Placeholder Image

字幕列表 影片播放

  • a little while ago, we made a compilation video where we answered your most pressing dog questions.

  • But we hear it's I show our pet non Ferguson's 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 years Hank, to explain how that's even possible.

  • Cats, We know what they like to chase lasers and lick their own butts.

  • There's a lot that we don't know about cute little whiskers like where 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 clues air pointing to domestic kiddies 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 9500 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 in 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 have 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, it's 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 Wildcat.

  • Phyllis Sylvester's specifically the near eastern subspecies your eyes.

  • Also, if you look at this, cat will back this evidence up because they look a lot like domestic cats.

  • So lots of signs point to domestic cats splitting off from their wildcat cousins in the fertile crescent hold on.

  • Some other scientists discovered probably domestic cat bones in 2001 in an ancient millet farming village in central China.

  • A close computer analysis of job own shapes showed that these cats weren't related to the wildcat at all.

  • Instead, they were a kind of leopard cash, which is in an entirely different genus from 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 cat's 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 that this domestication happened in different kinds of cats around 5300 years ago.

  • On the other side of this huge landmass up, 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.

  • Great, but remember, genetically, all of our modern cats seemed to be descended from the Wildcat, not the leopard cat.

  • Maybe the domestic Wildcats were just snuggle earlier and had a leg up to win our favor.

  • See, Domestication leaves its fingerprints in an animal's Gino, so even though any cat person will joke that they're 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 cats 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 reward.

  • 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 snugly.

  • 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 have contributed to the vast library of cat videos and maybe even added some science to the mix to next up.

  • Cats have lived with us for thousands of years, but they still share Bunty of features with their wild counterparts.

  • Like the keen senses of a nighttime hunter.

  • That's where they do that faintly alarming laser.

  • I think when you get up to go to the bathroom at 3 a.m. as Michael vividly explains, it could 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?

  • I'll 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 Mrs those cells isn't turned into.

  • A signals to your brain can't detect it.

  • Many species across the animal kingdom have the same basic ice structure from reptiles, two birds, two 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 Perretta.

  • But a lot of animals, especially nocturnal animals whose eyes have toe work well at night, have another way of detecting more light.

  • They have a structure called the tip Eatem lucid um, which is Latin for bright tapestry.

  • It's a layer of tissue that sits behind the retina and acts like a mirror to beatem.

  • Lucid, um, reflects light that goes through the retina back at those light sensitive cells, giving them another chance to detect.

  • But some of that reflected light flies back out of the animals pupils, which is what makes it seem like their eyes were glowing.

  • The color of that glow, also called I shine, depends on what the two PM lucid, um, is made of.

  • And different critters have different highly ordered molecules or fibers that create a reflective surface.

  • Some fish use Guan in one of the chemical building blocks of DNA and have white I shine.

  • She'd have collagen, which also provide structured of muscles and skin, and lots of animals, which leads to a blue or green glow, and cats use rival Flavin and zinc, among other molecules.

  • And the matter of zinc does a lot to determine how yellow or green or even blew their eye shine is so your kiddies 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 one.

  • We ought to know that none of our cats have displayed this behavior to date.

  • There's still time.

  • But while your cat may think they're a fierce, majestic predator patrolling the savannahs of your living room, they have more in common with smaller Wildcats than lions and tigers.

  • Can't roar like Big Cat scan, 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 upper.

  • 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?

  • That should be like give me some treats and then, like a ferocious roar, it would be so cool.

  • 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 a memory to find out exactly what's happened.

  • But we've known for a while that it probably involves the larynx, a k a.

  • The voice box.

  • Back in 18 34 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 at a more flexible highway.

  • The hyoid is a structure that supports the tongue and larynx humans, its horseshoe shaped.

  • It's basically the first bone under your chin in 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 highway is broken.

  • That's how we know that the murder was the squeezing that kind and 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.

  • In 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 a completely ossified hyoid Compper.

  • 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.

  • Oh, and thought that that flexibility was the key to roar.

  • 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 Ah, more flexible hyoid was what let cats vocal cords stretch enough for them to rot for a long time.

  • Pretty much everybody agreed with this idea.

  • They also assumed that hardened, bony Highwoods were the reason that all of the species of cats that couldn't roar could per.

  • 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 1916 scientists didn't really question the hyoid idea until the late 19 eighties.

  • That was when researchers realized that there is another difference between cats that can roar and 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 pitch sound.

  • Only lions, tigers, leopards and jaguars have these pads with no exceptions, not even snow leopards.

  • The 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 catch the roar can't per cats purr.

  • They vibrate their vocal folds 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 of the extra padding that allows lions, tigers, leopards and jaguars to roar would dampen the constant vibrations that they would need to purge.

  • The females of the species do make purring like noises when they're in heat, but those noises don't seem to be quite the same as Trooper Rig.

  • They're closer to a growl, so my cat can drawer because her vocal folds just aren't shaped for it.

  • But she can purr, and that's pretty dang cute.

  • I like it.

  • Me to Hank me to Slightly less majestic is the habit cats have of being completely blind to a treat.

  • That's right in front of them, like you've shaken 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 works 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 drawback.

  • 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 they're huge.

  • They're nearly as large as human eyes, even though their heads are less than half the size of ours.

  • There.

  • Slit shaped pupils also have a greater range of size.

  • Human pupils congratulate to 15 times their smallest size cats.

  • Pupils can dilate by 135 fold and get even wider than human pupils toe 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 to Pete um lucid um, 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 photo receptors, are what actually sends 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.

  • Cohen's air 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 toe 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 kitty's 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 looks, 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 knows the curled back lip in 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 sneer is actually what's known as the flame and response, and it gives cats and other animals like horses, llamas, dogs and giraffes.

  • Ah, 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 bomber.

  • Oh, nasal organs.

  • 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 nays.

  • Oh, Palestine canals.

  • If you look in your cat's mouth, you could even see the ends of these there behind the sharp incisors.

  • So good luck getting a cat to sit still while you like, take a look at the inside of its mouth anyway.

  • Because of the fluid of these ducts, sense don't passively drift up there, so to sniff airborne sense 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 response.

  • They're opening up those canals and starting the pumping action to take a deeper with.

  • They could just rely on their nose.

  • But the bomber, a nasal Oregon, has its own set of chemical receptors so it can smell different smells.

  • This system is primarily used to detect sent 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 Palestine ducts a long time ago.

  • And while there are some remnant cavities where your bomber nasal organs once were, it's been a while since they could detect anything, which is all to say.

  • Don't worry if 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 could make it up to them with some catnip.

  • Not every kid.

  • He loves this stuff, but those who do are just really cute when they splashed their faces in it and throw their toys all over.

  • Still, many cat owners air 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 roles in it and posit.

  • It's clearly enjoying itself, and all because of a compound that's a little too similar to its natural biological signals.

  • Catnip, a k a.

  • Deputy secretary A.

  • 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 an EPA.

  • Tilak Tonev, it'll act own, 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 me