As a scientist, and also as a human being, I've been trying to make myself susceptible to wonder. I think Jason Webley last night called it "conspiring to be part of the magic." So it's fortunate that my career as a biologist lets me dive deeply into the lives of some truly wondrous creatures that share our planet: fireflies.
Kao naučnik, a takođe i kao ljudsko biće, nastojala sam da učinim sebe prijemčivom za čuda. Mislim da je Džejson Vebli sinoć to nazvao "potajno planirati da postaneš deo magije". Zato je sreća da mi moja karijera biologa dozvoljava da zaronim duboko u živote nekih zaista čudesnih stvorenja koja dele našu planetu: svitaca.
Now, for many of you, I know that fireflies might conjure up some really great memories: childhood, summertime, even other TED Talks. Maybe something like this.
Sad, za mnoge od vas, znam da svici mogu prizvati neke zaista sjajne uspomene: iz detinjstva, letnjeg doba, čak i drugih TED govora. Možda nečeg kao što je ovo.
My seduction into the world of fireflies began when I was back in graduate school. One evening, I was sitting out in my backyard in North Carolina, and suddenly, these silent sparks rose up all around me, and I began to wonder: How do these creatures make light, and what's with all this flashing? Are they talking to one another? And what happens after the lights go out? I've been lucky enough to answer some of these questions as I've explored this nocturnal world.
Moja očaranost svetom svitaca je započela kada sam bila na postdiplomskim studijama. Jedne večeri, sedela sam u svom dvorištvu iza kuće u Severnoj Karolini, i iznenada, te neme iskre se pojaviše svuda oko mene, i počeh da se pitam: kako ova stvorenja proizvode svetlo, i šta je sa svim ovim blještanjem? Da li oni razgovaraju međusobno? I šta se događa nakon što se svetla ugase? Imala sam dovoljno sreće da odgovorim na neka od ovih pitanja dok sam istraživala ovaj noćni svet.
Now if you've ever seen or even heard about fireflies, then you'll know how magically they can transform our everyday landscape into something ethereal and otherworldly, and this happens around the globe, like this hillside in the Smoky Mountains that I saw transformed into a living cascade of light by the eerie glows of these blue ghost fireflies, or a roadside river that I visited in Japan as it was giving birth to the slow, floating flashes of these Genji fireflies, or in Malaysia, the mangrove trees that I watched blossom nightly not with flowers but with the lights of a thousand — (Bleep! Bleep!) — fireflies, all blinking together in stunning synchrony. These luminous landscapes still fill me with wonder, and they keep me connected to the magic of the natural world.
Ako ste ikada videli ili čuli za svice, znaćete onda kako mogu magično transformisati naš svakodnevni pejzaž u nešto eterično i van ovog sveta, i ovo se dešava širom zemljine kugle, kao na ovoj padini planina Smoki koju sam gledala kako se pretvara u žive slapove svetla jezivim sjajem ovih plavih svitaca duhova, ili na reci pokraj ulice koju sam posetila u Japanu dok je rađala spore, lebdeće bljeske ovih Gendži svitaca, ili u Maleziji, mangrov drveće koje sam posmatrala kako cveta noćima, ne cvetovima, već svetlima hiljada - (Blip! Blip!) - svitaca, koji svi trepću zajedno u zadivljujućoj sinhroniji. Ovi svetlosni pejzaži me još uvek ispunjavaju čuđenjem, i održavaju me povezanom sa magijom prirodnog sveta.
And I find it amazing that they're created by these tiny insects. In person, fireflies are charming. They're charismatic. They've been celebrated in art and in poetry for centuries. As I've traveled around the world, I've met many thoughtful people who have told me that God put fireflies on Earth for humans to enjoy. Other creatures can enjoy them too. I think these graceful insects are truly miraculous because they so beautifully illuminate the creative improvisation of evolution. They've been shaped by two powerful evolutionary forces: natural selection, the struggle for survival, and sexual selection, the struggle for reproductive opportunity. As a firefly junkie, the past 20 years have been quite an exciting ride. Together with my students at Tufts University and other colleagues, we've made lots of new discoveries about fireflies: their courtship and sex lives, their treachery and murder. So today I'd like to share with you just a couple of tales that we've brought back from our collective adventures into this hidden world.
