Nova (1974–…): Season 47, Episode 3 - Cat Tales - full transcript

The perplexing behaviors of cats have often raised the question of whether humans ever really domesticated felines.

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They're one of the world's
most popular furry pets.

Who's a good kitty?

Famously enigmatic
and totally unreadable.

We will often pretend

to know what they are thinking.

Are we right?

Maybe not.

Now biologists
and archaeologists

are unraveling
their secret histories.

Behavioral genes have
evolved a little bit

to make a domestic cat
more docile,



more friendly with humans.

Molecular genetics is
throwing new light

on the cat's journey from
wild animal to furry friend.

We can really drill down
and say definitively

where domestic cats come from.

Discoveries in neuroscience
are starting to explain

why we find cats so appealing.

It's clear
that these auditory sounds

are plugging straight
into our emotions.

Behavioral science is
giving us a hint

of what they think of us.

They are able to differentiate

between our different
expressions.

And why they aren't always
the ruthless predator



they sometimes pretend to be.

The cat likes to hide,
it likes to conceal itself.

It often likes to be up high,
where it feels safe.

What can science tell us
about their future?

Humans have hybridized
the domestic cat

with a completely
different species.

We're on the prowl
for "Cat Tales,"

right now, on "NOVA."

Major funding for "NOVA"
is provided by the following:

They are as enigmatic today

as when they first came in
from the wild.

Cats lead fantastic
double lives.

They disappear for hours,

and we don't know where they go.

So, yes, cats are mysterious...
they are the best secret agents.

So, where do these strange
house guests come from?

These were slightly larger
in size,

lived more in trees,
but otherwise,

they're going to have very
similar characteristics

that makes a cat a cat.

How did they end up
living with us?

People have been speculating
about it for hundreds of years.

And what about cat intelligence?

Cats are brilliant.

People really underestimate
the brilliance of a cat.

Do they even like us?

The right motivation for a lot
of cats is not to please us.

Or are they just in it
for the treats?

The great big motivator
is going to be food.

What is it about
these strange creatures

that makes them irresistible
to so many of us?

Welcome to Las Vegas
for the 40th TICA cat show,

one of the largest feline shows
in the U.S.A.

We have 447 cats.

And we have 247 exhibitors.

It is a testament
to our fascination with cats.

281 and 282...

Poppy is a Canadian sphinx.

They're a very sweet breed.

They call them Velcro kitties,

'cause they like to be
on your lap all the time.

- This is a toyger...
- I invented it.

He has a fantastic temperament.

Cats are popular

because they are simply
very charismatic,

they're independent, and
they're considered easy keepers.

It's nice being able
to come home,

relax, have your cat
come up to you,

meow, sit in your lap, and purr.

It just makes you feel
loved and welcome.

There are over 70 breeds
recognized

by the International
Cat Association.

He's a white Oriental shorthair,

which is a Siamese
in a designer coat.

Yeah, he's a sweet boy.

Then there are glamour cats,

like the Persian,
with its thick, luxurious coat;

the Maine coon, large, smart,
and a deadly hunter;

and the exotic, one of the
most popular breeds in the U.S.

And that's just a start.

You can get small cats,
you can get large cats,

you can get cats
with shortened legs,

you can get cats
with folded ears.

We estimate

about one out of five households
in the U.S. owns a cat.

One thing is clear:

owners really love their cats.

Cats are perfect for me, because
I just love their companionship.

They jump up on your lap,
and that's all I need...

just a little cup of tea
and a cat.

Who's a good kitty?

Why are so many people

obsessed with cats?

The latest scientific research

suggests owners literally
can't help themselves.

Professor Morten Kringelbach

works at the University
of Oxford.

He studies hedonia... pleasure.

Pleasure is probably one
of the most interesting tricks

that evolution ever
played on us.

It's basically making us do

what it is that we need to do
to survive.

To understand how humans
experience pleasure,

Kringelbach uses
a magnetoencephalograph,

or M.E.G.,

to map and measure

electrical activity
in our brains in real time.

What is really exciting
about this technique

is that it allows us
to basically look

at how the brain is thinking,

how the brain
is having emotions.

You can measure
over milliseconds

the way that the electromagnetic
signals in your brain changes.

And we can start to see

how the brain is unfolding
in real time.

The brain fires electrical
signals between neurons.

Each tiny electric current

produces
a minute magnetic field.

But these magnetic fields
are so small,

they can be swamped

by interference
from electronic equipment...

even from the magnetic field
of the Earth.

For the M.E.G.
to measure brain activity,

test subjects must be
locked away

in a heavily shielded room.

Okay, we're just about
ready to start.

Just sit nice and still
and just listen to the sounds.

