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

Prevoditelj: Ivan Stamenković Recezent: Senzos Osijek

A herd of wildebeests, a shoal of fish,

Stado divljih zvijeri, plova ribe

a flock of birds.

jato ptica.

Many animals gather in large groups

Mnoge životinje se okupljaju u velike skupine

that are among the most wonderful spectacles

koje su među najdivnijim prizorima

in the natural world.

u prirodnom svijetu.

But why do these groups form?

Ali zašto se ove grupe formiraju?

The common answers include things like

Uobičajeni odgovori uključuju stvari kao

seeking safety in numbers or hunting in packs

traženje sigurnosti u velikim brojkama ili lov u čoporu

or gathering to mate or breed,

ili skupljanje kako bi se parili ili razmnožavali

and all of these explanations,

i sva ova objašnjenja,

while often true,

iako su često točna,

make a huge assumption about animal behavior,

prave veliku pretpostavku vezanu uz ponašanje životinja,

that the animals are in control of their own actions,

da životinje imaju kontrolu nad vlastitim akcijama,

that they are in charge of their bodies.

da imaju kontrolu nad svojim tijelima.

And that is often not the case.

Što često nije slučaj.

This is Artemia, a brine shrimp.

Ovo je Artemia, mali škamp.

You probably know it better as a sea monkey.

Vjerojatno vam je poznatiji kao morski majmunčić.

It's small, and it typically lives alone,

Malen je, i uobičajeno živi sam,

but it can gather in these large red swarms

ali se može skupiti u ove velike crvene rojeve

that span for meters,

koji se prostiru metrima,

and these form because of a parasite.

te se oni formiraju zbog parazita.

These shrimp are infected with a tapeworm.

Ovi škampi zaraženi su trakavicom.

A tapeworm is effectively a long, living gut

Trakavica je zapravo dugo, živuće crijevo

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

sa genitalijama na jednom kraju i ustima s kukicama na drugom.

As a freelance journalist, I sympathize.

Kao novinar slobodnjak, suosjećam.

(Laughter)

(Smijeh)

The tapeworm drains nutrients from Artemia's body,

Trakavica uzima hranjive tvari iz Artemiina tijela,

but it also does other things.

ali također čini i druge stvari.

It castrates them,

Kastrira ih,

it changes their color from transparent to bright red,

mijenja im boju iz prozirne u žarko crvenu,

it makes them live longer,

tjera ih da dulje žive,

and as biologist Nicolas Rode has found,

i kako je biolog Nicolas Rode utvrdio,

it makes them swim in groups.

tjera ih da plivaju u grupi.

Why? Because the tapeworm, like many other parasites,

Zašto? Jer trakavica, kao i mnogi drugi paraziti

has a complicated life cycle

ima kompliciran životni ciklus

involving many different hosts.

koji uključuje puno različitih domaćina.

The shrimp are just one step on its journey.

Škampi su samo jedan korak na tom putovanju.

Its ultimate destination is this,

Njihovo krajnje odredište je ovo,

the greater flamingo.

veliki flamingo.

Only in a flamingo can the tapeworm reproduce,

Samo se u flamingu može razmnožavati trakavica,

so to get there, it manipulates its shrimp hosts

te kako bi došla tamo, manipulira svog škampa domaćina

into forming these conspicuous colored swarms

u formiranje ovih urotničkih obojenih rojeva

that are easier for a flamingo to spot

koji su lakši za uočavanje flamingu

and to devour,

kako bi ih pojeo,

and that is the secret of the Artemia swarm.

i to je tajna Artemia roja.

They aren't sociable through their own volition,

Nisu druželjubivi svojom voljom,

but because they are being controlled.

nego zato što ih kontroliraju.

It's not safety in numbers.

To nije sigurnost u brojkama.

It's actually the exact opposite.

To je čista suprotnost.

