Jellyfish predate dinosaurs. How have they survived so long? - David Gruber

Meduze su starije od dinosaurusa. Kako su preživele ovoliko dugo? - Dejvid Gruber

Prevodilac: Sonja Simijonovic Lektor: Mile Živković

Some are longer than a blue whale.

Neke su duže i od plavog kita.

Others are barely larger than a grain of sand.

Druge su jedva veće od zrna peska.

One species unleashes one of the most deadly venoms on Earth.

Jedna vrsta oslobađa jedan od najsmrtonosnijih otrova na svetu.

Another holds a secret that's behind some of the greatest breakthroughs in biology.

Druga čuva tajnu koja se krije iza nekih od najvećih otkrića u biologiji.

They've inhabited the ocean for at least half a billion years,

Nastanjuju okean već petsto miliona godina,

and they're still flourishing as the sea changes around them.

i dalje cvetajući dok se more oko njih menja.

Jellyfish are soft-bodied sea creatures that aren't really fish.

Meduze su morska stvorenja mekog tela koja zapravo nisu ribe.

They're part of a diverse team of gelatinous zooplankton,

One su deo raznovrsnog tima želatinoznog zooplanktona,

zooplankton being animals that drift in the ocean.

pri čemu su zooplanktoni životinje koje plutaju u okeanu.

There are more than 1,000 species of jellyfish,

Postoji više od 1000 vrsta meduza,

and many others that are often mistaken for them.

i mnogo drugih koje se često greškom ubrajaju u njih.

A noted feature of jellyfish is a translucent bell

Poznata karakteristika meduza je prozirno zvono

made of a soft delicate material called mesoglea.

sačinjeno od mekog i nežnog materijala zvanog mezogleja.

Sandwiched between two layers of skin,

Smeštena između dva sloja kože,

the mesoglea is more than 95% water held together by protein fibers.

mezogleja je više od 95% sačinjena od vode koju na okupu drže proteinska vlakna.

The jellyfish can contract and relax their bells to propel themselves.

Meduze mogu zgrčiti i opustiti svoja zvona kako bi se kretale.

They don't have a brain or a spinal cord,

Nemaju ni mozak ni kičmenu moždinu,

but a neural net around the bell's inner margin

ali neuronska mreža oko unutrašnje ivice zvona

forms a rudimentary nervous system

formira rudimentarni nervni sistem

that can sense the ocean's currents and the touch of other animals.

koji može da oseti okeanske struje i dodir drugih životinja.

Jellyfish don't have typical digestive systems, either.

Meduze nemaju ni tipične probavne sisteme.

These gelatinous carnivores consume plankton and other small sea creatures

Ovi pihtijasti mesojedi uvlače plankton i druga mala morska stvorenja

through a hole in the underside of their bells.

kroz rupu na donjoj strani svojih zvona.

The nutrients are absorbed by an inner layer of cells

Hranljive materije upija unutrašnji sloj ćelija

with waste excreted back through their mouths.

a otpad se opet izlučuje kroz njihova usta.

But the jellyfish's relatively simple anatomy

Ali relativno jednostavna anatomija meduze

doesn't prevent it from having some remarkable abilities.

ne sprečava je da poseduje neke izvanredne sposobnosti.

One kind of box jellyfish has 24 eyes.

Jedna vrsta kubomeduze ima 24 oka.

Scientists think it can see color and form images within its simple nervous system.

Naučnici misle da vidi boju i formira slike unutar svog prostog nervnog sistema.

Four of its eyes are curved upward on stalks.

Četiri oka su joj zakrivljena ka gore na stabljikama.

This allows the jellyfish to peer through the surface of the water,

Ovo omogućava meduzi da proviri kroz površinu vode,

looking for the canopy of the mangrove trees where it feeds.

tražeći krošnje drveća mangrove među kojima se hrani.

In fact, this may be one of the only creatures

Zapravo, ovo bi moglo biti jedno od retkih stvorenja

with a 360-degree view of its environment.

sa vidokrugom od 360 stepeni.

The jellyfish's sting, which helps it capture prey and defend itself,

Meduzina žaoka, koja joj pomaže u lovu i odbrani,

is its most infamous calling card.

njeno je najozloglašenije obeležje.

In the jelly's epidermis,

U epidermisu meduze,

cells called nematocysts lie coiled like poisonous harpoons.

