1 00:00:05,372 --> 00:00:07,373 ROWE: The universe... 2 00:00:07,474 --> 00:00:10,909 Vast, dynamic, and explosive. 3 00:00:11,011 --> 00:00:12,444 [explosion blasts] 4 00:00:12,545 --> 00:00:15,814 But this huge cosmos, with its billions of galaxies 5 00:00:15,915 --> 00:00:17,549 and countless stars, 6 00:00:17,650 --> 00:00:21,286 isn't the only one... We share our lives with 7 00:00:21,388 --> 00:00:22,488 another universe. 8 00:00:22,589 --> 00:00:24,390 The world of the small, 9 00:00:24,491 --> 00:00:27,693 of the viruses, of the bacteria. 10 00:00:27,794 --> 00:00:32,131 ROWE: We call this strange hidden kingdom the microcosmos. 11 00:00:32,232 --> 00:00:35,000 LANZA: The microcosmos is incredibly important. 12 00:00:35,101 --> 00:00:38,037 Even though we can't see it, it's everywhere. 13 00:00:38,138 --> 00:00:39,671 It's almost like another universe 14 00:00:39,773 --> 00:00:41,373 or another world all in its own. 15 00:00:42,842 --> 00:00:44,643 ROWE: It guided our evolution... 16 00:00:44,744 --> 00:00:47,646 We wouldn't be here without the microcosmos. 17 00:00:47,747 --> 00:00:49,548 ...and it keeps us alive. 18 00:00:49,649 --> 00:00:52,284 The microcosmos is responsible for 19 00:00:52,385 --> 00:00:54,853 the very oxygen that we breathe. 20 00:00:54,954 --> 00:00:58,123 ROWE: And it will influence our future as we venture out 21 00:00:58,224 --> 00:00:59,491 into space. 22 00:00:59,592 --> 00:01:02,528 OLUSEYI: And if we were ever to find a place where 23 00:01:02,629 --> 00:01:06,331 there is life, potentially a new microcosmos, 24 00:01:06,433 --> 00:01:09,401 we would have no immunity if they're bad. 25 00:01:09,502 --> 00:01:12,104 ROWE: We share our world with the microcosmos. 26 00:01:12,205 --> 00:01:16,141 Will we coexist in an uneasy peace, 27 00:01:16,242 --> 00:01:19,378 or will it destroy us? 28 00:01:21,614 --> 00:01:23,782 [explosion blasts] 29 00:01:32,592 --> 00:01:36,695 A strange invisible assassin stalks its prey. 30 00:01:36,796 --> 00:01:39,098 It attacks and hijacks the cell, 31 00:01:39,199 --> 00:01:42,067 forcing it to produce hundreds of new raiders. 32 00:01:43,837 --> 00:01:48,040 This is what happens when the microcosmos turns on us. 33 00:01:48,141 --> 00:01:51,110 In 2020, we experienced this invasion 34 00:01:51,211 --> 00:01:54,480 of the body snatchers first-hand. 35 00:01:54,581 --> 00:01:59,952 A tiny virus caused a global pandemic... COVID-19. 36 00:02:00,053 --> 00:02:02,721 This pandemic makes me see the world completely 37 00:02:02,789 --> 00:02:05,591 differently, because there was an invisible universe, 38 00:02:05,692 --> 00:02:07,693 one that covers me and is within me 39 00:02:07,794 --> 00:02:10,629 that I pretty much ignored for the most part. 40 00:02:11,831 --> 00:02:13,832 ROWE: Maybe we ignore this other universe 41 00:02:13,933 --> 00:02:16,668 because it's invisible to the naked eye. 42 00:02:16,769 --> 00:02:19,872 PLAIT: We live in a largely invisible universe. 43 00:02:19,973 --> 00:02:22,374 We can't see everything that's going on. 44 00:02:22,475 --> 00:02:24,643 Some of the biggest stuff we can't see very well, 45 00:02:24,744 --> 00:02:28,080 and, in fact, a lot of the littlest stuff we can't either. 46 00:02:28,181 --> 00:02:30,516 Just because something is too small to see 47 00:02:30,617 --> 00:02:32,251 doesn't mean it's not important. 48 00:02:32,352 --> 00:02:34,553 In fact, very, very tiny things 49 00:02:34,654 --> 00:02:37,489 have a huge impact on our lives. 50 00:02:37,590 --> 00:02:40,659 ROWE: Some of these impacts are beneficial, 51 00:02:40,760 --> 00:02:43,328 but they're overshadowed by the devastating effects 52 00:02:43,429 --> 00:02:44,997 of disease. 53 00:02:45,098 --> 00:02:49,401 The longest-running conflict that humanity has been 54 00:02:49,502 --> 00:02:51,436 engaged in is that against 55 00:02:51,538 --> 00:02:55,407 the microcosmos, our long running battle against 56 00:02:55,508 --> 00:02:57,442 the bacteria and viruses 57 00:02:57,544 --> 00:02:58,510 that are trying to kill us. 58 00:02:59,646 --> 00:03:03,115 ROWE: A century ago, we faced the Spanish flu. 59 00:03:03,216 --> 00:03:06,552 HOWETT: This absolutely annihilated Europe at the time. 60 00:03:06,653 --> 00:03:08,520 It caused millions upon millions of death. 61 00:03:08,621 --> 00:03:11,056 So this is definitely not the first pandemic, 62 00:03:11,157 --> 00:03:13,392 quite frankly, probably isn't the last one. 63 00:03:13,493 --> 00:03:16,528 In a way, the coronavirus has forced us to come 64 00:03:16,663 --> 00:03:19,431 to a greater understanding of the microscopic world. 65 00:03:21,201 --> 00:03:23,635 ROWE: The microcosmos is complex. 66 00:03:23,736 --> 00:03:28,106 While some parts kill us, others keep us alive. 67 00:03:28,208 --> 00:03:31,276 Microcosmos is important for us to survive, 68 00:03:31,377 --> 00:03:33,545 in order for us to do all of the things 69 00:03:33,646 --> 00:03:35,314 that our body does, in order for us to live 70 00:03:35,415 --> 00:03:36,815 and grow and thrive. 71 00:03:36,916 --> 00:03:39,518 Our lives depend on the microcosmos. 72 00:03:39,619 --> 00:03:43,188 The air we breathe and the surface of the Earth around 73 00:03:43,289 --> 00:03:46,992 us has been profoundly affected by the microcosmos. 74 00:03:47,093 --> 00:03:50,162 ROWE: Three invisible microcosmos operates 75 00:03:50,263 --> 00:03:52,197 in every part of the world. 76 00:03:52,298 --> 00:03:55,067 This world that you can't see is everywhere, 77 00:03:55,168 --> 00:03:58,370 from geothermal hot springs to glaciers 78 00:03:58,471 --> 00:04:01,540 to deep sea hydrothermal vent systems. 79 00:04:03,109 --> 00:04:05,744 ROWE: We have discovered that every cubic foot of 80 00:04:05,812 --> 00:04:08,747 Earth's atmosphere and its oceans contain millions 81 00:04:08,848 --> 00:04:10,315 of viruses. 82 00:04:10,416 --> 00:04:13,752 There are more viruses here on Earth 83 00:04:13,853 --> 00:04:16,622 than there are stars in the universe. 84 00:04:16,723 --> 00:04:18,724 That's incredible. 85 00:04:18,825 --> 00:04:21,360 ROWE: Even though they're around 1/400th 86 00:04:21,461 --> 00:04:24,696 the thickness of human hair, stuck end to end, 87 00:04:24,797 --> 00:04:27,232 all the viruses on Earth would stretch 88 00:04:27,333 --> 00:04:29,034 100 million light-years. 89 00:04:30,169 --> 00:04:32,738 That's 40 times the distance to our neighboring 90 00:04:32,839 --> 00:04:34,940 galaxy, Andromeda. 91 00:04:35,041 --> 00:04:36,675 RADEBAUGH: That really makes us ask, 92 00:04:36,776 --> 00:04:38,510 "Whose planet is this anyway?" 93 00:04:38,578 --> 00:04:40,279 If you just added this up by sheer numbers, 94 00:04:40,380 --> 00:04:43,181 you would say, "This is the virus planet." 95 00:04:43,283 --> 00:04:46,051 ROWE: The microcosmos has also taken over 96 00:04:46,152 --> 00:04:49,488 our bodies... We're only partly human. 97 00:04:49,589 --> 00:04:52,424 The fact that so little of my own body, of everyone's body, 98 00:04:52,525 --> 00:04:54,826 is human cells kind of leaves you wondering 99 00:04:54,927 --> 00:04:56,528 what's the rest of it made of, right? 100 00:04:56,629 --> 00:04:59,164 It is astonishing that we share our bodies with over 101 00:04:59,265 --> 00:05:02,367 380 trillion viruses. 102 00:05:02,468 --> 00:05:06,238 ROWE: And over 39 trillion bacterial cells. 103 00:05:06,339 --> 00:05:09,841 OLUSEYI: The average human has more bacterial cells 104 00:05:09,942 --> 00:05:14,279 inside their body than there are human cells inside their body. 105 00:05:14,380 --> 00:05:16,615 So what are we really? 