Why Don't Big Animals Get More Cancer? Reason for|||||| Mengapa|||||| Warum erkranken große Tiere nicht häufiger an Krebs? Why Don't Big Animals Get More Cancer? ¿Por qué los animales grandes no tienen más cáncer? なぜ大きな動物はがんになりにくいのか？ 큰 동물은 왜 암에 더 잘 걸리지 않을까요? Waarom krijgen grote dieren niet meer kanker? Porque é que os animais de grande porte não têm mais cancro? Почему крупные животные не болеют раком? Neden Büyük Hayvanlar Daha Fazla Kansere Yakalanmıyor? Чому великі тварини рідше хворіють на рак? 为什么大型动物不会患更多癌症？ 為什麼大型動物不會罹患更多癌症？

- Animals come in all shapes and sizes, |appear|||forms||varieties - 动物有各种形状和大小，

but every complex multicellular creature |||many-celled| mas todas as criaturas multicelulares complexas 但每一个复杂的多细胞生物

has one thing in common,

it started life as one cell. زندگی را به عنوان یک سلول آغاز کرد. começou a vida como uma célula. 它的生命始于一个细胞。

That cell and all of the cells that it spawns, |cell||||||||spawns |||||||||виводить آن سلول و تمام سلول هایی که تولید می کند، Essa célula e todas as células que ela gera, 该细胞和它产生的所有细胞，

copy themselves, divide and transform, replicate|||| copiam-se, dividem-se e transformam-se,

again, and again, and again,

to build specialized complex bodies, para construir corpos complexos especializados, 建立专门的复杂机构，

containing anywhere from millions of cells contendo desde milhões de células

to more than a thousand trillion individual living units. إلى|||||||| 超过一千万亿个个人居住单位。

A body like yours contains around 37 trillion cells. ||||||تريليون|

To build a human, factoring in the huge number of cells |||biological organism|Considering|||||| ||||факторинг||||||

that die and are lost along the way,

scientists estimate it takes 10 to the 16th cell visions.

During your lifetime, that's 10 million billion times, ||your lifetime||||

that the machinery of the cell and its DNA instructions

will be copied.

Which is a lot of chances to make mistakes.

Every cell division carries a risk

of creating errors and mutations.

Most of these are harmless.

But a few rare mutations can destroy

the genetic programs or break down the machinery

that control a cell's life and death, |||клітини|||

giving it the power to divide uncontrollably.

We call this cancer.

So logically speaking, the larger an animal is Therefore||||bigger|||

and the longer that it lives,

it should be more likely to get cancer.

In fact, because humans are living longer and longer,

the odds of developing cancer at some point in your lifetime ||||||||||entire life span

are about 20%.

And it's been found

that for every 10 centimeters taller a person is,

their risk of developing cancer goes up by 10%.

(somber music) похмура музика|

When you consider all of this the obvious conclusion

is biologically and mathematically speaking,

giant long-lived animals like elephants 大象等巨型长寿动物

should have all the cancer. (chuckles) 应该得了所有的癌症。 （笑声）

So should blue whales. |||blue whales

And hippos. 还有河马。

And giraffes.

And rhinoceroses. |носороги

And megalodon. |мегалодон

(gentle music) ніжна|

Hey smart people, Joe here.

Let's run some quick numbers.

The average human weighs about 70 kilograms

and has approximately 37 trillion cells in their body.

An elephant that weighs 5,000 kilograms.

Well that's 70 times more cells than a human has.

A blue whale, the largest thing to live on earth ever,

weighs about 150,000 kilograms.

Which means it has over 2000 times as many cells as a human.

About 79 million billion cells, which is nuts.

A giant animal means more cells.

More cells equals more cell divisions. ||дорівнює|||

And more cell divisions means more chances of mutations

that could let a cell become cancerous.

So an elephant should have like,

70 times higher odds of cancer than you or me.

And for a blue whale then,

it should be like 2000 times higher.

I think that math works out.

Well, logic says that giant animals

should get tons of cancer.

But the weird thing is they just don't.

This puzzle is known as Peto's paradox, |||||Пето|

because scientists love alliteration. |||alliteration |||алітерація

And because it's named after a scientist

named Richard Peto. ||Пето

Peto noticed that even though mice |||||миші

have a thousand times fewer cells than human,

and have lifespans 30 times shorter, ||тривалість життя||

both species get cancer at about the same rate.

And as scientists have looked across the animal kingdom,

body size, lifespan, and cancer rates 体型、寿命和癌症发生率

just don't seem to be associated 只是似乎没有关联

like you'd predict from numbers alone. 就像您仅根据数字进行预测一样。

So what is protecting 那么什么是保护

the animal kingdom's utmost examples of enormity and old age ||||||enormity||| |||максимальні|||величезність||| 动物王国中最伟大和年老的例子

from an unfortunate end, thanks to oncological illness? ||||||онкологічний|хвороба 由于肿瘤疾病而导致不幸的结局？

Was that too much?

Why big thing not get cancer?

It's possible

that large animals have evolved better mechanisms

for catching and correcting mutations

before they get too dangerous.

