a little while ago we made a compilation
video where we answered your most
pressing dog questions but we here at
scishow our pet non-partisans so
naturally we needed to make a
compilation dedicated to our feline
friends as well let's start with the
oldest question first it's often said
that we humans didn't domesticate cats
instead they domesticated themselves and
there's some truth to that what's less
often repeated however is the hypothesis
that it happened more than once here's
Hank to explain how that's even possible
cats we know what they like to chase
lasers and lick their own butts that
there's a lot that we don't know about
cute little whiskers like we're her
cuddly domestic ancestors came from and
when she evolved from wild animals we
used to think that the earliest
historical evidence for domestic cats
was from ancient Egypt like art and
mummified remains from around 4000 years
ago but now some glues are pointing to
domestic kitties older than that from
separate places across the globe the
oldest probably domestic cat skeleton
we've found was in 2001 on the island of
Cyprus in the Mediterranean Sea
scientists guessed that this cat lived
around 9,500 years ago which makes sense
historically that's after people started
farming in the Fertile Crescent that not
totally desert region in parts of
Western Asia and northern Africa farming
means you have to store extra crops
somewhere and piles of tasty grain
attract rodents and for hungry cats
that's an all-you-can-eat buffet
so one hypothesis is that feral cats
might have started snagging some meals
in getting cozy with humans humans were
happy to have them too because they took
care of the pests and were fluffy and
cute by this time we think humans had
domesticated other animals like dogs
cattle and sheep so adding another furry
friend wouldn't seem all that unusual
and we think this cat from Cyprus was a
pet for a couple of reasons
first of all Cyprus is an island with no
native cats so someone must have brought
them over on a boat and if they weren't
a little tame that would have been a
scratchy panicky animal mess like you
might know how hard it can be to get an
uncontrollable Kitty just to the vet
back plus the cat was buried with a
person presumably its owner and
surrounded with carved seashells wild
animals wouldn't get this special
treatment and if the cat was a meal its
bones would have been separate and
probably scattered all of this evidence
lines up with a study published in the
journal Science in 2007 which looked at
the genetic origins of domestic cats
those researchers found that our feline
friends are most closely related to the
wild cat felis Silvestri's specifically
the Near Eastern subspecies your eyes
also if you look at this cat will back
this evidence up cuz they look a lot
like domestic cats so lots of signs
point to domestic cats splitting off
from their wild cat cousins in the
Fertile Crescent but hold on some other
scientists discovered probably domestic
cat bones in 2001 and an ancient millet
for mning village in central China a
clue
computer analysis of jawbone shapes
showed that these cats weren't related
to the wild cat at all instead they were
a kind of leopard cat which is in an
entirely different genus some small
animal tunnels throughout the excavation
site and ceramic containers that looked
like they stored grain the researchers
were pretty sure that this village had a
rodent problem and by looking at the
carbon isotopes in cats bones it was
clear that they ate lots of small
animals that ate lots of human grown
millet this was the first convincing
evidence to support the domestic cats
eat pests that eat grain hypothesis but
this domestication happened in different
kinds of cats around fifty three hundred
years ago on the other side of this huge
landmass so what's the real story the
middle eastern or the Chinese
domestication of cats well there's no
reason to think that domestication
couldn't have happened twice in two
separate places with two separate cat
species when people started farming
grain but remember genetically all of
our modern cats seemed to be descended
from the wild cat not the leopard cat
maybe the domestic wild cats were just
snugly ER and had a leg up to win our
favor
see domestication leaves its
fingerprints in an animal's genome so
even though any cat person will joke
that their cats are too independent to
really be considered domesticated we can
look at these genetic fingerprints 2014
collaboration between a bunch of
American universities took a close look
at the domestic cat genome using 22
different breeds from different places
the study found recent changes in genes
that control the development of the
cat's nervous system these genes could
play a role in how domestic cats for
example behave less defensively in new
situations and can change their behavior
in response to rewards in other words
compared to a wild cat fluffy is
genetically more likely to walk up to
you with a friendly headbutt and beg for
treats this could explain why our cats
are extra snuggly the ones that got
along best with humans could take
advantage of our rodent pests and table
scraps and survived to pass on their
genes so in a way cats did domesticate
themselves and it seems like they did it
more than one time which kind of means
that the rise of cat videos was
practically inevitable
we like to think that we've contributed
