Ed Yong: Suicidal wasps, zombie roaches and other parasite tales

Prevodilac: Mile Živković Lektor: Ivana Korom

A herd of wildebeests, a shoal of fish,

Krdo zveri, jato riba,

a flock of birds.

jato ptica.

Many animals gather in large groups

Dosta životinja se skuplja u velike grupe

that are among the most wonderful spectacles

koje su među najlepšim spektaklima

in the natural world.

u svetu prirode.

But why do these groups form?

Ali zašto se formiraju ove grupe?

The common answers include things like

Česti odgovori su oni poput

seeking safety in numbers or hunting in packs

traženja bezbednosti u grupi ili lova u čoporima

or gathering to mate or breed,

ili skupljanja radi razmnožavanja,

and all of these explanations,

i sva ova objašnjenja,

while often true,

iako su često tačna,

make a huge assumption about animal behavior,

prave puno pretpostavki o ponašanju životinja,

that the animals are in control of their own actions,

da životinje kontrolišu svoje radnje,

that they are in charge of their bodies.

da kontrolišu svoje telo.

And that is often not the case.

To često nije istina.

This is Artemia, a brine shrimp.

Ovo je artemija, vrsta škampi.

You probably know it better as a sea monkey.

Verovatno su vam poznatije kao morski majmuni.

It's small, and it typically lives alone,

Male su i obično žive same,

but it can gather in these large red swarms

ali mogu da se skupljaju u velika crvena jata

that span for meters,

koja idu metrima u širinu,

and these form because of a parasite.

a stvaraju se zbog parazita.

These shrimp are infected with a tapeworm.

Ove škampe napada pantljičara.

A tapeworm is effectively a long, living gut

Pantljičara je dugo, živo crevo

with genitals at one end and a hooked mouth at the other.

sa genitaljama na jednoj i kukastim ustima na drugoj strani.

As a freelance journalist, I sympathize.

Kao honorarni novinar, imam saosećanja.

(Laughter)

(Smeh)

The tapeworm drains nutrients from Artemia's body,

Pantljičara izvlači hranljive sastojke iz tela artemije

but it also does other things.

ali radi i druge stvari.

It castrates them,

Kastrira ih,

it changes their color from transparent to bright red,

menja njihovu boju iz providne u jarko crvenu,

it makes them live longer,

čini da žive duže,

and as biologist Nicolas Rode has found,

i kako je otkrio biolog Nikolas Roud,

it makes them swim in groups.

čini da plivaju u grupama.

Why? Because the tapeworm, like many other parasites,

Zašto? Zato što pantljičara, poput mnogih drugih parazita,

has a complicated life cycle

ima komplikovan životni ciklus

involving many different hosts.

gde postoji dosta različitih domaćina.

The shrimp are just one step on its journey.

Škampi su samo jedan deo puta.

Its ultimate destination is this,

Krajnje odredište je ovo,

the greater flamingo.

ružičasti flamingo.

Only in a flamingo can the tapeworm reproduce,

Pantljičara može da se razmnožava samo u flamingu,

so to get there, it manipulates its shrimp hosts

tako da bi do njega došla, manipuliše domaćinima škampima

into forming these conspicuous colored swarms

da stvore ova upadljiva crvena jata

that are easier for a flamingo to spot

koja će flamingo lakše primetiti

and to devour,

i pojesti,

and that is the secret of the Artemia swarm.

i to je tajna jata artemija.

They aren't sociable through their own volition,

Nisu društvene svojom voljom,

but because they are being controlled.

već zato što ih neko kontroliše.

It's not safety in numbers.

Ne radi se o bezbednosti u grupi.

It's actually the exact opposite.

Zapravo je sasvim suprotno.

The tapeworm hijacks their brains and their bodies,

Pantljičara zaposeda njihove mozgove i tela,

turning them into vehicles

pretvarajući ih u sredstvo

for getting itself into a flamingo.

za dolazak do flaminga.

