[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.88,0:00:04.12,Default,,0000,0000,0000,,As a scientist, and also as a human being,
Dialogue: 0,0:00:04.12,0:00:06.12,Default,,0000,0000,0000,,I've been trying to make myself
Dialogue: 0,0:00:06.12,0:00:09.50,Default,,0000,0000,0000,,susceptible to wonder.
Dialogue: 0,0:00:09.50,0:00:12.37,Default,,0000,0000,0000,,I think Jason Webley last night called it
Dialogue: 0,0:00:12.37,0:00:16.40,Default,,0000,0000,0000,,"conspiring to be part of the magic."
Dialogue: 0,0:00:16.40,0:00:19.22,Default,,0000,0000,0000,,So it's fortunate that my career as a biologist
Dialogue: 0,0:00:19.22,0:00:21.86,Default,,0000,0000,0000,,lets me dive deeply into the lives
Dialogue: 0,0:00:21.86,0:00:24.38,Default,,0000,0000,0000,,of some truly wondrous creatures
Dialogue: 0,0:00:24.38,0:00:26.76,Default,,0000,0000,0000,,that share our planet:
Dialogue: 0,0:00:26.76,0:00:28.45,Default,,0000,0000,0000,,fireflies.
Dialogue: 0,0:00:28.45,0:00:30.74,Default,,0000,0000,0000,,Now, for many of you, I know that fireflies
Dialogue: 0,0:00:30.74,0:00:33.48,Default,,0000,0000,0000,,might conjure up some really great memories:
Dialogue: 0,0:00:33.48,0:00:36.53,Default,,0000,0000,0000,,childhood, summertime,
Dialogue: 0,0:00:36.53,0:00:38.30,Default,,0000,0000,0000,,even other TED Talks.
Dialogue: 0,0:00:38.30,0:00:42.44,Default,,0000,0000,0000,,Maybe something like this.
Dialogue: 0,0:00:45.36,0:00:47.82,Default,,0000,0000,0000,,My seduction into the world of fireflies
Dialogue: 0,0:00:47.82,0:00:51.66,Default,,0000,0000,0000,,began when I was back in graduate school.
Dialogue: 0,0:00:51.66,0:00:54.49,Default,,0000,0000,0000,,One evening, I was sitting out in my backyard
Dialogue: 0,0:00:54.49,0:00:56.43,Default,,0000,0000,0000,,in North Carolina,
Dialogue: 0,0:00:56.43,0:01:01.72,Default,,0000,0000,0000,,and suddenly, these silent sparks
Dialogue: 0,0:01:01.72,0:01:03.58,Default,,0000,0000,0000,,rose up all around me,
Dialogue: 0,0:01:03.58,0:01:04.96,Default,,0000,0000,0000,,and I began to wonder:
Dialogue: 0,0:01:04.96,0:01:07.65,Default,,0000,0000,0000,,How do these creatures make light,
Dialogue: 0,0:01:07.65,0:01:09.34,Default,,0000,0000,0000,,and what's with all this flashing?
Dialogue: 0,0:01:09.34,0:01:11.18,Default,,0000,0000,0000,,Are they talking to one another?
Dialogue: 0,0:01:11.18,0:01:14.37,Default,,0000,0000,0000,,And what happens after the lights go out?
Dialogue: 0,0:01:14.37,0:01:15.66,Default,,0000,0000,0000,,I've been lucky enough to answer
Dialogue: 0,0:01:15.66,0:01:17.03,Default,,0000,0000,0000,,some of these questions
Dialogue: 0,0:01:17.03,0:01:21.12,Default,,0000,0000,0000,,as I've explored this nocturnal world.
