1 00:00:04,780 --> 00:00:08,340 They're dazzling, priceless... 2 00:00:08,340 --> 00:00:11,790 at times, even glowing. 3 00:00:13,120 --> 00:00:17,420 How can one not fall in love with rocks and minerals? 4 00:00:18,560 --> 00:00:20,780 I mean, the colors, the shapes... 5 00:00:21,300 --> 00:00:25,400 ...and they're the building blocks of modern civilization. 6 00:00:25,400 --> 00:00:28,460 We wouldn't have televisions, we wouldn't have automobiles, we wouldn't have 7 00:00:28,480 --> 00:00:30,960 buildings without the mineral riches that we have. 8 00:00:31,720 --> 00:00:34,340 But could rocks and minerals also solve 9 00:00:34,340 --> 00:00:36,340 the greatest mystery of all time? 10 00:00:36,860 --> 00:00:39,020 The origin of life. 11 00:00:40,160 --> 00:00:42,160 The rocks we pick up tell a story 12 00:00:43,000 --> 00:00:44,760 that life couldn't have occurred without rocks. 13 00:00:45,380 --> 00:00:48,280 Could cold, lifeless stone hold the key 14 00:00:48,280 --> 00:00:50,980 to every living thing on Earth? 15 00:00:53,940 --> 00:00:56,940 From Australia, to Morocco, 16 00:00:57,480 --> 00:01:00,960 Nova goes around the world and back in time 17 00:01:01,420 --> 00:01:05,580 to investigate the origin and evolution of life. 18 00:01:06,100 --> 00:01:08,360 Look at a rock and you think ah, well, nothing. 19 00:01:08,360 --> 00:01:11,700 but this holds the signature of life. 20 00:01:12,360 --> 00:01:13,780 From its first spark... 21 00:01:13,780 --> 00:01:18,120 People were saying they've made Frankenstein in a test tube... 22 00:01:18,600 --> 00:01:20,520 ...To the survival of the fittest. 23 00:01:20,820 --> 00:01:26,220 These were immense creatures. Sharks that may have been 50 or 60 feet. 24 00:01:28,660 --> 00:01:32,380 Was it the secret link between rocks and life 25 00:01:32,380 --> 00:01:34,140 that made the difference? 26 00:01:36,020 --> 00:01:39,620 Life's rocky start. Right now, on Nova. 27 00:02:01,020 --> 00:02:02,940 The ancient market of Marrakech, 28 00:02:04,480 --> 00:02:09,400 a chaotic, colorful gathering place teeming with life for thousands of years, 29 00:02:11,000 --> 00:02:16,240 the perfect place to ask how did this exotic, beautiful and sometimes bizarre 30 00:02:16,250 --> 00:02:19,250 thing called life, begin? 31 00:02:26,520 --> 00:02:29,520 How did Earth go from a lifeless, molten rock... 32 00:02:32,540 --> 00:02:35,540 to a living planet? 33 00:02:36,060 --> 00:02:39,060 Full of diverse and spectacular creatures. 34 00:02:44,100 --> 00:02:46,840 it's a question that has long perplexed scientists. 35 00:02:51,760 --> 00:02:56,739 Now, Robert Hazen, a geologist, is trying to show we are missing an essential 36 00:02:56,740 --> 00:02:59,709 ingredient in the recipe for life. 37 00:02:59,709 --> 00:03:01,680 -look at that vein of calcite... 38 00:03:01,680 --> 00:03:02,900 Rocks. 39 00:03:03,400 --> 00:03:06,460 Nothing seems more lifeless than a rock. 40 00:03:07,000 --> 00:03:12,159 it's inanimate, it's the antithesis of a living thing, but we're beginning to 41 00:03:12,159 --> 00:03:17,260 realize that rocks played an absolutely fundamental role in the origin of life. 42 00:03:19,819 --> 00:03:25,489 Hazen is out to expose a secret relationship between rocks and life that 43 00:03:25,489 --> 00:03:31,579 helped drive both the origin of life and its evolution into complex creatures. 44 00:03:33,469 --> 00:03:38,750 This is a very new set of understandings and the more we look, the more we see 45 00:03:38,750 --> 00:03:41,540 that life depends on rocks, rocks depend on life. 46 00:03:41,540 --> 00:03:43,580 This has been going on for four billion years. 