In previous trials,

Kringelbach's team tracked
the brain's responses

to the sound of a newborn baby.

So, what we're seeing here is

how the signal gets
into the auditory cortex,

this bit here and here.

It's basically just near
to your ears.

And you can see that after
about 130 milliseconds,

you get the maximal response.

Now, when you're listening
to an infant crying,

you also get activity in
the orbitofrontal cortex,

and it's happening
at exactly the same time

as when you are actually
trying to make sense

of what it is
that you're hearing.

The orbitofrontal cortex
is central

to processing emotions,

and the experiments suggested
that the sound of a baby crying

triggered a response there,

before the subjects

had consciously
identified the sound.

It seems to be an instinctive
emotional reaction

that may not even require
rational thought.

This may be because
the need to care for infants

is an essential
species-survival skill.

It's clear
that these auditory sounds

are plugging straight
into our emotions.

In tests where subjects listened
to the sound of an adult crying,

a much weaker response arose
in the orbitofrontal cortex,

suggesting only certain sounds

trigger a strong
emotional response.

But there was another sound
that produced the same reaction

as a baby's cry.

A cat's meow.

There seems to be
striking similarities

between the way
that we process a cat meowing

and that of baby crying.

We get activity
in the auditory cortices,

just like we do
with anything else.

But before we become
conscious of it,

we get activity
in the orbitofrontal cortex,

suggesting
that this is something

that we need to take care of.

The fact that a newborn's cry
and a cat's meow

initiated
the same emotional response

could have been a coincidence...
except for one thing.

Meowing in adult cats
is really interesting,

because it turns out
that they only really do it

to humans.

When cats meow to us,

it's as if they are hijacking
our emotional responses

to make us
love and care for them.

But are they doing it
on purpose?

It's not necessarily
something that is conscious.

It's just that they know
that this works,

just like we know that
smiling at our parents worked

when we were kids.

Here, come here, you monster.

They probably don't mean
to manipulate us, but they do.

So, we have some idea

of what's going on
in our heads about cats.

But will we ever know
what's going on in their heads?

I definitely think cats
are more aloof than dogs.

I do think they can be
very emotionally distant.

We will often pretend to know
what they are thinking.

Are we right?

Maybe not,
but it's fun to imagine.

Cats are famously enigmatic.

So it's tough to figure out
what they're feeling

by looking at their faces.

Happy cat.

Angry cat.

Sad cat.

Or is that the sad cat?

We may not be able to figure out
what our cats are feeling,

but can science shed any light
on it?

Historically, cats aren't seen

as very expressive.

So there is that idea
that they are particularly cold

when it comes
to interacting with us.

Compare that to a dog,

whose face seems
full of expression...

empathy,

happiness,

sadness,

guilt.

Why aren't cats
as communicative?

They're not really able to frown

or have that sad, sort of
puppy-dog-eye expression.

They don't seem to have
the right musculature for that.

Both dogs and humans
have a muscle

that is responsible
for raising the inner eyebrow,

which we use for showing things
like sadness and concern.

Cats don't have this muscle.

So cats are physically incapable

of having faces
as expressive as dogs.

However,
Finka's research suggests

that cats can communicate
some emotion on their faces.

It's just we don't
speak their language.

So, we know that the muscles
of the cat's face

are quite different
from other species,

and certainly from humans.

They use the muscles
in different ways,

and they also have
different types of muscles,

and different collections
of muscles

will do different things.

Finka studies
how cats' faces change

when illness or injury
produces pain.

This is the only feeling she can
currently say with confidence

that a cat is experiencing.

We are looking at cats
when they come into the vet's

with a painful condition,

and we do know

that they're actually changing
their expressions

in relation to how they're
feeling and if they're in pain.

She has identified a set
of incredibly subtle markers

to help track their feelings.

We have a series
of 48 facial coordinates.

And we can actually look to see

how these coordinates
are altering

based on what
the cat's experiencing.

So, whether they're
in pain or not in pain,

or whether they're
relaxed and comfortable

or perhaps fearful
or frustrated.

Finka has identified
some telltale signs,

such as a cat's ears turning
very slightly outwards and down;

or a tiny reduction
in the distance

between the cheeks, mouth,
and nose region.

These are all signs

that the cat is not happy
and in pain.

But if you think
this is going to usher in

a new age
of cat-human communication,

think again.

It's very, very subtle.

So, statistically,
it's significant,

but in terms
of the average cat owner

trying to look
at their cat's face,

it might be a little bit
more problematic.

Our struggle
to read cats' feelings

isn't going to get much easier
anytime soon.

But can cats read our emotions
any better?

To find out,

researchers conducted
a series of behavioral tests.

Because it's quite difficult
to test cats,

we know a lot less
about their cognitive abilities

compared to dogs.