Dialogue: 0,0:01:21.12,0:01:23.46,Default,,0000,0000,0000,,Now if you've ever seen
Dialogue: 0,0:01:23.46,0:01:25.56,Default,,0000,0000,0000,,or even heard about fireflies,
Dialogue: 0,0:01:25.56,0:01:28.21,Default,,0000,0000,0000,,then you'll know how magically they can transform
Dialogue: 0,0:01:28.21,0:01:30.60,Default,,0000,0000,0000,,our everyday landscape into something
Dialogue: 0,0:01:30.60,0:01:32.50,Default,,0000,0000,0000,,ethereal and otherworldly,
Dialogue: 0,0:01:32.50,0:01:34.44,Default,,0000,0000,0000,,and this happens around the globe,
Dialogue: 0,0:01:34.44,0:01:36.53,Default,,0000,0000,0000,,like this hillside in the Smoky Mountains
Dialogue: 0,0:01:36.53,0:01:40.62,Default,,0000,0000,0000,,that I saw transformed into a living cascade of light
Dialogue: 0,0:01:40.62,0:01:44.98,Default,,0000,0000,0000,,by the eerie glows of these blue ghost fireflies,
Dialogue: 0,0:01:44.98,0:01:47.100,Default,,0000,0000,0000,,or a roadside river that I visited in Japan
Dialogue: 0,0:01:47.100,0:01:52.10,Default,,0000,0000,0000,,as it was giving birth to the slow, floating flashes
Dialogue: 0,0:01:52.10,0:01:54.74,Default,,0000,0000,0000,,of these Genji fireflies,
Dialogue: 0,0:01:54.74,0:01:57.30,Default,,0000,0000,0000,,or in Malaysia, the mangrove trees
Dialogue: 0,0:01:57.30,0:01:59.62,Default,,0000,0000,0000,,that I watched blossom nightly
Dialogue: 0,0:01:59.62,0:02:01.06,Default,,0000,0000,0000,,not with flowers
Dialogue: 0,0:02:01.06,0:02:03.92,Default,,0000,0000,0000,,but with the lights of a thousand — \N(Bleep! Bleep!) — fireflies,
Dialogue: 0,0:02:03.92,0:02:05.25,Default,,0000,0000,0000,,all blinking together
Dialogue: 0,0:02:05.25,0:02:08.41,Default,,0000,0000,0000,,in stunning synchrony.
Dialogue: 0,0:02:08.41,0:02:10.51,Default,,0000,0000,0000,,These luminous landscapes
Dialogue: 0,0:02:10.51,0:02:12.90,Default,,0000,0000,0000,,still fill me with wonder,
Dialogue: 0,0:02:12.90,0:02:15.42,Default,,0000,0000,0000,,and they keep me connected to the magic
Dialogue: 0,0:02:15.42,0:02:17.83,Default,,0000,0000,0000,,of the natural world.
Dialogue: 0,0:02:17.83,0:02:19.44,Default,,0000,0000,0000,,And I find it amazing that they're created
Dialogue: 0,0:02:19.44,0:02:22.73,Default,,0000,0000,0000,,by these tiny insects.
Dialogue: 0,0:02:22.73,0:02:25.62,Default,,0000,0000,0000,,In person, fireflies are charming.
Dialogue: 0,0:02:25.62,0:02:27.44,Default,,0000,0000,0000,,They're charismatic.
Dialogue: 0,0:02:27.44,0:02:29.12,Default,,0000,0000,0000,,They've been celebrated in art
Dialogue: 0,0:02:29.12,0:02:31.59,Default,,0000,0000,0000,,and in poetry for centuries.
Dialogue: 0,0:02:31.59,0:02:32.99,Default,,0000,0000,0000,,As I've traveled around the world,
Dialogue: 0,0:02:32.99,0:02:35.01,Default,,0000,0000,0000,,I've met many thoughtful people
Dialogue: 0,0:02:35.01,0:02:37.84,Default,,0000,0000,0000,,who have told me that God put fireflies on Earth
Dialogue: 0,0:02:37.84,0:02:39.99,Default,,0000,0000,0000,,for humans to enjoy.
Dialogue: 0,0:02:39.99,0:02:42.39,Default,,0000,0000,0000,,Other creatures can enjoy them too.
Dialogue: 0,0:02:42.39,0:02:46.72,Default,,0000,0000,0000,,I think these graceful insects are truly miraculous
Dialogue: 0,0:02:46.72,0:02:50.72,Default,,0000,0000,0000,,because they so beautifully illuminate
Dialogue: 0,0:02:50.72,0:02:54.95,Default,,0000,0000,0000,,the creative improvisation of evolution.
Dialogue: 0,0:02:54.95,0:02:56.76,Default,,0000,0000,0000,,They've been shaped by two powerful
Dialogue: 0,0:02:56.76,0:02:58.29,Default,,0000,0000,0000,,evolutionary forces:
Dialogue: 0,0:02:58.29,0:03:01.95,Default,,0000,0000,0000,,natural selection, the struggle for survival,
Dialogue: 0,0:03:01.95,0:03:04.10,Default,,0000,0000,0000,,and sexual selection,
Dialogue: 0,0:03:04.10,0:03:08.16,Default,,0000,0000,0000,,the struggle for reproductive opportunity.
Dialogue: 0,0:03:08.16,0:03:10.51,Default,,0000,0000,0000,,As a firefly junkie, the past 20 years
Dialogue: 0,0:03:10.51,0:03:12.100,Default,,0000,0000,0000,,have been quite an exciting ride.