47 00:03:44,740 --> 00:03:46,740 As a geologist, it's no surprise 48 00:03:46,740 --> 00:03:49,900 that Hazen is searching for answers written in stone. 49 00:03:50,900 --> 00:03:51,900 But is he right? 50 00:03:53,720 --> 00:03:56,360 Are rocks the missing spark of life? 51 00:04:04,000 --> 00:04:06,960 The history of Earth is unimaginably long. 52 00:04:08,800 --> 00:04:14,000 If it were sped up to the equivalent of a single day, all of humankind from the 53 00:04:14,000 --> 00:04:19,880 earliest skeletons to the invention of the iphone would have occurred in only 54 00:04:19,880 --> 00:04:23,300 the last four seconds. 55 00:04:23,300 --> 00:04:26,990 Dinosaurs were still roaming earth about 20 minutes before that, 56 00:04:28,620 --> 00:04:35,610 but the creation of our planet occurred more than 23 hours earlier, two cycles on 57 00:04:35,610 --> 00:04:37,140 this clock 58 00:04:37,140 --> 00:04:39,800 or 4.5 billion years ago. 59 00:04:43,000 --> 00:04:47,180 Comprehending Earth's vast history is a formidable task. 60 00:04:49,400 --> 00:04:54,460 It is four and a half billion years of change, but you can divide it into half a dozen ways of 61 00:04:54,460 --> 00:04:56,380 describing Earth through time. 62 00:04:58,940 --> 00:05:03,200 Bob Hazen has come up with another way to visualize Earth's long history that 63 00:05:03,210 --> 00:05:07,260 reveals this special relationship between rocks and life. 64 00:05:12,040 --> 00:05:17,180 He has divided it into six stages, each represented by a different color 65 00:05:19,420 --> 00:05:24,360 to understand how we ended up with green earth, the planet we now know, requires us 66 00:05:24,370 --> 00:05:28,060 to turn the clock back to before there was any life at all. 67 00:05:30,040 --> 00:05:33,280 Stage one was the creation of black Earth. 68 00:05:43,600 --> 00:05:50,020 Back in Morocco, Hazen and Adam Aaronson, a meteorite expert, seek out a small rock 69 00:05:50,020 --> 00:05:52,280 from the beginning of our cosmos. 70 00:05:55,040 --> 00:05:56,920 -Wow look at this pile here. -yeah. 71 00:05:56,920 --> 00:06:00,600 These are meteorites. Rocks that have fallen from space. 72 00:06:00,820 --> 00:06:05,420 -This is Tamta. This is the one that fell 20 kilometers up the road from here. 73 00:06:05,420 --> 00:06:08,620 People saw it fall. 74 00:06:08,640 --> 00:06:13,680 A recent meteorite fall in Siberia was captured in videos that have shown up on Youtube. 75 00:06:15,380 --> 00:06:19,080 Other space rocks have ended up for sale here in Morocco. 76 00:06:20,000 --> 00:06:21,680 -Say you'd buy this without doing tests... 77 00:06:21,680 --> 00:06:24,520 -I'll drop the cash right now here and give me a good price. 78 00:06:26,300 --> 00:06:28,020 Meteorites here can sell 79 00:06:28,020 --> 00:06:32,860 for tens of thousands of dollars. That may seem a steep price for a lump of 80 00:06:32,870 --> 00:06:38,000 rock, but these are some of the very oldest objects in our solar system. 81 00:06:38,510 --> 00:06:44,600 This is the oldest object you could ever hold in your hand. It's 4.6 billion years 82 00:06:44,600 --> 00:06:49,910 old and is formed before Earth formed. This is the very first solid material, 83 00:06:49,910 --> 00:06:56,300 the very first rock in our solar system and these came together to build all the planets. 84 00:07:03,340 --> 00:07:10,000 Our Earth was created out of the rocks and dust present at the start of our solar system. 