The tapeworm hijacks their brains and their bodies,

Trakavica otima njihove mozgove i tijela,

turning them into vehicles

pretvarajući ih u vozila

for getting itself into a flamingo.

kojima dolaze do flaminga.

And here is another example

I evo još jednog primjera

of a parasitic manipulation.

parazitske manipulacije.

This is a suicidal cricket.

Ovo je cvrčak samoubojica.

This cricket swallowed the larvae of a Gordian worm,

Ovaj cvrčak progutao je larvu Gordijskog crva,

or horsehair worm.

ili crva konjske dlake.

The worm grew to adult size within it,

Crv je narastao do svoje odrasle veličine u njemu,

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

ali treba doći u vodu kako bi se pario,

and it does that by releasing proteins

i to čini tako što ispušta proteine

that addle the cricket's brain,

koji utječu na cvrčkov mozak,

causing it to behave erratically.

uzrokujući neočekivano ponašanje.

When the cricket nears a body of water,

Kada se cvrčak približi vodi,

such as this swimming pool,

kao što je bazen,

it jumps in and drowns,

on uskoči i utopi se,

and the worm wriggles out

i crv izmigolji van

of its suicidal corpse.

iz svog suicidalnog leša.

Crickets are really roomy. Who knew?

Cvrčci su zaista prostrani. Tko bi rekao?

The tapeworm and the Gordian worm are not alone.

Trakavica i Gordijski crv nisu usamljeni.

They are part of an entire cavalcade

Oni su dio čitave kavalkade

of mind-controlling parasites,

parazita koji kontroliraju um,

of fungi, viruses, and worms and insects and more

gljivica, virusa, crva i insekata i drugih

that all specialize in subverting and overriding

koji se specijaliziraju u rušenju i premošćivanju

the wills of their hosts.

volje njihovih domaćina.

Now, I first learned about this way of life

Prvi puta sam saznao za ovakav način života

through David Attenborough's "Trials of Life"

kroz "Iskušenja života" Davida Attenborougha

about 20 years ago,

prije dvadesetak godina,

and then later through a wonderful book called

i onda kasnije kroz predivnu knjigu naziva

"Parasite Rex" by my friend Carl Zimmer.

"Parazit Rex" moga prijatelja Carl Zimmera.

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

I od tada pišem o ovim bićima.

Few topics in biology enthrall me more.

Malo tema u biologiji me više zaokuplja.

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

To je kao da su paraziti premostili moj vlastiti mozak.

Because after all, they are always compelling

Jer nakon svega oni su uvijek neodoljivi

and they are delightfully macabre.

i divno jezivi.

When you write about parasites,

Kada pišete o parazitima,

your lexicon swells with phrases like

vaš riječnik vrvi frazama kao što su

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

"živ pojeden" i "prsne iz svog tijela."

(Laughter)

(Smijeh)

But there's more to it than that.

Ali ima više u tome od navedenog.

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

Ja sam pisac, i ostali pisci u publici

will know that we love stories.

znaju da svi mi volimo priče.

Parasites invite us to resist the allure

Paraziti nas pozivaju da se odupremo privlačnosti

of obvious stories.

očitih priča.

Their world is one of plot twists

Njihov svijet je svijet pun zapleta radnje

and unexpected explanations.

i neočekivanih objašnjenja.

Why, for example,

Zašto, na primjer,

does this caterpillar

ova gusjenica

start violently thrashing about

započne s nasilnim bacakanjem

when another insect gets close to it

kada joj se približi drugi insekt

and those white cocoons that it seems

i bijelim ličinkama koje izgledaju

to be standing guard over?

kao da ih čuva?

Is it maybe protecting its siblings?

Štiti li možda svoju braću?

No.

Ne.

This caterpillar was attacked

Ova je gusjenica napadnuta

by a parasitic wasp which laid eggs inside it.

od strane parazitske ose koja je u nju položila jaja.