Dialogue: 0,0:03:12.100,0:03:15.50,Default,,0000,0000,0000,,Together with my students at Tufts University
Dialogue: 0,0:03:15.50,0:03:16.51,Default,,0000,0000,0000,,and other colleagues,
Dialogue: 0,0:03:16.51,0:03:20.12,Default,,0000,0000,0000,,we've made lots of new discoveries about fireflies:
Dialogue: 0,0:03:20.12,0:03:22.13,Default,,0000,0000,0000,,their courtship and sex lives,
Dialogue: 0,0:03:22.13,0:03:25.02,Default,,0000,0000,0000,,their treachery and murder.
Dialogue: 0,0:03:25.02,0:03:26.84,Default,,0000,0000,0000,,So today I'd like to share with you
Dialogue: 0,0:03:26.84,0:03:29.31,Default,,0000,0000,0000,,just a couple of tales that we've brought back
Dialogue: 0,0:03:29.31,0:03:31.79,Default,,0000,0000,0000,,from our collective adventures
Dialogue: 0,0:03:31.79,0:03:35.50,Default,,0000,0000,0000,,into this hidden world.
Dialogue: 0,0:03:35.50,0:03:38.66,Default,,0000,0000,0000,,Fireflies belong to a very beautiful
Dialogue: 0,0:03:38.66,0:03:42.90,Default,,0000,0000,0000,,and diverse group of insects, the beetles.
Dialogue: 0,0:03:42.90,0:03:47.51,Default,,0000,0000,0000,,Worldwide, there are more than 2,000 firefly species,
Dialogue: 0,0:03:47.51,0:03:49.67,Default,,0000,0000,0000,,and these have evolved remarkably diverse
Dialogue: 0,0:03:49.67,0:03:51.03,Default,,0000,0000,0000,,courtship signals,
Dialogue: 0,0:03:51.03,0:03:54.66,Default,,0000,0000,0000,,that is, different ways to find and attract mates.
Dialogue: 0,0:03:54.66,0:03:56.92,Default,,0000,0000,0000,,Around 150 million years ago,
Dialogue: 0,0:03:56.92,0:04:00.04,Default,,0000,0000,0000,,the very first fireflies probably looked like this.
Dialogue: 0,0:04:00.04,0:04:01.40,Default,,0000,0000,0000,,They flew during the daytime
Dialogue: 0,0:04:01.40,0:04:03.66,Default,,0000,0000,0000,,and they didn't light up.
Dialogue: 0,0:04:03.66,0:04:06.84,Default,,0000,0000,0000,,Instead, males used their fantastic antennae
Dialogue: 0,0:04:06.84,0:04:10.95,Default,,0000,0000,0000,,to sniff out perfumes given off by their females.
Dialogue: 0,0:04:10.95,0:04:14.56,Default,,0000,0000,0000,,In other fireflies, it's only the females who light up.
Dialogue: 0,0:04:14.56,0:04:18.90,Default,,0000,0000,0000,,They are attractively plump and wingless,
Dialogue: 0,0:04:18.90,0:04:20.82,Default,,0000,0000,0000,,so every night, they climb up onto perches
Dialogue: 0,0:04:20.82,0:04:22.79,Default,,0000,0000,0000,,and they glow brightly for hours
Dialogue: 0,0:04:22.79,0:04:27.98,Default,,0000,0000,0000,,to attract their flying but unlit males.
Dialogue: 0,0:04:27.98,0:04:29.83,Default,,0000,0000,0000,,In still other fireflies, both sexes
Dialogue: 0,0:04:29.83,0:04:33.22,Default,,0000,0000,0000,,use quick, bright flashes to find their mates.
Dialogue: 0,0:04:33.22,0:04:34.69,Default,,0000,0000,0000,,Here in North America,
Dialogue: 0,0:04:34.69,0:04:37.83,Default,,0000,0000,0000,,we have more than 100 different kinds of firefly
Dialogue: 0,0:04:37.83,0:04:41.41,Default,,0000,0000,0000,,that have the remarkable ability to shine energy
Dialogue: 0,0:04:41.41,0:04:43.64,Default,,0000,0000,0000,,out from their bodies
Dialogue: 0,0:04:43.64,0:04:45.97,Default,,0000,0000,0000,,in the form of light.
Dialogue: 0,0:04:45.97,0:04:48.42,Default,,0000,0000,0000,,How do they do that?