Smatram naverovatnim da su ih stvorili ovi sićušni insekti. Sami po sebi, svici su šarmantni. Oni su harizmatični. Veličani su u umetnosti i poeziji vekovima. Dok sam putovala svetom, sretala sam mnoge pažljive ljude koji su mi rekli da je bog postavio svice na Zemlju da bi ljudi uživali. Druga stvorenja mogu takođe uživati u njima. Smatram da su ovi ljupki insekti zaista čudesni jer tako prelepo obasjavaju kreativnu improvizaciju evolucije. Oblikovale su ih dve moćne evolucione sile: prirodna selekcija, borba za opstanak, i seksualna selekcija, borba za mogućnost razmnožavanja. Kao zavisniku od svitaca, poslednjih 20 godina je bilo prilično uzbudjiva vožnja. Zajedno sa svojim studentima na Univerzitetu Tafts i drugim kolegama, došli smo do mnogih novih otkrića o svicima: njihovom udvaranju i seksualnim životima, njihovoj izdaji i ubistvu. Danas bih želela da podelim sa vama samo par priča o onome što smo doneli sa sobom sa naših zajedničkih avantura iz ovog skrivenog sveta.
Fireflies belong to a very beautiful and diverse group of insects, the beetles. Worldwide, there are more than 2,000 firefly species, and these have evolved remarkably diverse courtship signals, that is, different ways to find and attract mates. Around 150 million years ago, the very first fireflies probably looked like this. They flew during the daytime and they didn't light up. Instead, males used their fantastic antennae to sniff out perfumes given off by their females. In other fireflies, it's only the females who light up. They are attractively plump and wingless, so every night, they climb up onto perches and they glow brightly for hours to attract their flying but unlit males. In still other fireflies, both sexes use quick, bright flashes to find their mates. Here in North America, we have more than 100 different kinds of firefly that have the remarkable ability to shine energy out from their bodies in the form of light. How do they do that? It seems totally magical, but these bioluminescent signals arise from carefully orchestrated chemical reactions that happen inside the firefly lantern. The main star is an enzyme called luciferase, which in the course of evolution has figured out a way to wrap its tiny arms around an even smaller molecule called luciferin, in the process getting it so excited that it actually gives off light. Incredible.
Svici pripadaju veoma lepoj i raznolikoj grupi insekata, tvrdokrilcima. Širom sveta, postoji više od 2000 vrsta svitaca, i one su razvile znatno različite signale udvaranja, odnosno, različite načine za pronalaženje i privlačenje partnera. Pre oko 150 miliona godina, prvi svici su verovatno izgledali ovako. Oni su leteli za vreme dana i nisu svetleli. Umesto toga, mužjaci su koristili svoje fantastične antene kako bi nanjušili mirise koje su odavale njihove ženke. Kod drugih svitaca, samo ženke su te koje svetle. One su privlačno krupnije i bez krila, pa se svake noći penju na uzvišenja i blistavo sijaju satima kako bi privukle svoje leteće ali nesvetleće mužjake. Kod nekih drugih svitaca, oba pola koriste brze, sjajne bleske da bi pronašle svoje partnere. Ovde u Severnoj Americi, imamo više od 100 različitih vrsta svitaca koji imaju izuzetnu sposobnost da zrače energiju iz svojih tela u obliku svetla. Kako oni to čine? To deluje sasvim čarobno, ali ovi bioluminescentni signali proističu iz pažljivo orkestriranih hemijskih reakcija koje se dešavaju unutar svetiljke svica. Glavna zvezda je enzim koji se zove luciferaza, koji je tokom evolucije shvatio kako da obavije svoje malene grane oko još manjeg molekula zvanog luciferin, toliko se uzbuđujući u tom procesu da čak odaje svetlo. Neverovatno.