to the vast library of cat videos and
maybe even added some science to the mix
- next up cats have lived with us for
thousands of years but they still share
plenty of features with their wild
counterparts like the keen senses of a
nighttime hunter that's why they do that
faintly alarming laser eye thing when
you get up to go to the bathroom at 3:00
a.m. as Michael vividly explains
it can be terrifying to wake up in the
middle of the night to a pair of glowing
eyes staring at you from the darkness
only to realize that it's just your cat
or is it lots of animals including
alligators fruit bats and dogs all have
a shiny structure in their eyes that
gives them better night vision which
also causes this creepy glow the layer
of tissue at the back of your eyes is
called the retina and it's made up of
special light-sensitive cells light that
hits those cells gets turned into an
electrical signal that sent along the
optic nerve which sits behind the retina
that signal travels all the way to the
brain and light that misses those cells
isn't turned into a signal so your brain
can't detect it many species across the
animal kingdom have this same basic eye
structure from reptiles to birds to
other mammals like cats one way animals
have evolved to see better is to have
more of these light-sensitive cells in
each eye humans for example have over 95
million of them per retina but a lot of
animals especially nocturnal animals
whose eyes have to work well at night
have another way of detecting more light
they have a structure called the tepee
dome lucidum which is Latin for bright
tapestry it's a layer of tissue that
sits behind the retina and acts like a
mirror to be dim lucidum reflects light
that goes through the retina back at
those light-sensitive cells giving them
another chance to detect it but some of
that reflected light flies back out of
the animals pupils which is what makes
it seem like their eyes are glowing the
color of that glow also called eyes
shine
depends on what the tepee dome lucidum
is made of and different critters have
different highly ordered molecules or
fibers that create a reflective surface
some fish use guanine one of the
chemical building blocks in DNA and have
white eye shine sheep have collagen
which also provides structure to muscles
and skin in lots of animals which leads
to a blue or green glow and cats use
riboflavin and zinc among other
molecules and the amount of zinc does a
lot to determine how yellow or green or
even blue their eye shine is so your
Kitty's eyes aren't actually like little
flashlights they're just reflecting some
of the ambient light in your room but if
they start glowing red and shooting
laser beams you should probably run
we ought to note that none of our cats
have displayed this behavior to date
there's still time though but while your
cat may think they're a fierce majestic
predator patrolling the savannas of your
living room they have more in common
with smaller wild cats than lions and
tigers they can't war like big cats can
for example they can purr though and
that seems like more than a fair trade
here's Hank to explain why it's usually
one or the other
I have a cat her name is cameo she is
adorable and recently she peed inside of
a potted plant but can you imagine how
amazing it would be if she could roar
while peeing inside of a potted plant
she'd be like give me some treats and
then like ferocious roar it would be so
cute
but domestic cats cannot roar only four
species in the cat family can lions
tigers leopards and jaguars here's the
weird thing though
zoologists are pretty sure that those
four species of cats can't purr so even
though my cat can't roar the reason
probably has a lot to do with the things
in her throat that let her purse now we
still aren't this is amazing totally
sure how cats purr there is no like per
box that we can locate in a cat and no
one's ever stuck a purring cat into an
MRI to find out exactly what's happened
but we've known for a while that it
probably involves the larynx aka the
voice box back in 1834 a British
zoologist named Richard Owen noticed
that there was an anatomical difference
between the cat species that purred and
the ones that roared roaring cats had a
more flexible hyoid the hyoid is a
structure that supports the tongue and
larynx in humans its horseshoe shaped
it's basically the first bone under your
chin and the front of your neck although
you shouldn't be able to feel it from
the outside so maybe don't go squeezing
up around in there on the murder shows
it's how they know people got strangled
and when they got killed they're always
like the hyoid is broken that's how we
know that the murder was the squeezing
that kind in cats the hyoid is more of a
hook that hangs down and connects the
back of the skull to the front of the
larynx and the base of the tongue most
species of cat including the domestic
cat the hyoid bone is very bony it's
said to be completely ossified meaning
that it's fully hardened bone and all
the cats that have it completely
ossified hyoid can purr but don't roar
the cats the do roar don't have a fully
ossified hyoid meaning that it hasn't
fully hardened into bone so it's a lot
more flexible the tissue is more like
the ligaments that normally connect
bones to each other Owen thought that
that flexibility was the key to roaring
roaring is a low deep resonant sound so