Dialogue: 0,0:04:48.42,0:04:50.45,Default,,0000,0000,0000,,It seems totally magical,
Dialogue: 0,0:04:50.45,0:04:51.74,Default,,0000,0000,0000,,but these bioluminescent signals
Dialogue: 0,0:04:51.74,0:04:55.04,Default,,0000,0000,0000,,arise from carefully orchestrated chemical reactions
Dialogue: 0,0:04:55.04,0:04:57.93,Default,,0000,0000,0000,,that happen inside the firefly lantern.
Dialogue: 0,0:04:57.93,0:05:01.24,Default,,0000,0000,0000,,The main star is an enzyme called luciferase,
Dialogue: 0,0:05:01.24,0:05:02.100,Default,,0000,0000,0000,,which in the course of evolution
Dialogue: 0,0:05:02.100,0:05:06.19,Default,,0000,0000,0000,,has figured out a way to wrap its tiny arms
Dialogue: 0,0:05:06.19,0:05:09.78,Default,,0000,0000,0000,,around an even smaller molecule called luciferin,
Dialogue: 0,0:05:09.78,0:05:12.46,Default,,0000,0000,0000,,in the process getting it so excited
Dialogue: 0,0:05:12.46,0:05:15.83,Default,,0000,0000,0000,,that it actually gives off light.
Dialogue: 0,0:05:15.83,0:05:17.51,Default,,0000,0000,0000,,Incredible.
Dialogue: 0,0:05:17.51,0:05:19.33,Default,,0000,0000,0000,,But how could these bright lights
Dialogue: 0,0:05:19.33,0:05:23.48,Default,,0000,0000,0000,,have benefited some proto-firefly?
Dialogue: 0,0:05:23.48,0:05:25.59,Default,,0000,0000,0000,,To answer this question, we need to flip back
Dialogue: 0,0:05:25.59,0:05:29.95,Default,,0000,0000,0000,,in the family album to some baby pictures.
Dialogue: 0,0:05:29.95,0:05:33.66,Default,,0000,0000,0000,,Fireflies completely reinvent\Ntheir bodies as they grow.
Dialogue: 0,0:05:33.66,0:05:35.97,Default,,0000,0000,0000,,They spend the vast majority of their lifetime,
Dialogue: 0,0:05:35.97,0:05:37.71,Default,,0000,0000,0000,,up to two years,
Dialogue: 0,0:05:37.71,0:05:40.57,Default,,0000,0000,0000,,in this larval form.
Dialogue: 0,0:05:40.57,0:05:42.82,Default,,0000,0000,0000,,Their main goal here, like my teenagers,
Dialogue: 0,0:05:42.82,0:05:45.98,Default,,0000,0000,0000,,is to eat and grow.
Dialogue: 0,0:05:45.98,0:05:48.43,Default,,0000,0000,0000,,And firefly light first originated
Dialogue: 0,0:05:48.43,0:05:50.48,Default,,0000,0000,0000,,in these juveniles.
Dialogue: 0,0:05:50.48,0:05:52.91,Default,,0000,0000,0000,,Every single firefly larva can light up,
Dialogue: 0,0:05:52.91,0:05:55.79,Default,,0000,0000,0000,,even when their adults can't.
Dialogue: 0,0:05:55.79,0:05:56.88,Default,,0000,0000,0000,,But what's the point
Dialogue: 0,0:05:56.88,0:06:00.52,Default,,0000,0000,0000,,to being so conspicuous?
Dialogue: 0,0:06:00.52,0:06:02.13,Default,,0000,0000,0000,,Well, we know that these juveniles
Dialogue: 0,0:06:02.13,0:06:04.11,Default,,0000,0000,0000,,make nasty-tasting chemicals
Dialogue: 0,0:06:04.11,0:06:07.73,Default,,0000,0000,0000,,that help them survive their extended childhood,
Dialogue: 0,0:06:07.73,0:06:11.56,Default,,0000,0000,0000,,so we think these lights first evolved as a warning,
Dialogue: 0,0:06:11.56,0:06:16.12,Default,,0000,0000,0000,,a neon sign that says, "Toxic! Stay away!"
Dialogue: 0,0:06:16.12,0:06:19.01,Default,,0000,0000,0000,,to any would-be predators.
Dialogue: 0,0:06:19.01,0:06:21.96,Default,,0000,0000,0000,,It took many millions of years
Dialogue: 0,0:06:21.96,0:06:23.36,Default,,0000,0000,0000,,before these bright lights
Dialogue: 0,0:06:23.36,0:06:25.90,Default,,0000,0000,0000,,evolved into a smart communication tool
Dialogue: 0,0:06:25.90,0:06:28.92,Default,,0000,0000,0000,,that could be used not just to\Nward off potential predators
Dialogue: 0,0:06:28.92,0:06:31.89,Default,,0000,0000,0000,,but to bring in potential mates.
