Pratica di Shadowing: Why Pandas Are Impressively Bad at Existing - Impara a parlare inglese con i video
Creazione lezione...
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I think it's easy to look at a panda and forget it's an actual, real animal.
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It's hard to conceive that the incredible forces of evolution that create highly effective, lethal predators would turn one into this?
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And for all the creationists
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that are inevitably frothing to write a comment about how this is proof that animals are created and not evolved,
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why would our Lord Creator create something so terrible?
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This spherical ball of evolutionary mistakes is clinging to existence.
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And while this is very sad, because they are very cute,
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they don't necessarily garner a ton of sympathy when you learn just how bad they are at being animals.
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Pandas have evolved to eat a very narrow range of food, a range so narrow it's basically just one thing, bamboo.
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A plant that has almost no nutritional value and is full of cyanide.
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It's so toxic that pretty much all other animals avoid it, and it's so nutritionally deficient that they have to spend up to 12 hours a day,
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almost all of their waking hours, eating enough of it to survive.
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And for a bear, this makes even less sense.
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They're members of the Ursidae family, related to grizzly bears, polar bears, and black bears.
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Every other species in the Ursidae family eats meat, either as omnivores or as obligate carnivores like polar bears.
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And scientists think that pandas need to eat so much bamboo
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that in the wild they have to keep their distance from one another to get enough.
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This means that they can have a hard time finding a mate.
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This contributes to pandas having an exceedingly low birth rate, which contributes to the fact that they are this close to not existing anymore.
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And on top of this uphill battle that they've already created for themselves, they act as if they have absolutely no survival instincts hardwired into their brains.
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They fall off and get stuck in trees, and just generally act like every day is their first day on earth.
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And on top of this, one of their favorite hobbies is poop.
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They poop over 40 times a day, and given the chance, pandas will absolutely cover themselves in horse poop.
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I am talking head to toe, full body immersion.
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The official term for a group of pandas is an embarrassment of pandas.
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And even if they are lovable, it sure seems like they are an evolutionary accident that maybe came about just for our amusement.
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But as we all know, evolution doesn't work like that.
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Everything evolves for some reason.
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But how is being a clumsy idiot beneficial?
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And why would they evolve to eat the worst thing imaginable?
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And why are they absolutely obsessed with poop?
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Giant pandas are herbivorous bears native to the bamboo forests of south central China.
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And although they are members of the Ursidae family, they have taken a unique evolutionary path.
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Around 40 million years ago, the ancestors of bears split away from the other caniforms.
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Then, around 23 .4 million years ago, the Ursidae family split in two.
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The genus Aeleropoda was all alone on one branch, and this is what pandas evolved from.
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All the other bear species evolved on the other side of that branch.
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And as pandas continued to evolve, they did something truly baffling.
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They evolved to stop eating meat, transitioning to eating almost exclusively bamboo.
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Scientists assume this happened between 6 -7 million years ago, and they make that assumption about the timing
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because of one adaptation they seemed to have gained that allowed for better bamboo manipulation, a pseudo -thumb.
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This is like a whole extra weird little thumb, essentially one of their wrist bones grew extra large so
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that it curves in an opposite direction as the other five of their fingers.
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The thumb isn't as widely useful as a human thumb, but it's perfect for grasping bamboo.
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But at first glance, suddenly adapting to only eat bamboo fundamentally makes no sense.
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And in most ways, pandas still look like the other bears.
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They have sharp claws and sharp canines foods, even their guts still resemble the gut of other carnivores.
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When we look at carnivores vs herbivores, carnivores have much shorter and simpler digestive tracks.
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That's because their high protein diet requires a lot less digestion time to extract all the nutrients they need.
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Herbivores take longer to digest plant foods because there are higher levels of indigestible materials, like cellulose, the main structural molecule in plant cells.
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It's tough and hard to break down, which is why certain herbivores, like cows, have multiple stomach compartments.
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They spend a long time digesting so that they can extract as many carbohydrates and other nutrients as possible.
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But pandas, surprisingly, have a carnivore gut.
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They don't have the multi -chambered stomachs of ruminants, so of their nearly 100 % diet of bamboo, they can only digest around 20 % of it.