106 00:05:16,716 --> 00:05:18,784 There are moments in the history of science that I actually 107 00:05:18,885 --> 00:05:21,086 remember where I was when they happened... when, 108 00:05:21,187 --> 00:05:23,355 for example, we detected two colliding black holes 109 00:05:23,456 --> 00:05:24,456 or something like that. 110 00:05:24,557 --> 00:05:27,225 But another one was when I realized that 111 00:05:27,327 --> 00:05:30,562 almost half our body is actually not human. 112 00:05:30,663 --> 00:05:33,332 - I mean, that is crazy. - For people that are 113 00:05:33,433 --> 00:05:35,000 scared of bacteria, that's a really interesting 114 00:05:35,101 --> 00:05:36,635 thing to know, right? 115 00:05:36,736 --> 00:05:40,672 ROWE: Bacteria help us digest food, 116 00:05:40,773 --> 00:05:44,309 produce vitamins, and even influence our mood. 117 00:05:45,411 --> 00:05:47,179 But what are they? 118 00:05:47,280 --> 00:05:51,683 Bacteria are single-celled organisms with a cell wall 119 00:05:51,784 --> 00:05:54,653 and a central nucleus containing genetic material, 120 00:05:54,754 --> 00:05:56,655 RNA or DNA. 121 00:05:58,524 --> 00:06:00,559 They can move around and replicate. 122 00:06:02,362 --> 00:06:04,763 Viruses are completely different. 123 00:06:04,864 --> 00:06:06,098 In the universe, 124 00:06:06,199 --> 00:06:08,100 there are some mysteries that have actually personally made 125 00:06:08,201 --> 00:06:09,434 me kind of pause, 126 00:06:09,535 --> 00:06:11,837 give me goosebumps, and strangely enough, 127 00:06:11,938 --> 00:06:14,306 one of them is viruses. 128 00:06:14,407 --> 00:06:16,341 ROWE: The mystery is how viruses can 129 00:06:16,442 --> 00:06:18,643 have so much impact on the world, 130 00:06:18,745 --> 00:06:21,813 despite their tiny size and apparent simplicity. 131 00:06:24,083 --> 00:06:26,952 Most are just a strand of genetic material, 132 00:06:27,053 --> 00:06:30,021 sometimes encased in a shell of protein. 133 00:06:30,123 --> 00:06:32,257 I mean, compared to bacteria, 134 00:06:32,358 --> 00:06:34,693 which behave kind of like other normal cells that we're 135 00:06:34,794 --> 00:06:39,664 used to, to some degree, viruses are very strange. 136 00:06:39,766 --> 00:06:41,633 We don't really understand viruses. 137 00:06:41,734 --> 00:06:44,202 We... we don't even know if they're alive or not. 138 00:06:44,303 --> 00:06:47,572 The question are viruses alive is actually 139 00:06:47,673 --> 00:06:50,475 more difficult to answer than you might think. 140 00:06:50,576 --> 00:06:52,811 What is the definition of life? 141 00:06:52,912 --> 00:06:55,981 What does it mean to be alive? 142 00:06:56,082 --> 00:06:59,017 ROWE: NASA's definition of life is a self-sustained 143 00:06:59,118 --> 00:07:02,754 chemical system capable of Darwinian evolution. 144 00:07:02,855 --> 00:07:07,659 Entities that feed make energy and reproduce. 145 00:07:07,760 --> 00:07:09,961 Viruses can't do that on their own. 146 00:07:10,062 --> 00:07:12,531 They have to have a host cell to do that. 147 00:07:12,632 --> 00:07:15,233 They have the genetic material that they need, 148 00:07:15,334 --> 00:07:16,701 but none of the machinery. 149 00:07:16,803 --> 00:07:20,605 So they really have to infect a host. 150 00:07:20,706 --> 00:07:22,040 If not, they're useless. 151 00:07:23,609 --> 00:07:26,445 ROWE: Inside a host's body, viruses latch 152 00:07:26,512 --> 00:07:28,079 onto the surface of cells 153 00:07:29,816 --> 00:07:31,716 and then take control. 154 00:07:31,818 --> 00:07:36,154 A virus's life cycle is effectively to hack 155 00:07:36,255 --> 00:07:37,355 another cell. 156 00:07:37,457 --> 00:07:38,990 They have to inject that genetic material 157 00:07:39,091 --> 00:07:40,358 into a living cell. 158 00:07:40,460 --> 00:07:42,761 And then the cell is hijacked and starts making copies of 159 00:07:42,895 --> 00:07:44,095 the virus. 160 00:07:44,197 --> 00:07:48,233 Which then have to burst out of this cell almost literally 161 00:07:48,334 --> 00:07:51,837 like that gory, grotesque scene in "Aliens." 162 00:07:51,938 --> 00:07:54,172 They burst out from the inside. 163 00:07:54,273 --> 00:07:56,708 That's like a cellular level horror movie. 164 00:07:59,212 --> 00:08:01,546 ROWE: This method of replicating is chilling 165 00:08:03,049 --> 00:08:05,183 and doesn't answer the question of whether 166 00:08:05,284 --> 00:08:06,351 they're alive. 167 00:08:08,654 --> 00:08:12,157 That uncertainty may influence our search for life in space. 168 00:08:14,160 --> 00:08:16,795 BYWATERS: One of the interesting things to think about is 169 00:08:16,896 --> 00:08:19,865 if we found a virus on another planetary surface, 170 00:08:19,966 --> 00:08:21,633 would we classify that as life? 171 00:08:21,734 --> 00:08:24,035 Would we say that we have found life? 172 00:08:24,136 --> 00:08:27,672 ROWE: We don't know, but space viruses could be 173 00:08:27,773 --> 00:08:31,409 a sign of other extraterrestrial life forms. 174 00:08:31,511 --> 00:08:34,212 BYWATERS: Viruses have to have a host cell to replicate, 175 00:08:34,313 --> 00:08:37,749 so if you find a virus, in essence, you've found life. 176 00:08:39,519 --> 00:08:42,854 ROWE: Viruses might lead us to extraterrestrial life. 177 00:08:42,955 --> 00:08:45,657 Now, new research suggests that life 178 00:08:45,758 --> 00:08:48,927 on Earth may have come from space, 179 00:08:49,028 --> 00:08:52,631 brought to us in a cosmic bombardment 180 00:08:52,732 --> 00:08:54,199 when our planet was young. 181 00:09:05,244 --> 00:09:08,947 ROWE: We find the microcosmos in every feature of Earth. 182 00:09:09,048 --> 00:09:11,950 But where did this strange kingdom of the very small 183 00:09:12,051 --> 00:09:13,218 come from? 184 00:09:13,319 --> 00:09:16,755 Some of its members are so weird, they look like aliens. 185 00:09:16,856 --> 00:09:19,124 Could they have come from space? 186 00:09:19,225 --> 00:09:22,794 There's this idea that microbes could have hitched 187 00:09:22,895 --> 00:09:24,629 a ride on a chunk of an asteroid 188 00:09:24,730 --> 00:09:26,631 that would fall to Earth. 189 00:09:26,732 --> 00:09:29,000 HOWETT: They could form on a different planet. 190 00:09:29,101 --> 00:09:30,268 Something hits that planet. 191 00:09:30,369 --> 00:09:32,470 The rock that they're sitting on gets lifted 192 00:09:32,572 --> 00:09:35,106 and then hits the Earth as a meteorite. 193 00:09:35,207 --> 00:09:38,510 ROWE: The idea of hitchhiking bugs sounds a bit wild, 194 00:09:38,611 --> 00:09:42,814 but we have found chunks of Mars on Earth. 195 00:09:42,915 --> 00:09:46,084 Perhaps these space rocks brought life. 196 00:09:46,185 --> 00:09:48,887 PLAIT: It's not completely ridiculous. 197 00:09:48,988 --> 00:09:50,589 We know that rocks, for example, 198 00:09:50,690 --> 00:09:52,724 could come from Mars and land on Earth. 199 00:09:52,825 --> 00:09:55,327 A giant asteroid impact on Mars could blow 200 00:09:55,428 --> 00:09:58,530 shrapnel into space that could land on Earth. 201 00:09:58,631 --> 00:10:01,333 ROWE: To learn how we must return to the early 202 00:10:01,434 --> 00:10:04,736 solar system, 4.5 billion years ago. 203 00:10:04,837 --> 00:10:07,572 Many infant planets orbit a new star, 204 00:10:07,673 --> 00:10:12,477 our sun... this infant solar system is chaotic. 205 00:10:12,578 --> 00:10:16,181 Collisions between planets are inevitable. 206 00:10:16,282 --> 00:10:19,284 OLUSEYI: The early solar system was like a pinball machine. 