1 00:00:14,226 --> 00:00:15,931 Imagine a place so dark 2 00:00:15,931 --> 00:00:18,149 you can't see the nose on your face. 3 00:00:18,149 --> 00:00:21,217 Eyes opened or closed, it's all the same 4 00:00:21,217 --> 00:00:23,985 because the sun never shines there. 5 00:00:23,985 --> 00:00:26,073 Up ahead, you see a light. 6 00:00:26,073 --> 00:00:27,961 When you creep in to investigate, 7 00:00:27,961 --> 00:00:30,212 a blue light flits around you. 8 00:00:30,212 --> 00:00:32,396 "I could watch this forever," you think. 9 00:00:32,396 --> 00:00:33,417 But you can't 10 00:00:33,417 --> 00:00:36,268 because the mouth of an anglerfish has just sprung open 11 00:00:36,268 --> 00:00:38,471 and eaten you alive. 12 00:00:38,471 --> 00:00:40,046 You are just one of many creatures 13 00:00:40,046 --> 00:00:42,352 at the bottom of the ocean who learn too late 14 00:00:42,352 --> 00:00:45,939 to appreciate the power of bioluminescence. 15 00:00:45,939 --> 00:00:48,233 Bioluminescence refers to the ability 16 00:00:48,233 --> 00:00:50,858 of certain living things to create light. 17 00:00:50,858 --> 00:00:52,535 The human body can make stuff 18 00:00:52,535 --> 00:00:55,626 like ear wax and toe nails, 19 00:00:55,626 --> 00:00:57,214 but these organisms can turn 20 00:00:57,214 --> 00:00:59,862 parts of their body into glow sticks. 21 00:00:59,862 --> 00:01:02,230 It's like nature made them ready to rave. 22 00:01:02,230 --> 00:01:03,203 Why? 23 00:01:03,203 --> 00:01:04,539 In one way or another, 24 00:01:04,539 --> 00:01:08,601 bioluminescence improves a living thing's chances of survival. 25 00:01:08,601 --> 00:01:10,044 Take the firefly. 26 00:01:10,044 --> 00:01:11,603 It's ability to glow green 27 00:01:11,603 --> 00:01:14,434 helps it attract a mate on a warm, summer night, 28 00:01:14,434 --> 00:01:17,342 but it's just one of many living things that can glow. 29 00:01:17,342 --> 00:01:20,054 The railroad worm, Phrixothrix hirtus, 30 00:01:20,054 --> 00:01:21,936 can light up its body in two colors: 31 00:01:21,936 --> 00:01:23,171 red and green. 32 00:01:23,171 --> 00:01:24,261 Would you eat something 33 00:01:24,261 --> 00:01:26,561 that looks like an airport runway? 34 00:01:26,561 --> 00:01:28,813 Neither would any sensible predator. 35 00:01:28,813 --> 00:01:31,719 The flashing lights keep the worm safe. 36 00:01:31,719 --> 00:01:33,778 Then there's the deep sea shrimp, 37 00:01:33,778 --> 00:01:35,527 Acantherphyra purpurea. 38 00:01:35,527 --> 00:01:36,862 When it feels threatened, 39 00:01:36,862 --> 00:01:40,027 it spews a cloud of glowing goo from its mouth. 40 00:01:40,027 --> 00:01:41,326 Who doesn't run the other way 41 00:01:41,326 --> 00:01:43,600 when they've just been puked on? 42 00:01:43,600 --> 00:01:46,143 Plus, that puke attracts bigger predators 43 00:01:46,143 --> 00:01:48,386 who want to eat the shrimp's enemy. 44 00:01:48,386 --> 00:01:50,687 So what if you can't bioluminesce? 45 00:01:50,687 --> 00:01:51,741 No problem! 46 00:01:51,741 --> 00:01:53,322 There are other ways for living things 47 00:01:53,322 --> 00:01:55,524 to make bioluminescence work for them, 48 00:01:55,524 --> 00:01:58,556 even if they weren't born with the equipment to glow. 49 00:01:58,556 --> 00:02:00,400 Let's revisit the anglerfish 50 00:02:00,400 --> 00:02:02,402 moments before it tried to eat you. 51 00:02:02,402 --> 00:02:04,196 That glowing bait on top of its head? 52 00:02:04,196 --> 00:02:07,181 It comes from a pocket of skin called the esca. 53 00:02:07,181 --> 00:02:10,035 The esca holds bioluminescent bacteria. 