85 00:07:19,310 --> 00:07:24,620 Over time, small fragments of orbiting rock collided, coming together into the 86 00:07:24,620 --> 00:07:27,620 planet circling the Sun. 87 00:07:29,240 --> 00:07:33,440 At first, Earth was molten with temperatures in the thousands of degrees, 88 00:07:35,660 --> 00:07:42,260 but in the cold vacuum of space this hot rock began to cool and change. 89 00:07:54,300 --> 00:07:55,280 Nothing. 90 00:07:55,280 --> 00:07:59,600 Not a speck of dust is believed to have survived from the period of black Earth. 91 00:08:02,940 --> 00:08:05,940 It was a hellishly unpleasant time. 92 00:08:11,100 --> 00:08:14,100 Volcanoes spewed hot lava from deep inside the planet. 93 00:08:17,420 --> 00:08:26,580 When it cooled, it covered Earth with its first rock called basalt 94 00:08:26,580 --> 00:08:29,980 and it was black. 95 00:08:35,039 --> 00:08:43,159 It seems like a desolate landscape, but some ingredients that life will need are 96 00:08:43,159 --> 00:08:47,560 already here in these rocks. 97 00:08:47,560 --> 00:08:50,580 Look inside and you begin to understand how intriguing 98 00:08:50,580 --> 00:08:53,940 even an ordinary rock is. 99 00:08:53,940 --> 00:08:56,040 Every rock, you slice it open 100 00:08:56,050 --> 00:09:00,820 you look inside, there's something special. Rocks are made up mostly of 101 00:09:00,820 --> 00:09:06,040 minerals, which are crystals like quartz or diamonds. Looking through a microscope 102 00:09:06,040 --> 00:09:13,180 at super thin slices of a rock lets you see its mineral composition. 103 00:09:13,180 --> 00:09:19,520 This is the rock Peridotite, made up of small crystals, including olivine and pyroxene. 104 00:09:20,760 --> 00:09:25,320 Even a simple black basalt rock, spewed from a volcano, becomes a 105 00:09:25,330 --> 00:09:27,910 patchwork of colorful minerals. 106 00:09:27,910 --> 00:09:32,800 It's sort of like a fruitcake, you know I slice it open, there's nuts and there's 107 00:09:32,800 --> 00:09:35,740 dried fruit and maybe some lemon peel. 108 00:09:35,740 --> 00:09:39,190 It's made of lots of little things and it is not until you slice into that fruitcake 109 00:09:39,190 --> 00:09:42,730 that you see all the stuff inside that makes it special. 110 00:09:51,050 --> 00:09:55,670 What makes them special is not only their beauty. Minerals have remarkable 111 00:09:55,670 --> 00:10:00,400 chemical and physical properties and are a source of many of the elements - 112 00:10:00,680 --> 00:10:03,680 nature's building blocks. 113 00:10:05,250 --> 00:10:09,420 That is why they are essential in our modern world to make everything from 114 00:10:09,420 --> 00:10:11,400 skyscrapers taller 115 00:10:11,400 --> 00:10:14,590 - mobile phones smaller. 116 00:10:16,020 --> 00:10:23,600 Extract the element molybdenum from the mineral molybdenite to make steel stronger. 117 00:10:24,080 --> 00:10:28,640 Or add a pinch of cobalt and your iphone battery will last longer. 118 00:10:30,660 --> 00:10:36,569 Minerals are the fundamental building block of societies. We wouldn't have 119 00:10:36,569 --> 00:10:40,259 televisions, we wouldn't have automobiles, we wouldn't have buildings without the 120 00:10:40,259 --> 00:10:43,250 mineral riches that we have. 121 00:10:43,250 --> 00:10:47,660 So, were the remarkable chemical properties of minerals also key in 122 00:10:47,660 --> 00:10:50,660 creating life? 123 00:10:51,620 --> 00:10:55,040 If so, Earth would mean more than it started with 124 00:11:00,550 --> 00:11:05,709 It's estimated that the meteorites that formed Earth had only about 250 minerals, 125 00:11:05,709 --> 00:11:09,339 sort of a chemical starter kit, containing many of the elements. 