Psychedelics, mind control, radiation-eating: The secret superpowers of fungi - Max G. Levy — Transcript

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1. 0:06When scientists sample the soil, bodies of water, or even the air for DNA,
2. 0:13they routinely unmask thousands of tiny mysteries—
3. 0:17unique fragments of fungal DNA that don't match any known species.
4. 0:23This DNA belongs to cryptic organisms, often referred to as “dark fungi,”
5. 0:30which, like dark matter and dark energy,
6. 0:33are simultaneously all around us and yet elude discovery.
7. 0:38Scientists estimate that somewhere between 2 and 12 million species of fungi
8. 0:45remain undiscovered—
9. 0:47their physical structures yet to be seen,
10. 0:49either because they’re microscopic, live hidden within other species,
11. 0:54or for other unknown reasons.
12. 0:57The diverse fungal kingdom,
13. 0:59which includes everything from baker's yeast to edible mushrooms
14. 1:03to foot infections,
15. 1:05has long defied assumptions.
16. 1:08For centuries, biologists mistakenly classified them as plants,
17. 1:13for what they’d argue were good reasons:
18. 1:16many grow from the soil atop branching, root-like networks.
19. 1:20But at the biological level, they're very different.
20. 1:24Unlike plants that harness energy from the Sun,
21. 1:27fungi eat by decomposing matter or siphoning nutrients from other organisms.
22. 1:34Rather than cellulose, their cell walls are made of chitin,
23. 1:38the same material in exoskeletons of insects, like beetles,
24. 1:43and crustaceans, like shrimps.
25. 1:46Fungi are actually more closely related to animals than plants,
26. 1:51sharing a common ancestor
27. 1:53which first appeared over 1 billion years ago.
28. 1:58Over time, fungi evolved to occupy a range of ecological roles,
29. 2:03including intertwined relationships with plants.
30. 2:07Many plants can't survive without these fungal partners.
31. 2:11Ectomycorrhizal fungi envelop plant roots,
32. 2:15trading nutrients they forage in the soil, like phosphorus and nitrogen,
33. 2:20for carbon to fuel their growth.
34. 2:23Another guild, called arbuscular mycorrhizal fungi,
35. 2:27goes so far as puncturing plant root cells like straws to aid in this exchange.
36. 2:33This relationship enabled plants to colonize land 470 million years ago,
37. 2:40when nutrients were far more difficult to obtain from the barren, rocky ground.
38. 2:46Other fungi evolved remarkable strategies to defend against, exploit,
39. 2:52and manipulate their neighbors,
40. 2:54often by producing an arsenal of compounds
41. 2:57like antibiotics, toxins, and even psychedelics.
42. 3:02Many mushrooms in the genus Psilocybe produce psilocybin,
43. 3:06a molecule that binds to serotonin receptors
44. 3:09in the bodies and brains of animals.
45. 3:12This causes hallucinogenic effects in humans,
46. 3:16though psilocybin likely evolved to deter hungry slugs or snails.
47. 3:21Clathrus archeri, a cluster of red tentacle-like mushrooms,
48. 3:26sometimes called “devil’s fingers,”
49. 3:29emits a sticky, spore-filled slime called gleba.
50. 3:34It smells like rotting flesh,
51. 3:36attracting nearby flies that feed on it and carry spores away on their bodies.
52. 3:42Other fungi take a more extreme approach.
53. 3:45Many species of Cordyceps infect ants,
54. 3:49chemically hijacking their nervous systems with toxins
55. 3:53and connecting directly to muscle fibers to puppeteer their movements.
56. 3:58The infected ants become zombies,
57. 4:00compelled to climb to high places and eject millions of fungal spores.
58. 4:07Still other fungi are more self-reliant,
59. 4:10carving out solitary lives in extreme environments,
60. 4:13like the walls of nuclear wastelands.
61. 4:16Researchers have observed at least 37 species of fungi
62. 4:20living among the ruins in Chernobyl,
63. 4:23home to one of the world’s worst nuclear disasters.
64. 4:26Many are rich in melanin,
65. 4:28a pigment that can absorb harmful radiation to protect fungal cells and DNA.
66. 4:34But some don’t just endure radiation— they eat it.
67. 4:38Studies conducted on the International Space Station revealed
68. 4:42that species like Cryptococcus neoformans can convert absorbed gamma radiation
69. 4:49into useful energy,
70. 4:50establishing a previously unknown metabolic strategy,
71. 4:54and redefining the perceived limits of life.
72. 4:59The planet-wide consequences of this fleet of fungal functions
73. 5:03are still making themselves known.
74. 5:06In the Arctic tundra, fungi form a vast underground network,
75. 5:11helping plants survive the harsh winters,
76. 5:14while stockpiling carbon from the atmosphere.
77. 5:17Scientists suspect these soils may be particularly rich in rare, dark fungi.
78. 5:24And these fungal networks, along the plants they support,
79. 5:28may sequester about 1 trillion metric tons of carbon—
80. 5:3210 times more than the entire Amazon rainforest—
81. 5:36potentially keeping Earth resilient against climate change.
82. 5:41The fungal world we see is vast and wild.
83. 5:45Who knows what other wonders might be growing just beyond our view.