Why Is Our Skeleton On the Inside? Warum ist unser Skelett auf der Innenseite? Why Is Our Skeleton On the Inside? ¿Por qué nuestro esqueleto está en el interior? Pourquoi notre squelette est-il à l'intérieur ? Perché il nostro scheletro è all'interno? なぜ骨格は内側にあるのか？ 골격이 안쪽에 있는 이유는 무엇인가요? Kodėl mūsų skeletas yra viduje? Waarom zit ons skelet aan de binnenkant? Porque é que o nosso esqueleto está do lado de dentro? Почему наш скелет находится внутри? İskeletimiz Neden İçeride? 为什么我们的骨骼在里面？ 為什麼我們的骨骼在裡面？

Game of Thrones star Hafthor “The Mountain” Bjornsson recently broke the deadlift world La estrella de Juego de Tronos Hafthor "La Montaña" Bjornsson ha roto recientemente el récord mundial de peso muerto. ゲーム・オブ・スローンズのスター、ハフソー「ザ・マウンテン」ビョルンソンは最近、デッドリフトの世界を壊しました Game of Thrones-ster Hafthor "The Mountain" Bjornsson brak onlangs de deadlift-wereld

record with a 501 kilogram lift… which is absolutely, completely bonkers, but if he récord con un levantamiento de 501 kilogramos... que es absolutamente, completamente loco, pero si él

had the lifting power of a leafcutter ant, he'd be able to lift a medium sized sedan

completely over his head, and carry it home.

Not bad.

And if The Mountain had the same relative strength as the taurus scarab dung beetle, Y si La Montaña tuviera la misma fuerza relativa que el escarabajo pelotero taurus, En als The Mountain dezelfde relatieve kracht had als de taurus scarabee mestkever, І якби Гора мала таку ж відносну силу, як і гнойовий жук-скарабей таурус,

he could pull a fully loaded Boeing 787 Dreamliner. podría arrastrar un Boeing 787 Dreamliner completamente cargado.

Compared to us, ants and dung beetles and nature's other miniature weightlifters are Compared to us, ants and dung beetles and nature's other miniature weightlifters are У порівнянні з нами, мурахи, гнойові жуки та інші мініатюрні важкоатлети природи

special because they pull off their amazing feats of strength without bones. speciaal omdat ze hun verbazingwekkende krachtsinspanningen zonder botten afleveren.

And it turns out, for every species with an internal skeleton like ours, Earth is home

to around 20 species without one – and maybe more. до приблизно 20 видів без нього - а може, й більше.

And that got me thinking, why did we end up with our skeletons on the inside instead of І це змусило мене замислитися, чому ми опинилися зі своїми скелетами всередині замість того, щоб

the outside?

[OPEN]

Hey smart people, Joe here.

It's time to face the truth. Het is tijd om de waarheid onder ogen te zien.

You're just meat, in a sack, tied to a bunch of carefully organized rocks. No eres más que carne, en un saco, atada a un montón de rocas cuidadosamente organizadas. Ти просто м'ясо в мішку, прив'язане до купи ретельно організованого каміння.

That is basically what it means to be a vertebrate.

And we owe everything we are and that we do to our bones.

Skeletons are rigid enough for this, and flexible enough for this.

It's said that we're built with 206 bones, but 1 in 8 of us have an extra pair of ribs,

some people can even have a pair less.

And that doesn't count sesamoids in tendons in our hands, feet, and elsewhere. Y eso sin contar los sesamoideos de los tendones de nuestras manos, pies y otros lugares. En dat geldt niet voor sesamoïden in pezen in onze handen, voeten en elders.

And speaking of feet, you have 52 bones in your feet alone, twice as many as in your

spine.

Our hands and feet have more than half the bones in our bodies.

Consider that rocks in your fingers were moved by muscles and nerves to help you click this Considera que las piedras de tus dedos fueron movidas por músculos y nervios para ayudarte a pulsar este

video.

The oxygen powering the brain that is watching this is being fed by blood made in your bones. El oxígeno que alimenta el cerebro que está viendo esto está siendo alimentado por la sangre fabricada en sus huesos.

You are only even able to hear me talking thanks to tiny bones in your ears.

All of this from body parts that are about 70% mineral, made of an inorganic material Todo esto a partir de partes del cuerpo que son aproximadamente 70% minerales, hechas de un material inorgánico

called hydroxyapatite that is stiff when compressed, combined with flexible protein called collagen genaamd hydroxyapatiet dat stijf is wanneer het wordt samengedrukt, gecombineerd met flexibel eiwit dat collageen wordt genoemd

to keep you from shattering. para evitar que te hagas añicos.