Doesn't mean

that they don't necessarily
have the same level

of skills and abilities.

It just means
that it's much harder for us

to find the right context
to test them in

and get them to play ball in
the way that we need them to.

Pepper the cat has been placed
in a room with her handler,

who makes various faces at her.

First up, scowling.

Can Pepper detect
this is a negative emotion?

It appears cats are less likely

to react positively
to someone they know

if they have
an angry expression.

Next, a positive, smiling face.

By running the test
multiple times,

scientists gathered results

suggesting
that a cat may be more likely

to approach
someone they recognize

if they are smiling at it.

What the research suggests
is that they are able

to differentiate between
our different expressions,

and they're using
this information

to change the way
that they are responding.

The limited study also suggested
that cats react more strongly

to both the positive
and negative emotions

of their owners

than to those of strangers.

The behavior of owners is
much more important to the cats,

because we're the ones
that feed the cats,

and we look after them.

So maybe they're more interested
in paying attention to us

for that reason.

We may struggle
to read cat faces,

but we're probably
less inscrutable to them.

So, what led
to this unlikely partnership

between human and cat?

To answer that, it helps
to understand their origins.

Domestic cats are part of
a much larger and wilder family,

a family with some very
big footprints to fill:

the lion, the tiger,
the leopard...

predators at the top
of their food chains.

But whatever
the apparent similarity,

these are not
our cats' direct ancestors.

All felines, or felids,
evolved from the Proailurus,

an animal living in Eurasia
roughly 25 million years ago.

These felids were probably
slightly larger in size,

lived more in trees
than our domestic cats do.

But otherwise, it's going to
have the same teeth and claws,

just like a domestic cat does.

So, all cats, whether
you're a lion, a tiger,

or a little domestic cat
sitting on your lap,

they're going to have
very similar characteristics

that makes a cat a cat.

DNA and fossil evidence
tells us that big cats...

the lion, the tiger,
the jaguar...

separated
from the common ancestor

around 10.8 million years ago.

Large American cats,
like the lynx and bobcat,

separated 7.2 million years ago.

The domestic cat's ancestor,

the most recent branch
of the felid tree,

established itself
3.4 million years ago...

Felis silvestris, the wildcat.

It's a much smaller subspecies
of feline

that relies more on surprise
and stealth than brute force.

This explains the origins

of some of the strange behaviors
owners see in their pets.

There are several clues
in cats' behavior

that they're perhaps not
the apex predators,

and, in fact, are prey,
as well as predators.

For example,
the cat likes to hide,

it likes to conceal itself.

It often likes to be up high,
where it feels safe

and where it can be
very vigilant.

According to genetic research,

Felis silvestris split
into five distinct subspecies:

the European wildcat,
the Chinese mountain cat,

the Southern and
North African wildcats,

and the Central Asian wildcat.

But which one is the actual
ancestor of our domestic cat?

People have been speculating
about it for hundreds of years...

about where they came from,

whether or not they came
from many different species

or many different subspecies
of one species.

In 2007, geneticist
Carlos Driscoll

started a groundbreaking study,

collecting DNA samples
from wildcats

and comparing their DNA
to domestic cats.

With the advent
of molecular genetic techniques,

we can really drill down
and say definitively

where domestic cats come from.

Each subset of Felis silvestris

has a distinct DNA signature

made up by different
combinations

of the four chemical bases,
A, T, C, and G.

By comparing these
to the domestic cat,

Driscoll was able to pinpoint

which subspecies
was its ancestor.

Domestic cats are derived
from one single group

of Felis silvestris in the wild,

Felis silvestris lybica.

Felis silvestris lybica,

the North African wildcat...

a solitary animal found
throughout Northern Africa

and the Middle East,

longer-legged
than our domestic cats,

with a coat that ranges
from reddish to grey,

to camouflage
in different habitats.

But when did this wildcat
become our domestic companion?

In 2004,

on the small Mediterranean
island of Cyprus,

archaeologists found evidence
of the earliest known encounter

between cat and human.

A team lead by Jean-Denis Vigne

was excavating a
9,500-year-old human settlement.

During the excavation,
they discovered a grave...

a grave that had two occupants:

the skeletal remains
of a man and a cat,

a Felis silvestris lybica.

It was amazing to find
a complete animal,

and especially a cat,

beside a human.

And it was so early
that it was really surprising

to have such an evidence
of connection

between one cat and one human.

The way the bones were laid out

suggested that the cat had been
intentionally placed

next to the man.

They were facing each other
in death, in the afterlife.

And this is a, a scene which
has been arranged by people.

But what really caught
scientists' interest

was the fact
that Cyprus is an island,

and no trace has ever been found
of native wildcats.