ćelije zvane nematociste leže uvijene kao otrovni harpuni.

When they're triggered by contact, they shoot with an explosive force.

Kada dođe do dodira, ispaljuju se eksplozivnom silom.

It exerts over 550 times the pressure of Mike Tyson's strongest punch

Ona stvara više od 550 puta veći pritisak od najjačeg udarca Majka Tajsona

to inject venom into the victim.

da bi ubrizgala otrov u žrtvu.

Some jellyfish stings barely tingle,

Ubodi nekih meduza jedva da golicaju,

but others cause severe skin damage.

dok drugi izazivaju ozbiljno oštećenje kože.

The venom of one box jellyfish can kill a human in under five minutes,

Otrov jedne kubomeduze može da ubije čoveka za manje od pet minuta,

making it one of the most potent poisons of any animal in the world.

što ovaj otrov čini jednim od najmoćnijih životinjskih otrova na svetu.

Other jellyfish superpowers are less lethal.

Druge supermoći meduza su manje smrtonosne.

One species of jellyfish glows green when it's agitated,

Jedna vrsta meduze sija zeleno kada je iritirana

mostly thanks to a biofluorescent compound called green fluorescent protein,

zahvaljujući biofluorescentnom jedinjenju, zelenom fluorescentnom proteinu,

or GFP.

ili ZFP-u.

Scientists isolated the gene for GFP

Naučnici su izolovali gen za ZFP

and figured out how to insert it into the DNA of other cells.

i pronašli način da ga ubace u DNK drugih ćelija.

There, it acts like a biochemical beacon,

Tamo služi kao biohemijski svetionik,

marking genetic modifications,

praveći genetske modifikacije

or revealing the path of critical molecules.

ili otkrivajući putanje bitnih molekula.

Scientists have used the glow of GFP to watch cancer cells proliferate,

Naučnici su koristili sjaj ZFP-a da prate razmnožavanje ćelija raka,

track the development of Alzheimer's,

posmatraju razvoj Alchajmerove bolesti,

and illuminate countless other biological processes.

i razjasne brojne druge biološke procese.

Developing the tools and techniques from GFP

Razvoj alata i tehnika vezanih za ZFP

has netted three scientists a Nobel Prize in 2008,

doneo je Nobelovu nagradu 2008. za trojicu naučnika,

and another three in 2014.

a 2014. za još trojicu.

But it's jellyfish who may be the most successful organisms on Earth.

Ali meduze su te koje bi mogle biti najuspešniji organizmi na svetu.

Ancient fossils prove that jellyfish have inhabited the seas

Drevni fosili dokazuju da meduze nastanjuju mora

for at least 500 million years,

barem poslednjih 500 miliona godina,

and maybe go back over 700 million.

a možda su postojale i pre 700 miliona godina.

That's longer than any other multiorgan animal.

To je duže od bilo koje višeorganske životinje.

And as other marine animals are struggling to survive

Dok se druge morske životinje bore za opstanak

in warmer and more acidic oceans,

u toplijim i kiselijim okeanima,

the jellyfish are thriving,

meduze cvetaju,

and perhaps getting even more numerous.

a broj im se čak možda i povećava.

It doesn't hurt that some can lay as many as 45,000 eggs in a single night.

Ne škodi ni to što neke mogu položiti i do 45 hiljada jaja u toku jedne noći.

And there's some jellyfish whose survival strategy

Postoje i meduze čija strategija za preživljavanje

almost sounds like science fiction.

zvuči skoro kao naučna fantastika.

When the immortal jellyfish is sick, aging, or under stress,

Kada je besmrtna meduza bolesna, stara ili pod stresom,

its struggling cells can change their identity.

njene ćelije mogu promeniti svoj identitet.

The tiny bell and tentacles deteriorate

Maleno zvono i pipci propadaju

and turn into an immature polyp

i pretvaraju se u nezreli polip

that spawns brand new clones of the parent.

koji stvara nove klonove roditelja.

As far as we know, these are the only animals who found a loophole

Koliko znamo, ovo su jedine životinje koje su našle "rupu"

when facing mortality.

u zakonu smrtnosti.

That's pretty sophisticated for species that are 95% water

To je poprilično napredno za vrstu koju sačinjava 95% vode

and predate the dinosaurs.

i koja je starija od dinosaurusa.