207 00:10:19,385 --> 00:10:20,619 Stuff was hitting, 208 00:10:20,720 --> 00:10:22,654 knocking stuff off, that would land somewhere 209 00:10:22,755 --> 00:10:24,556 and knock stuff off. 210 00:10:24,657 --> 00:10:27,492 ROWE: The young Mars is in the line of fire. 211 00:10:27,593 --> 00:10:30,795 It already has primitive oceans and perhaps 212 00:10:30,896 --> 00:10:32,097 primitive life. 213 00:10:32,198 --> 00:10:36,534 A huge space rock smashes into the surface. 214 00:10:36,636 --> 00:10:40,772 We call the event the Borealis Impact. 215 00:10:40,873 --> 00:10:45,143 It blows quadrillion tons of rock into space. 216 00:10:45,244 --> 00:10:49,247 It's not crazy to think that one of these chunks of 217 00:10:49,348 --> 00:10:51,683 rock traveling through our solar system has some 218 00:10:51,784 --> 00:10:53,351 hitchhikers on board. 219 00:10:53,452 --> 00:10:56,354 If there's some microbe riding on an asteroid that got blasted 220 00:10:56,422 --> 00:10:59,324 off of Mars, kind of feel sorry for it, right? 221 00:10:59,425 --> 00:11:01,726 It's just living there on Mars, 222 00:11:01,827 --> 00:11:04,029 doing whatever little Martian microbes do. 223 00:11:04,130 --> 00:11:07,432 And then a giant impact ejects this thing into space. 224 00:11:09,268 --> 00:11:13,238 DARTNELL: In order to get from one planet to another, 225 00:11:13,339 --> 00:11:16,641 a cell would have to run a gauntlet. 226 00:11:16,742 --> 00:11:20,612 It's almost like winning a survival game show. 227 00:11:20,713 --> 00:11:24,315 You've got to survive being blasted off your home world. 228 00:11:24,417 --> 00:11:28,486 You've then got to survive the interplanetary journey 229 00:11:28,587 --> 00:11:30,689 inside a small lump of rock, 230 00:11:30,790 --> 00:11:34,526 being exposed to the vacuum of outer space, to cosmic rays, 231 00:11:34,627 --> 00:11:38,897 to UV radiation, being dried out and frozen. 232 00:11:38,998 --> 00:11:41,299 So the idea of moving life around 233 00:11:41,400 --> 00:11:44,969 the solar system or through... Around the galaxy on asteroids 234 00:11:45,071 --> 00:11:48,039 poses a lot of different challenges. 235 00:11:48,140 --> 00:11:51,743 ROWE: Events like the Borealis Impact ejected so much rock 236 00:11:51,844 --> 00:11:54,946 from Mars, there were lots of opportunities for hitchhiking 237 00:11:55,047 --> 00:11:57,315 bugs to run the gauntlet of space. 238 00:11:57,416 --> 00:12:01,219 But could they survive the journey? 239 00:12:01,320 --> 00:12:04,789 To find out, astronauts on the International 240 00:12:04,890 --> 00:12:09,961 Space Station grew simple bacteria outside in space. 241 00:12:11,931 --> 00:12:17,268 After a year of being in open space, miraculously, 242 00:12:17,369 --> 00:12:19,471 some of these microbes survived. 243 00:12:19,572 --> 00:12:22,640 It's incredible. These microbes just could not 244 00:12:22,742 --> 00:12:25,443 be killed, even though they were in the worst possible 245 00:12:25,544 --> 00:12:27,278 environment for life. 246 00:12:27,379 --> 00:12:30,381 DARTNELL: The mission, therefore, shows us that 247 00:12:30,483 --> 00:12:34,285 life can survive the environment in outer space. 248 00:12:34,386 --> 00:12:37,555 Life could be transferred between planets. 249 00:12:37,656 --> 00:12:40,725 Maybe life did get started on Mars, 250 00:12:40,826 --> 00:12:42,427 on our next door neighbor planet, 251 00:12:42,528 --> 00:12:45,096 and then was transferred here 252 00:12:45,197 --> 00:12:46,431 inside a meteorite. 253 00:12:46,532 --> 00:12:50,335 Maybe we are immigrants from Mars. 254 00:12:50,436 --> 00:12:52,904 ROWE: Hitchhiking bugs may have arrived on 255 00:12:53,005 --> 00:12:56,741 Earth and kick-started the microcosmos. 256 00:12:56,842 --> 00:13:00,044 But now, recent studies of meteorites suggest that 257 00:13:00,146 --> 00:13:03,548 even if living microbes didn't make the journey, 258 00:13:03,649 --> 00:13:06,251 the building blocks that made them did. 259 00:13:06,352 --> 00:13:08,419 [explosion blasts] 260 00:13:08,521 --> 00:13:11,790 In November 2019, an international research team 261 00:13:11,891 --> 00:13:13,458 found an organic molecule 262 00:13:13,559 --> 00:13:17,028 called ribose in meteorites that had crashed on Earth. 263 00:13:18,531 --> 00:13:21,166 Ribose is a sugar. 264 00:13:21,267 --> 00:13:23,067 It's a simple sugar, 265 00:13:23,169 --> 00:13:24,869 but it is a sugar that is 266 00:13:24,970 --> 00:13:30,041 absolutely crucial to all life on Earth. 267 00:13:30,142 --> 00:13:35,079 Ribose is the sugar that makes up RNA, and RNA 268 00:13:35,181 --> 00:13:39,317 sits right in the linchpin of every cell. 269 00:13:40,519 --> 00:13:42,153 ROWE: RNA is a simple form of 270 00:13:42,254 --> 00:13:45,056 genetic material that controls cellular function. 271 00:13:45,157 --> 00:13:48,193 It's found in most primitive creatures. 272 00:13:48,294 --> 00:13:53,965 Finding ribose on a meteorite is so important for us to 273 00:13:54,066 --> 00:13:56,467 understand the origins of 274 00:13:56,569 --> 00:13:58,136 the microcosmos, because these are 275 00:13:58,237 --> 00:14:01,139 the building blocks, these are the things that it needs to 276 00:14:01,240 --> 00:14:02,307 get started, 277 00:14:02,408 --> 00:14:06,411 so understanding where these building blocks come from 278 00:14:06,512 --> 00:14:11,382 allows us to understand how the microcosmos might have 279 00:14:11,483 --> 00:14:13,718 evolved and started. 280 00:14:13,819 --> 00:14:16,855 ROWE: The Rosetta Mission found another building block 281 00:14:16,956 --> 00:14:18,323 for life out in space... 282 00:14:18,424 --> 00:14:21,192 A form of phosphorus on the comet, 283 00:14:21,293 --> 00:14:23,528 67P. 284 00:14:23,629 --> 00:14:24,762 SHIELDS: This was astounding. 285 00:14:24,864 --> 00:14:28,967 Comet 67P was formed at the birth of the solar system, 286 00:14:29,068 --> 00:14:31,469 4.67 billion years ago, 287 00:14:31,570 --> 00:14:33,338 and it hasn't changed since then. 288 00:14:33,439 --> 00:14:35,807 It's a time capsule from the birth 289 00:14:35,908 --> 00:14:37,542 of the sun and the planets. 290 00:14:37,676 --> 00:14:40,845 DARTNELL: And it's been in the deep freeze ever since. 291 00:14:40,946 --> 00:14:45,416 So these forms of phosphorus that we found on comet 67P 292 00:14:45,517 --> 00:14:47,418 tell us what was available at 293 00:14:47,519 --> 00:14:49,721 the time the Earth was forming and then 294 00:14:49,822 --> 00:14:53,591 when life was getting started on primordial Earth. 295 00:14:53,692 --> 00:14:55,793 ROWE: The early solar system 296 00:14:55,895 --> 00:14:58,196 contained many chemicals needed for life. 297 00:14:59,598 --> 00:15:00,965 BYWATERS: It's an important discovery, 298 00:15:01,066 --> 00:15:02,767 because it means that these compounds 299 00:15:02,868 --> 00:15:05,169 were around when the solar system was forming, 300 00:15:05,271 --> 00:15:07,906 so they would have been readily available for life to 301 00:15:08,007 --> 00:15:12,710 tap into and use to start forming cellular structure. 302 00:15:12,811 --> 00:15:16,214 ROWE: These discoveries not only show that essential chemicals 303 00:15:16,315 --> 00:15:17,348 came to Earth, 304 00:15:17,449 --> 00:15:21,386 but that they exist throughout the solar system. 305 00:15:21,487 --> 00:15:23,788 LANZA: We tend to think of the microcosmos as only 306 00:15:23,889 --> 00:15:26,591 existing on Earth in the sense that only Earth 307 00:15:26,692 --> 00:15:27,926 has these building blocks, 308 00:15:28,027 --> 00:15:31,796 but now, these new observations suggest that a microcosmos, 309 00:15:31,897 --> 00:15:34,599 at least the building blocks for one, could exist 310 00:15:34,700 --> 00:15:37,101 beyond Earth and throughout the solar system. 