cats need long vocal folds to do it just
like people with longer vocal folds have
deeper voices and own figured a more
flexible hyoid was what let cats
vocal cords stretch enough for them to
roar for a long time pretty much
everybody agreed with this idea they
also assumed that hardened bony hoids
were the reason that all of the species
of cats that couldn't roar could purr
but there is one exception the snow
leopard snow leopards don't have a fully
hardened hyoid they have the more
flexible kind that Lions do but they
cannot roar and even though we've known
about the snow leopard exception since
at least in 1916 scientists didn't
really question the hyoid idea until the
late 1980s that was when researchers
realized that there is another
difference between cats that can roar in
cats that can't
roaring cats have thick pads of tissue
in their vocal folds the pads make their
vocal folds longer and heavier which
allows them to vibrate slowly and make a
lower pitched sound only lions tigers
leopards and jaguars have these pads
with no exceptions not even snow
leopards so roaring isn't entirely about
the hyoid bone sure the extra
flexibility might help but they also
need that extra tissue that our domestic
cat friends don't have these pads also
help explain why cats that roar can't /
cats purr they vibrate their vocal folds
at about 26 times per second there seems
to be some mechanism in their brains
that controls the vibrations as they
inhale and exhale the vocal folds open
and close which is what makes the
purring sound it's like how you can make
that motorboat sound by vibrating your
lips except they do it inside of them
with their vocal folds so the extra
padding that allows lions tigers
leopards and jaguars to roar would
dampen the constant vibrations that they
would need to purr the females of those
species do make purring like noises when
they're in heat but those noises don't
seem to be quite the same as true
purring they're closer to a growl so my
cat can't roar because her vocal folds
just aren't shaped for it but she can
purr and that's pretty dang cute I like
it
me too Hank me too slightly less
majestic is the habit cats have of being
completely blind to a tree that's right
in front of them like you shake it treat
bag and they'll come running but once
they get there they sometimes just
search around and give you this really
disappointed look like they can't find
their snack you know it's right there
it's right there okay this happens
because cat's eyes work differently than
ours and they actually are literally
blind to that piece of freeze-dried
chicken and inch away from their nose
cats are masterful predators capable of
spotting prey from meters away in the
dead of night but place a Treat in front
of them and they're basically blind but
why how can such good hunters be so
lousy at seeing what's right in front of
them it turns out that their vision
isn't always amazing since being able to
see so well at night comes with some
drawbacks cats are crepuscular that
means they're most active at dawn and
dusk as a result their eyes have evolved
to see best when the light is low for
one thing their eyes are huge they're
nearly as large as human eyes even
though their heads are less than half
the size of ours they're slit shaped
pupils also have a greater range of size
human pupils can dilate to 15 times
their smallest size cats pupils can
dilate by 135 fold and get even wider
than human pupils to let in a lot more
light the parts of their eyes that let
in and focus light their corneas and
lenses are also proportionally larger
which ultimately means more light
reaches the light sensing tissue in the
back called the retina and they have an
extra reflective layer behind the retina
called the tepee 'tom lucidum which
reflects back any light that reaches it
giving the retina a second chance to
catch what it missed special cells in
the retina called photoreceptors are
what actually sense light and like us
cats have two types of photoreceptors
rods and cones rods work best in low
light but don't sense color very well
cones are used in color vision but they
only really work if there's a good
amount of light cats have almost three
times as many rods as we do but only 10%
as many cones that makes for killer
night vision but in bright light those
rods become overloaded and can switch
off completely
that leaves the handful of cones to do
the heavy lifting which makes for some
pretty paltry daytime vision and those
huge eyes they're really hard to focus
to zero in on a nearby object you need
to bend that hard part of your eyeball
called the lens enough to reshape how
light enters your eye you have muscles
in your eyes that can do that quickly
when you need to focus on something
close up but the massive lenses in cat
eyes just aren't as flexible so they
don't Bend as well as yours do
ultimately this means that cats simply
can't focus on anything closer than
about 25 centimeters to them so when you
hold a treat in front of your kitties
face
all they see is a washed out blur
luckily their sense of smell is twice as
sharp as yours so if you hold that treat
long enough they're bound to sniff it
out eventually
that doesn't explain the disapproving
look but actually we can explain that
too
if you're a cat person like me you've
probably seen your furry friend looking
disgusted with you there's this face