The eggs hatched and the young wasps

Jaja su se izlegla i mlade ose

devoured the caterpillar alive

proždrle su gusjenicu živu

before bursting out of its body.

prije nego su se probile van iz njenog tijela.

See what I mean?

Vidite što mislim?

Now, the caterpillar didn't die.

Sad, gusjenica nije umrla.

Some of the wasps seemed to stay behind

Neke od osa su očito ostale

and controlled it into defending their siblings

i kontrolirale ju da brani njihovu braću

which are metamorphosing

koja su prolazila kroz metamorfozu

into adults within those cocoons.

u odrasle jedinke u tim ličinkama.

This caterpillar is a head-banging zombie bodyguard

Ova gusjenica je zombi čuvar koji mlati glavom

defending the offspring

braneći potomke

of the creature that killed it.

bića koje ga je ubilo.

(Applause)

(Pljesak)

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

Imamo puno toga za proći. Imam samo 13 minuta. (Smijeh)

Now, some of you are probably just

Sad, neki od vas vjerojatno

desperately clawing for some solace

očajnički traže neku utjehu

in the idea that these things are oddities

u ideji da su ove stvari samo nepravilnosti

of the natural world, that they are outliers,

prirodnog svijeta, da su to rijetki slučajevi,

and that point of view is understandable,

i takav pogled je razumljiv,

because by their nature, parasites are quite small

jer po prirodi, paraziti su poprilično mali

and they spend a lot of their time

i provode puno svog vremena

inside the bodies of other things.

unutar tijela drugih stvari.

They're easy to overlook,

Lako ih je previdjeti,

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

ali to ne znači da nisu važni.

A few years back, a man called Kevin Lafferty

Prije nekoliko godina, čovjek imena Kevin Lafferty

took a group of scientists into three Californian estuaries

poveo je grupu znanstvenika na tri Kalifornijska estuarija

and they pretty much weighed and dissected

i vagali su, razrezali

and recorded everything they could find,

i zabilježili sve što su mogli naći,

and what they found

i ono što su pronašli

were parasites in extreme abundance.

bili su paraziti u ekstremno velikim brojkama,

Especially common were trematodes,

Naročito uobičajeni bili su trematodi,

tiny worms that specialize in castrating their hosts

maleni crvi koji se specijaliziraju za kastraciju svojih domaćina

like this unfortunate snail.

kao ovog nesretnog puža.

Now, a single trematode is tiny, microscopic,

Sad, jedna trematoda je minijaturna, mikroskopska,

but collectively they weighed as much

ali zajedno težile su

as all the fish in the estuaries

kao sve ribe u estuarijima

and three to nine times more than all the birds.

i od tri do devet puta više nego sve ptice.

And remember the Gordian worm that I showed you,

I sjećate se Gordijskog crva kojeg sam vam pokazao,

the cricket thing?

stvar sa cvrčkom?

One Japanese scientist called Takuya Sato

Jedan Japanski znanstvenik imena Takuya Saro

found that in one stream,

pronašao je da u jednom potoku,

these things drive so many crickets

ove stvari tjeraju toliko cvrčaka

and grasshoppers into the water

i skakavaca na utapanje u vodi

that the drowned insects

da utopljeni insekti

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

čine oko 60 posto ishrane lokalnih pastrva.

Manipulation is not an oddity.

Manipulacija nije nešto čudno.

It is a critical and common part

To je kritični i uobičajeni dio

of the world around us,

svijeta oko nas,

and scientists have now found

i znanstvenici su našli

hundreds of examples of such manipulators,

stotine primjera takve manipulacije,

and more excitingly, they're starting to understand

i što je još uzbudljivije, počinju razumjevati

exactly how these creatures control their hosts.

točno kako ova bića kontroliraju svoje domaćine.

And this is one of my favorite examples.

I ovo je jedan od meni najdražih primjera.

