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  • Imagine a place so dark

  • you can't see the nose on your face.

  • Eyes opened or closed, it's all the same

  • because the sun never shines there.

  • Up ahead, you see a light.

  • When you creep in to investigate,

  • a blue light flits around you.

  • "I could watch this forever," you think.

  • But you can't

  • because the mouth of an anglerfish has just sprung open

  • and eaten you alive.

  • You are just one of many creatures

  • at the bottom of the ocean who learn too late

  • to appreciate the power of bioluminescence.

  • Bioluminescence refers to the ability

  • of certain living things to create light.

  • The human body can make stuff

  • like ear wax and toe nails,

  • but these organisms can turn

  • parts of their body into glow sticks.

  • It's like nature made them ready to rave.

  • Why?

  • In one way or another,

  • bioluminescence improves a living thing's chances of survival.

  • Take the firefly.

  • It's ability to glow green

  • helps it attract a mate on a warm, summer night,

  • but it's just one of many living things that can glow.

  • The railroad worm, Phrixothrix hirtus,

  • can light up its body in two colors:

  • red and green.

  • Would you eat something

  • that looks like an airport runway?

  • Neither would any sensible predator.

  • The flashing lights keep the worm safe.

  • Then there's the deep sea shrimp,

  • Acantherphyra purpurea.

  • When it feels threatened,

  • it spews a cloud of glowing goo from its mouth.

  • Who doesn't run the other way

  • when they've just been puked on?

  • Plus, that puke attracts bigger predators

  • who want to eat the shrimp's enemy.

  • So what if you can't bioluminesce?

  • No problem!

  • There are other ways for living things

  • to make bioluminescence work for them,

  • even if they weren't born with the equipment to glow.

  • Let's revisit the anglerfish

  • moments before it tried to eat you.

  • That glowing bait on top of its head?

  • It comes from a pocket of skin called the esca.

  • The esca holds bioluminescent bacteria.

  • The anglerfish can't glow there by itself,

  • so it holds a sack of glowing bacteria instead.

  • Remember the firefly?

  • It can actually make itself glow.

  • Inside its lantern are two chemicals,

  • a luciferin and a luciferase.

  • When firefly luciferase and luciferin mix together

  • in the presence of oxygen

  • and fuel for the cell, called ATP,

  • the chemical reaction gives off energy in the form of light.

  • Once scientists figured out

  • how the firefly creates its luciferase and luciferin,

  • they used genetic engineering

  • to make this light-producing reaction

  • occur inside other living things that can't glow.

  • For example, they inserted the genes,

  • or instructions, for a cell

  • to create firefly luciferase and luciferin into a tobacco plant.

  • Once there, the tobacco plant followed the instructions

  • slipped into its DNA and lit up like a Christmas tree.

  • The beauty of bioluminescence,

  • unlike the light from the sun or an incandescent bulb,

  • is that it's not hot.

  • It takes place in a range of temperatures

  • that don't burn a living thing.

  • And unlike a glow stick,

  • which fades out as the chemicals inside get used up,

  • bioluminescent reactions use replenishable resources.

  • That's one reason engineers

  • are trying to develop bioluminescent trees.

  • Just think, if planted on the side of highways,

  • they could light the way, using only oxygen

  • and other freely available, clean resources to run.

  • Talk about survival advantage!

  • That could help our planet live longer.

  • Do you find yourself thinking of other ways

  • to put bioluminescence to good use?

  • That glow stick you swing at a rave

  • may help you find a mate,

  • but how else can bioluminescence improve your survival?

  • If you start thinking in this way,

  • you have seen the light.

Imagine a place so dark

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B1 TED-Ed bioluminescence glow firefly glowing living

【TED-Ed】The brilliance of bioluminescence - Leslie Kenna

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    Zenn posted on 2014/05/31
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