And here is another example

Evo još jednog primera

of a parasitic manipulation.

manipulacije parazita.

This is a suicidal cricket.

Ovo je cvrčak samoubica.

This cricket swallowed the larvae of a Gordian worm,

Cvrčak je progutao larve gordijevog crva,

or horsehair worm.

ili crva konjske dlake.

The worm grew to adult size within it,

Crv unutar njega raste do odrasle veličine

but it needs to get into water in order to mate,

ali mora da dođe do vode kako bi se razmnožavao,

and it does that by releasing proteins

i to radi tako što oslobađa proteine

that addle the cricket's brain,

koji zbunjuju mozak cvrčka

causing it to behave erratically.

zbog čega se ponaša pomahnitalo.

When the cricket nears a body of water,

Kada se cvrčak približi vodi,

such as this swimming pool,

poput bazena,

it jumps in and drowns,

uskače i davi se,

and the worm wriggles out

a crv se izmigolji

of its suicidal corpse.

iz tela koje je izvršilo samoubistvo.

Crickets are really roomy. Who knew?

Cvrčci su baš prostrani. Ko bi rekao?

The tapeworm and the Gordian worm are not alone.

Pantljičara i gordijev crv nisu sami.

They are part of an entire cavalcade

Deo su čitave armije

of mind-controlling parasites,

parazita koji kontrolišu um,

of fungi, viruses, and worms and insects and more

gljiva, virusa, crva, insekata i ostalog

that all specialize in subverting and overriding

koji se svi usavršavaju u podrivanju i zaobilaženju

the wills of their hosts.

volje svojih domaćina.

Now, I first learned about this way of life

Prvi put sam saznao za ovaj način života

through David Attenborough's "Trials of Life"

kroz "Procese života" Dejvida Atenboroa

about 20 years ago,

pre oko 20 godina,

and then later through a wonderful book called

a kasnije i kroz divnu knjigu koja se zove

"Parasite Rex" by my friend Carl Zimmer.

"Parazit Reks" mog prijatelja Karla Cimera.

And I've been writing about these creatures ever since.

Od tada pišem o ovim stvorenjima.

Few topics in biology enthrall me more.

Ima malo tema u biologiji koje me više uzbuđuju.

It's like the parasites have subverted my own brain.

Kao da su paraziti omamili moj mozak.

Because after all, they are always compelling

Ipak su uvek ubedljivi

and they are delightfully macabre.

i predivno sablasni.

When you write about parasites,

Kada pišete o parazitima,

your lexicon swells with phrases like

vaš rečnik prepun je izraza poput

"devoured alive" and "bursts out of its body."

"živ proždran" i "iskače iz svog tela."

(Laughter)

(Smeh)

But there's more to it than that.

Ali tu postoji više od toga.

I'm a writer, and fellow writers in the audience

Pisac sam, a kolege pisci iz publike

will know that we love stories.

znaju da mi volimo priče.

Parasites invite us to resist the allure

Paraziti nas pozivaju da se odupremo mamcu

of obvious stories.

očiglednih priča.

Their world is one of plot twists

Njihov svet prepun je obrta

and unexpected explanations.

i neočekivanih objašnjenja.

Why, for example,

Zašto, na primer,

does this caterpillar

ova gusenica

start violently thrashing about

počinje divlje da mlati

when another insect gets close to it

kada se drugi insekt približi

and those white cocoons that it seems

njoj i tim belim čaurama

to be standing guard over?

koje ona kao da brani?

Is it maybe protecting its siblings?

Da li možda štiti braću i sestre?

No.

Ne.

This caterpillar was attacked

Gusenicu je napala

by a parasitic wasp which laid eggs inside it.

osa parazit koja je snela jaja unutar nje.

The eggs hatched and the young wasps

Jaja su se izlegla i mlade ose

devoured the caterpillar alive

su proždrale gusenicu dok je živa

before bursting out of its body.

pre nego što joj izlete iz tela.

See what I mean?