126 00:11:13,310 --> 00:11:17,779 Then, in the intense heat and pressures in the creation of our planet, new 127 00:11:17,779 --> 00:11:25,760 minerals began to form. This changed the appearance of our Earth from black to 128 00:11:25,760 --> 00:11:28,760 gray. 129 00:11:37,850 --> 00:11:41,600 Yosemite national park is a relatively new piece of Earth, 130 00:11:44,510 --> 00:11:48,830 but the kind of rock that makes up these dramatic cliffs goes back much further. 131 00:11:54,290 --> 00:12:01,910 These huge walls are granite containing minerals like quartz and feldspar. 132 00:12:06,160 --> 00:12:11,520 Granite became the foundation of our continents, leading Earth into the gray period. 133 00:12:17,400 --> 00:12:22,020 At this point, earth is still a long way from the glorious diversity of plants 134 00:12:22,020 --> 00:12:25,300 and animals that makes Yosemite so picturesque. 135 00:12:28,380 --> 00:12:31,740 But the stage is set for the next character in our planet story: 136 00:12:33,230 --> 00:12:40,220 Water, which will turn Earth blue. Water plays a central role in every model for 137 00:12:40,220 --> 00:12:42,500 the origin of life. 138 00:12:42,500 --> 00:12:47,210 That's because water is such a great solvent. All these different kinds of 139 00:12:47,210 --> 00:12:51,350 molecules can be floating around the water and then they have the potential to 140 00:12:51,350 --> 00:12:55,190 interact together. The starting point is the water. 141 00:12:56,840 --> 00:13:00,290 So when did Earth cool enough to have liquid water, 142 00:13:00,860 --> 00:13:04,150 this element key to life? 143 00:13:04,150 --> 00:13:08,530 One of the biggest unknowns in this whole idea of going from black to gray 144 00:13:08,530 --> 00:13:12,010 to a blue water-covered earth, is how quickly it happened. 145 00:13:12,700 --> 00:13:15,700 The timing is a big mystery. 146 00:13:24,630 --> 00:13:29,910 The Pilbara in Western Australia is one of the oldest places on Earth 147 00:13:29,910 --> 00:13:34,560 and so, one of the best places to solve the mystery of the planet's first oceans. 148 00:13:37,960 --> 00:13:42,480 Hazen joins an all-star team of geologists, including Martin Van Kranendonk 149 00:13:42,480 --> 00:13:47,730 from the University of New South Wales and John Valley of the University 150 00:13:47,730 --> 00:13:50,720 of Wisconsin. 151 00:13:53,080 --> 00:13:58,160 Valley is collecting rocks that could hold clues to when water first appeared. 152 00:13:58,700 --> 00:14:02,270 We could get zircons and other minerals that date all the way back to 153 00:14:02,270 --> 00:14:03,740 4.4 billion years old. 154 00:14:03,740 --> 00:14:06,300 Hopefully. 155 00:14:06,300 --> 00:14:11,640 Some rocks here contain sand-sized grains that wheathered from even older rocks. 156 00:14:12,300 --> 00:14:17,400 one in a million, literally, is a crystal called zircon, one of the longest lasting 157 00:14:17,400 --> 00:14:20,400 materials in nature. 158 00:14:22,710 --> 00:14:28,980 Zircon is a popular gemstone, but the microscopic zircon found here is even 159 00:14:28,980 --> 00:14:30,480 more precious. 160 00:14:30,480 --> 00:14:34,980 Zircon crystals are especially amazing. Gemstone zircons of course are valued, but 161 00:14:34,980 --> 00:14:39,270 these tiny ones the geologists value are microscopic that make a lousy ring, but 162 00:14:39,270 --> 00:14:42,270 they tell an incredible story. 163 00:14:42,910 --> 00:14:48,190 To tell that story, John Valley must first find the tiny crystals, 164 00:14:48,190 --> 00:14:51,280 the ultimate needle in a haystack. 