English 字幕

← The invisible life hidden beneath Antarctica's ice

获得嵌入代码
55种语言

Showing Revision 8 created 07/20/2020 by Erin Gregory.

  1. Can you guess what this is?
  2. What if I told you there's a place
    where the creatures are made of glass?
  3. Or that there are life-forms
    that are invisible to us,
  4. but astronauts see them all the time?
  5. These invisible glass creatures
    aren't aliens on a faraway exoplanet.

  6. They're diatoms:
  7. photosynthetic, single-celled algae
    responsible for producing oxygen
  8. and helping seed clouds
    on a planetary scale
  9. and with intricately sculpted,
    geometric exoskeletons made of --
  10. yeah, glass.
  11. You can see them in swirls
    of ocean-surface colors from space.
  12. And when they die,
  13. their glass houses sink
    to the depths of the oceans,
  14. taking carbon out of the air
  15. and with them to the grave,
  16. accounting for a significant amount
    of carbon sequestration in the oceans.
  17. We live on an alien planet.

  18. There is so much weird life
    here on Earth to study,
  19. and so much of it lives
    at the edges of our world,
  20. of our sight and of our understanding.
  21. One of those edges is Antarctica.
  22. Typically, when we think about Antarctica,

  23. we think of a place
    that's barren and lifeless ...
  24. except for a few penguins.
  25. But Antarctica should instead
    be known as a polar oasis of life,
  26. host to countless creatures
    that are utterly fascinating.
  27. So why haven't we seen them
    on the latest nature documentary?
  28. Well, they lurk beneath the snow and ice,
  29. virtually invisible to us.
  30. They're microbes:
  31. tiny plants and animals living
    embedded inside of glaciers,
  32. underneath the sea ice
  33. and swimming in subglacial ponds.
  34. And they're no less charismatic
    than any of the megafauna
  35. that you're used to seeing
    in a nature documentary.
  36. But how do you compel people
    to explore what they can't see?

  37. I recently led a five-week
    expedition to Antarctica
  38. to essentially become a wildlife
    filmmaker at the microbial scale.
  39. With 185 pounds of gear,
  40. I boarded a military aircraft
  41. and brought microscopes into the field
  42. to film and investigate
    these microscopic extremophiles,
  43. so that we can become more familiar
    with a poorly understood ecosystem
  44. that we live with here on Earth.
  45. To film these invisible
    creatures in action,

  46. I needed to see where they call home --
  47. I needed to venture under the ice.
  48. Every year, the sea ice nearly doubles
    the entire size of Antarctica.
  49. To get a glimpse below
    the nine-feet-thick ice,
  50. I climbed down a long, metal tube
    inserted into the sea ice
  51. to witness a hidden
    ecosystem full of life,
  52. while being suspended between the seafloor
    and the illuminated ceiling of ice.
  53. Here's what that looked like
    from the outside.
  54. It was just absolutely magical.
  55. Some of the critters I found
    were delightful things like seed shrimp
  56. and many more beautiful,
    geometric diatoms.
  57. I then went farther afield
    to camp out in the Dry Valleys

  58. for a couple of weeks.
  59. 98 percent of Antarctica
    is covered with ice
  60. and the Dry Valleys are the largest area
    of Antarctica where you can actually see
  61. what the continent itself
    looks like underneath all of it.
  62. I sampled bacteria at Blood Falls,
  63. a natural phenomenon of a subglacial pond
    spurting out iron oxide
  64. that was thought to be utterly lifeless
    until a little more than a decade ago.
  65. And I hiked up a glacier
    to drill down into it,
  66. revealing countless, hardcore critters
    living their best lives
  67. while embedded inside layers of ice.
  68. Known as cryoconite holes,
  69. they form when tiny pieces
    of darkly colored dirt
  70. get blown onto the glacier
  71. and begin to melt down into soupy holes
    that then freeze over,
  72. preserving hundreds of dirt pucks
    inside the glacier,
  73. like little island universes
  74. each with its own unique ecosystem.
  75. Some of the critters I found
    you may recognize,

  76. like this adorable tardigrade --
  77. I absolutely love them,
  78. they're like little
    gummy bears with claws.
  79. Also known as a water bear,
  80. they're famous for possessing superpowers
  81. that allow them to survive
    in extreme conditions,
  82. including the vacuum of space.
  83. But you don't need to travel to space
    or even Antarctica to find them.
  84. They live in moss all over this planet,
  85. from sidewalk cracks to parks.
  86. You likely walk right by tons
    of these invisible animals every day.
  87. Others may look familiar,

  88. but be stranger still, like nematodes.
  89. Not a snake nor an earthworm,
  90. nematodes are a creature all of their own.
  91. They can't regenerate like an earthworm
    or crawl like a snake,
  92. but they have tiny, dagger-like
    needles inside their mouths
  93. that some of them use to spearfish
    their prey and suck out the insides.
  94. For every single human on this planet,
  95. there exist 57 billion nematodes.
  96. And some of the critters
    you may not recognize at all

  97. but live out equally fascinating lives,
  98. such as rotifers with amazing crowns
    that turn into Roomba-like mouths,
  99. ciliates with digestive systems
    so transparent that it's almost TMI,
  100. and cyanobacteria that look like party
    confetti exploded all over a petri dish.
  101. A lot of times what we see
    in popular media

  102. are scanning electron microscope
    images of microorganisms
  103. looking like scary monsters.
  104. Without seeing them move
    their lives remain elusive to us
  105. despite them living nearly
    everywhere we step outside.
  106. What's their daily life like?
  107. How do they interact
    with their environment?
  108. If you only ever saw a photo
    of a penguin at a zoo,
  109. but you never saw one waddle around
    and then glide over ice,
  110. you wouldn't fully understand penguins.
  111. By seeing microcreatures in motion,
  112. we gain better insights into the lives
    of the otherwise invisible.
  113. Without documenting the invisible life
    in Antarctica and our own backyards,
  114. we don't understand just how many
    creatures we share our world with.
  115. And that means we don't yet
    have the full picture
  116. of our weird and whimsical home planet.
  117. Thank you.