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This means they have to eat a lot of bamboo, up to 35 kilograms per day.
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Which is also why they poop 40 times per day.
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The food stays in their guts a little longer than most carnivores, but still, this seems wildly inefficient.
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And not only do pandas have a digestive tract that looks like that of a carnivore, their gut microbes also match the pattern of carnivores.
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Gut microbiome diversity is highest in herbivores, then omnivores, with carnivores coming in last.
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You'd think that millions of years of only eating bamboo would introduce a bit of diversity into the panda's gut bacteria, but that's not the case.
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In fact, once panda cubs are weaned off their mother's milk and transition to eating bamboo, the diversity of their gut bacteria decreased.
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As the scientists write in their paper on the subject,
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a carnivorous digestive system fed with a bamboo dominated diet is not a typical feature of evolution.
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But as dumb as this seems, there's usually a reason behind long -standing animal adaptations.
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And in this instance, starting to eat bamboo kind of made sense for pandas, sort of.
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Bamboo may be low in energy, but in southern China, when this adaptation came about, it was abundant.
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Plus, it grows exceptionally quickly.
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Bamboo is one of the world's fastest growing plants, plants, with one species growing more than one meter per day,
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and reaching its maximum height of 20 meters in just under two months.
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And the highest diversity of species of bamboo is in southern China, and as it so happens,
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it perfectly overlaps the limited territory that giant pandas exist in, even though they probably lived over a much wider range in the past.
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Bamboo is such a dominant species, that in a bamboo forest, almost no other plant life grows.
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And not many other animals eat bamboo.
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So for any animal that can evolve to consume it, bamboo provides a bounty of food unlike anything else.
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But it does seem particularly weird for a meat eater to
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suddenly be okay going from eating delicious succulent meat to poisonous sticks.
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But scientists think pandas underwent another strange adaptation to make them fine with this, an adaptation that is as weird as it is sad.
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Around 4 .2 million years ago, pandas lost the function of their T1R1 gene, which is what's involved in detecting umami flavors in meat,
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which are driven by L -glutamate.
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L -glutamate is an amino acid present in high quantities in protein, so it signals that something is especially full of calories and nutrition.
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And suddenly, pandas could no longer detect it, which probably made meat a lot less enticing, at least going by flavor.
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What a curse.
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Likely at first, pandas just adapted to eat a little bit of bamboo due to its abundance, and then after a long time,
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they gradually lost their ability to enjoy meat, and thus lost most of their hunting instincts.
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They might have still People eaten fruit for a while, and even today they'll eat fruit if you give them some, but almost no fruit grows in a bamboo forest.
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Given all of these factors, some scientists think that pandas were probably eating nothing but bamboo as far back as 2 .4 million years.
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But regardless of when it happened, a carnivore evolving to eat only bamboo is unprecedented evolutionarily speaking.
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In fact, anything eating only bamboo is kind of unthinkable.
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Because even if there is a bounty of bamboo, it's still toxic.
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Bamboo is full of cyanide, in quantities high enough that eating it raw would kill most mammals.
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In fact, there have been numerous cases of poisoning among humans who accidentally ate raw bamboo or prepared it incorrectly badly.
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Other herbivores have a way to detoxify cyanide using an enzyme called mitochondrial rodanese,
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because many plants use cyanide as a defense mechanism and herbivores encounter it in small doses over their lifetime.
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But pandas have far less of this detoxification enzyme than normal herbivores.
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And yet these pandas are consuming up to 66 mg of cyanide every day, close to a fatal dose for humans, and they seem just fine.
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It might seem like they are too stupid to realize they're supposed to die.
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but it turns out they actually have a way to get
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around this poison that's different from the way most herbivores do it.
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When researchers looked more closely at the panda's gut bacteria, as diverse as it wasn't,
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they found an abundance of one unique and powerful bacteria, Pseudomonas fluorescens.
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This bacteria helps degrade cyanide compounds, which seems to completely protect the pandas.
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Plus, pandas are strategic in what parts of the bamboo they eat.
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Depending on the species of bamboo and time of year, the pandas may target different parts of the plant to avoid the highest dose of cyanide.