311 00:15:38,671 --> 00:15:40,538 ROWE: Comets and asteroids may have brought 312 00:15:40,639 --> 00:15:43,207 chemicals to kick-start the microcosmos. 313 00:15:45,878 --> 00:15:48,546 Now, explosive new research suggests that 314 00:15:48,647 --> 00:15:52,283 space rocks hitting Earth did even more. 315 00:15:52,384 --> 00:15:55,153 Could the violent impacts themselves 316 00:15:55,254 --> 00:15:57,488 have helped life get started? 317 00:16:00,259 --> 00:16:02,660 [explosion blasts] 318 00:16:12,004 --> 00:16:16,307 ROWE: How did the microcosmos and life on Earth start? 319 00:16:16,408 --> 00:16:18,910 Did asteroids and comets deliver the building 320 00:16:19,011 --> 00:16:21,212 blocks, phosphorus, 321 00:16:21,313 --> 00:16:23,681 ribose, and other organic compounds? 322 00:16:23,782 --> 00:16:26,484 Or did they start life in other ways? 323 00:16:26,585 --> 00:16:29,988 New research suggests the impact of crashing 324 00:16:30,089 --> 00:16:33,324 space rocks could have provided the spark for life. 325 00:16:34,426 --> 00:16:37,729 The force of the impact actually triggered the creation 326 00:16:37,830 --> 00:16:40,732 of these molecules that are the building blocks of life. 327 00:16:45,170 --> 00:16:47,572 ROWE: The energy from the impact breaks down 328 00:16:47,673 --> 00:16:51,175 and reforms molecules into new compounds. 329 00:16:51,276 --> 00:16:53,711 You can actually strip apart atoms and molecules, 330 00:16:53,812 --> 00:16:56,914 re-combine them in more complex ways, and make the stuff 331 00:16:57,016 --> 00:16:59,350 of life in an impact. 332 00:16:59,451 --> 00:17:01,419 ROWE: Over millions of years, 333 00:17:01,520 --> 00:17:05,223 complex organic materials fill Earth's oceans. 334 00:17:05,324 --> 00:17:08,860 Then, around 3.5 billion years ago, 335 00:17:08,961 --> 00:17:12,830 the process that kick-started life began. 336 00:17:12,931 --> 00:17:15,933 THALLER: Going back to the origins of life on Earth, 337 00:17:16,035 --> 00:17:19,037 it was a process... you began with large molecules 338 00:17:19,138 --> 00:17:22,807 that almost accidentally began to make copies of themselves. 339 00:17:22,908 --> 00:17:26,144 These became the first genetic material... some of these larger 340 00:17:26,245 --> 00:17:29,313 molecules bound together and became the first sort of 341 00:17:29,415 --> 00:17:30,615 protocells. 342 00:17:30,716 --> 00:17:33,785 A protocell could represent 343 00:17:33,886 --> 00:17:39,123 this earliest pre-life stage of evolution. 344 00:17:41,427 --> 00:17:44,162 ROWE: Protocells lack the full chemical machinery of 345 00:17:44,263 --> 00:17:45,997 modern cells. 346 00:17:46,098 --> 00:17:49,233 They're a simple cell membrane surrounding a glob of 347 00:17:49,334 --> 00:17:53,237 genetic material like RNA, built from ribose 348 00:17:53,338 --> 00:17:54,672 and phosphorus. 349 00:17:54,773 --> 00:17:57,008 Now you have a barrier. 350 00:17:57,109 --> 00:17:59,710 Now you can actually control which chemicals come into 351 00:17:59,812 --> 00:18:03,448 the cell and which go out, and you protect the genetic 352 00:18:03,549 --> 00:18:06,250 code intact, inside the cell. 353 00:18:06,351 --> 00:18:09,821 Once that happened, evolution began to run with it. 354 00:18:10,856 --> 00:18:14,058 ROWE: These simple cells grew more and more complicated 355 00:18:14,159 --> 00:18:16,527 until shazam, 356 00:18:16,628 --> 00:18:19,230 you get all life on Earth... 357 00:18:19,331 --> 00:18:22,600 All cellular life, anyway. 358 00:18:22,701 --> 00:18:26,838 Unlike bacteria, viruses are not cells. 359 00:18:26,939 --> 00:18:30,374 Scientists debate if they're even living things. 360 00:18:30,476 --> 00:18:33,811 So how, then, do viruses fit into the birth of life? 361 00:18:33,912 --> 00:18:37,315 Viruses aren't really thought of as playing a role 362 00:18:37,416 --> 00:18:38,916 in our evolutionary history, 363 00:18:39,017 --> 00:18:41,119 but we're just beginning to understand that 364 00:18:41,220 --> 00:18:42,487 that's simply not the case. 365 00:18:42,588 --> 00:18:44,856 What if viruses themselves were 366 00:18:44,957 --> 00:18:48,426 an essential cog in the machinery of life? 367 00:18:48,527 --> 00:18:50,194 ROWE: How can we investigate if 368 00:18:50,295 --> 00:18:52,997 viruses helped life on Earth develop? 369 00:18:53,098 --> 00:18:56,634 They don't leave many clues about their past. 370 00:18:56,735 --> 00:18:59,403 BYWATERS: The hard thing with understanding 371 00:18:59,505 --> 00:19:00,805 the evolutionary history 372 00:19:00,906 --> 00:19:03,674 of viruses is they don't leave a fossil record. 373 00:19:03,775 --> 00:19:07,712 There's no geology that we can go back and dig up and say, 374 00:19:07,813 --> 00:19:10,748 Aha! This is when viruses first came about. 375 00:19:12,651 --> 00:19:14,952 ROWE: We don't know when viruses entered 376 00:19:15,053 --> 00:19:16,921 the evolutionary game of life. 377 00:19:17,022 --> 00:19:21,459 Was it near the beginning, or a little bit later? 378 00:19:21,560 --> 00:19:25,129 There's this crazy idea that viruses might actually 379 00:19:25,230 --> 00:19:27,064 have come first in the tree of life. 380 00:19:27,166 --> 00:19:29,767 THALLER: When you think about the real origins of life, 381 00:19:29,868 --> 00:19:32,136 it had to start with something that simple, 382 00:19:32,237 --> 00:19:34,205 something that was just a molecule that could 383 00:19:34,306 --> 00:19:35,206 start replicating. 384 00:19:35,307 --> 00:19:38,409 A virus may be our best example of that 385 00:19:38,510 --> 00:19:41,212 transition from just complex chemistry 386 00:19:41,313 --> 00:19:43,114 to the beginnings of life. 387 00:19:43,215 --> 00:19:46,250 In this scenario, chemicals floating 388 00:19:46,351 --> 00:19:47,985 in the 3.5-billion-year-old 389 00:19:48,086 --> 00:19:51,189 oceans formed a shell of protein around some simple 390 00:19:51,290 --> 00:19:53,124 genetic material. 391 00:19:54,226 --> 00:19:58,196 But did viruses evolve before anything else? 392 00:19:58,297 --> 00:20:03,134 BYWATERS: The flaw in the virus first hypothesis is that 393 00:20:03,235 --> 00:20:07,138 a virus has to have a host organism to replicate. 394 00:20:07,239 --> 00:20:10,975 So without a host, how does the virus replicate? 