Vidite o čemu pričam?

Now, the caterpillar didn't die.

Gusenica nije uginula.

Some of the wasps seemed to stay behind

Neke ose kao da zaostaju

and controlled it into defending their siblings

i kontrolišu je da brani njihovu braću i sestre

which are metamorphosing

koje se pretvaraju

into adults within those cocoons.

u odrasle jedinke u tim čaurama.

This caterpillar is a head-banging zombie bodyguard

Ova gusenica je zombi čuvar koji mlati glavom

defending the offspring

i brani potomstvo

of the creature that killed it.

stvorenja koje ju je ubilo.

(Applause)

(Aplauz)

We have a lot to get through. I only have 13 minutes. (Laughter)

Imamo dosta toga da pređemo. Imam samo 13 minuta. (Smeh)

Now, some of you are probably just

Neki od vas verovatno

desperately clawing for some solace

očajnički traže neku utehu

in the idea that these things are oddities

u ideji da su ove stvari neobičnosti

of the natural world, that they are outliers,

prirodnog sveta, da su pojedinačne

and that point of view is understandable,

i to gledište je veoma razumljivo,

because by their nature, parasites are quite small

jer su paraziti po prirodi veoma mali

and they spend a lot of their time

i veliki deo vremena provode

inside the bodies of other things.

unutar tela drugih organizama.

They're easy to overlook,

Lako je prevideti ih,

but that doesn't mean that they aren't important.

ali to ne znači da nisu bitni.

A few years back, a man called Kevin Lafferty

Pre nekoliko godina, čovek zvani Kevin Laferti

took a group of scientists into three Californian estuaries

poveo je grupu naučnika u tri estuara u Kaliforniji

and they pretty much weighed and dissected

i u principu su merili i disecirali

and recorded everything they could find,

i snimali sve što su našli

and what they found

i otkrili su

were parasites in extreme abundance.

ogromne količine parazita.

Especially common were trematodes,

Naročito prisutni su bili metilji,

tiny worms that specialize in castrating their hosts

crvi koji se specijalizuju za kastriranje svojih domaćina,

like this unfortunate snail.

poput ovog nesrećnog puža.

Now, a single trematode is tiny, microscopic,

Jedan metilj je sićušan, mikroskopske veličine

but collectively they weighed as much

ali zajedno imaju težinu

as all the fish in the estuaries

koliko i sve ribe u estuarima

and three to nine times more than all the birds.

i tri do devet puta više od svih ptica.

And remember the Gordian worm that I showed you,

Sećate li se gordijevog crva kojeg sam vam pokazao,

the cricket thing?

sa cvrčkom?

One Japanese scientist called Takuya Sato

Jedan japanski naučnik, Takuja Soto,

found that in one stream,

otkrio je da u jednom potoku

these things drive so many crickets

ove stvari vode toliko cvrčaka

and grasshoppers into the water

i skakavaca u vodu

that the drowned insects

da udavljeni insekti

make up some 60 percent of the diet of local trout.

čine oko 60% ishrane lokalne pastrmke.

Manipulation is not an oddity.

Manipulacija nije poseban slučaj.

It is a critical and common part

To ključni i čest deo

of the world around us,

sveta oko nas,

and scientists have now found

i naučnici su sada otkrili

hundreds of examples of such manipulators,

stotine primera takvih manipulatora,

and more excitingly, they're starting to understand

i što je zanimljivije, počinju da razumevaju

exactly how these creatures control their hosts.

tačno kako ova stvorenja kontrolišu svoje domaćine.

And this is one of my favorite examples.

Ovo je jedan od mojih omiljenih primera.

This is Ampulex compressa,

Ovo je Ampulex compressa,

the emerald cockroach wasp,

smaragdna osa,

and it is a truth universally acknowledged

i generalno se priznaje

that an emerald cockroach wasp in possession

da kada smaragdna osa poseduje

of some fertilized eggs

neka oplođena jaja,

must be in want of a cockroach.

ona mora da traži bubašvabu.