they make like with the wrinkled up nose
the curled back lip and the open mouth
that looks like they're just absolutely
revolted good news your cat doesn't
actually think you're gross or if they
do that face isn't how they show it that
smear is actually what's known as the
flamin response and it gives cats and
other animals like horses llamas dogs
and giraffes a supercharged way to smell
the environment around them while it
might look like cats are expressing
their distaste what they're actually
doing with that face is sniffing using a
specialized organ called the vomeronasal
organ it's it's kind of underneath the
nose in the roof of the mouth and it's
actually connected to the mouth by the
small fluid filled ducts called nazo
Palatine canals if you look in your
cat's mouth you can even see the ends of
these they're behind the sharp incisor
is so good luck getting a cat to sit
still while you'd like take a look at
the inside of its mouth anyway because
of the fluid of these ducts since
don't passively drift up there so to
sniff airborne scents have to be taken
in through the mouth dissolved in fluid
and then pumped up until they come into
contact with the organ sensory cells and
that is where that funny face comes in
when a cat or giraffe or horse pulls
back their lips into the grimace of the
flame and responds they're opening up
those canals and starting the pumping
action to take a deeper width they could
just rely on their nose but the
vomeronasal organ has its own set of
chemical receptors so it can smell
different smells
this system is primarily used to detect
scent signals from members of their own
species though different animals and
even different sexes of the same animal
can use this secondary smelling system
in different ways and that might explain
why people tend to associate the flame
and face with cats and horses more than
with dogs even though all of them can
sniff this way in case you're wondering
though you cannot humans lost all of
those nasal Palatine ducts a long time
ago and while there are some remnant
cavities where your vomer and nasal
organs once were it's been a while since
they could detect anything which is all
to say don't worry
your cats are making weird faces at you
they don't hate you but they might think
you smell
I'm pretty sure they'll get over it and
maybe you can make it up to them with
some catnip not every kitty loves the
stuff but those who do are just really
cute when they smush their faces in it
and throw their toys all over still many
cat owners are puzzled by their response
to this stuff I mean what's the big deal
fortunately we do have some ideas about
the chemistry of catnip and why it makes
whiskers go bananas
ever seen a cat dip into some
recreational catnip it usually makes the
cat act a little strange it rubs up
against the catnip rolls in it and pause
it it's clearly enjoying itself and all
because of a compound that's a little
too similar to its natural biological
signals catnip aka nepeta cataria is a
plant that's a member of the mint family
when cats react to catnip they're really
reacting to an organic molecule released
by the plant known as nepeta lactone
nepeta lactone is made up of two
connected rings of mostly carbons and
the plant uses it to repel insects like
mosquitoes ticks and mites but most cats
are attracted to the stuff they'll first
start sniffing the catnip then lick and
chew it sometimes rubbing their cheeks
and chin or even their whole body
against the leaves some cats will meow
or even drool I mean they're obviously
into it but the effects only lasts about
15 minutes after that catnip will have
no effect on the cat for anywhere from
30 minutes to a couple of hours so
what's going on well researchers think
nepeta lactone is similar to a cat's
natural pheromones the molecules it uses
to communicate once the compound gets
into the cat's nose it bonds with the
same receptors pheromones do and the
cat's brain gets a signal that basically
says lots of pheromones over here a
catnip stimulates three main areas of
the cat's brain the olfactory bulb which
processes scent the amygdala which is
involved in emotions and decisions and
the hypothalamus which is in charge of
sexual response among other things the
last one helps explain why cats exposed
to catnip will often roll on the ground
like a female cat in heat it's also
probably why kittens don't usually
respond to catnip until they're sexually
mature when they're around six months
old but not every cat does respond to
catnip only about 50 to 70 percent of
cats do it's genetic and scientists are
still looking to identify the gene
involved and learn more about what
exactly is going on in the cat's brain
when it's reacting to catnip some big
cats like lions and jaguars also respond
to catnip but other animals don't use
the same pheromones or have the same
receptors so catnip doesn't affect them
and it's not just catnip other plants
will also attract cats probably for
similar reasons they produce
pounds that act like cat pheromone
silver vine for example produces a cat
pheromone like molecule called act in
Adeem in general these cat attracting
plants seem to be perfectly safe for
cats
they aren't addictive but a cat that's
often exposed to the stuff can become
less sensitive to it so if your kitty
likes catnip it's totally okay for them
to indulge once in a while
once your cat comes down from there