395 00:20:11,076 --> 00:20:13,611 And this is the question we have to ask ourselves 396 00:20:13,712 --> 00:20:16,314 when we think of viruses coming first on 397 00:20:16,415 --> 00:20:18,649 the evolutionary tree. 398 00:20:18,750 --> 00:20:22,286 ROWE: Modern viruses can't replicate without a host. 399 00:20:22,387 --> 00:20:26,257 It's likely that ancient viruses couldn't either, 400 00:20:26,358 --> 00:20:29,961 but could early cells and viruses have joined 401 00:20:30,062 --> 00:20:33,264 forces in a way that benefited them both? 402 00:20:33,365 --> 00:20:36,434 Some new theories are suggesting that viruses 403 00:20:36,535 --> 00:20:41,539 and cellular life co-evolved and actually helped each other out, 404 00:20:41,640 --> 00:20:44,909 and potentially even helped out the evolution of 405 00:20:45,010 --> 00:20:47,044 human life. 406 00:20:47,145 --> 00:20:49,747 ROWE: How did this co-evolution work? 407 00:20:49,848 --> 00:20:53,484 We know that viruses today inject their genetic material 408 00:20:53,585 --> 00:20:56,454 into cells to manipulate them. 409 00:20:56,555 --> 00:20:59,257 Perhaps early viruses manipulated the genes 410 00:20:59,324 --> 00:21:02,426 of the first cells the same way. 411 00:21:02,527 --> 00:21:07,331 Think of this primordial soup and the genes, the RNA, that's 412 00:21:07,432 --> 00:21:10,768 in this primordial soup being swapped between organisms, 413 00:21:10,869 --> 00:21:12,136 kind of like a swap meet. 414 00:21:12,237 --> 00:21:14,038 You bring something you don't need any more, 415 00:21:14,139 --> 00:21:16,073 and you pass it along to somebody else. 416 00:21:16,174 --> 00:21:19,644 So in this way, organisms sharing their genetic material 417 00:21:19,778 --> 00:21:22,313 back and forth offers a competitive advantage 418 00:21:22,414 --> 00:21:23,681 to each one. 419 00:21:23,749 --> 00:21:26,217 ROWE: The virus might break off bits of 420 00:21:26,318 --> 00:21:29,887 the host's genetic material and mix it with their own. 421 00:21:31,189 --> 00:21:33,524 When the virus attacks another cell, 422 00:21:33,625 --> 00:21:36,794 it could pass on the mixed genes to its next host. 423 00:21:37,963 --> 00:21:39,764 In this sense, then, 424 00:21:39,865 --> 00:21:43,134 viruses help stir things up. 425 00:21:43,235 --> 00:21:46,337 They shuttle genes between wildly different 426 00:21:46,438 --> 00:21:51,842 organisms and therefore help drive evolution itself. 427 00:21:51,943 --> 00:21:54,145 Now, probably almost all of these injections did 428 00:21:54,246 --> 00:21:56,447 nothing useful or maybe even killed the cell. 429 00:21:56,515 --> 00:21:58,849 But if one in a million injection changed 430 00:21:58,950 --> 00:22:00,017 something for the better, 431 00:22:00,118 --> 00:22:03,354 made it more complex, made it more able to survive, 432 00:22:03,455 --> 00:22:05,723 then that cell reproduced even more. 433 00:22:05,824 --> 00:22:10,494 ROWE: If virally enhanced cells thrived in the primeval oceans, 434 00:22:10,595 --> 00:22:11,662 over time, 435 00:22:11,763 --> 00:22:14,198 they might have evolved into more complex creatures 436 00:22:14,299 --> 00:22:17,101 and eventually, into us. 437 00:22:17,169 --> 00:22:18,536 RADEBAUGH: What's so crazy is to think about 438 00:22:18,637 --> 00:22:20,371 the fact that we could actually be descended 439 00:22:20,472 --> 00:22:21,472 from viruses. 440 00:22:21,573 --> 00:22:23,874 I am sure that a lot of my genetic 441 00:22:23,975 --> 00:22:27,812 code originally came from the injection of a virus. 442 00:22:27,913 --> 00:22:31,082 I love the idea that I might be descendant from a virus, 443 00:22:31,183 --> 00:22:33,684 just coming from something that simple 444 00:22:33,785 --> 00:22:35,152 and evolving into something 445 00:22:35,253 --> 00:22:38,989 this complex is just a feat of nature. 446 00:22:39,091 --> 00:22:42,593 ROWE: Viruses played a major part in human evolution. 447 00:22:42,694 --> 00:22:47,365 Around 8% of human DNA came from ancient viral infections. 448 00:22:47,466 --> 00:22:49,734 In fact, without them, 449 00:22:49,835 --> 00:22:50,868 we wouldn't be human. 450 00:22:52,237 --> 00:22:56,207 BYWATERS: In our brains, we actually have relic viral DNA. 451 00:22:56,308 --> 00:22:58,776 So DNA that came from a virus, 452 00:22:58,877 --> 00:23:00,611 but this helps us. 453 00:23:00,712 --> 00:23:04,215 Without this, we don't think we would have consciousness. 454 00:23:05,717 --> 00:23:08,486 ROWE: We also think that viral DNA helped us develop 455 00:23:08,587 --> 00:23:09,620 an immune system 456 00:23:09,721 --> 00:23:13,624 to fight off infection and gave us the ability to 457 00:23:13,725 --> 00:23:15,326 digest starch. 458 00:23:16,895 --> 00:23:20,030 The microcosmos has guided our evolution. 459 00:23:20,132 --> 00:23:22,700 It even created the air we breathe. 460 00:23:22,801 --> 00:23:25,536 But in doing so, it also triggered 461 00:23:25,637 --> 00:23:29,607 the largest mass extinction the Earth has ever seen. 462 00:23:40,085 --> 00:23:44,588 ROWE: Planet Earth, 2.5 billion years ago. 463 00:23:44,689 --> 00:23:49,160 The microcosmos colonizes Earth's oceans. 464 00:23:49,261 --> 00:23:52,830 This is not a world we would recognize today. 465 00:23:52,931 --> 00:23:56,967 If you were to travel back in time, just on Earth, to see what 466 00:23:57,068 --> 00:23:59,503 it was like 2.5 billion years ago, 467 00:23:59,604 --> 00:24:02,907 it would look really different in many ways. 468 00:24:03,008 --> 00:24:06,477 There were oceans, and they had life in those oceans. 469 00:24:06,578 --> 00:24:10,548 But there weren't any land plants or land animals. 470 00:24:10,649 --> 00:24:12,249 There was just bare rock. 471 00:24:12,350 --> 00:24:14,752 So to think about a human going back in time to visit 472 00:24:14,853 --> 00:24:16,287 the really early Earth, 473 00:24:16,388 --> 00:24:19,190 they would find an utterly inhospitable planet. 474 00:24:19,291 --> 00:24:22,059 LANZA: As a human, you'd be out of luck because there was 475 00:24:22,160 --> 00:24:24,061 no oxygen in the atmosphere at that time, 476 00:24:24,162 --> 00:24:25,629 so hopefully, you brought a space suit. 477 00:24:27,098 --> 00:24:28,599 ROWE: The atmosphere was fine for 478 00:24:28,700 --> 00:24:31,869 the billions of inhabitants of the early microcosmos. 479 00:24:33,071 --> 00:24:35,406 They were very slow-paced, and they did 480 00:24:35,507 --> 00:24:38,409 everything they did without any oxygen in the air. 481 00:24:38,510 --> 00:24:42,613 ROWE: But this tranquil existence was about to change. 482 00:24:42,714 --> 00:24:45,015 PLAIT: For a long time, conditions on Earth were 483 00:24:45,116 --> 00:24:48,619 fairly static, but then, about 2.5 billion years ago, 484 00:24:48,720 --> 00:24:52,456 an evolutionary glitch changed everything. 485 00:24:52,557 --> 00:24:54,592 ROWE: A clue to that glitch 486 00:24:54,693 --> 00:24:58,128 rests in strange rocky mounds, 487 00:24:58,230 --> 00:24:59,430 stromatolites. 488 00:24:59,531 --> 00:25:05,369 DARTNELL: Stromatolites are almost like microbial cities. 489 00:25:05,470 --> 00:25:10,574 If you zoom down onto their scale, you'll see layer 490 00:25:10,675 --> 00:25:13,010 upon layer of bacteria, 491 00:25:13,111 --> 00:25:16,580 almost like the high-rise skyscrapers in one of 492 00:25:16,681 --> 00:25:18,649 our cities. 493 00:25:18,750 --> 00:25:23,220 ROWE: The microcosmic high rises are full of cyanobacteria. 494 00:25:23,321 --> 00:25:26,891 These bacteria can photosynthesize. 495 00:25:26,992 --> 00:25:29,593 Photosynthesis is a chemical reaction that 496 00:25:29,694 --> 00:25:33,998 takes place inside a plant, producing food. 497 00:25:34,099 --> 00:25:37,868 Today, it's an important part of our planet's existence. 498 00:25:37,969 --> 00:25:42,039 2.5 billion years ago, it was revolutionary. 499 00:25:43,475 --> 00:25:47,411 And it happened when ancient cyanobacteria similar to those 500 00:25:47,512 --> 00:25:49,213 in the stromatolites mutated. 501 00:25:49,314 --> 00:25:53,450 This mutation allowed cyanobacteria 502 00:25:53,552 --> 00:25:56,487 to take the energy from sunlight and use it to make 503 00:25:56,588 --> 00:25:59,924 sugars out of water and carbon dioxide. 504 00:26:00,025 --> 00:26:04,929 ROWE: This gave cyanobacteria a huge evolutionary edge. 505 00:26:05,030 --> 00:26:06,497 They could now make more energy for 506 00:26:06,598 --> 00:26:10,100 themselves so they could grow and reproduce faster. 507 00:26:11,403 --> 00:26:14,038 For everything else, it was a catastrophe. 508 00:26:14,139 --> 00:26:18,075 It produced oxygen as a waste product. 