When she finds one,

Kada je nađe,

she stabs it with a stinger

ubada je žaokom

that is also a sense organ.

koja je takođe čulni organ.

This discovery came out three weeks ago.

Ovo otkriće je nastalo pre tri nedelje.

She stabs it with a stinger that is a sense organ

Ubada je žaokom koja je čulni organ

equipped with small sensory bumps

sa malim malim čulnim izbočinama

that allow her to feel the distinctive texture

koje je joj omogućavaju da oseti posebnu teksturu

of a roach's brain.

mozga bubašvabe.

So like a person blindly rooting about in a bag,

Kao osoba koja naslepo opipava torbu,

she finds the brain, and she injects it with venom

nalazi mozak i u njega ubacuje otrov,

into two very specific clusters of neurons.

u posebna dva skupa neurona.

Israeli scientists Frederic Libersat and Ram Gal

Izraelski naučnici Frederik Libersat i Ram Gal

found that the venom is a very specific chemical weapon.

otkrili su da je otrov veoma posebno hemijsko oružje.

It doesn't kill the roach, nor does it sedate it.

Ne ubija bubašvabu, niti je omami.

The roach could walk away

Bubašvaba može da odšeta,

or fly or run if it chose to,

odleti ili otrči ako želi,

but it doesn't choose to,

ali ona to ne radi,

because the venom nixes its motivation to walk,

jer joj otrov uništava motivaciju da hoda,

and only that.

i samo to.

The wasp basically un-checks the escape-from-danger box

Osa zapravo isključuje sistem za bežanje od opasnosti

in the roach's operating system,

u operativnom sistemu bubašvabe,

allowing her to lead her helpless victim

što joj pomaže da bespomoćnu žrtvu

back to her lair by its antennae

odvede u svoje sklonište držeći je za antene

like a person walking a dog.

kao kada bi neko šetao psa.

And once there, she lays an egg on it,

Kada je tamo, ona položi jaja u nju,

egg hatches, devoured alive, bursts out of body,

jaja se izlegu, pojedu je živu, izleću iz tela,

yadda yadda yadda, you know the drill.

bla bla bla, znate već kako ide.

(Laughter) (Applause)

(Smeh) (Aplauz)

Now I would argue that, once stung,

Rekao bih da, kada je ubode osa,

the cockroach isn't a roach anymore.

bubašvaba nije više bubašvaba.

It's more of an extension of the wasp,

Više je produžetak ose,

just like the cricket was an extension of the Gordian worm.

kao što je cvrčak bio produžetak gordijevog crva.

These hosts won't get to survive or reproduce.

Ovi domaćini neće preživeti i neće se razmnožavati.

They have as much control over their own fates

Nad svojom sudbinom imaju kontrolu

as my car.

koliko i moj auto.

Once the parasites get in,

Kada paraziti uđu,

the hosts don't get a say.

domaćini se ništa ne pitaju.

Now humans, of course,

Ljudi su naravno,

are no stranger to manipulation.

takođe skloni manipulaciji.

We take drugs to shift the chemistries of our brains

Uzimamo lekove da promenimo hemijski sastav svojih mozgova

and to change our moods,

i da promenimo raspoloženje,

and what are arguments or advertising or big ideas

i šta su argumenti, reklame ili velike ideje

if not an attempt to influence someone else's mind?

ako ne pokušaj da se utiče na nečije mišljenje?

But our attempts at doing this

Ali naši pokušaji da radimo ovo

are crude and blundering compared

grubi su i prosti u poređenju

to the fine-grained specificity of the parasites.

sa istančanim pojedinostima parazita.

Don Draper only wishes he was as elegant

Don Drejper bi voleo da je elegantan

and precise as the emerald cockroach wasp.

i precizan kao smaragdna osa.

Now, I think this is part of what makes parasites

Mislim da je ovo deo onoga što parazite čini

so sinister and so compelling.

tako zlobnim i ubedljivim.