catnip induced hi
they might settle in for a nap in which
case they might exhibit one of the most
objectively adorable cat behaviors
making biscuits not literal biscuits
that would probably be a health code
violation somehow I'm talking about
meeting a cute boss mush thing they do
when they're getting all cozy here's
Hank to tell us why they do it
so you know when your cat comes up to
you and it starts to look at you and it
seems happy its purring and then it
tries to make biscuits out of your body
it's so cute it's cute because kitty
loves you but it's also painful because
kitties love is made out of little tiny
knives why does it do that why there are
theories of course some animal
behaviorist believe that it's another
way for cats to mark their territory
since paws have scent lands in them it
was popular theory however is that
meaning is a neo Tenakee havior a
juvenile trait that is retained in
adulthood because kittens need their
mothers bellies to stimulate milk
production this would explain why some
adult cats also suckle whatever it is
that they're needing however adult wild
cats do not need so why have domestic
cats retain this trait well neo tonic
behaviors are most often found in
domesticated animals like house cats
partly because over the millennia humans
have selected for traits that make
animals more social less aggressive and
generally nicer to be around but the
animals have probably also held on to
some of their more social baby-like
behavior just because it serves them
well when they're around people they got
I don't know if you've heard this but
wild cats are not super social they
don't come up and cuddle so much as just
try and eat your flesh
felis Silvestri's the ancestor of all
domestic cats is a solitary hunter that
only socializes with members of his own
species when it's time to breed so wild
cats only develop social behaviors for
two situations one is hey baby why don't
you come back to my burrow and we could
make a little something-something and
the other is caretaking behaviors
between mother cats and their kittens
unlike wild cats though domesticated
cats have a lot of social behaviors as
adults because they're not wild loners
anymore they have us to cuddle with con
treats out of and demand food from so
their innate tendencies for snuggling
with mom and hitting on the lady cats
are put to good use on us hence needing
originally a behavior that kittens
needed to survive is now a way for adult
cats to show that they trust you and
feel safe and if you had a soft pelt
like mom you wouldn't feel so much of
the little knives
here's another way to help Kitty feel
nice and safe its corrugated it's
recyclable it's a cardboard box it turns
out if I fits ice it's reflects some
pretty ancient feline instincts here's
Michael to tell us why cats love boxes
so much
if you have a cat or have ever spent
much time on the Internet
you know that cats like to sit in boxes
or any other small container adorable no
if it fits they six but have you ever
wondered why they do this well for one
it helps their anxiety I know
considering they sleep 12 hours a day
they don't really seem like anxious
animals but cats experience stress like
any other mammal and when they're
sitting in a box cats feel like they're
in a protected place where they can
observe and hunt without worrying about
being attacked this makes sense since
cats are ambush predators meaning
they're always looking to surprise their
next target to better understand how
boxes help cats calm down one study
published in the journal applied animal
behavior science observed a group of
cats that had just arrived at a new
animal shelter new environments can be
difficult for cats so stress levels were
pretty hot and scientists were able to
rank the cat's anxiety by looking at
factors like their activity levels and
their ear and tail position this system
is known as the Kessler and Turner cat
stress score now when some of the cats
were given boxes to hide in their stress
levels went way down in only three days
and the effect was observed in nearly
all of the animals with boxes for
comparison the cats who didn't get boxes
eventually reached the same low level of
stress but it took them two weeks so
especially in high-stress situations
it's important for cats to have an
enclosed space to retreat to and feel
protected this is also true of large
cats like tigers and jaguars except
instead of hiding in your latest Amazon
box they'll hide in trees caves or other
concealed spaces but there's another
reason cats like boxes so much
apparently our houses are too cold while
you might enjoy a comfortable 24 degrees
Celsius cats prefer much warmer
temperatures between 30 and 36 degrees
according to a study by the National
Research Council by curling up in a
cardboard box cats can trap some of
their body heat to make up a few of
those degrees that's also why cats like
basking in sunlight or curling up on top
of your heating vent so if you have a
kitty at home and you want to keep cat
stress at bay just make sure they have a
nice cozy box to sits in
thanks for watching this extra fluffy
compilation please pet all your cats for
me and tell them I love them and thanks
to our patrons who help us make videos
answering questions like these if you're
interested in lending a hand-- check out
patreon.com/scishow
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