So, how did this cat get here?

The fact that this burial
was found on Cyprus

means that somebody brought
these cats to the island,

by boat.

The Cyprus settlement

closely matches sites
found in Turkey,

so archaeologists believe that's
where the settlers originated,

and where we know that Felis
silvestris lybica was common.

It suggests these people
or their ancestors

must have brought a cat
with them.

But the Cyprus cat was different
from mainland wildcats

in one very significant respect.

This cat was very big.

This meant that, probably,
it has been fed.

So maybe it was
more or less a pet.

A larger skeleton indicates

that the cat is domesticated,

because he's getting
enough nutrition

that he can devote

all that energy
obtained from food

into growth.

Cats in the wild are less able

to spare the energy to grow big.

There's a time cost to hunting.

So, you would have
energy diverted

into fueling your hunts,

then therefore,
you'll be smaller.

On its own,

the evidence of the Cyprus cat
is not enough to confirm

that this nine-and-a-half-
thousand-year-old cat

was domesticated.

But there's now evidence
from genetic research

that supports this theory.

To date the split between
wildcats and domestic cats,

scientists use
mitochondrial DNA.

Unlike other DNA,

mitochondrial material
comes almost exclusively

from the mother,

so it's passed
down the generations unaltered,

except for random mutations
that happen at a known rate.

By calculating
that rate of mutation,

we can actually
calculate the age

of a specimen
that we're studying.

So, we use
the mitochondrial clock a lot

with different organisms

to try to figure out their age
in evolutionary time.

And it shows that our domestic
cats split from wildcats

approximately 10,000 years ago...

very close to the time
of the Cyprus cat.

Why did it happen then?

Well, at that moment in history,

humans societies were also going
through a big transformation...

becoming farmers.

This started in an area
of the Near East

archaeologists call
the Fertile Crescent.

And Turkey, where
the Cyprus cat originated,

was part of it.

The Fertile Crescent was
so rich an area

for hunting and gathering

that people could have
little encampments

that eventually grew into towns.

So throughout all seasons,
they could be in one spot.

This new way of life
relied not only

on the ability to grow food,
but also to store it.

What's the dawn of civilization

got to do
with cat domestication?

Humans by this point
were harvesting grains

and caching them,

putting big stores of grains
in baskets

in holes in the floors
of their houses.

But the grain stores
were an easy target

for hungry wild rodents.

They had the potential
to devour these new food stores.

Luckily for our ancestors,

this new concentration
of rodents

attracted something else...
something wild.

Cats were likely drawn
into these new human settlements

because they could hear
something we couldn't.

Cat hearing is really
just truly amazing.

So, they can actually hear
very low frequencies

and very high frequencies.

And of course,
much of their prey

is squeaking
at high frequencies.

Humans can't hear
some rodent squeaks at all,

as they vocalize at a frequency
beyond our hearing range.

But cats have
ultrasonic hearing.

When we hear nothing,
they hear this.

The pitch of these squeaks
must be lowered by 90%

to make them audible to humans.

Cats also have
unique anatomical gifts

that help them zero in
on their next meal.

The outside of their ear has an
amazing amount of muscles in it,

so they can turn their ear
all the way around.

That allows the cat
to really hone in

on where the mice are, rats are,
where they're communicating,

and hence, they're going to
capture them for their meals.

This makes cats
rodent terminators...

unstoppable killers.

The allure of easy pickings in
the first human settlements...

namely, rodents...

would have been irresistible.

And you'd be forgiven

for thinking that cats still
like to show off this prowess

10,000 years later.

She brings us gifts.

Maybe once a month, we have
a mouse appear in the house.

It is a bit disgusting.

We get leaves, leaves. Oh,
yeah, they brought a leaf in,

and Rita brought a piece
of stale toast in once

from the back garden.

So, lots of people think

that their pet cats
bring them gifts

in the form of small rodents
or birds,

but actual fact, the cat
doesn't believe it is a gift.

The cat will often bring home
the prey that it has caught

because the home represents
the core territory to the cat,

the place that it feels safe.

But 10,000 years ago,

this would have been
very effective PR,

proving to our ancestors

that cats protected
valuable food resources.

This was a creature you'd want
to have hanging around.

Maybe you set out
some food for a cat

to keep it around your house.

You might have done that because
you thought it was eating mice

and keeping your grain stores
clean.

So, the domestic cat split
around 10,000 years ago

in the Near East.

But how much have they changed
from their wild ancestors?

The wildcat in the wild

feeds only on meat.

They're obligate carnivores,
or hyper-carnivores.

So they can only
process proteins.

They're metabolically incapable
of digesting carbohydrates.

House cats are different.