This is Ampulex compressa,

Ovo je Ampulex compressa,

the emerald cockroach wasp,

smaragdna žoharova osa,

and it is a truth universally acknowledged

i to je istina koja je univerzalno prihvaćena,

that an emerald cockroach wasp in possession

da osa u posjedu

of some fertilized eggs

oplođenih jaja

must be in want of a cockroach.

mora biti u potrazi za žoharom.

When she finds one,

Kada ga pronađe,

she stabs it with a stinger

ubode ga žalcem

that is also a sense organ.

koji je također i taktilni organ.

This discovery came out three weeks ago.

Ovo otkriće dogodilo se prije otprilike tri tjedna.

She stabs it with a stinger that is a sense organ

Ubode ga žalcem koji je taktilni organ

equipped with small sensory bumps

opremljen malenim senzorskim kvrgama

that allow her to feel the distinctive texture

koje joj dozvoljavaju da ispipa teksture

of a roach's brain.

žoharova mozga.

So like a person blindly rooting about in a bag,

Kao što osoba naslijepo kopa po torbi,

she finds the brain, and she injects it with venom

ona pronalazi mozak, i ubrizgava mu otrov

into two very specific clusters of neurons.

u dva vrlo specifična klastera neurona.

Israeli scientists Frederic Libersat and Ram Gal

Izraelski znanstvenici Frederic Libersat i Ram Gal

found that the venom is a very specific chemical weapon.

pronašli su da je otrov posebna vrsta kemijskog oružja.

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

On ne ubija žohara, niti ga omamljuje.

The roach could walk away

Žohar bi mogao odšetati

or fly or run if it chose to,

ili odletjeti ili pobjeći ako bi to odlučio,

but it doesn't choose to,

no ne odlučuje to,

because the venom nixes its motivation to walk,

jer mu otrov poništava motivaciju za hodanjem,

and only that.

i čini samo to.

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

Osa u osnovi odznačuje kućicu za bježanje od opasnosti

in the roach's operating system,

u operacijskom sustavu žohara,

allowing her to lead her helpless victim

dozvoljavajući joj da vodi svoju bespomoćnu žrtvu

back to her lair by its antennae

natrag u svoju jazbinu za njenu antenu

like a person walking a dog.

kao što osoba šeta psa.

And once there, she lays an egg on it,

I kad je tamo, polaže jaje na njega,

egg hatches, devoured alive, bursts out of body,

jaje se izlegne, proždire ga živog, probije se iz tijela,

yadda yadda yadda, you know the drill.

bla bla bla, znate kako to ide.

(Laughter) (Applause)

(Smijeh) (Pljesak)

Now I would argue that, once stung,

Sad, razmotrio bih stav, da kada je uboden,

the cockroach isn't a roach anymore.

žohar više nije žohar.

It's more of an extension of the wasp,

Više je produžetak ose,

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

baš kao što je cvrčak produžetak Gordijskog crva.

These hosts won't get to survive or reproduce.

Ovi domaćini neće preživjeti ili se reproducirati.

They have as much control over their own fates

Imaju onoliko kontrole nad svojom sudbinom

as my car.

koliko i moj automobil.

Once the parasites get in,

Jednom kada paraziti uđu,

the hosts don't get a say.

domaćini nemaju pravo glasa.

Now humans, of course,

Ljudima, naravno,

are no stranger to manipulation.

nije nepoznata manipulacija.

We take drugs to shift the chemistries of our brains

Uzimamo lijekove kako bismo pomaknuli kemiju našeg mozga

and to change our moods,

i promijenili svoje raspoloženje,

and what are arguments or advertising or big ideas

i što su argumenti ili oglašavanje ili velike ideje

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

ako ne pokušaj da utječemo na nečiji um?

But our attempts at doing this

Ali naš pokušaj da to učinimo

are crude and blundering compared

je jednostavan i nepromišljen u usporedbi

to the fine-grained specificity of the parasites.

sa fino vezenom specifičnošću parazita.