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This targeted feeding is also the case when it comes to nutrients.
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In fact, although 99 % of the pandas diet is bamboo, a recent study found that they're actually eating the same amount of protein as carnivores.
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How?
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Because young bamboo shoots roots actually have a lot of protein in them, and so do the leaves at certain points in their life cycle.
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And pandas target these to get as much protein as wild cats do.
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In the end, their bamboo diet is 61 % protein energy, 23 % carb energy, and 16 % fat.
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This is even reflected in panda milk, which has a higher ratio of protein than the milk of herbivorous mammals.
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So at first, I'm kind of impressed that pandas found a way to cheat the system and turn a crappy food source into something usable.
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But this feeling doesn't last long.
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Because even if pandas can technically get enough nutrients out of bamboo, they still have to eat an ungodly amount of it to get enough nutrients,
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spending pretty much their entire life doing nothing else but gorging on it.
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To cope with this, their metabolism has adapted to slow way down, and they can't afford to move around that much.
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They are fairly sedentary animals trying to hold on to every ounce of energy that they can.
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And while this is a somewhat effective evolutionary reaction, it doesn't solve all of their problems.
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The winters in China can be brutally cold, and unlike other bear species that can pack on fat and hibernate for the winter,
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pandas can't afford to ever stop eating.
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So they just have to endure it, meaning they have to spend even more energy using thermoregulation to maintain a stable internal temperature.
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Eating bamboo became a positive feedback loop requiring them to eat more and more bamboo, and it might also explain why they're so clumsy,
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or at least why they appear to be.
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Pandas look clumsy in part because they're always looking for the lowest energy way to get around, and sometimes the easiest way to get somewhere is to fall there.
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And their round shape just lends itself to rolling.
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Scientists think they might partly do this just for fun.
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So at this point in the panda story, it seems like they've found a sort of novel way to get enough nutrients,
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something they don't have to compete with other species for and is readily abundant.
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Which is sort of an evolutionary win as long as they can eat enough of it.
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But there are still even more problems with this plan.
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Although they don't have to compete with other species much for bamboo, they still sort of have to compete with each other.
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And because they need to eat so much of it, each wild panda keeps a large territory to themselves.
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They live solitary lives, using their sense of smell to avoid each other as best as they can.
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Male pandas tend to have territories that are around 6 .5 square kilometers, while female territories are usually about 4 .5 square kilometers.
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This isn't a problem in itself.
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They don't seem to mind living solitary lives.
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However, it becomes a big problem when it's time to mate.
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Pandas only seek out other pandas in spring for mating.
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And female pandas have a fertility window of just two to seven days per year.
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And conception has to be timed exactly.
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Like, come on guys, I'm actually just getting annoyed at this point.
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So when it's getting close to time to mate, pandas leave scent messages for one another by rubbing their scent glands on trees, rocks, and grass, and they just hope
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that other pandas get the message in time to hike miles over mountainous terrain to mate in the minuscule two -day window.
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If they succeed, which they rarely do, female pandas are pregnant for five months before giving birth to a tiny cub about 1 800th of their size.
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Half of panda pregnancies result in twins.
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Awesome.
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Except for the weaker of the two cubs is often abandoned.
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Pandas can typically only care for one infant at a time, because the tiny cubs need constant and careful attention.
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I get that this happens in many animals, but this just seems like yet another way pandas are begging to go extinct.
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Their evolutionary path is just kind of an impossible one.
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But what about the poop thing?
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Could this maybe be the secret to their ongoing survival?
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Giant pandas in central China's Foping National Nature Reserve have been seen absolutely smearing horse poop all over their entire bodies,
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really focusing on their face and necks.
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Is this fun?
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Or is this some other weird adaptation that somehow helps them?
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Recently scientists think they made a breakthrough in this horse poop mystery.
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They noticed that the pandas seemed to do this most when it was cold outside.
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Could it somehow be a way to keep them warm?
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Because pandas are fiercely protected, scientists rarely get access to do direct experiments with them.
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So for this scientific question, the researchers used mice.