Dialogue: 0,0:06:31.89,0:06:34.69,Default,,0000,0000,0000,,Driven now by sexual selection,
Dialogue: 0,0:06:34.69,0:06:36.58,Default,,0000,0000,0000,,some adult fireflies
Dialogue: 0,0:06:36.58,0:06:38.97,Default,,0000,0000,0000,,like this proud male
Dialogue: 0,0:06:38.97,0:06:42.76,Default,,0000,0000,0000,,evolved a shiny new glow-in-the-dark lantern
Dialogue: 0,0:06:42.76,0:06:44.61,Default,,0000,0000,0000,,that would let them take courtship
Dialogue: 0,0:06:44.61,0:06:48.39,Default,,0000,0000,0000,,to a whole new level.
Dialogue: 0,0:06:48.39,0:06:50.84,Default,,0000,0000,0000,,These adults only live a few weeks,
Dialogue: 0,0:06:50.84,0:06:55.76,Default,,0000,0000,0000,,and now they're single-mindedly focused on sex,
Dialogue: 0,0:06:55.76,0:06:57.73,Default,,0000,0000,0000,,that is, on propelling their genes
Dialogue: 0,0:06:57.73,0:07:00.50,Default,,0000,0000,0000,,into the next firefly generation.
Dialogue: 0,0:07:00.50,0:07:03.77,Default,,0000,0000,0000,,So we can follow this male out into the field
Dialogue: 0,0:07:03.77,0:07:06.79,Default,,0000,0000,0000,,as he joins hundreds of other males
Dialogue: 0,0:07:06.79,0:07:11.17,Default,,0000,0000,0000,,who are all showing off their new courtship signals.
Dialogue: 0,0:07:11.17,0:07:14.16,Default,,0000,0000,0000,,It's amazing to think that the luminous displays
Dialogue: 0,0:07:14.16,0:07:15.84,Default,,0000,0000,0000,,we admire
Dialogue: 0,0:07:15.84,0:07:18.28,Default,,0000,0000,0000,,here and in fact everywhere around the world
Dialogue: 0,0:07:18.28,0:07:22.48,Default,,0000,0000,0000,,are actually the silent love songs
Dialogue: 0,0:07:22.48,0:07:25.45,Default,,0000,0000,0000,,of male fireflies.
Dialogue: 0,0:07:25.45,0:07:29.54,Default,,0000,0000,0000,,They're flying and flashing their hearts out.
Dialogue: 0,0:07:29.54,0:07:33.08,Default,,0000,0000,0000,,I still find it very romantic.
Dialogue: 0,0:07:33.08,0:07:36.50,Default,,0000,0000,0000,,But meanwhile, where are all the females?
Dialogue: 0,0:07:36.50,0:07:38.09,Default,,0000,0000,0000,,Well, they're lounging down below
Dialogue: 0,0:07:38.09,0:07:39.83,Default,,0000,0000,0000,,surveying their options.
Dialogue: 0,0:07:39.83,0:07:41.76,Default,,0000,0000,0000,,They have plenty of males to choose from,
Dialogue: 0,0:07:41.76,0:07:45.85,Default,,0000,0000,0000,,and these females turn out to be very picky.
Dialogue: 0,0:07:45.85,0:07:48.22,Default,,0000,0000,0000,,When a female sees a flash
Dialogue: 0,0:07:48.22,0:07:50.86,Default,,0000,0000,0000,,from an especially attractive male,
Dialogue: 0,0:07:50.86,0:07:53.84,Default,,0000,0000,0000,,she'll aim her lantern in his direction,
Dialogue: 0,0:07:53.84,0:07:56.37,Default,,0000,0000,0000,,and give him a flash back.
Dialogue: 0,0:07:56.37,0:07:59.77,Default,,0000,0000,0000,,It's her "come hither" sign.
Dialogue: 0,0:07:59.77,0:08:03.37,Default,,0000,0000,0000,,So he flies closer and he flashes again.
Dialogue: 0,0:08:03.37,0:08:04.49,Default,,0000,0000,0000,,If she still likes him,
Dialogue: 0,0:08:04.49,0:08:07.70,Default,,0000,0000,0000,,they'll strike up a conversation.
Dialogue: 0,0:08:07.70,0:08:10.40,Default,,0000,0000,0000,,These creatures speak their love
Dialogue: 0,0:08:10.40,0:08:13.30,Default,,0000,0000,0000,,in the language of light.
Dialogue: 0,0:08:13.30,0:08:18.20,Default,,0000,0000,0000,,So what exactly do these females consider sexy?