Don Draper only wishes he was as elegant

Don Draper samo želi biti elegantan

and precise as the emerald cockroach wasp.

i precizan kao smaragdna žoharova osa.

Now, I think this is part of what makes parasites

Sad, mislim da je ovo dio onoga što čini parazite

so sinister and so compelling.

tako zlokobnima i zaokupljajućima.

We place such a premium on our free will

Stavljamo takvu važnost na našu slobodnu volju

and our independence

i našu neovisnost

that the prospect of losing those qualities

da mogućnost gubitka tih kvaliteta

to forces unseen

od strane neviđenih sila

informs many of our deepest societal fears.

potiče mnoge od naših najdubljih društvenih strahova.

Orwellian dystopias and shadowy cabals

Orwellovska distopija i sjenovita kabala

and mind-controlling supervillains --

i super-zločinci koji kontroliraju umove --

these are tropes that fill our darkest fiction,

ovo su stvari koje ispunjavaju našu najmračniju fikciju,

but in nature, they happen all the time.

ali u prirodi, to se događa cijelo vrijeme.

Which leads me to an obvious

Što me vodi do očitog

and disquieting question:

i uznemirujućeg pitanja:

Are there dark, sinister parasites

Postoje li mračni, zlokobni paraziti

that are influencing our behavior

koji utječu na naše ponašanje

without us knowing about it,

bez da mi znamo za to,

besides the NSA?

osim NSA?

If there are any —

Ako ima --

(Laughter) (Applause)

(Smijeh)(Pljesak)

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

Imam crvenu točku na čelu sad, zar ne?

(Laughter)

(Smijeh)

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

Ako ih ima, ovo je dobar kandidat za njih.

This is Toxoplasma gondii, or Toxo, for short,

Ovo je Toxoplasma gondii, ili skraćeno Toxo,

because the terrifying creature

zato što zastrašujuća bića

always deserves a cute nickname.

uvijek zaslužuju simpatični nadimak.

Toxo infects mammals,

Toxo može zaraziti sisavce,

a wide variety of mammals,

širok raspon sisavaca,

but it can only sexually reproduce in a cat.

ali se može seksualno razmnožavati jedino u mački.

And scientists like Joanne Webster have shown that

I znanstvenici kao što je Joanne Webster pokazali su nam da

if Toxo gets into a rat or a mouse,

ako se Toxo nastani u mišu ili štakoru,

it turns the rodent into a cat-seeking missile.

on pretvori glodavca u raketu koja traži mačke.

If the infected rat smells the delightful odor

Ako zaraženi štakor namiriše divni miris

of cat piss,

mačje mokraće,

it runs towards the source of the smell

trči prema izvoru mirisa

rather than the more sensible direction of away.

rađe nego u razumnom drugom smjeru.

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

Mačka pojede štakora. Toxo se može seksati.

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

To je klasična priča Jedi, lovi, voli.

(Laughter) (Applause)

(Smijeh)(Pljesak)

You're very charitable, generous people.

Vi ste vrlo velikodušni, dobrotvorni ljudi.

Hi, Elizabeth, I loved your talk.

Hej, Elizabeth, svidio mi se tvoj govor.

How does the parasite control its host

Kako parazit kontrolira domaćina

in this way?

na ovaj način?

We don't really know.

Zaista ne znamo.

We know that Toxo releases an enzyme

Znamo da Toxo ispušta enzim

that makes dopamine, a substance involved

koji stvara dopamin, supstancu koja je povezana

in reward and motivation.

sa nagrađivanjem i motivacijom.

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

Znamo da cilja određene dijelove žoharova mozga,

including those involved in sexual arousal.

ukljućujući i one koji su povezani sa seksualnim uzbuđenjem.

But how those puzzle pieces fit together

Ali kako se ovi dijelovi slagalice slažu

is not immediately clear.

nije odmah 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.

Ovo nema živčani sustav.

It has no consciousness.

Nema svijest.