While wildcats only eat meat,

their domestic cousins
have evolved the ability

to digest some plant matter.

The domestic cat,
for thousands of years now,

has been living off of scraps...

not just scraps of meat,

but also scraps
of grains and vegetables.

And the result of that
is that domestic cats

have a slightly longer
intestinal length

than their wild ancestor.

And Darwin hypothesized

that this is because
the cats are trying to squeeze

as much nutrients out of
this poor food as they can.

This irresistible combination of
rodents and edible human refuse

could explain why the wildcat
decided to come in from the wild

and live alongside humans.

Wildcats genetically predisposed
to find humans less scary

would have hung around
the settlements.

Anything that has to do
with aggression or boldness

are probably genes
that are involved

with the actual
domestication process,

because those had to change

between the wild progenitor
and the domestic cat

in order for the cat
to cohabitate with humans.

Breeding between these animals

would have positively
selected genes

that allowed them to live
more closely with humans.

Certainly, there have been
some genes that have changed

between an African wildcat
and the domestic cat itself,

because we know
the behaviors are different.

Behavioral genes,
which are genes

that are involved with our brain
and our neurology,

those are genes that have
evolved a little bit

to make a domestic cat
more docile,

more friendly with humans.

Geneticists have found 13 genes
that have changed

in the domestic cat,
compared to its wild ancestor:

genes like DCC and G.R.I.A.1,

which are associated
with making cats friendlier

and less afraid of people.

We may never know
who initiated first contact,

but it's safe to assume

that cats determined
the terms of the relationship.

So, it's not a stretch to say

that we didn't domesticate
the cat,

the cat domesticated itself.

Genetics has confirmed
that domestic cats originated

in the Fertile Crescent,

but it's also revealed something
genuinely surprising...

one country had more influence
on the genes of modern cats

than any other.

And it was a long way
from Turkey.

Egypt.

Professor Salima Ikram is an
expert in all things Egyptian,

including their obsession
with cats.

The ancient Egyptians
really loved animals,

but they also revered them.

Cats were perhaps
the most popular

and the most highly venerated,

because of their utilitarian
as well as metaphysical values.

In Egypt 4,000 years ago,

the first images of cats
start appearing...

wall carvings and paintings
of cats living with humans.

Egyptians especially valued
the cat's killer instincts.

Ancient texts tell us that
not only do cats kill rodents,

but they also kill snakes.

So, of course,
the Egyptians love this,

because they were much safer
as a result.

Imagine if you're a mother,

and your child
is crawling around,

and then a snake approaches,
and your pet cat kills it.

Also, for them, the idea
that a cat was killing a snake

meant that the sun god Ra was
killing the evil snake Apophis.

So, it was sort of
doing double duty.

This mystic battle playing out
in homes across Egypt

would have done wonders
for the cat's PR.

The cat became
so important to Egyptians

that they turned it
into a goddess.

The cult of Bastet,
the cat goddess,

had always been popular
in Egypt,

but it really came to prominence
3,000 years ago,

about 500, 600 B.C.

Bastet, the daughter of Ra,

would often take
the form of a cat.

Bastet was very much
about self-indulgence and beauty

and love and fertility,
which was very important.

Unfortunately for cats,

being worshipped as a goddess
had a very unfortunate downside.

We're about to go
into the tomb of Raia,

who was a New Kingdom official.

It's a really ancient tomb,

and it's not been open
to the public for ages.

Wow.

Nice.

They lived

about three-and-a-half
thousand years ago,

just at the beginning
of the time of Tutankhamen.

But that's not the most
interesting thing for me

about this tomb.

For me, the most exciting thing
is actually

that it was reused
to bury cats in.

This tomb is packed
with cat mummies.

The downside of being
worshipped as a goddess

was that it led to cat sacrifice
on a huge scale.

Pilgrims would buy these cats
to give a blood sacrifice.

And so for the cat goddess
Bastet,

you would offer up a cat,
which would then be killed.

And because it was
her titulary animal,

it would attract her attention
in the afterlife.

The demand for sacrificial cats
became so great,

Egyptians were breeding
hundreds of thousands of them.

People were breeding
these animals

specifically for sacrifice.

So, we think

that there might have been
catteries

scattered all over the country,

where purpose-bred cats were
being given to the temples

for the priests to sacrifice.

This breeding program
was so intensive,

it may have changed the physical
appearance of some cats.

Here, this really sweet
little paw,

is part of the foreleg
of the cat.

But what's extraordinary is

that you can still see
some of the fur here,

and it's a ginger kitty.

And a lot of the cats in
paintings are ginger cats.

They were favored,

because they brought out
the idea of the sun god Ra,

and you can see this color here.

Seeing a ginger or orange cat
today isn't unusual.