As a result the 20 or so pounds of bones in the average body can withstand one ton of

compression.

And for most of us, they are the last thing we'll leave behind.

Bones are pretty awesome.

And also oss-ome. А також ос-ом.

That's the Latin root for “bone”…

ANYWAY…

Where did bones come from?

That story goes back at least 1.5 billion years.

Which is a weird place to start because animals… didn't even exist yet.

But at that moment, violently shifting tectonic plates were washing tons of minerals into Pero en ese momento, el violento desplazamiento de las placas tectónicas estaba arrastrando toneladas de minerales hacia el interior de la Tierra.

ancient oceans.

The minerals that would one day become skeletons.

Life stayed pretty squishy for a while. La vida siguió siendo bastante blanda durante un tiempo.

Early multicellular life depended on the water in which it lived to support their skeleton-less La vida multicelular primitiva dependía del agua en la que vivía para mantener su esqueleto.

bodies.

But then, around 558 million years ago, through a happy accident of evolution, life split

in two, and two different skeleton stories began.

On one branch, strange creatures began to develop the first hard protective parts, the

precursors of exoskeletons.

And this set off an arms race of armor. Y esto desencadenó una carrera armamentística de blindajes.

Newly shielded organisms might have gotten eaten less, maybe they were better protected Los nuevos organismos protegidos podrían haber sido comidos menos, tal vez estaban mejor protegidos

from the ocean, but partially hard creatures survived more than their squishy friends, del océano, pero las criaturas parcialmente duras sobrevivieron más que sus blandas amigas,

and like I always say, that's what matters in the game of natural selection.

Early exoskeletons got fancier and we began to see animals with crushing mouthparts, pinchers, Los primeros exoesqueletos se hicieron más sofisticados y empezamos a ver animales con piezas bucales aplastantes, pinzas,

and full suits of armor. en volledige harnassen.

It was during this period that we see the earliest arthropods, the group that includes

modern insects and crustaceans.

But on that other branch, in squishy tadpole-like creatures, something else was happening. Pero en esa otra rama, en criaturas blandas parecidas a renacuajos, ocurría otra cosa. Maar op die andere tak, in squishy kikkervisjesachtige wezens, gebeurde iets anders.

Soft cartilage-like back rods began to form in order to provide scaffolding for muscles Comenzaron a formarse varillas posteriores blandas similares a cartílagos para proporcionar andamiaje a los músculos Почали формуватися м'які хрящоподібні спинні стрижні, які слугували риштуванням для м'язів

and movement.

And on the outside, some of these fishy creatures evolved a cement-like armor. Y en el exterior, algunas de estas criaturas piscícolas desarrollaron una armadura parecida al cemento.

This was the precursor of bone, and soon, this hard stuff formed the basis for new structures Era el precursor del hueso, y pronto, este material duro formó la base de nuevas estructuras

like jaws.

Very big jaws.

Later, this mineral armor was slowly internalized, and those early backbones became mineralized, Later werd dit minerale pantser langzaam geïnternaliseerd, en die vroege ruggengraat werd gemineraliseerd.

and together these became the key parts of the vertebrate skeleton as we know it.

Over the eons, nature has stumbled on many different ways of desquishifying organisms. A lo largo de los siglos, la naturaleza ha encontrado muchas formas diferentes de destruir organismos.

There's the lignin and cellulose of plants, calcium-rich shells of mollusks and coral Er is de lignine en cellulose van planten, calciumrijke schelpen van weekdieren en koraal

reefs, and mineral bones like ours.

But insects and crustaceans build exoskeletons made from chains of modified sugars called

chitin. chitine.

Chitin is molecularly similar to the cellulose we find in plants, but it's harder and more

stable.

If you were to zoom into a lobster's shell on the microscopic scale you'd see chitin

crystals arranged like stacks of plywood. cristales dispuestos como pilas de contrachapado.

These special nanostructure arrangements make chitin exoskeletons incredibly tough for their

weight.

And that's why insects are so strong pound for pound… or gram for gram. Y por eso los insectos son tan fuertes libra a libra... o gramo a gramo.

So if exoskeletons are so strong, why don't we have them?

Like most things in nature, there are tradeoffs.

For starters, opting for an armored exterior skeleton makes growing more difficult. Para empezar, optar por un esqueleto exterior blindado dificulta el crecimiento.

Every time a lobster or a cockroach is ready to size up, they have to molt, shedding their

old skeleton and leaving them soft and vulnerable for days or weeks while they wait for a new

outer shell to harden. cáscara exterior se endurezca.

There's also a weight problem.