We place such a premium on our free will

Toliko cenimo našu slobodnu volju

and our independence

i nezavisnost

that the prospect of losing those qualities

da mogućnost da nam ih oduzmu

to forces unseen

neviđene sile,

informs many of our deepest societal fears.

budi neke od naših najdubljih društvenih strahova.

Orwellian dystopias and shadowy cabals

Orvelovske distopije i sumnjive spletke

and mind-controlling supervillains --

i zlikovci koji kontrolišu um -

these are tropes that fill our darkest fiction,

ovo su tropi koji ispunjavaju najtamnije delove naše mašte,

but in nature, they happen all the time.

ali se u prirodi stalno dešavaju.

Which leads me to an obvious

Što me dovodi do očiglednog

and disquieting question:

i uznemirujućeg pitanja:

Are there dark, sinister parasites

Ima li tamnih, zlobnih parazita

that are influencing our behavior

koji utiču na naše ponašanje

without us knowing about it,

a da mi to ne znamo,

besides the NSA?

pored NSA?

If there are any —

Ako postoje -

(Laughter) (Applause)

(Smeh) (Aplauz)

I've got a red dot on my forehead now, don't I?

Stoji mi crvena tačka na čelu, zar ne?

(Laughter)

(Smeh)

If there are any, this is a good candidate for them.

Ako postoje, ovo je dobar kandidat.

This is Toxoplasma gondii, or Toxo, for short,

Ovo je Toxoplasma gondii ili ukratko Tokso,

because the terrifying creature

jer zastrašujućem stvorenju

always deserves a cute nickname.

uvek pogoduje simpatičan nadimak.

Toxo infects mammals,

Tokso pogađa sisare,

a wide variety of mammals,

veliki broj sisara,

but it can only sexually reproduce in a cat.

ali seksualno može da se razmnožava samo u mačkama.

And scientists like Joanne Webster have shown that

Naučnici poput Džoen Vebster su pokazali da,

if Toxo gets into a rat or a mouse,

ako Tokso uđe u pacova ili miša,

it turns the rodent into a cat-seeking missile.

pretvara glodara u projektil koji traži mačku.

If the infected rat smells the delightful odor

Ako inficirani pacov namiriše predivnu aromu

of cat piss,

mačjeg urina,

it runs towards the source of the smell

on trči prema izvoru mirisa

rather than the more sensible direction of away.

umesto smislenijeg pravca koji podrazumeva bežanje.

The cat eats the rat. Toxo gets to have sex.

Mačka pojede pacova. Tokso ima seksualni odnos.

It's a classic tale of Eat, Prey, Love.

Klasična priča "Jedi, lovi, voli."

(Laughter) (Applause)

(Smeh) (Aplauz)

You're very charitable, generous people.

Vi ste veoma milosrdni i darežljivi ljudi.

Hi, Elizabeth, I loved your talk.

Zdravo Elizabet, jako mi se dopao tvoj govor.

How does the parasite control its host

Kako parazit kontroliše domaćina

in this way?

na ovaj način?

We don't really know.

Zaista ne znamo.

We know that Toxo releases an enzyme

Znamo da Tokso ispušta enzim

that makes dopamine, a substance involved

koji proizvodi dopamin, supstancu koja ima veze

in reward and motivation.

sa nagrađivanjem i motivacijom.

We know it targets certain parts of a rodent's brain,

Znamo da cilja na određene delove mozga glodara,

including those involved in sexual arousal.

uključujući i one za seksualno uzbuđenje.

But how those puzzle pieces fit together

Ali kako se ti delići slagalice uklapaju,

is not immediately clear.

nije sasvim jasno.

What is clear is that this thing

Jasno je da je ova stvar

is a single cell.

jedna ćelija.

This has no nervous system.

Nema nervni sistem.

It has no consciousness.

Nema svest.

It doesn't even have a body.

Čak nema ni telo.

But it's manipulating a mammal?