But 4,000 years ago, before
the Egyptian breeding program,

nearly every cat in the world
looked like this tabby.

The striped pattern,
which is the mackerel tabby,

was the original "wild-type"
version of a cat's coat.

The mackerel pattern helps it
to have better camouflage

in the environment
that it has evolved in.

Orange coloring isn't good
for camouflage.

These cats would have been less
well adapted to the wild,

but in the catteries of Egypt,

there was no need
for camouflage.

In the wild,

these new coat color patterns
wouldn't be tolerated.

They don't provide
any advantage.

But when you're around humans,

they become selected by humans,

because they're odd
and different.

It's called novelty selection.

So, when we see
these odd colorations

showing up in a species,

that is a clear sign
of domestication.

The orange mutation may not
have occurred first in Egypt,

but it was certainly established
and protected here.

So, if it wasn't
for the Egyptians,

we may not have
orange cats at all.

The intensive
Egyptian breeding program

didn't just change
the way cats looked.

It changed their behavior,
as well.

It's absolutely changing
the cat's personality,

making it more domesticated

by putting these cats
into large groups.

After generations of selecting
for cats

that go from a solitary animal

to being a group species now,

you're probably changing
the cat's behavior

to be a less stressed animal,

a more bold and loving animal
with humans.

So, Egyptians produced cats that
were more attractive to humans.

This could explain
why the DNA of Egyptian cats

makes up so much
of a modern cat's DNA,

compared with cats
from elsewhere.

For any given species,

not all lineages
are going to survive.

So for the domestic cat,
the Egyptian lineage of cats

really dominated
and was more popular,

and so probably out-competed
the other different lineages

that were from different places
of the world.

But how did cats bred in Egypt
spread across the world?

The same way many invading
forces did at the time...

by boat.

Egypt was a major trading hub
in the ancient world.

Precious metals, gems,
and timber came in.

Grain from the fertile Nile
went out.

And much of that trade
went by sea.

Because the trade ships were
filled with grain, primarily,

there were so many rats about,

that, of course,
cats were really welcome,

because they not only
protected the grain,

but they also protected
the sailors from being bitten

and also their own food.

So, cats were really stars
on these boats.

Cats began traveling
the known world on ships.

For thousands of years,
Egyptian, then Roman,

then Viking ships transported
cats across the world.

Vikings, in particular,

seemed to have favored
the unusual color mutation

that had originated in Egypt.

You can almost map
where Vikings were

by looking at the gene frequency
of orange in Europe.

Vikings clearly
couldn't get enough

of their orange Egyptian cats.

It was probably true

in Viking society,

as it is true in most other
early seafaring societies,

that having a cat on board
a ship was good luck.

And it could be that
the Vikings selected orange cats

to bring on their boats

for some reason
that we don't know.

Egyptian cat genes
conquered the known world.

But it seems not everyone
was happy about that.

Because by the Middle Ages,
in Europe,

cats weren't being worshipped...

they were being persecuted,
mainly thanks to this man,

Pope Gregory IX.

This 13th-century pope produced
a papal anti-cat edict.

It accused cats of being
in league with Satan.

And because what the pope said
was the word of God,

God hated cats.

The solution
to the satanic cat menace

was simple and straightforward...

kill them all.

In late medieval Europe,

there were festivals formed

around the torturing
and killing of cats.

And of course, when tortured,

they made, to sadists, a very
satisfying amount of racket.

So, what was it

about these relatively harmless
furry creatures

that was so alarming
to medieval society?

Cats are creepy creatures
to a lot of human beings.

So, there's always this tension

between an animal that actually
shouldn't be in your home

and is a predator
and quite menacing,

and yet is affectionate
and cuddly

and purry and furry and warm.

Another reason medieval people
could have found cats disturbing

was because of their
serpent-like eyes.

Cats have unique adaptations
in their eyes

that allow them to be
superb hunters at night.

One of these adaptations is

the reflective layer in the back
of the eye called the tapetum.

Light entering the eye

is picked up by the
photoreceptors in the retina.

It hits the tapetum lucidum,
reflects back,

and gets picked up
by the photoreceptors again.

This adaptation helps give a cat

six times greater night-vision
acuity than a human.

However, this membrane
makes the cat's eyes

appear to glow in the dark...

not ideal in the age of
witchcraft and superstition.

We are a diurnal species.

We're suited to daylight,
we can't see in the dark.

The night for us is
disempowering, scary,

and positively dangerous,

whereas to a cat, it is simply
a natural environment.

Isn't it, Moses?

Isn't it, Moses?

By the end of the Middle Ages,

cats had colonized almost
every continent on the planet.

And they had started to diverge

further and further
from their Near East origins.