Dialogue: 0,0:08:18.20,0:08:20.94,Default,,0000,0000,0000,,We decided to conduct some firefly opinion polls
Dialogue: 0,0:08:20.94,0:08:22.70,Default,,0000,0000,0000,,to find out.
Dialogue: 0,0:08:22.70,0:08:25.91,Default,,0000,0000,0000,,When we tested females using blinking LED lights,
Dialogue: 0,0:08:25.91,0:08:28.22,Default,,0000,0000,0000,,we discovered they prefer males
Dialogue: 0,0:08:28.22,0:08:32.28,Default,,0000,0000,0000,,who give longer-lasting flashes.
Dialogue: 0,0:08:32.28,0:08:35.89,Default,,0000,0000,0000,,(Laughter) (Applause)
Dialogue: 0,0:08:35.89,0:08:37.07,Default,,0000,0000,0000,,I know you're wondering,
Dialogue: 0,0:08:37.07,0:08:40.27,Default,,0000,0000,0000,,what gives these males their sex appeal?
Dialogue: 0,0:08:40.27,0:08:41.65,Default,,0000,0000,0000,,Now we get to see what happens
Dialogue: 0,0:08:41.65,0:08:44.21,Default,,0000,0000,0000,,when the lights go out.
Dialogue: 0,0:08:44.21,0:08:45.68,Default,,0000,0000,0000,,The first thing we discovered
Dialogue: 0,0:08:45.68,0:08:48.45,Default,,0000,0000,0000,,is that once a male and female hook up like this,
Dialogue: 0,0:08:48.45,0:08:51.19,Default,,0000,0000,0000,,they stay together all night long,
Dialogue: 0,0:08:51.19,0:08:52.42,Default,,0000,0000,0000,,and when we looked inside
Dialogue: 0,0:08:52.42,0:08:53.85,Default,,0000,0000,0000,,to see what might be happening,
Dialogue: 0,0:08:53.85,0:08:56.14,Default,,0000,0000,0000,,we discovered a surprising new twist
Dialogue: 0,0:08:56.14,0:08:58.10,Default,,0000,0000,0000,,to firefly sex.
Dialogue: 0,0:08:58.10,0:08:59.28,Default,,0000,0000,0000,,While they're mating,
Dialogue: 0,0:08:59.28,0:09:01.08,Default,,0000,0000,0000,,the male is busy giving the female
Dialogue: 0,0:09:01.08,0:09:03.05,Default,,0000,0000,0000,,not just his sperm
Dialogue: 0,0:09:03.05,0:09:07.16,Default,,0000,0000,0000,,but also a nutrient-filled package
Dialogue: 0,0:09:07.16,0:09:11.78,Default,,0000,0000,0000,,called a nuptial gift.
Dialogue: 0,0:09:11.78,0:09:13.71,Default,,0000,0000,0000,,We can zoom in to look more closely
Dialogue: 0,0:09:13.71,0:09:15.27,Default,,0000,0000,0000,,inside this mating pair.
Dialogue: 0,0:09:15.27,0:09:16.97,Default,,0000,0000,0000,,We can actually see the gift —
Dialogue: 0,0:09:16.97,0:09:18.38,Default,,0000,0000,0000,,it's shown here in red —
Dialogue: 0,0:09:18.38,0:09:22.33,Default,,0000,0000,0000,,as it's being passed from the male to the female.
Dialogue: 0,0:09:22.33,0:09:25.46,Default,,0000,0000,0000,,What makes this gift so valuable
Dialogue: 0,0:09:25.46,0:09:27.32,Default,,0000,0000,0000,,is that it's packed with protein
Dialogue: 0,0:09:27.32,0:09:31.78,Default,,0000,0000,0000,,that the female will use to provision her eggs.
Dialogue: 0,0:09:31.78,0:09:35.65,Default,,0000,0000,0000,,So females are keeping their eyes on this prize
Dialogue: 0,0:09:35.65,0:09:37.92,Default,,0000,0000,0000,,as they size up potential mates.
Dialogue: 0,0:09:37.92,0:09:40.79,Default,,0000,0000,0000,,We discovered that females use male flash signals
Dialogue: 0,0:09:40.79,0:09:42.84,Default,,0000,0000,0000,,to try to predict which males
Dialogue: 0,0:09:42.84,0:09:44.91,Default,,0000,0000,0000,,have the biggest gifts to offer,
Dialogue: 0,0:09:44.91,0:09:49.75,Default,,0000,0000,0000,,because this bling helps the female lay more eggs
Dialogue: 0,0:09:49.75,0:09:52.100,Default,,0000,0000,0000,,and ultimately launch more of her own offspring
Dialogue: 0,0:09:52.100,0:09:55.75,Default,,0000,0000,0000,,into the next generation.