509 00:26:18,176 --> 00:26:21,045 Oxygen was no use to them, so they released it into 510 00:26:21,146 --> 00:26:23,847 the air, transforming Earth's atmosphere 511 00:26:23,949 --> 00:26:26,483 over millions of years. 512 00:26:26,585 --> 00:26:29,720 ROWE: This by-product, oxygen, is extremely toxic. 513 00:26:30,922 --> 00:26:33,524 THALLER: The reason oxygen is so dangerous is that 514 00:26:33,625 --> 00:26:34,692 it's very reactive. 515 00:26:34,793 --> 00:26:37,094 It loves to combine with everything, 516 00:26:37,228 --> 00:26:40,397 so think about something rusting... iron rusts because 517 00:26:40,498 --> 00:26:43,033 oxygen is actually combining with the molecules. 518 00:26:43,134 --> 00:26:45,069 It's called oxidation. 519 00:26:45,170 --> 00:26:47,037 So when oxygen was first released, 520 00:26:47,138 --> 00:26:49,473 it was tremendously dangerous. 521 00:26:49,574 --> 00:26:52,376 ROWE: The new oxygen built up in the atmosphere, 522 00:26:52,477 --> 00:26:56,313 killing off species of microbes everywhere on the planet. 523 00:26:56,414 --> 00:26:59,516 Right when this happened, you would have had 524 00:26:59,618 --> 00:27:01,285 a mass extinction. 525 00:27:01,386 --> 00:27:04,955 This would have been a global mass extinction event. 526 00:27:05,056 --> 00:27:08,592 This was an unprecedented environmental disaster, 527 00:27:08,693 --> 00:27:11,629 probably in the entire history of the Earth up to that point. 528 00:27:11,730 --> 00:27:13,230 And I'm not even sure it's been paralleled, 529 00:27:13,331 --> 00:27:14,732 even up to today. 530 00:27:14,799 --> 00:27:15,699 This may have been the single 531 00:27:15,800 --> 00:27:18,602 biggest catastrophe in our planet's history. 532 00:27:18,703 --> 00:27:22,006 This was the Great Oxidation Event, and it changed 533 00:27:22,107 --> 00:27:24,508 our atmosphere, it changed our planet, 534 00:27:24,609 --> 00:27:26,877 and it didn't just end there. 535 00:27:26,978 --> 00:27:28,579 Something changed again. 536 00:27:28,680 --> 00:27:33,450 Another mutation allowed some of these bacteria to use that 537 00:27:33,551 --> 00:27:36,053 oxygen in their own metabolism, 538 00:27:36,154 --> 00:27:39,223 and that was a huge change. 539 00:27:41,159 --> 00:27:44,328 ROWE: The ability to use oxygen was an incredible leap forward. 540 00:27:45,597 --> 00:27:48,532 The beauty of oxygen is that it allows 541 00:27:48,633 --> 00:27:53,037 the metabolism to process nutrients much more rapidly. 542 00:27:53,138 --> 00:27:57,307 It basically helps bodies burn these materials so that 543 00:27:57,409 --> 00:28:00,177 they can generate a lot more energy a lot more quickly. 544 00:28:00,278 --> 00:28:04,348 Organisms that figured out how to use oxygen for respiration 545 00:28:04,449 --> 00:28:06,150 ended up getting a huge kick-start 546 00:28:06,251 --> 00:28:08,052 of energy and gave them a huge advantage 547 00:28:08,153 --> 00:28:09,453 over other organisms. 548 00:28:09,554 --> 00:28:13,757 It supplied enough energy that organisms could become 549 00:28:13,858 --> 00:28:14,958 more complex, 550 00:28:15,060 --> 00:28:19,863 larger, multicellular, really the tapping into 551 00:28:19,964 --> 00:28:25,369 oxygen and being able to use oxygen in our metabolism meant 552 00:28:25,470 --> 00:28:26,870 that it was a game changer, 553 00:28:26,971 --> 00:28:29,440 that we could evolve in ways that never would 554 00:28:29,541 --> 00:28:33,444 have been possible without cyanobacteria. 555 00:28:33,545 --> 00:28:36,613 ROWE: Simple organisms became more complex. 556 00:28:36,715 --> 00:28:40,317 Single-celled creatures became multicellular. 557 00:28:40,418 --> 00:28:43,387 SHIELDS: This gradual accumulation of oxygen 558 00:28:43,488 --> 00:28:44,955 into the atmosphere of the Earth 559 00:28:45,056 --> 00:28:48,859 was huge for the multicellular animal and life explosion, 560 00:28:48,960 --> 00:28:51,261 um, that occurred as a result and was 561 00:28:51,362 --> 00:28:54,098 one of the most important events in Earth's history. 562 00:28:54,199 --> 00:28:56,767 BYWATERS: This would have been a complete transformation 563 00:28:56,868 --> 00:28:59,636 of the Earth's atmosphere and physical setting. 564 00:28:59,738 --> 00:29:03,574 This is when the green Earth started to evolve. 565 00:29:03,675 --> 00:29:07,945 ROWE: The Great Oxidation Event changed the course of evolution, 566 00:29:08,046 --> 00:29:11,849 leading to our complex world. 567 00:29:11,950 --> 00:29:13,784 It is really hard to overemphasize 568 00:29:13,885 --> 00:29:15,652 the importance of the microcosmos. 569 00:29:15,754 --> 00:29:17,454 Just the fact that I'm speaking to you, 570 00:29:17,555 --> 00:29:18,989 I'm breathing in and out, 571 00:29:19,090 --> 00:29:20,624 I wouldn't be doing that without 572 00:29:20,725 --> 00:29:23,827 the tiniest organisms on the planet. 573 00:29:23,928 --> 00:29:26,563 ROWE: The microcosmos gave us life. 574 00:29:26,664 --> 00:29:29,700 Now, it could wipe us out. 575 00:29:29,801 --> 00:29:31,168 Global warming is releasing 576 00:29:31,269 --> 00:29:34,138 potentially lethal bacteria and viruses. 577 00:29:35,907 --> 00:29:39,710 Are we facing a microcosmic zombie apocalypse? 578 00:29:47,919 --> 00:29:50,754 ROWE: Siberia, present day. 579 00:29:50,855 --> 00:29:54,892 Rising temperatures are melting the Arctic permafrost, 580 00:29:54,993 --> 00:29:58,395 revealing land sealed under ice for tens 581 00:29:58,496 --> 00:30:00,597 of thousands of years. 582 00:30:00,698 --> 00:30:03,167 DARTNELL: As that permafrost begins thawing out 583 00:30:03,268 --> 00:30:05,202 and melting with climate change, 584 00:30:05,303 --> 00:30:08,739 maybe that will release pathogens that have 585 00:30:08,840 --> 00:30:12,476 been locked up for potentially thousands of years. 586 00:30:12,577 --> 00:30:14,278 ROWE: In 2014, 587 00:30:14,379 --> 00:30:19,216 researchers investigated melting Siberian tundra, 588 00:30:19,317 --> 00:30:22,052 a region larger than the USA. 589 00:30:22,153 --> 00:30:24,922 I've seen a lot of science fiction movies where scientists 590 00:30:25,023 --> 00:30:26,990 are digging around in the ice and find something bad 591 00:30:27,091 --> 00:30:28,158 from a long time ago. 592 00:30:28,259 --> 00:30:30,427 ROWE: Scientists took samples of 593 00:30:30,528 --> 00:30:33,630 tundra soil to the lab and examined the contents. 594 00:30:33,731 --> 00:30:38,035 They found a frozen ancient virus. 595 00:30:38,136 --> 00:30:44,708 A virus locked in ice from over 30,000 years ago. 596 00:30:44,809 --> 00:30:46,710 Isn't this the start of, 597 00:30:46,811 --> 00:30:50,747 like, every horror movie? A scientist uncovers some deep 598 00:30:50,849 --> 00:30:52,850 secret of nature and then just 599 00:30:52,951 --> 00:30:56,320 open it up and unleash it on the world? 600 00:30:56,421 --> 00:30:58,388 ROWE: Just like in a B movie, 601 00:30:58,489 --> 00:31:00,290 The team fed the virus to 602 00:31:00,391 --> 00:31:04,394 living single-celled creatures called amoebas 603 00:31:04,495 --> 00:31:06,597 to see if the virus still functioned 604 00:31:06,698 --> 00:31:09,967 after being frozen for thousands of years. 605 00:31:10,068 --> 00:31:15,272 The virus woke up, attacked the amoebas, and replicated. 606 00:31:15,373 --> 00:31:18,542 BYWATERS: Bringing this ancient virus back to life 607 00:31:18,643 --> 00:31:21,778 was sort of waking up the undead. 608 00:31:23,414 --> 00:31:27,551 ROWE: Scientists had no idea how this zombie virus would behave. 609 00:31:30,421 --> 00:31:33,857 Something about it was very, very different. 