165 00:14:51,280 --> 00:14:54,000 If you want to find a needle in a haystack, the first thing you do is you 166 00:14:54,010 --> 00:14:56,230 burn down the haystack. 167 00:14:56,230 --> 00:15:01,300 Then you sip through the ash to look for the needle. Rocks are pulverized into 168 00:15:01,300 --> 00:15:07,860 sand sized grains and sorted by weight in a machine developed to pan for gold. 169 00:15:10,180 --> 00:15:15,120 The gold that Valley is looking for are heavy zircon crystals which get 170 00:15:15,130 --> 00:15:18,130 channeled into different tracks. 171 00:15:20,280 --> 00:15:24,780 Then, grain by grain, with a very steady hand, 172 00:15:24,920 --> 00:15:30,180 thousands of small crystals are sorted and analyzed. 173 00:15:31,000 --> 00:15:35,860 The chemical structure of a zircon crystal holds evidence of both the environment 174 00:15:35,860 --> 00:15:40,220 and the age when it formed. 175 00:15:43,260 --> 00:15:46,980 Some of these tiny crystals go very far back, 176 00:15:47,490 --> 00:15:50,730 just over a hundred million years after Earth formed. 177 00:15:52,850 --> 00:15:56,089 They are the oldest pieces of Earth ever discovered. 178 00:15:57,160 --> 00:16:02,240 So they could shed light on what our young planet looked like. 179 00:16:08,320 --> 00:16:13,400 It's totally amazing. To hold this grain of sand in the palm of your hand 180 00:16:13,410 --> 00:16:16,470 is literally to see back through time. 181 00:16:17,160 --> 00:16:20,160 It is a time machine. 182 00:16:23,270 --> 00:16:27,680 Valley expected these crystal time machines would confirm the long-held 183 00:16:27,680 --> 00:16:33,620 view that the young Earth was covered in molten lava, still cooling after its 184 00:16:33,620 --> 00:16:36,620 violent formation. 185 00:16:38,019 --> 00:16:41,379 I think the zircon on the left looks very promising. 186 00:16:42,249 --> 00:16:48,339 So what he discovered was shocking, because this type of zircon created 4.3 187 00:16:48,340 --> 00:16:54,480 billion years ago could only have formed in the presence of liquid water. 188 00:16:56,420 --> 00:17:01,280 But how could there be water if Earth was still hot and hell-like? 189 00:17:03,980 --> 00:17:07,280 The implications were that the early Earth had water, 190 00:17:07,280 --> 00:17:10,280 it was cooler and it was wet. 191 00:17:11,400 --> 00:17:14,400 It's starting to look very much more familiar. 192 00:17:14,780 --> 00:17:18,420 And if water is a key starting point for life 193 00:17:18,800 --> 00:17:21,800 could there be life that early too? 194 00:17:25,859 --> 00:17:30,340 The science of the zircon is telling us that the Earth for a very, very long time 195 00:17:30,340 --> 00:17:36,130 was a habitable environment, not necessarily that there was life then. 196 00:17:36,130 --> 00:17:39,880 We don't know that yet, but there's no reason why there couldn't have been life 197 00:17:39,880 --> 00:17:42,340 as early as 4.3 billion years ago. 198 00:17:42,880 --> 00:17:49,920 So, if life were possible that early, it begs the question: how did life begin? 199 00:17:53,500 --> 00:17:59,020 In 1871, Charles Darwin speculated in a letter to a friend that a warm little 200 00:17:59,020 --> 00:18:02,020 pond might be life's birthplace. 201 00:18:08,770 --> 00:18:14,110 A warm soup of chemicals bathed by energy from the Sun would have been, well, 202 00:18:14,110 --> 00:18:19,580 comfortable for molecules to come together in new ways and create life. 203 00:18:22,460 --> 00:18:25,460 Darwin was way, way ahead of his time. 204 00:18:25,980 --> 00:18:30,300 A nice little warm soup is gonna get you a long way. 205 00:18:32,880 --> 00:18:37,620 Jeff Boda of the Scripps Institution of Oceanography in San Diego has spent his 206 00:18:37,620 --> 00:18:42,320 career working to understand the early Earth's soup of chemicals. 