But how could these bright lights have benefited some proto-firefly? To answer this question, we need to flip back in the family album to some baby pictures. Fireflies completely reinvent their bodies as they grow. They spend the vast majority of their lifetime, up to two years, in this larval form. Their main goal here, like my teenagers, is to eat and grow. And firefly light first originated in these juveniles. Every single firefly larva can light up, even when their adults can't.
Ali kako su ova sjajna svetla mogla koristiti nekom proto-svicu? Da bismo odgovorili na ovo pitanje, moramo da okrenemo unazad porodični album do bebinih slika. Svici potpuno preosmišljavaju svoja tela dok odrastaju. Oni provode veliku većinu svog života, do dve godine, u ovom obliku larve. Njihov glavni cilj ovde, kao mojim tinejdžerima, je da jedu i rastu. A svetlo svitaca je prvo nastalo kod ovih mladih. Svaka larva svitaca može da zasvetli, čak i kada njihovi odrasli ne mogu.
But what's the point to being so conspicuous? Well, we know that these juveniles make nasty-tasting chemicals that help them survive their extended childhood, so we think these lights first evolved as a warning, a neon sign that says, "Toxic! Stay away!" to any would-be predators. It took many millions of years before these bright lights evolved into a smart communication tool that could be used not just to ward off potential predators but to bring in potential mates. Driven now by sexual selection, some adult fireflies like this proud male evolved a shiny new glow-in-the-dark lantern that would let them take courtship to a whole new level. These adults only live a few weeks, and now they're single-mindedly focused on sex, that is, on propelling their genes into the next firefly generation. So we can follow this male out into the field as he joins hundreds of other males who are all showing off their new courtship signals. It's amazing to think that the luminous displays we admire here and in fact everywhere around the world are actually the silent love songs of male fireflies. They're flying and flashing their hearts out. I still find it very romantic.
Ali šta je svrha tolike upadljivosti? Pa, znamo da ovi mladi prave hemikalije gadnog ukusa koje im pomažu da prežive svoje produženo detinjstvo, tako da mislimo da su se ova svetla najpre razvila kao upozorenje, neonski znak koji kaže: "Otrovno! Drži se podalje!" bilo kojim nameračenim predatorima. Bilo je potrebno mnogo miliona godina pre nego što su ova blistava svetla evoluirala u sredstvo pametne komunikacije koje se može koristiti ne samo za odbijanje potencijalnih predatora već i za privlačenje potencijalnih partnera. Sada vođeni seksualnom selekcijom, neki odrasli svici kao što je ovaj ponosni mužjak, razvili su novu blistavu svetiljku koja svetli u mraku i koja će im omogućiti da dovedu udvaranje na potpuno novi nivo. Ovi odrasli žive svega nekoliko nedelja, i jednoumno su fokusirani na seks, odnosno, na prenošenje svojih gena na sledeću generaciju svitaca. Možemo pratiti ovog mužjaka u polju dok se priključuje stotinama drugih mužjaka koji pokazuju svoje nove signale za udvaranje. Neverovatno je kad razmislite da su svetlosni prikazi kojima se divimo ovde i u stvari svuda širom sveta, zapravo neme ljubavne pesme mužjaka svitaca. Oni lete i blješte od sveg srca. Još uvek to smatram veoma romantičnim.
But meanwhile, where are all the females? Well, they're lounging down below surveying their options. They have plenty of males to choose from, and these females turn out to be very picky. When a female sees a flash from an especially attractive male, she'll aim her lantern in his direction, and give him a flash back. It's her "come hither" sign. So he flies closer and he flashes again. If she still likes him, they'll strike up a conversation. These creatures speak their love in the language of light.
