The brilliance of bioluminescence - Leslie Kenna

2,331,786 views ・ 2013-05-15

TED-Ed


Please double-click on the English subtitles below to play the video.

00:00
Translator: Andrea McDonough Reviewer: Jessica Ruby
0
0
7000
00:14
Imagine a place so dark
1
14226
1705
00:15
you can't see the nose on your face.
2
15931
2218
00:18
Eyes opened or closed, it's all the same
3
18149
3068
00:21
because the sun never shines there.
4
21217
2768
00:23
Up ahead, you see a light.
5
23985
2088
00:26
When you creep in to investigate,
6
26073
1888
00:27
a blue light flits around you.
7
27961
2251
00:30
"I could watch this forever," you think.
8
30212
2184
00:32
But you can't
9
32396
1021
00:33
because the mouth of an anglerfish has just sprung open
10
33417
2851
00:36
and eaten you alive.
11
36268
2203
00:38
You are just one of many creatures
12
38471
1575
00:40
at the bottom of the ocean who learn too late
13
40046
2306
00:42
to appreciate the power of bioluminescence.
14
42352
3587
00:45
Bioluminescence refers to the ability
15
45939
2294
00:48
of certain living things to create light.
16
48233
2625
00:50
The human body can make stuff
17
50858
1677
00:52
like ear wax and toe nails,
18
52535
3091
00:55
but these organisms can turn
19
55626
1588
00:57
parts of their body into glow sticks.
20
57214
2648
00:59
It's like nature made them ready to rave.
21
59862
2368
01:02
Why?
22
62230
973
01:03
In one way or another,
23
63203
1336
01:04
bioluminescence improves a living thing's chances of survival.
24
64539
4062
01:08
Take the firefly.
25
68601
1443
01:10
It's ability to glow green
26
70044
1559
01:11
helps it attract a mate on a warm, summer night,
27
71603
2831
01:14
but it's just one of many living things that can glow.
28
74434
2908
01:17
The railroad worm, Phrixothrix hirtus,
29
77342
2712
01:20
can light up its body in two colors:
30
80054
1882
01:21
red and green.
31
81936
1235
01:23
Would you eat something
32
83171
1090
01:24
that looks like an airport runway?
33
84261
2300
01:26
Neither would any sensible predator.
34
86561
2252
01:28
The flashing lights keep the worm safe.
35
88813
2906
01:31
Then there's the deep sea shrimp,
36
91719
2059
01:33
Acantherphyra purpurea.
37
93778
1749
01:35
When it feels threatened,
38
95527
1335
01:36
it spews a cloud of glowing goo from its mouth.
39
96862
3165
01:40
Who doesn't run the other way
40
100027
1299
01:41
when they've just been puked on?
41
101326
2274
01:43
Plus, that puke attracts bigger predators
42
103600
2543
01:46
who want to eat the shrimp's enemy.
43
106143
2243
01:48
So what if you can't bioluminesce?
44
108386
2301
01:50
No problem!
45
110687
1054
01:51
There are other ways for living things
46
111741
1581
01:53
to make bioluminescence work for them,
47
113322
2202
01:55
even if they weren't born with the equipment to glow.
48
115524
3032
01:58
Let's revisit the anglerfish
49
118556
1844
02:00
moments before it tried to eat you.
50
120400
2002
02:02
That glowing bait on top of its head?
51
122402
1794
02:04
It comes from a pocket of skin called the esca.
52
124196
2985
02:07
The esca holds bioluminescent bacteria.
53
127181
2854
02:10
The anglerfish can't glow there by itself,
54
130035
2255
02:12
so it holds a sack of glowing bacteria instead.
55
132290
4037
02:16
Remember the firefly?
56
136327
1674
02:18
It can actually make itself glow.
57
138001
2082
02:20
Inside its lantern are two chemicals,
58
140083
2591
02:22
a luciferin and a luciferase.
59
142674
2516
02:25
When firefly luciferase and luciferin mix together
60
145190
2905
02:28
in the presence of oxygen
61
148095
1294
02:29
and fuel for the cell, called ATP,
62
149389
2085
02:31
the chemical reaction gives off energy in the form of light.
63
151474
3710
02:35
Once scientists figured out
64
155184
1460
02:36
how the firefly creates its luciferase and luciferin,
65
156644
2962
02:39
they used genetic engineering
66
159606
1587
02:41
to make this light-producing reaction
67
161193
1917
02:43
occur inside other living things that can't glow.
68
163110
3149
02:46
For example, they inserted the genes,
69
166259
2202
02:48
or instructions, for a cell
70
168461
1662
02:50
to create firefly luciferase and luciferin into a tobacco plant.
71
170123
4240
02:54
Once there, the tobacco plant followed the instructions
72
174363
2853
02:57
slipped into its DNA and lit up like a Christmas tree.
73
177216
4015
03:01
The beauty of bioluminescence,
74
181231
1563
03:02
unlike the light from the sun or an incandescent bulb,
75
182794
2750
03:05
is that it's not hot.
76
185544
1592
03:07
It takes place in a range of temperatures
77
187136
2286
03:09
that don't burn a living thing.
78
189422
1984
03:11
And unlike a glow stick,
79
191406
1438
03:12
which fades out as the chemicals inside get used up,
80
192844
2876
03:15
bioluminescent reactions use replenishable resources.
81
195720
3746
03:19
That's one reason engineers
82
199466
1465
03:20
are trying to develop bioluminescent trees.
83
200931
3290
03:24
Just think, if planted on the side of highways,
84
204221
2546
03:26
they could light the way, using only oxygen
85
206767
2050
03:28
and other freely available, clean resources to run.
86
208817
3647
03:32
Talk about survival advantage!
87
212464
2075
03:34
That could help our planet live longer.
88
214539
2618
03:37
Do you find yourself thinking of other ways
89
217157
2337
03:39
to put bioluminescence to good use?
90
219494
2869
03:42
That glow stick you swing at a rave
91
222363
2039
03:44
may help you find a mate,
92
224402
1599
03:46
but how else can bioluminescence improve your survival?
93
226001
3753
03:49
If you start thinking in this way,
94
229754
1877
03:51
you have seen the light.
95
231631
1835
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7