Now for a cell to go down the pathway to cancer,

it usually requires more than one mutation 它通常需要多个突变

in more than one type of cancer causing gene. 存在于不止一种类型的致癌基因中。

There are so called oncogenic or tumor producing genes. ||||онкогенні||||

Now, when these are mutated and broken,

they're basically always on and they're telling the cell

to keep dividing uncontrollably.

But they are all also genes

whose job it is to keep cells from doing that.

The so-called tumor suppressor genes. ||||супресор|

Tumor suppressor genes work

by acting as a kind of roadblock,

keeping cell division from moving forward.

Or as signals to self destruct the cell, if things go wrong.

Now, interestingly,

when scientists looked at the genome of elephants,

for one particular tumor suppressor gene,

they had 20 copies of it, and we have just one copy of it.

This means that an elephant's ||||слона

tumor preventing security system

has like 20 layer redundancy.

Larger animals also have slower metabolic rates

than smaller animals.

So smaller animals create more DNA damaging byproducts

which means larger animals may get fewer mutations per cell.

Now, of course,

no one's out there putting blue whales in CAT scans.

So it could be that some large animals

actually do get cancer,

but it just doesn't kill them, so we don't notice it.

And this is where giant size could be a lifesaver.

You can imagine that in an animal to size of a bus,

a tumor needs to be pretty gigantic

to actually impact the animal's health.

But hungry cancer cells

also compete viciously with each other for resources. ||жорстоко|||||

So the larger that a tumor gets,

smaller hyper tumors may act as kind of parasites

on the original tumor and starve it

so that it can't grow large enough to be deadly.

Cancer is probably as ancient as multicellular life.

I mean, as soon as an organism evolves

to have multiple specialized cells working together

for the good of the whole,

there's serious evolutionary pressure

to make sure that one cell doesn't mutate

and try to out-compete all the rest.

Especially at the expense of killing the whole organism.

So, any animal that evolved to be giant,

also had to evolve stronger defenses against cancer

or else it probably didn't survive.

Basically, if your species gets big and lives a long time,

that means you figured out a way not to be a walking tumor.

The paradox actually makes a lot of sense

when you put it that way.

But what scientists hope

is that by studying how these giant animals

don't die of cancer, maybe we can learn some new tricks

for fighting cancer in our own species.

Because part of the paradox

may just be that cancer rates in humans are shockingly high.

And this may have something to do

with our modern diet and lifestyle.

The scientists have found across the animal kingdom,

cancer mortality is tightly linked to what an animal eats.

With mammals that eat other mammals

facing the highest rates of cancer death.

Now cancer isn't new in humans.

A handful of ancient mummies ||||мумії

have been diagnosed with tumors.

But cancer rate in people are higher today than ever before.

In modern industrialized nations, ||індустріалізованих|

thanks to a combination of less physical activity

and diets that are loaded

with calories and sugar and salt and fat,

increased weight alone puts humans at risk

of at least 13 types of cancer.

And this lifestyle has spread around the world

with pretty sad results.

Within a couple of decades

of switching to a Western-type diet,

people living on Pacific and Indian ocean islands,

experienced a massive surge |||increase |||сплеск

in so-called diseases of civilization

like diabetes and cancer.

Another major factor is how much pollution

and cancer causing chemicals

we've put into the environment around us.

These environmental carcinogens, ||carcinogens ||канцерогени навколишнього середовища

they play a role in up to 75% of human cancers.

Even whales are not immune from this one.

The one place in the world

where whales get as much cancer as humans,

is Canada's Saint Lawrence river estuary. |Канади|святий|Лоренц||естуарій

Where agricultural and industrial pollutants

have accumulated for decades.

And of course, a few lifestyle habits

that can lead to cancer are uniquely human.

I mean, whales don't use tobacco products or drink alcohol. |||||тютюн||||алкогольні напої

That we know of.

It's pretty clear there's not one single answer

to Peto's paradox.

As usual, evolution has come up with many answers

to the cancer problem in large and long living animals.

Life as they say, finds a way.

Humans, well, we can't accelerate our own evolution

to become naturally cancer-free.

But we do have one unique advantage.

We can study evolution's answers

and figure out new ways to treat the cancers that we do get.

It wouldn't hurt to eat a little better too, I guess.

Maybe krill's the next cancer fighting super food. |крила||||||

Stay curious.

And just one more thing.

I know what you're thinking.

You're like, "How could I possibly support this show

more than like just watching their videos?"

Well, you could join our Patreon.

There's a link down in description

where you can learn more about our perks

and the various levels of support.

We literally could not do this

without all of our wonderful supporters.

Thank you.

And we'll see you in the next video.

Assuming you,

click the button.

You're gonna click it, right?

Go check it out.

Hmm?

Very large bison.

And polar bears.

Hmm? Okay?

What? Yeah. Mm-hmm.

Huh? You done yet.

Okay.

That's my, cries and tall person, face. ||плаче|||| Essa é a minha cara, de quem chora e de quem é alto.

Okay. One take (indistinct) |||indistinct Está bem. Um take (indistinto)