Ali manipuliše sisarom?

We are mammals.

Mi smo sisari.

We are more intelligent than a mere rat, to be sure,

Sigurno smo inteligentniji od pacova,

but our brains have the same basic structure,

ali naši mozgovi imaju istu osnovnu strukturu,

the same types of cells,

istu vrstu ćelija,

the same chemicals running through them,

iste hemikalije koje idu kroz njih,

and the same parasites.

i iste parazite.

Estimates vary a lot, but some figures suggest

Procene variraju, ali po nekim brojkama,

that one in three people around the world

jedna od tri osobe u svetu

have Toxo in their brains.

imaju Tokso u svojim mozgovima.

Now typically, this doesn't lead to any overt illness.

Ovo obično ne vodi ni do kakve bolesti.

The parasite holds up in a dormant state

Parazit stoji u uspavanom stanju

for a long period of time.

dug period vremena.

But there's some evidence that those people

Ali postoje neki dokazi da ti ljudi

who are carriers score slightly differently

koji nose parazite imaju pomalo drugačije rezultate

on personality questionnaires than other people,

na ispitivanjima ličnosti od drugih ljudi,

that they have a slightly higher risk of car accidents,

imaju neznatno veći rizik od saobraćajnih nesreća,

and there's some evidence that people with schizophrenia

i postoje neki dokazi da ljudi sa šizofrenijom

are more likely to be infected.

imaju veću sklonost da se zaraze.

Now, I think this evidence is still inconclusive,

Mislim da dokazi još uvek nisu jasni,

and even among Toxo researchers,

i čak među istraživačima Toksoa

opinion is divided as to whether the parasite

su podeljena mišljenja o tome da li parazit

is truly influencing our behavior.

zaista utiče na naše ponašanje.

But given the widespread nature of such manipulations,

Ali s obzirom na rasprostranjenost takvih manipulacija,

it would be completely implausible

bilo bi potpuno neverovatno

for humans to be the only species

da ljudi budu jedina vrsta

that weren't similarly affected.

koja nije slično pogođena.

And I think that this capacity to constantly

Mislim da ovaj kapacitet da stalno

subvert our way of thinking about the world

podrivaju način na koji mislimo o svetu

makes parasites amazing.

čini parazite izuzetnim.

They're constantly inviting us to look at the natural world sideways,

Stalno nas pozivaju da na prirodni svet gledamo sa strane,

and to ask if the behaviors we're seeing,

i da se pitamo da su li ponašanja koja vidimo

whether they're simple and obvious

jednostavna i očigledna

or baffling and puzzling,

ili zbunjujuća i zagonetna,

are not the results of individuals

da nisu posledica pojedinaca

acting through their own accord

koji se ponašaju po svom nahođenju

but because they are being bent

već ih nešto drugo

to the control of something else.

upravlja i kontroliše.

And while that idea may be disquieting,

Iako je ta ideja možda uznemirujuća,

and while parasites' habits may be very grisly,

i dok su navike parazita jezive,

I think that ability to surprise us

mislim da ih ta mogućnost da nas iznenade

makes them as wonderful and as charismatic

čini divnim i harizmatičnim

as any panda or butterfly or dolphin.

poput bilo kog pande, leptira ili delfina.

At the end of "On the Origin of Species,"

Na kraju "Porekla vrsta",

Charles Darwin writes about the grandeur of life,

Čarls Darvin piše o veličanstvenosti života,

and of endless forms most beautiful

i o beskrajnim oblicima, prelepim

and most wonderful,

i predivnim,

and I like to think he could easily have been talking

i mislim da je veoma lako mogao da priča

about a tapeworm that makes shrimp sociable

o pantljičari koja čini škampe društvenijim

or a wasp that takes cockroaches for walks.

ili osi koja šeta bubašvabe.

But perhaps, that's just a parasite talking.

Ali možda to samo priča parazit.

Thank you.

Hvala vam.

(Applause)

(Aplauz)