Ali u međuvremenu, gde su sve ženke? Pa, one se izležavaju ispod preispitujući svoje opcije. One imaju mnoštvo mužjaka koje mogu odabrati, i za ove ženke se ispostavilo da su veoma probirljive. Kada ženka vidi bljesak od naročito privlačnog mužjaka, uperiće svoju svetiljku u njegovom pravcu, i uzvratiti mu bljeskom. To je njen znak za "dođi ovamo". Tako on leti bliže i ponovo zasvetli. Ako joj se još uvek sviđa, započeće razgovor. Ova stvorenja saopštavaju svoju ljubav jezikom svetla. Dakle šta tačno ove ženke smatraju da je seksi?
So what exactly do these females consider sexy? We decided to conduct some firefly opinion polls to find out. When we tested females using blinking LED lights, we discovered they prefer males who give longer-lasting flashes. (Laughter) (Applause) I know you're wondering, what gives these males their sex appeal? Now we get to see what happens when the lights go out.
Odlučili smo da sprovedemo anketu svitaca kako bismo to saznali. Kada smo testirali ženke koristeći trepereća LED svetla, otkrili smo da preferiraju mužjake koji im daju dugotrajnije bljeske. (Smeh) (Aplauz) Znam da se pitate, šta daje mužjacima njihovu seksualnu privlačnost? Sada možemo da vidimo šta se dešava kada se svetla ugase. Prva stvar koju smo otkrili
The first thing we discovered is that once a male and female hook up like this, they stay together all night long, and when we looked inside to see what might be happening, we discovered a surprising new twist to firefly sex. While they're mating, the male is busy giving the female not just his sperm but also a nutrient-filled package called a nuptial gift. We can zoom in to look more closely inside this mating pair. We can actually see the gift — it's shown here in red — as it's being passed from the male to the female. What makes this gift so valuable is that it's packed with protein that the female will use to provision her eggs. So females are keeping their eyes on this prize as they size up potential mates. We discovered that females use male flash signals to try to predict which males have the biggest gifts to offer, because this bling helps the female lay more eggs and ultimately launch more of her own offspring into the next generation.
je da kada se jedom mužjak i ženka spoje ovako, oni ostaju zajedno čitave noći, i kada smo pogledali unutra da vidimo šta bi moglo da se dešava, otkrili smo iznenađujuć novi preokret u seksu svitaca. Dok se pare, mužjak je okupiran dajući ženki ne samo svoju spermu već takođe i paket pun hranljivih materija zvani svadbeni poklon. Možemo uveličati da pogledamo bliže ovaj par koji se pari. Možemo zaista videti poklon - ovde je prikazan crvenom bojom - dok se prenosi od mužjaka do ženke. Ono što čini ovaj poklon tako dragocenim jeste to što je pun proteinima koje će ženka koristiti da obezbedi svoja jaja. Zato ženke drže na oku ovu nagradu dok odmeravaju potencijalne partnere. Otkrili smo da ženke koriste muške blještave signale kako bi predvidele koji mužjaci imaju najveće poklone u ponudi, jer ovaj dragulj pomaže ženki da nosi više jaja i na kraju iznese više sopstvenih potomaka u narednu generaciju. [Mračna strana svitaca]
So it's not all sweetness and light. Firefly romance is risky. For the most part, these adult fireflies don't get eaten because like their juveniles they can manufacture toxins that are repellent to birds and other insectivores, but somewhere along the line, one particular group of fireflies somehow lost the metabolic machinery needed to make their own protective toxins. This evolutionary flaw, which was discovered by my colleague Tom Eisner, has driven these fireflies to take their bright lights out into the night with treacherous intent. Dubbed "femme fatales" by Jim Lloyd, another colleague, these females have figured out how to target the males of other firefly species. So the hunt begins with the predator — she's shown here in the lower left — where she's sitting quietly and eavesdropping on the courtship conversation of her intended prey, and here's how it might go. First the prey male flashes, "Do you love me?" His own female responds, "Maybe." So then he flashes again. But this time, the predator sneaks in a reply that cleverly mimics exactly what the other female just said. She's not looking for love: she's looking for toxins. If she's good, she can lure this male close enough to reach out and grab him, and he's not just a light snack. Over the next hour, she slowly exsanguinates this male leaving behind just some gory remains. Unable to make their own toxins, these females resort to drinking the blood of other fireflies to get these protective chemicals. So a firefly vampire, brought to you by natural selection.