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They covered the mice in the poop compounds of interest, and found that poop -treated mice walked on cold surfaces more readily, and huddled together for warmth less.
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And what the researchers realized was that these poop compounds inhibit cold receptors in mice, and also in pandas.
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Some experts argue that this could be a way for the pandas to endure those brutally cold winters while forgoing hibernation.
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But while it might be a coping mechanism, it seems like it could be an incredibly bad one.
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If their bodies no longer feel the sensation of cold, this could prevent them from seeking shelter, and would actually be incredibly dangerous.
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Because of this, some scientists aren't convinced, and they think the pandas just really like poop for fun.
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So at best, this behavior is weird and gross, and at worst, it's downright stupid and maybe suicidal.
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Horse poop is probably not the secret sauce to their unlikely ongoing survival.
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I know I'm kind of joking about all of this, but it really looks like pandas are just simply bad at surviving.
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It looks like they exploited the environmental niche of bamboo, but at a great cost, basically dooming themselves.
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Because of all of this, certain simulations make some scientists think that pandas have been on the decline for thousands of years or even longer.
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Some argue that if humanity had never existed, the panda would still go extinct in the very near future.
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It's undeniable that they are slow to adapt, and that their very specific niche puts them at a disadvantage if any single thing in that environment changes.
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But humans are really, really good at changing the environment.
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So even if pandas have been declining without humans, humans have undoubtedly made it worse.
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Panda population decline accelerated rapidly in the 1700s, when agriculture and human civilization expanded rapidly in central China.
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And ever since then, panda habitat has been wildly fragmented.
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Dams, roads, and railways divide panda habitats, making it even more difficult for them to find each other to mate,
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and reducing the amount of bamboo forests needed for them to get enough food.
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This along with poaching absolutely slashed panda numbers.
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Today, only around 1800 pandas are left in the wild.
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Regardless, if we don't intervene, pandas would absolutely go extinct.
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Captive breeding programs have saved pandas from the brink of oblivion,
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and now humans are working to create corridors between forest reserves to link up wild pandas once again.
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Do we as humans spend a ridiculous amount of money trying to keep an animal
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that seems to want to go extinct alive?
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Yes.
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But is it maybe our responsibility to try?
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Also yes.
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Evolution did them dirty, but so did we.
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Sometimes we just have to take care of the idiots amongst us.
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My favorite part of studying biology is looking at these evolutionary questions.
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The big causes and effects that shape every animal on earth.
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How competitive pressure and genetic mutations led to the supremely weird bamboo diet for pandas.
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How a drying climate caused ants to become fungus farmers.
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How becoming upright animals allowed us to become extremely smart animals.
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The path to higher intelligence in humans is unlike anything else in the animal kingdom.
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And it's something I've explored in depth in a five -part Nebula original mini -series called Becoming Human.
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In this series, I explore the major steps in human evolution, from toolmaking, to hunting, to long -distance running,
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to language, to the birth of consciousness as we know it.
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Nebula is the streaming platform we built for exactly this reason.
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To create original content that takes a little longer, has a higher production value, and explores areas that we want to take a deep dive into,
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things that don't always work on YouTube.
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And right now for the holiday period, we're offering gift cards to Nebula for you to give to your friends or family members.
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Lifetime subscriptions, whether it's for yourself or as a gift, help fund original series like Becoming Human and so many others.
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Vocabolario e note di pronuncia per questa lezione
Questo video contiene 226 frasi e 3509 parole da ripetere con lo shadowing. Il parlato dura 22:28. Chi parla ha un ritmo naturale di circa 156 parole al minuto, vicino a una conversazione quotidiana. Solo il 78% delle parole rientra nelle 3.000 più comuni dell’inglese, quindi il lessico è impegnativo.