207 00:18:44,420 --> 00:18:49,160 He began under the direction of perhaps the most famous scientist in origin of 208 00:18:49,170 --> 00:18:50,550 life research, 209 00:18:50,550 --> 00:18:53,550 Stanley Miller. 210 00:18:54,140 --> 00:18:58,940 There are in the history of science turning points where we suddenly see the 211 00:18:58,940 --> 00:19:03,680 history of Earth and life differently. In the early nineteen fifties, Stanley 212 00:19:03,680 --> 00:19:07,310 Miller, the eager graduate student, and Harold Urey, the Nobel Prize winning 213 00:19:07,310 --> 00:19:11,660 mentor at the University of Chicago conducted this astonishing experiment 214 00:19:11,660 --> 00:19:14,660 where they made an early Earth environment. 215 00:19:15,530 --> 00:19:20,210 It looks like this sort of a Frankenstein type apparatus, but actually 216 00:19:20,210 --> 00:19:26,210 it's a very carefully thought out design. Boda sets up a modern-day test of the 217 00:19:26,210 --> 00:19:30,320 nineteen fifties experiment on Miller's original lab equipment. 218 00:19:32,360 --> 00:19:37,360 One flask contains water. That's to simulate the ocean. 219 00:19:38,640 --> 00:19:42,460 The other flask has just got the gases in it, so this is the atmosphere. 220 00:19:47,140 --> 00:19:52,600 Just as it does in nature, water from the ocean evaporates and rises into the 221 00:19:52,600 --> 00:19:57,360 atmosphere, where it condenses and returns to the ocean. 222 00:19:59,400 --> 00:20:03,600 Miller simulated what he believed to be the atmosphere of early Earth with 223 00:20:03,610 --> 00:20:06,610 different gases like ammonia and methane. 224 00:20:10,140 --> 00:20:13,140 Then he added a spark of genius. 225 00:20:19,480 --> 00:20:23,640 Miller and Urey decided to use a spark to simulate lightning, because that's 226 00:20:23,640 --> 00:20:27,120 such a ubiquitous process in the atmosphere of the Earth. 227 00:20:28,600 --> 00:20:31,820 That was the real inspiration. These little electric sparks that acted like 228 00:20:31,820 --> 00:20:37,190 simulated lightning. The energy from the spark of lightning breaks down the gas 229 00:20:37,190 --> 00:20:42,680 and water molecules so they can undergo further chemical reactions. 230 00:20:48,170 --> 00:20:52,640 To their astonishment, when they turn this apparatus on, after only a couple of days, 231 00:20:52,640 --> 00:20:56,860 you started seeing this pink color developing. 232 00:20:58,120 --> 00:21:00,120 In a few more days, black 233 00:21:00,120 --> 00:21:03,160 oily goo is forming around the electrodes. 234 00:21:07,130 --> 00:21:10,130 The electrodes get covered with new substances. 235 00:21:11,660 --> 00:21:15,480 Organic compounds, usually associated with life. 236 00:21:18,720 --> 00:21:24,120 And it wasn't just any organic compound. It was amino acids that make proteins, 237 00:21:24,120 --> 00:21:27,200 the ingredients for life. 238 00:21:30,060 --> 00:21:33,100 Amino acids are the building blocks of life. 239 00:21:35,560 --> 00:21:41,120 They form proteins, which are the key component of muscles and other tissues. 240 00:21:42,980 --> 00:21:46,400 People thought "aha!". This is a key step in the origin of life. 241 00:21:46,460 --> 00:21:50,480 And you really believe that you can bring life to the dead? 242 00:21:50,480 --> 00:21:54,800 That body is not dead, it has never lived. 