54 00:02:10,035 --> 00:02:12,290 The anglerfish can't glow there by itself, 55 00:02:12,290 --> 00:02:16,327 so it holds a sack of glowing bacteria instead. 56 00:02:16,327 --> 00:02:18,001 Remember the firefly? 57 00:02:18,001 --> 00:02:20,083 It can actually make itself glow. 58 00:02:20,083 --> 00:02:22,674 Inside its lantern are two chemicals, 59 00:02:22,674 --> 00:02:25,190 a luciferin and a luciferase. 60 00:02:25,190 --> 00:02:28,095 When firefly luciferase and luciferin mix together 61 00:02:28,095 --> 00:02:29,389 in the presence of oxygen 62 00:02:29,389 --> 00:02:31,474 and fuel for the cell, called ATP, 63 00:02:31,474 --> 00:02:35,184 the chemical reaction gives off energy in the form of light. 64 00:02:35,184 --> 00:02:36,644 Once scientists figured out 65 00:02:36,644 --> 00:02:39,606 how the firefly creates its luciferase and luciferin, 66 00:02:39,606 --> 00:02:41,193 they used genetic engineering 67 00:02:41,193 --> 00:02:43,110 to make this light-producing reaction 68 00:02:43,110 --> 00:02:46,259 occur inside other living things that can't glow. 69 00:02:46,259 --> 00:02:48,461 For example, they inserted the genes, 70 00:02:48,461 --> 00:02:50,123 or instructions, for a cell 71 00:02:50,123 --> 00:02:54,363 to create firefly luciferase and luciferin into a tobacco plant. 72 00:02:54,363 --> 00:02:57,216 Once there, the tobacco plant followed the instructions 73 00:02:57,216 --> 00:03:01,231 slipped into its DNA and lit up like a Christmas tree. 74 00:03:01,231 --> 00:03:02,794 The beauty of bioluminescence, 75 00:03:02,794 --> 00:03:05,544 unlike the light from the sun or an incandescent bulb, 76 00:03:05,544 --> 00:03:07,136 is that it's not hot. 77 00:03:07,136 --> 00:03:09,422 It takes place in a range of temperatures 78 00:03:09,422 --> 00:03:11,406 that don't burn a living thing. 79 00:03:11,406 --> 00:03:12,844 And unlike a glow stick, 80 00:03:12,844 --> 00:03:15,720 which fades out as the chemicals inside get used up, 81 00:03:15,720 --> 00:03:19,466 bioluminescent reactions use replenishable resources. 82 00:03:19,466 --> 00:03:20,931 That's one reason engineers 83 00:03:20,931 --> 00:03:24,221 are trying to develop bioluminescent trees. 84 00:03:24,221 --> 00:03:26,767 Just think, if planted on the side of highways, 85 00:03:26,767 --> 00:03:28,817 they could light the way, using only oxygen 86 00:03:28,817 --> 00:03:32,464 and other freely available, clean resources to run. 87 00:03:32,464 --> 00:03:34,539 Talk about survival advantage! 88 00:03:34,539 --> 00:03:37,157 That could help our planet live longer. 89 00:03:37,157 --> 00:03:39,494 Do you find yourself thinking of other ways 90 00:03:39,494 --> 00:03:42,363 to put bioluminescence to good use? 91 00:03:42,363 --> 00:03:44,402 That glow stick you swing at a rave 92 00:03:44,402 --> 00:03:46,001 may help you find a mate, 93 00:03:46,001 --> 00:03:49,754 but how else can bioluminescence improve your survival? 94 00:03:49,754 --> 00:03:51,631 If you start thinking in this way, 95 00:03:51,631 --> 00:03:53,466 you have seen the light.