Vocaboli chiave di questo video
15 parole del video che vale la pena imparare, con pronuncia e significato:
| Parola | Pronuncia | Significato |
|---|---|---|
| bamboo sostantivo | /bæmˈbu/ | bambù |
| poop sostantivo | /ˈpuːp/ | cacca |
| evolutionary aggettivo | /ˌiː.vəˈluː.ʃən.ɛɹ.i/ | evoluzionario, evolutivo |
| nutrient sostantivo | /ˈnuː.tɹi.ənt/ | nutriente, principe nutritivo |
| evolution sostantivo | /ˌiːvəˈluːʃ(ə)n/ | evoluzione |
| subscription sostantivo | /səbˈskɹɪpʃən/ | abbonamento |
| survival sostantivo | /sɚˈvaɪ.vəl/ | sopravvivenza |
| diversity sostantivo | /daɪˈvɜː(ɹ)sɪti/ | diversità |
| mouse sostantivo | /maʊs/ | topo, sorcio |
| thumb sostantivo | /ˈθʌm/ | pollice, dito grosso |
| compete verbo | /kəmˈpiːt/ | competere, gareggiare |
| lifetime sostantivo | /ˈlaɪf.taɪm/ | durata, vita utile |
| incredibly avverbio | /ɪŋˈkɹɛdɪbli/ | incredibilmente |
| compound sostantivo | /ˈkɑmpaʊnd/ | composto, miscuglio |
| adapt verbo | /əˈdæpt/ | adattare |
I phrasal verb che sentirai
| Parola | Significato |
|---|---|
| turn out verbo | risultare |
La grammatica di questo video
Le strutture che chi parla usa di più, con le parole esatte del video:
| Struttura | Nel video |
|---|---|
| Frasi condizionali if + frase, will/would + verbo — una condizione e il suo risultato | if we don't intervene, pandas would absolutely |
| Present perfect have/has + participio passato — un’azione passata che conta ancora adesso | have evolved · they've already created · have taken |
| Forma passiva be + participio passato — conta ciò che accade, non chi lo fa | are created · are weaned · are driven |
| Frasi relative who / which + frase — un’informazione in più su una persona o una cosa | down, which is · gene, which is · milk, which has |
Pronuncia a cui fare attenzione
Chi parla usa 33 contrazioni e forme ridotte, come don't, they're, doesn't. Pronunciale nella forma breve, così come le senti.
- I suoni “th”: thumb /ˈθʌm/, sympathy /ˈsɪm.pəθ.i/, lethal /ˈliː.θəl/
- I suoni “sh” e “zh”: evolutionary /ˌiː.vəˈluː.ʃən.ɛɹ.i/, evolution /ˌiːvəˈluːʃ(ə)n/, subscription /səbˈskɹɪpʃən/, adaptation /ˌæd.æpˈteɪ.ʃən/, sharp /ʃɑɹp/
- Parole lunghe — attenzione all’accento: evolutionary /ˌiː.vəˈluː.ʃən.ɛɹ.i/, evolution /ˌiːvəˈluːʃ(ə)n/, adaptation /ˌæd.æpˈteɪ.ʃən/, diversity /daɪˈvɜː(ɹ)sɪti/, incredibly /ɪŋˈkɹɛdɪbli/
Come esercitarsi con questo video
- Ascolta tutto il video una volta senza parlare e annota le parole che non conosci.
- Inizia a velocità 0,75×, fai shadowing frase per frase e torna alla velocità normale quando diventa facile.
- Registrati e confronta con l’originale, facendo attenzione a parole come bamboo, poop, evolutionary.
Cos'è la tecnica dello Shadowing?
Shadowing è una tecnica di apprendimento delle lingue supportata da studi scientifici, originariamente sviluppata per la formazione dei traduttori professionisti e resa popolare dal poliglotta Dr. Alexander Arguelles. Il metodo è semplice ma potente: ascolti un audio in inglese di madrelingua e lo ripeti immediatamente ad alta voce — come un'ombra che segue il parlante con un ritardo di solo 1–2 secondi. A differenza dell'ascolto passivo o degli esercizi di grammatica, lo shadowing costringe il tuo cervello e i muscoli della bocca a elaborare e riprodurre simultaneamente i modelli di discorso reale. La ricerca dimostra che migliora significativamente la precisione della pronuncia, l'intonazione, il ritmo, il discorso connesso, la comprensione dell'ascolto e la fluidità del parlato — rendendolo uno dei metodi più efficaci per la preparazione alla prova di speaking dell'IELTS e per la comunicazione reale in inglese.