243 00:21:54,980 --> 00:21:56,920 I created it. 244 00:21:59,500 --> 00:22:03,580 The experiment raised a fear that a Frankenstein creation, like in this 245 00:22:03,590 --> 00:22:07,010 classic film, was just around the corner. 246 00:22:07,010 --> 00:22:11,540 People were saying they had made Frankenstein in a test tube. 247 00:22:19,940 --> 00:22:24,040 Had Miller and Urey cooked up life in a test tube? 248 00:22:24,040 --> 00:22:27,620 many of the news headlines were saying "life created in the laboratory", 249 00:22:28,280 --> 00:22:32,180 "life created in a test tube". Of course, that was wrong. 250 00:22:32,420 --> 00:22:36,900 The real news was, he made these compounds that are part of life. 251 00:22:40,520 --> 00:22:45,840 By creating amino acids, the Miller-Urey experiment seemed to confirm that Darwin 252 00:22:45,840 --> 00:22:47,010 was right. 253 00:22:47,010 --> 00:22:51,780 Life must have begun in a shallow pond. 254 00:22:58,300 --> 00:23:01,280 But then, 24 years later, a shocking 255 00:23:01,280 --> 00:23:04,220 discovery radically challenged that idea. 256 00:23:05,530 --> 00:23:09,520 On a dark ocean floor, more than a mile below the surface, 257 00:23:10,330 --> 00:23:16,030 explorers found hot, mineral rich hydrothermal vents, like underwater 258 00:23:16,030 --> 00:23:18,190 volcanoes. 259 00:23:18,190 --> 00:23:23,620 Temperatures reached more than 600 degrees and yet here, 260 00:23:23,620 --> 00:23:30,140 life was thriving. Not off the Sun's energy, but through chemical energy from the vents. 261 00:23:31,000 --> 00:23:35,160 No one realized that life could thrive without sunlight. 262 00:23:36,140 --> 00:23:40,080 Here you have this extreme temperature and extreme pressure and so you have to shift your 263 00:23:40,090 --> 00:23:43,509 perceptions and realize that just because it's extreme to us doesn't mean 264 00:23:43,509 --> 00:23:46,020 it's extreme to those microbes. 265 00:23:47,300 --> 00:23:49,700 Instead of the warm shallow pond, 266 00:23:49,740 --> 00:23:54,980 could this dark and unlikely environment be where life began? 267 00:23:56,220 --> 00:23:57,400 To answer that, 268 00:23:57,400 --> 00:24:01,880 Hazen decided to try creating life's building blocks in the conditions of a 269 00:24:01,899 --> 00:24:03,690 deep-sea vent. 270 00:24:03,690 --> 00:24:07,409 My first thought was "why don't we do a Miller-Urey experiment but do it 271 00:24:07,409 --> 00:24:09,580 at high temperature, high pressures?" 272 00:24:10,840 --> 00:24:12,840 Hazen's laboratory is at the Carnegie 273 00:24:12,840 --> 00:24:16,740 Institution for Science, which is famous for experiments that simulate the 274 00:24:16,740 --> 00:24:22,740 intense pressures deep inside Earth with powerful tools called pressure bombs. 275 00:24:22,920 --> 00:24:26,840 They're called bombs for a reason, because things can explode. 276 00:24:36,540 --> 00:24:40,820 Hazen and his colleagues adapted these pressure bombs to model the environment 277 00:24:40,820 --> 00:24:44,260 of the deep sea vents in a small gold tube. 278 00:24:47,180 --> 00:24:50,800 What they discovered came as a surprise. 279 00:24:51,500 --> 00:24:53,680 Nothing happened. 280 00:24:53,980 --> 00:24:56,660 You can take basic gases. 281 00:24:57,260 --> 00:25:02,060 Nitrogen, CO2, maybe some sulfur compounds, 282 00:25:02,560 --> 00:25:06,080 you can mix those, you can put them in a gold tube, you can heat them up, you don't get much 283 00:25:06,080 --> 00:25:08,960 much that is very interesting. 284 00:25:09,860 --> 00:25:14,200 Simply squeezing and heating the ingredients had little effect. 