610 00:31:33,958 --> 00:31:37,394 It was huge compared to normal viruses. 611 00:31:37,528 --> 00:31:41,465 It was substantially larger than any 612 00:31:41,566 --> 00:31:43,800 virus that we had seen before. 613 00:31:43,902 --> 00:31:48,572 This is the Goliath of Goliaths among viruses. 614 00:31:48,673 --> 00:31:52,509 ROWE: So large it looks more like bacteria than a virus. 615 00:31:52,610 --> 00:31:58,015 We call these kinds of giant viruses mimiviruses, 616 00:31:58,116 --> 00:32:02,419 because they mimic other creatures, like bacteria. 617 00:32:03,688 --> 00:32:06,290 ROWE: One way the virus mimics bacteria is 618 00:32:06,391 --> 00:32:08,725 in the amount of its genetic material. 619 00:32:08,826 --> 00:32:14,064 It has 900 genes, eight times as many as a regular virus. 620 00:32:14,165 --> 00:32:17,234 SUTTER: Viruses are very simple. 621 00:32:17,335 --> 00:32:19,770 They don't require a lot of genes to function, 622 00:32:19,871 --> 00:32:25,542 but this virus has more genes than necessary. 623 00:32:25,643 --> 00:32:30,180 What is it doing with all these extra genes? 624 00:32:30,281 --> 00:32:33,383 ROWE: We have now found other mimiviruses. 625 00:32:33,484 --> 00:32:35,752 20 years ago, we had no idea 626 00:32:35,853 --> 00:32:39,156 that this complex type of virus even existed. 627 00:32:39,257 --> 00:32:42,192 We still don't know what all the extra genes do. 628 00:32:43,561 --> 00:32:46,396 This type of virus might even be able to generate 629 00:32:46,497 --> 00:32:47,798 its own energy, 630 00:32:47,899 --> 00:32:52,135 making it closer to bacteria than other viruses. 631 00:32:52,236 --> 00:32:55,739 Because it has so many extra genes, 632 00:32:55,840 --> 00:33:00,143 this is a virus that is not acting like a virus. 633 00:33:00,244 --> 00:33:01,778 ROWE: We can't be sure how 634 00:33:01,879 --> 00:33:05,882 the Siberian mimivirus will behave if released, 635 00:33:05,984 --> 00:33:09,653 and even if it only attacks amoebas, there could be 636 00:33:09,754 --> 00:33:13,056 other large, complex viruses buried in the ice. 637 00:33:14,492 --> 00:33:16,526 They may not be so safe. 638 00:33:16,627 --> 00:33:19,963 We know that there are large regions of 639 00:33:20,064 --> 00:33:22,599 the Earth that are locked in ice right now. 640 00:33:22,700 --> 00:33:28,205 There could be viruses that live inside that ice that if 641 00:33:28,306 --> 00:33:32,075 the Earth gets too warm, could reactivate. 642 00:33:32,176 --> 00:33:35,879 And these viruses could potentially be a threat to us. 643 00:33:37,382 --> 00:33:40,584 ROWE: Recently, other dangerous frozen zombies 644 00:33:40,685 --> 00:33:44,554 have reanimated, hidden in the dead. 645 00:33:44,655 --> 00:33:46,156 We tend to think of people who died in 646 00:33:46,257 --> 00:33:49,326 the past as not being able to affect us all, right? 647 00:33:49,427 --> 00:33:51,194 They're gone, their germs are gone. 648 00:33:51,295 --> 00:33:53,497 Unfortunately, this isn't exactly true. 649 00:33:53,598 --> 00:33:57,801 So for people who are buried in tundra that's been frozen, 650 00:33:57,902 --> 00:33:59,369 they never really disappeared. 651 00:33:59,470 --> 00:34:02,372 And now, unfortunately, as the climate warms, 652 00:34:02,473 --> 00:34:08,011 these tundra environments are releasing frozen people 653 00:34:08,112 --> 00:34:12,716 and animals who died thousands of years ago. 654 00:34:12,817 --> 00:34:14,718 ROWE: But it's not the dead people and animals 655 00:34:14,819 --> 00:34:18,021 that threaten us... It's the microbes inside them. 656 00:34:19,824 --> 00:34:22,826 In 2016, that threat became real 657 00:34:22,927 --> 00:34:25,328 when another area of Siberia thawed. 658 00:34:26,597 --> 00:34:28,432 A 12-year-old boy died, 659 00:34:28,533 --> 00:34:31,768 and dozens of people needed medical treatment. 660 00:34:31,869 --> 00:34:35,539 2,000 reindeer also perished. 661 00:34:35,640 --> 00:34:39,276 The culprit? Reanimated bacteria called 662 00:34:39,377 --> 00:34:42,813 anthrax inside a melting reindeer. 663 00:34:42,914 --> 00:34:47,417 Anthrax is a common microbe found in soil. 664 00:34:47,518 --> 00:34:49,753 In medieval times, 665 00:34:49,854 --> 00:34:53,390 sometimes farmers would come back to find entire fields 666 00:34:53,491 --> 00:34:55,292 of dead animals. 667 00:34:55,393 --> 00:34:57,461 They didn't understand at the time what was going on. 668 00:34:57,562 --> 00:35:00,864 They attribute it to cursed fields. 669 00:35:00,965 --> 00:35:05,268 But we now know these are outbreaks of anthrax. 670 00:35:05,369 --> 00:35:09,306 ROWE: The defrosted reindeer died nearly a century ago. 671 00:35:10,508 --> 00:35:13,844 The anthrax that killed it was safely locked away in 672 00:35:13,945 --> 00:35:15,312 the ice. 673 00:35:15,413 --> 00:35:17,948 DARTNELL: The thawing out of regions 674 00:35:18,049 --> 00:35:20,617 like the Siberian permafrost 675 00:35:20,718 --> 00:35:24,321 could be almost like the inadvertent opening of 676 00:35:24,422 --> 00:35:25,989 Pandora's box. 677 00:35:26,090 --> 00:35:28,792 Once you open it, you don't know what's gonna come out. 678 00:35:28,893 --> 00:35:33,563 DARTNELL: It could be releasing ancient preserved microbes, 679 00:35:33,664 --> 00:35:36,166 bacteria, or viruses 680 00:35:36,267 --> 00:35:39,302 that have been laying dormant for hundreds, 681 00:35:39,403 --> 00:35:41,671 if not thousands of years. 682 00:35:41,772 --> 00:35:45,008 LANZA: If these microbes are actually very different 683 00:35:45,109 --> 00:35:47,144 from what we have on Earth today, 684 00:35:47,245 --> 00:35:50,447 if we encountered these microbes, it's not really clear 685 00:35:50,548 --> 00:35:52,849 what would happen with our immune systems. 686 00:35:52,950 --> 00:35:55,452 You know, it could be totally fine, 687 00:35:55,553 --> 00:35:58,588 but it could also wreak complete havoc on us. 688 00:35:58,689 --> 00:36:02,259 ROWE: It's also not clear if modern drugs would 689 00:36:02,360 --> 00:36:05,929 help us beat any ancient microbes we unleash. 690 00:36:07,632 --> 00:36:11,735 Now, as humanity expands beyond Earth to new worlds, 691 00:36:11,836 --> 00:36:15,772 will we carry our microcosmos with us into space? 692 00:36:15,873 --> 00:36:18,775 Or have we already infected 693 00:36:18,876 --> 00:36:20,310 our cosmic neighborhood? 694 00:36:30,588 --> 00:36:35,192 ROWE: Space is no longer the final frontier of the future. 695 00:36:35,293 --> 00:36:37,394 We're already exploring the solar system. 696 00:36:38,896 --> 00:36:40,997 We've sent probes to the planets 697 00:36:41,098 --> 00:36:42,332 and put boots on the moon. 698 00:36:43,868 --> 00:36:47,237 Now, NASA plans to land astronauts on Mars 699 00:36:47,338 --> 00:36:48,872 by the 2030s. 700 00:36:50,441 --> 00:36:53,944 As a science fiction nerd myself, without even breaking 701 00:36:54,045 --> 00:36:55,879 a sweat, I could name 10 movies 702 00:36:55,980 --> 00:36:58,949 where people go to another planet, and some disease, 703 00:36:59,050 --> 00:37:01,251 some alien life form, is unleashed on humans 704 00:37:01,352 --> 00:37:03,220 and kills us all. 705 00:37:03,321 --> 00:37:05,288 I think that has it exactly backwards. 706 00:37:05,389 --> 00:37:09,059 If we try to settle on other planets, we have to be really, 707 00:37:09,160 --> 00:37:11,528 really careful and really, really think about 708 00:37:11,629 --> 00:37:14,164 how we are affecting them. 709 00:37:14,265 --> 00:37:17,701 ROWE: As we launch more and more missions into space, we risk 710 00:37:17,802 --> 00:37:21,538 sending Earth's microcosmos with them, endangering 711 00:37:21,639 --> 00:37:23,106 the health of the solar system. 