test your knowledge
of dog breeds

and where in the world
they come from.