Dialogue: 0,0:09:57.69,0:09:59.70,Default,,0000,0000,0000,,So it's not all sweetness and light.
Dialogue: 0,0:09:59.70,0:10:02.47,Default,,0000,0000,0000,,Firefly romance is risky.
Dialogue: 0,0:10:02.47,0:10:04.94,Default,,0000,0000,0000,,For the most part, these adult fireflies
Dialogue: 0,0:10:04.94,0:10:07.63,Default,,0000,0000,0000,,don't get eaten because like their juveniles
Dialogue: 0,0:10:07.63,0:10:10.56,Default,,0000,0000,0000,,they can manufacture toxins that are repellent
Dialogue: 0,0:10:10.56,0:10:13.62,Default,,0000,0000,0000,,to birds and other insectivores,
Dialogue: 0,0:10:13.62,0:10:16.12,Default,,0000,0000,0000,,but somewhere along the line,
Dialogue: 0,0:10:16.12,0:10:18.44,Default,,0000,0000,0000,,one particular group of fireflies
Dialogue: 0,0:10:18.44,0:10:21.57,Default,,0000,0000,0000,,somehow lost the metabolic machinery
Dialogue: 0,0:10:21.57,0:10:25.37,Default,,0000,0000,0000,,needed to make their own protective toxins.
Dialogue: 0,0:10:25.37,0:10:27.65,Default,,0000,0000,0000,,This evolutionary flaw,
Dialogue: 0,0:10:27.65,0:10:30.36,Default,,0000,0000,0000,,which was discovered by my colleague Tom Eisner,
Dialogue: 0,0:10:30.36,0:10:32.30,Default,,0000,0000,0000,,has driven these fireflies
Dialogue: 0,0:10:32.30,0:10:35.70,Default,,0000,0000,0000,,to take their bright lights out into the night
Dialogue: 0,0:10:35.70,0:10:39.38,Default,,0000,0000,0000,,with treacherous intent.
Dialogue: 0,0:10:39.38,0:10:41.01,Default,,0000,0000,0000,,Dubbed "femme fatales"
Dialogue: 0,0:10:41.01,0:10:43.50,Default,,0000,0000,0000,,by Jim Lloyd, another colleague,
Dialogue: 0,0:10:43.50,0:10:46.41,Default,,0000,0000,0000,,these females have figured out how to target
Dialogue: 0,0:10:46.41,0:10:50.22,Default,,0000,0000,0000,,the males of other firefly species.
Dialogue: 0,0:10:50.22,0:10:52.12,Default,,0000,0000,0000,,So the hunt begins with the predator —
Dialogue: 0,0:10:52.12,0:10:54.17,Default,,0000,0000,0000,,she's shown here in the lower left —
Dialogue: 0,0:10:54.17,0:10:56.22,Default,,0000,0000,0000,,where she's sitting quietly
Dialogue: 0,0:10:56.22,0:10:59.35,Default,,0000,0000,0000,,and eavesdropping on the courtship conversation
Dialogue: 0,0:10:59.35,0:11:00.79,Default,,0000,0000,0000,,of her intended prey,
Dialogue: 0,0:11:00.79,0:11:02.80,Default,,0000,0000,0000,,and here's how it might go.
Dialogue: 0,0:11:02.80,0:11:06.67,Default,,0000,0000,0000,,First the prey male flashes, "Do you love me?"
Dialogue: 0,0:11:06.67,0:11:10.78,Default,,0000,0000,0000,,His own female responds, "Maybe."
Dialogue: 0,0:11:10.78,0:11:13.60,Default,,0000,0000,0000,,So then he flashes again.
Dialogue: 0,0:11:13.60,0:11:17.16,Default,,0000,0000,0000,,But this time, the predator sneaks in a reply
Dialogue: 0,0:11:17.16,0:11:22.83,Default,,0000,0000,0000,,that cleverly mimics exactly\Nwhat the other female just said.
Dialogue: 0,0:11:22.83,0:11:27.30,Default,,0000,0000,0000,,She's not looking for love: she's looking for toxins.
Dialogue: 0,0:11:27.30,0:11:31.18,Default,,0000,0000,0000,,If she's good, she can lure this male close enough
Dialogue: 0,0:11:31.18,0:11:34.17,Default,,0000,0000,0000,,to reach out and grab him,
Dialogue: 0,0:11:34.17,0:11:36.61,Default,,0000,0000,0000,,and he's not just a light snack.