712 00:37:24,375 --> 00:37:26,643 LANZA: And if we find a planet that actually has 713 00:37:26,744 --> 00:37:29,746 its own biosphere, that has life of its own, 714 00:37:29,847 --> 00:37:32,148 we need to be very careful about how we introduce 715 00:37:32,250 --> 00:37:34,217 our microbes to their microbes, 716 00:37:34,318 --> 00:37:36,353 because it could really be catastrophic for them. 717 00:37:36,454 --> 00:37:38,888 PLAIT: It's serious, because we're looking at places 718 00:37:38,990 --> 00:37:40,991 like Mars, like Titan, 719 00:37:41,092 --> 00:37:44,794 Saturn's moon, like comets where life or at least 720 00:37:44,895 --> 00:37:46,563 prebiotic life could have existed. 721 00:37:46,664 --> 00:37:48,231 Or, in the past, there could 722 00:37:48,332 --> 00:37:51,534 have been a much more habitable environment. 723 00:37:51,636 --> 00:37:55,138 So it's entirely possible that we are polluting, 724 00:37:55,239 --> 00:38:00,543 we are infecting these other objects with our own bacteria. 725 00:38:00,645 --> 00:38:03,413 ROWE: If we contaminate a pristine world, 726 00:38:03,514 --> 00:38:06,216 we won't know which microbes were there first. 727 00:38:07,518 --> 00:38:10,186 Our bugs could even kill off the native ones. 728 00:38:11,689 --> 00:38:13,023 It may have already happened. 729 00:38:15,726 --> 00:38:17,227 OVER RADIO: You're looking good. 730 00:38:17,328 --> 00:38:20,397 ROWE: The Apollo 12 mission brought back bits of the lunar 731 00:38:20,498 --> 00:38:24,567 robotic probe Surveyor 3 it found on the moon. 732 00:38:24,669 --> 00:38:29,072 Analysis of the probe found a bacterial contamination. 733 00:38:29,173 --> 00:38:31,374 We don't know where it came from. 734 00:38:31,475 --> 00:38:33,677 PLAIT: If that thing was infected before we sent it 735 00:38:33,778 --> 00:38:35,378 to the moon, and it sat on the moon's surface 736 00:38:35,479 --> 00:38:38,782 for two years in a vacuum, changing temperatures, 737 00:38:38,883 --> 00:38:42,085 radiation from space, that really is telling us that 738 00:38:42,186 --> 00:38:44,888 we can infect other planets and we should 739 00:38:44,989 --> 00:38:47,190 take this very seriously. 740 00:38:47,291 --> 00:38:49,959 SUTTER: We're ramping up our space missions, 741 00:38:50,061 --> 00:38:52,061 we're sending probe after probe 742 00:38:52,129 --> 00:38:55,365 to planets all throughout the solar system. 743 00:38:55,466 --> 00:39:00,437 Taking care to not send our own diseases out onto 744 00:39:00,538 --> 00:39:03,039 other planets is something we actually have to care about. 745 00:39:03,140 --> 00:39:06,009 ROWE: NASA does care. 746 00:39:06,110 --> 00:39:09,479 Before launching a new probe, a planetary protection team 747 00:39:09,580 --> 00:39:11,514 deep cleans every inch. 748 00:39:12,917 --> 00:39:15,385 You try to bake the spacecraft, you try to disinfect things. 749 00:39:15,486 --> 00:39:19,356 You build everything and keep everything within a clean room, 750 00:39:19,457 --> 00:39:23,693 which has a pressure that blows dust out. 751 00:39:23,794 --> 00:39:25,929 Everybody wears what are called bunny suits, 752 00:39:26,030 --> 00:39:27,897 so nobody touches anything directly. 753 00:39:27,998 --> 00:39:29,666 But then, that's still not enough, 754 00:39:29,767 --> 00:39:32,669 because microbes are incredibly hardy. 755 00:39:32,770 --> 00:39:35,605 ROWE: It's even more difficult to kill microcosmic 756 00:39:35,706 --> 00:39:38,675 stowaways if they're traveling inside an astronaut. 757 00:39:40,144 --> 00:39:42,379 DARTNELL: In the not too distant future, 758 00:39:42,480 --> 00:39:47,183 we'll start sending not robot explorers, not probes to Mars, 759 00:39:47,284 --> 00:39:52,222 but people, an inherently dirty, mucky organism 760 00:39:52,323 --> 00:39:53,923 like myself. 761 00:39:54,024 --> 00:39:55,458 You can't sterilize a human. 762 00:39:55,559 --> 00:39:57,961 You can't remove all bacteria. 763 00:39:58,062 --> 00:40:00,497 We have to realize that we are bringing the microcosmos 764 00:40:00,598 --> 00:40:03,533 with us, and we may change worlds entirely 765 00:40:03,634 --> 00:40:05,034 without even noticing it. 766 00:40:05,136 --> 00:40:07,904 Potentially, our impact could be absolutely devastating on... 767 00:40:08,005 --> 00:40:10,907 On worlds that are either have life or emerging life, 768 00:40:11,008 --> 00:40:14,077 and so we just need to take that responsibility seriously 769 00:40:14,178 --> 00:40:16,780 and be careful with the way in which we explore them. 770 00:40:18,048 --> 00:40:19,783 ROWE: Humans bear a responsibility 771 00:40:19,884 --> 00:40:21,418 for the safety of the cosmos. 772 00:40:21,519 --> 00:40:24,053 Our track record on Earth isn't good. 773 00:40:25,623 --> 00:40:28,124 RADEBAUGH: When we look at the pattern of exploration 774 00:40:28,225 --> 00:40:32,395 or colonization that we use as humans, we are really invasive. 775 00:40:32,496 --> 00:40:34,631 We see a lot of destruction in our path, 776 00:40:34,732 --> 00:40:37,400 and we have to wonder if that's what we're going to do 777 00:40:37,501 --> 00:40:39,502 when we start to really explore and colonize 778 00:40:39,603 --> 00:40:41,805 outside of Earth. 779 00:40:41,906 --> 00:40:44,207 Like viruses, we also insist on spreading. 780 00:40:44,308 --> 00:40:45,708 We insist on spreading around 781 00:40:45,810 --> 00:40:47,877 our world, around our solar system. 782 00:40:47,978 --> 00:40:49,913 There is a great chance 783 00:40:50,014 --> 00:40:52,715 that we will cause utter destruction wherever we go. 784 00:40:54,018 --> 00:40:58,388 ROWE: Our relationship with the microcosmos is complicated. 785 00:40:58,489 --> 00:41:01,124 It's killed millions of people, 786 00:41:01,225 --> 00:41:03,493 but without it, we wouldn't be here. 787 00:41:04,762 --> 00:41:07,197 RADEBAUGH: This time we're living in is really causing us 788 00:41:07,264 --> 00:41:09,332 to reflect on the microcosmos, and the better 789 00:41:09,433 --> 00:41:11,201 we understand these microorganisms, 790 00:41:11,302 --> 00:41:14,604 the better able we are to deal with what's happening today. 791 00:41:14,705 --> 00:41:16,840 ROWE: The coronavirus crisis reminds us 792 00:41:16,941 --> 00:41:19,609 we need to respect the world we cannot see 793 00:41:19,710 --> 00:41:22,712 and recognize that the microcosmos is 794 00:41:22,813 --> 00:41:25,949 every bit as important to us as the greater universe. 795 00:41:27,251 --> 00:41:29,552 It's so easy, especially right now in history, 796 00:41:29,653 --> 00:41:31,754 to hear the word virus and think about how harmful they 797 00:41:31,856 --> 00:41:33,156 are, how dangerous they are. 798 00:41:33,257 --> 00:41:35,692 But remember that you are actually a creature built 799 00:41:35,793 --> 00:41:37,126 of viruses yourself. 800 00:41:37,228 --> 00:41:40,597 As far as we know, we've never been without the microcosmos. 801 00:41:40,698 --> 00:41:42,332 Microbes were here before us. 802 00:41:42,433 --> 00:41:46,402 They'll probably be here after us, and we need them to live. 803 00:41:47,905 --> 00:41:50,807 BYWATERS: The microcosmos... It's absolutely essential. 804 00:41:50,908 --> 00:41:52,909 We couldn't function. We wouldn't survive. 805 00:41:53,010 --> 00:41:55,512 We wouldn't be here without it. 806 00:41:55,613 --> 00:41:58,181 But it's also our greatest ally, 807 00:41:58,282 --> 00:42:00,783 and it's also our greatest enemy.