It doesn't even have a body.

Nema čak ni tijelo.

But it's manipulating a mammal?

Ali manipulira sisavcem?

We are mammals.

Mi smo sisavci.

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

Mi smo inteligentniji od štakora, to je sigurno,

but our brains have the same basic structure,

ali naš mozak ima istu osnovnu strukturu,

the same types of cells,

iste vrste stanica,

the same chemicals running through them,

iste kemikalije koje teku kroz njih,

and the same parasites.

i iste parazite.

Estimates vary a lot, but some figures suggest

Procjene variraju, ali neke brojke sugeriraju

that one in three people around the world

da jedna od tri osobe u svijetu

have Toxo in their brains.

ima Toxo u svom mozgu.

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

Najčešće, ovo ne vodi u neke očite bolesti.

The parasite holds up in a dormant state

Parazit ostaje u latentnom stanju

for a long period of time.

duga vremenska razdoblja.

But there's some evidence that those people

Ali postoje dokazi da ljudi

who are carriers score slightly differently

koji su nositelji imaju malo drugačije rezultate

on personality questionnaires than other people,

na upitnicima ličnosti nego drugi ljudi,

that they have a slightly higher risk of car accidents,

da imaju nešto viši rizik od automobilskih nesreća,

and there's some evidence that people with schizophrenia

i postoje neki dokazi da su ljudi koji imaju šizofreniju

are more likely to be infected.

ćešće zaraženi.

Now, I think this evidence is still inconclusive,

Vjerujem da su ovi dokazi još nepotpuni,

and even among Toxo researchers,

čak među istraživačima Toxo-a,

opinion is divided as to whether the parasite

mišljenja su podijeljena oko toga može li parazit

is truly influencing our behavior.

zaista utjecati na naše ponašanje.

But given the widespread nature of such manipulations,

Ali zbog raširene prirode ovakvih manipulacija

it would be completely implausible

bilo bi potpuno nevjerojatno

for humans to be the only species

da su ljudi jedina vrsta

that weren't similarly affected.

na koju nemaju sličan utjecaj.

And I think that this capacity to constantly

I mislim da ovaj kapacitet da stalno

subvert our way of thinking about the world

mijenjaju naš način razmišljanja o svijetu

makes parasites amazing.

čini parazite zadivljujućima.

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

Stalno nas pozivaju da gledamo svijet postrance,

and to ask if the behaviors we're seeing,

i da se pitamo jesu li ponašanja koja vidimo

whether they're simple and obvious

jednostavna i očita

or baffling and puzzling,

ili zbunjujuća i složena,

are not the results of individuals

nisu rezultat individualaca

acting through their own accord

koji djeluju po vlastitom nahođenju

but because they are being bent

nego zato što se povijaju

to the control of something else.

kontroli nečeg drugog.

And while that idea may be disquieting,

I iako je ta ideja uznemirjuća,

and while parasites' habits may be very grisly,

iako su navike parazita vrlo grozne,

I think that ability to surprise us

mislim da je mogućnost da nas iznenade

makes them as wonderful and as charismatic

ono što ih čini divnima i karizmatičnima poput

as any panda or butterfly or dolphin.

bilo koje pande, leptira ili delfina.

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

Na kraju "O porijeklu vrsta,"

Charles Darwin writes about the grandeur of life,

Charles Darwin piše o veličanstvenosti života,

and of endless forms most beautiful

i o beskrajnim predivnim oblicima

and most wonderful,

i najdivnijim,

and I like to think he could easily have been talking

i volio bih misliti da je lako mogao pričati

about a tapeworm that makes shrimp sociable

o trakavici koja čini škamp društvenim

or a wasp that takes cockroaches for walks.

ili osi koja vodi žohare u šetnju.

But perhaps, that's just a parasite talking.

Ali možda, možda je to samo parazit koji progovara iz mene.

Thank you.

Hvala vam.

(Applause)

(Pljesak)