One of the more famous and
striking of these new cats

was the Siamese.

Siamese cats are
very interesting,

because they're sort of
a natural breed

that occurred in Thailand.

The Siamese evolved
in a different direction

from its Egyptian ancestors,

losing the tabby coloration
completely,

opting for something
totally unique.

So, this beautiful girl has got
a classic Siamese coat color

with the, the browner ears
and nose and tail and feet,

and that's the result
of a thermosensitive mutation

in a tyrosine gene

that inhibits the production
of melanin on these cats.

And so, the warm parts
of her body lose the color,

and the cooler parts keep it.

The DNA of the Siamese

show they separated
from the Mediterranean breeds

centuries ago

and evolved independently
on the other side of the world.

It's not believed that anybody
set out to breed these cats.

What happened is, is, a mutation
occurred, and it stayed

in this very small
isolated population

in Thailand.

And from there,
it drifted into fixation

in a certain number of cats.

This process is called
genetic drift.

It occurs
when a particular mutation

becomes accidentally dominant
in an isolated population

that doesn't mix much
with the rest of the world.

If a mutation occurs
in a small population,

it's got a very good chance
of drifting to fixation,

which means that 100%
of the cats in that population

will then have that mutation.

The Siamese is
an extremely unusual breed,

because its looks result
from a natural genetic process.

Most cats in the world arose
by more artificial means...

a sudden and huge expansion
of cat breeding.

During the late 1800s
and into the 1900s and on,

cats have become
a status symbol.

Europeans realized that there
were different variety of cats

from all around the world.

They then incorporated that
into their breeding programs.

People started selecting cats

because they had
unique varieties.

The Angora cat came
from the Near East;

the Abyssinian came
from Ethiopia;

the Manx cat, which had no tail,
came from the Isle of Man.

And this new trend
of cat breeding

was enthusiastically taken up
in the U.S. in short order.

One of the first is
the Maine coon,

the natural long-hair cat

that really actually came over
with the Pilgrims,

but now was indigenous
to the United States.

Another very interesting
cat breed

that developed
in the United States

is the ragdoll.

This cat developed from cats
that were in California.

Breeding, both natural
and human-assisted,

has given cat owners
an astonishing level of choice.

So, you might think,

that after 10,000 years
and all this effort,

we've bred out their wild side.

Apparently not.

These are feral cats.

They are not wild animals,
despite how it may look.

These cats,
or their close relatives,

were once normal house pets.

Take a domestic cat
out of the home,

and they can turn
a lot less loving.

Feral cats typically will
start up with fight-or-flight

when people come into play.

This suggests all domestic cats
have this wildness within them.

So why don't they all
turn feral?

The socialization window
for cats is very important.

If you want a friendly cat,

a cat that is accepting
of people and new experiences,

this is usually between two
to seven or eight weeks of age.

If they miss that window,

it's more likely to have
a cat that's more fearful

and more what we consider feral.

U.S. cities like Atlanta have a
serious problem with feral cats.

We don't want
to euthanize a cat,

because you know what happens

when you remove cats
from the outdoor environment?

Is that new cats come in.

So, we actually maintain
a stable population

so we don't add more cats
into that area.

So, veterinarians
like Dr. Ashley Randall

work on programs to try
and control the situation.

Neutering and spaying is
really, really important

when it comes
to feral populations,

especially if we're trying
to control the numbers.

Any time a population
gets really, really high,

you run the risk for disease,

and that's for people
and for pets.

Helping Dr. Randall with
Atlanta's feral-cat problem

are Lizzy and Kasia
from the Pets for Life Program.

We are out today doing
some cat-trapping

for what's called TNR...
trap, neuter, release.

A female cat

will have kittens
every two months,

and she will be impregnable
right after she delivers.

So, pretty much, you can assume
that every female cat

in the wild out here

is pregnant at all times.

Lizzy and Kasia are tracking
a feral cat active in the area.

So they've left a series
of traps filled with food.

Well, it looks like
somebody's in there.

Yeah.

Hi, there.

Let's see what we've got.

Hi.

Looks like the right one.

We're going to take you
to the vet.

Let's get him in the van.

Okay.

On average, they catch
15 cats a week.

It's okay, buddy.

Each receives a welcome
health check, vaccinations,

and neutering or spaying.

Okay, so, his heart sounds good.

And his gums are nice and pink.

Very good, big guy.

All right, so we are going
to put him on his side,

and then we are going
to give him his sedative.

All right.

All we're doing is

taking away
the reproductive organs,

so we're taking away organs
that they can live without

very easily.

For males, they're up

within about 20 minutes
of that procedure.

So he is going to go back
outside and live out his life.

All righty, big boy.

The whole procedure takes
less than ten minutes.