The strength of ants' legs work at their miniscule mass, but scale that ant up to our

size and it would be crushed under its own weight.

And a few more leg days won't cut it. Y unos días más de piernas no bastarán.

Because as a creature gets bigger, its volume and mass increase faster than the tubular

strength of its hollow exoskeleton legs. fuerza de sus patas de exoesqueleto hueco.

On the other hand, or leg, our internal skeletons provide bigger attachments for muscles than Por otro lado, o pierna, nuestros esqueletos internos proporcionan mayores fijaciones para los músculos que

exoskeletons would, and our bones grow with our muscles as we get bigger and stronger.

But there's also a tradeoff here.

Bulkier vertebrates have to have more massive bones. Los vertebrados más voluminosos tienen que tener huesos más macizos.

An elephant is about 13% bone by weight, not super agile.

A shrew is 4%, and while it's quick, it's easy to squish.

Humans are about 8.5%, a compromise between strength and mobility, and if we had more Los humanos somos aproximadamente un 8,5%, un compromiso entre fuerza y movilidad, y si tuviéramos más

bone to be stronger then we wouldn't move as well.

Another problem is that a human-sized ant would suffocate. Otro problema es que una hormiga de tamaño humano se asfixiaría.

Insects don't really have blood.

They have very limited circulatory systems filled with a fluid called hemolymph, mostly Ze hebben een zeer beperkte bloedsomloop, meestal gevuld met een vloeistof die hemolymfe wordt genoemd

full of metabolic stuff and immune cells.

Insects breathe through tiny holes in their exoskeletons that deliver oxygen to their

tissues through a series of internal tubes.

The distance oxygen can travel down the tubes depends on its concentration in the air.

During prehistoric times, two-foot dragonflies did exist, because atmospheric oxygen levels Durante la prehistoria, existían libélulas de dos pies, porque los niveles de oxígeno atmosférico

were higher.

And plus, having all your muscles attached to your outside means that while you're

strong, you're not that flexible.

Yeah, let's see you do this, super strong grasshopper. Sí, veamos cómo lo haces, saltamontes súper fuerte.

So.

Chitin exoskeleton: super strong, but only if you're small.

A human-sized ant, very lethargic, very crumpled, can't do yoga. Una hormiga de tamaño humano, muy letárgica, muy arrugada, no puede hacer yoga.

Remember that split that we talked about earlier?

One branch led to bugs and exoskeletons, and the other branch eventually led to you and

me and every other vertebrate.

And what's crazy to think about it that we are this way because of luck, or chance.

Because when our ancestors began to build hard bodies, the only ingredients they had

to choose from were what nature provided.

Those shifting tectonic plates a billion and a half years ago?

Well, when slabs of rock that make up earth's crust rub together, all the minerals they're Pues bien, cuando las losas de roca que forman la corteza terrestre se rozan, todos los minerales que están Welnu, als rotsblokken waaruit de aardkorst bestaat, tegen elkaar wrijven, worden alle mineralen die ze vormen...

made of wash into the sea. hecho de lavar en el mar.

And one of those minerals, calcium carbonate, happens to be a very useful building material.

Evolution is a lot like a chef stuck at home during COVID quarantine, by which I mean, La evolución se parece mucho a un chef atrapado en casa durante la cuarentena de COVID, con lo que quiero decir,

you've gotta use whatever ingredients you've got around.

Our very distant relatives were bathed in calcium from those grinding tectonic plates, Nuestros parientes muy lejanos se bañaron en el calcio de esas placas tectónicas molientes,

and so they used this to build the earliest bone-like tissues.

The evolution of bone wasn't a grand aha! moment in the story of evolution, it is just

one of many such chance events, influenced by the environment, that sent one arm of life uno de los muchos sucesos fortuitos, influidos por el entorno, que enviaron un brazo de la vida

on earth on a completely new course. sobre la tierra en un rumbo completamente nuevo.

And vertebrates aren't the only ones who ended up building bodies out of calcium. Y los vertebrados no son los únicos que acabaron construyendo cuerpos de calcio.

Invertebrates from mollusks to coral to starfish all use calcium to build their bodies' support

structures.

Exoskeleton-having animals like insects and other arthropods just went another way, building Los animales con exoesqueleto, como los insectos y otros artrópodos, siguieron otro camino, construyendo

chitin exoskeletons, thanks to the chance events of evolution, and if we played the

story of back again from the beginning, perhaps our line would be built differently too.

Which means, as we know now, we'd be very small.

But at least we'd have armor.

And maybe some sweet pincers.

And even some horns.

But then… what would ants look like… Pero entonces... ¿cómo serían las hormigas...?

Stay curious