Tako da nije sve med i mleko. Romansa svitaca je rizična. Najvećim delom, ovi odrasli svici ne budu pojedeni jer kao i njihovi mladi mogu da proizvode otrove koji su odbojni za ptice i druge insektojede, ali u nekom trenutku, jedna određena grupa svitaca je nekako izgubila metabolički aparat koji je neophodan za proizvodnju sopstvenih zaštitnih otrova. Ova evoluciona greška, koju je otkrio moj kolega Tom Ajsner, je naterala ove svice da odvedu svoja jarka svetla u noć sa podmuklim namerama. Nazvane "fatalnim ženama" od strane Džima Lojda, drugog kolege, ove ženke su otkrile kako da nišane mužjake drugih vrsta svitaca. Lov počinje sa predatorom - prikazana je ovde u donjem levom uglu - gde sedi tiho i prisluškuje razgovor udvaranja plena na koji se ustremila, i evo kako to može da ide. Prvo mužjak žrtva bljesne: "Da li me voliš?" Njegova ženka odgovara: "Možda." Zatim on bljesne ponovo. Ali ovog puta, predator ušunja odgovor koji mudro oponaša tačno ono što je druga ženka upravo rekla. Ona ne traži ljubav: ona traži otrove. Ako je dobra, može da namami ovog mužjaka dovoljno blizu da se pruži do njega i zgrabi ga, a on nije samo lagana užina. Tokom narednog sata, ona polako izvlači krv iz ovog mužjaka ostavljajući za sobom samo nešto krvavih ostataka. Nesposobne da prave sopstvene otrove, ove ženke pribegavaju ispijanju krvi drugih svitaca da bi dobile ove zaštitne hemikalije. Dakle, eto svica vampira, kojeg vam je omogućila prirodna selekcija.
We still have a lot to learn about fireflies, but it looks like many stories will remain untold, because around the world, firefly populations are blinking out. The main culprit: habitat loss. Pretty much everywhere, the fields and forests, the mangroves and meadows that fireflies need to survive, are giving way to development and to sprawl.
[Svici koji nestaju] Još uvek imamo dosta toga da naučimo o svicima, ali izgleda da će mnoge priče ostati neispričane, jer širom sveta, populacije svitaca se gase. Glavni krivac: gubitak staništa. Gotovo svuda, polja i šume, mangrovi i livade koje su svicima potrebne da bi preživeli,
Here's another problem: we've conquered darkness, but in the process, we spill so much extra light out into the night that it disrupts the lives of other creatures, and fireflies are especially sensitive to light pollution because it obscures the signals that they use to find their mates.
povlače se pred razvojem i širenjem. Evo drugog problema: pobedili smo tamu, ali u tom procesu, rasipamo toliko dodatne svetlosti u noć da to razara živote drugih stvorenja, a svici su naročito osetljivi na svetlosno zagađenje jer čini nejasnim signale
Do we really need fireflies? After all, they're just one tiny bit of Earth's biodiversity. Yet every time a species is lost, it's like extinguishing a room full of candles one by one. You might not notice when the first few flames flicker out, but in the end, you're left sitting in darkness. As we work together to craft a planetary future, I hope we can find a way to keep these bright lights shining.
koje oni koriste kako bi pronašli svoje partnere. Da li su nam zaista potrebni svici? Na kraju krajeva, oni su samo jedan delić Zemljine bioraznolikosti. Ipak, svaki put kada je vrsta izgubljena, to je kao gašenje sobe pune sveća jedne po jedne. Možda ne primetite kada prvih nekoliko plamenova istrepere, ali na kraju, ostali ste da sedite u mraku. Dok zajednički radimo da kreiramo budućnost planete, nadam se da možemo naći način da održimo sijanje ovih blještavih svetala.
Thank you.
Hvala vam.
(Applause)
(Aplauz)