And a few hours later,

the cat is released
back onto the streets.

It's okay, buddy, we're home.

The reason that we trap, neuter,
and return feral cats...

versus keeping them
and adopting them out...

is, they're truly not happy
to live inside with people.

This way.

The vet said

he was pretty healthy,
surgery went well.

So he might be a little drowsy
this evening,

and then he'll be back
to full energy tomorrow,

ready to take on the world.

There you go.

So, domestication may
only be skin-deep,

and cats are essentially
still wild animals...

wild animals
that now live with us.

This essential wildness
may explain in part

why cats are not trainable
in the way dogs are.

Dogs want to please
their owners;

they are what is known
as hyper-social.

Cats don't really care
what their owners want.

It's a lot more difficult
to train a cat compared to a dog

because dogs were specifically
selected for their trainability,

whereas cats have
shorter attention spans,

and people also
really don't spend

a lot of time training cats.

But just because they aren't
as cooperative as dogs

doesn't mean they aren't
as smart or trainable.

You just have to make it
worth their while.

Meet Samantha Martin.

This is Meowy Manor.

Samantha is the manager
of a traveling troupe...

or, more accurately, pride...

of performing cats.

Most of the training
happens in here.

Cats are brilliant.

People really underestimate
the brilliance of a cat.

By training them,
they get to use their brain.

They have to figure out what
it is that I want from them.

To train her cats,

Samantha uses a method
called operant conditioning,

also known as clicker training.

This is the target stick,

so he was trained to jump up

to wherever I pointed
the target stick.

And once he had all four paws
up on the barrel,

I'd just click and treat.

The clicker acts
as a bridge or a marker

to let the cat know that
they'd just done a behavior

that's going to give them
a reward.

Got it, you got it.

Once the behavior's learned,

I no longer need
the target stick or the clicker,

just the prop itself.

And they know
what to do with the prop.

So, that's the finished trick.

The question is,

are the cats training
to please their owner,

or are they just there
for the food?

If you want to train a cat,
the great big motivator

is going to be food.

Food is a primary reinforcer.

It's something
that they can't live without.

So, most cats can be trained
to work for that food.

Compared to dogs,
there hasn't been much research

into cat cognition
and intelligence.

But cats are clearly clever...
when they choose to be.

The Acro-Cats play to full
houses as they tour the U.S.A...

audiences crammed
with envious cat owners

wondering why their pet
won't do this.

Experience and hard work says,

"Reward with food, and you
might have a little more luck."

So, where next
for our wild feline friends?

Well, some people have plans
to completely reinvent the cat.

All domestic cats
up until the last 20 years

have been purely
Felis silvestris.

Humans have, very interestingly,

now hybridized the domestic cat

with a completely
different species.

Anthony Hutcherson
has been breeding

one such hybrid...
Come on, buddy.

The Bengal cat.

Bengals come from a cross

between domestic cats
and a wildcat species

called the Asian leopard cat.

Personality-wise,

they are a little different
from other cats,

and they're pretty active
and interested and intelligent.

So, if you just want a cat
to sit on your lap,

this is not the cat for you.

The difference

between a domestic cat
and an Asian leopard cat

is about six million years
of evolutionary time.

That's on the same range
as the difference

between a human
and a chimpanzee.

Bengal adults, 207 through 216.

With such a huge
evolutionary difference,

can these new hybrid cats
still share our homes?

Come on, buddy.

The challenge lies

in getting those physical traits
that attract your eye

and have excited humanity
since the beginning of time

without those traits
you don't want on the inside:

getting scared easily,
peeing in the corners,

you know, needing to eat
a lot of raw, bloody meat.

The Bengal is not
the only exotic breed

trying to inject
a wild look into cats.

The Chausie is a cross
between a domestic cat

and another
non-Felis silvestris,

the jungle cat.

And the savannah is a cross

between a domestic cat
and a serval,

a cat that broke away
from the wildcat's line

over eight-and-a-half million
years ago.

I think these cats
are both the future

and the past of domestic cats.

They represent the thing
that people love and want

as a bit of the wild
in their house,

which is kind of the oldest
reason people love cats anyway.

10,000 years ago,

our first feline furry
house guests moved in.

Since then,
they've traveled the world,

been feared by popes,
and worshipped like gods.

They've hijacked human instincts
for their benefit,

apparently learned
to read human emotions,

but kept their own feelings
under wraps.

They can even entertain us...

as long as we make it
worth their while.

And though they've gone
through subtle genetic changes,

their wild nature has endured
despite our best efforts.

What's more, they've leveraged
some of those traits

to become
the ultimate consumer pet,

bringing a little bit
of the wild

into millions of homes.

And what do cats
make of all this?

As usual, they're not saying.

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