Dialogue: 0,0:11:36.61,0:11:39.45,Default,,0000,0000,0000,,Over the next hour, she slowly
Dialogue: 0,0:11:39.45,0:11:42.31,Default,,0000,0000,0000,,exsanguinates this male
Dialogue: 0,0:11:42.31,0:11:46.00,Default,,0000,0000,0000,,leaving behind just some gory remains.
Dialogue: 0,0:11:46.00,0:11:48.75,Default,,0000,0000,0000,,Unable to make their own toxins,
Dialogue: 0,0:11:48.75,0:11:51.09,Default,,0000,0000,0000,,these females resort to drinking the blood
Dialogue: 0,0:11:51.09,0:11:55.78,Default,,0000,0000,0000,,of other fireflies to get these protective chemicals.
Dialogue: 0,0:11:55.78,0:12:01.63,Default,,0000,0000,0000,,So a firefly vampire,
Dialogue: 0,0:12:01.63,0:12:05.98,Default,,0000,0000,0000,,brought to you by natural selection.
Dialogue: 0,0:12:05.98,0:12:09.16,Default,,0000,0000,0000,,We still have a lot to learn about fireflies,
Dialogue: 0,0:12:09.16,0:12:12.54,Default,,0000,0000,0000,,but it looks like many stories will remain untold,
Dialogue: 0,0:12:12.54,0:12:14.97,Default,,0000,0000,0000,,because around the world, firefly populations
Dialogue: 0,0:12:14.97,0:12:17.63,Default,,0000,0000,0000,,are blinking out.
Dialogue: 0,0:12:17.63,0:12:20.22,Default,,0000,0000,0000,,The main culprit: habitat loss.
Dialogue: 0,0:12:20.22,0:12:22.70,Default,,0000,0000,0000,,Pretty much everywhere, the fields and forests,
Dialogue: 0,0:12:22.70,0:12:25.65,Default,,0000,0000,0000,,the mangroves and meadows\Nthat fireflies need to survive,
Dialogue: 0,0:12:25.65,0:12:29.28,Default,,0000,0000,0000,,are giving way to development and to sprawl.
Dialogue: 0,0:12:29.28,0:12:33.47,Default,,0000,0000,0000,,Here's another problem: we've conquered darkness,
Dialogue: 0,0:12:33.47,0:12:36.96,Default,,0000,0000,0000,,but in the process, we spill so\Nmuch extra light out into the night
Dialogue: 0,0:12:36.96,0:12:40.09,Default,,0000,0000,0000,,that it disrupts the lives of other creatures,
Dialogue: 0,0:12:40.09,0:12:43.53,Default,,0000,0000,0000,,and fireflies are especially sensitive to light pollution
Dialogue: 0,0:12:43.53,0:12:46.16,Default,,0000,0000,0000,,because it obscures the signals
Dialogue: 0,0:12:46.16,0:12:50.61,Default,,0000,0000,0000,,that they use to find their mates.
Dialogue: 0,0:12:50.61,0:12:52.59,Default,,0000,0000,0000,,Do we really need fireflies?
Dialogue: 0,0:12:52.59,0:12:54.63,Default,,0000,0000,0000,,After all, they're just one tiny bit
Dialogue: 0,0:12:54.63,0:12:56.90,Default,,0000,0000,0000,,of Earth's biodiversity.
Dialogue: 0,0:12:56.90,0:13:00.21,Default,,0000,0000,0000,,Yet every time a species is lost,
Dialogue: 0,0:13:00.21,0:13:02.90,Default,,0000,0000,0000,,it's like extinguishing a room full of candles
Dialogue: 0,0:13:02.90,0:13:05.82,Default,,0000,0000,0000,,one by one.
Dialogue: 0,0:13:05.82,0:13:06.77,Default,,0000,0000,0000,,You might not notice
Dialogue: 0,0:13:06.77,0:13:10.06,Default,,0000,0000,0000,,when the first few flames flicker out,
Dialogue: 0,0:13:10.06,0:13:14.44,Default,,0000,0000,0000,,but in the end, you're left sitting in darkness.
Dialogue: 0,0:13:19.59,0:13:24.41,Default,,0000,0000,0000,,As we work together to craft a planetary future,
Dialogue: 0,0:13:24.41,0:13:26.88,Default,,0000,0000,0000,,I hope we can find a way
Dialogue: 0,0:13:26.88,0:13:30.33,Default,,0000,0000,0000,,to keep these bright lights shining.
Dialogue: 0,0:13:30.33,0:13:32.36,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:13:32.36,0:13:34.67,Default,,0000,0000,0000,,(Applause)