285 00:25:15,540 --> 00:25:20,040 Hazen was missing the spark like in the Miller-Urey experiment. 286 00:25:20,080 --> 00:25:24,180 The thing that kick-starts the chemistry. 287 00:25:28,860 --> 00:25:31,240 So he said, what's going on? What's different? 288 00:25:31,900 --> 00:25:34,460 Well, look at the natural environment. There is all these rocks and minerals. 289 00:25:34,460 --> 00:25:37,460 Let's try putting some rocks and minerals in. 290 00:25:38,120 --> 00:25:45,180 They recreate the early Earth cocktail, but this time grind in powder from rocks and minerals. 291 00:25:47,460 --> 00:25:51,300 But will Hazen's beloved rocks do the trick? 292 00:25:53,140 --> 00:25:56,120 They run the experiment again. 293 00:25:57,620 --> 00:26:05,000 And this time, the atoms reform into new organic molecules, including amino acids. 294 00:26:06,119 --> 00:26:11,129 As soon as you put powdered rocks and minerals into the gold capsules then all 295 00:26:11,129 --> 00:26:13,469 sorts of really amazing things started happening. 296 00:26:13,469 --> 00:26:18,359 You made organic molecules, they became more stable, they lasted longer, and it 297 00:26:18,360 --> 00:26:22,880 really pointed us in the direction of "aha", this has got to be part of the story. 298 00:26:23,740 --> 00:26:29,360 While scientists still argue if life began in shallow ponds or deep sea vents, 299 00:26:29,800 --> 00:26:32,759 both sides wonder what part of the story 300 00:26:32,760 --> 00:26:35,760 did rocks and minerals play? 301 00:26:43,800 --> 00:26:50,920 One possible answer may be found in London in the powerful properties of mud. 302 00:26:51,200 --> 00:26:53,580 Most people will be familiar with the material. 303 00:26:53,800 --> 00:27:00,160 It's very gungy. That's a British word that refers to something which is 304 00:27:00,160 --> 00:27:06,250 soft and unpleasant generally. Peter Coveney of University College, London is busy 305 00:27:06,250 --> 00:27:10,800 playing in mud at a very sophisticated level. 306 00:27:11,820 --> 00:27:16,530 He has created powerful computer simulations that can track the precise 307 00:27:16,530 --> 00:27:20,260 movement of up to 10 million atoms. 308 00:27:22,460 --> 00:27:28,440 Mud can contain clay, which is made up of some of Earth's most common minerals. 309 00:27:29,840 --> 00:27:35,680 What makes it so gungy, and perhaps essential in the origin of life, can be seen 310 00:27:35,680 --> 00:27:41,800 deep in its atomic makeup. You can see here the basic structure of any play is 311 00:27:41,800 --> 00:27:47,640 comprised of a large number of stacked sheets like a deck of cards. 312 00:27:48,160 --> 00:27:55,300 Sheets of clay have spaces between them that fill up with water and other molecules. 313 00:27:59,440 --> 00:28:05,580 These extensive surface areas can help create more complex molecules, 314 00:28:06,240 --> 00:28:12,560 potentially even RNA, an essential part of life's genetic code 315 00:28:15,900 --> 00:28:20,240 One of the most challenging questions in the origin of life is how we get from 316 00:28:20,240 --> 00:28:24,980 the simple building blocks to the complicated structures we know are 317 00:28:24,980 --> 00:28:27,580 fundamental to living systems. 318 00:28:28,280 --> 00:28:31,820 Clays provide a clear mechanism for achieving that. 319 00:28:32,820 --> 00:28:39,580 These simulations show that the secret to clay lies in its surfaces. 320 00:28:40,160 --> 00:28:44,400 The surfaces of these minerals are incredible. They do all sorts of chemical tricks. 321 00:28:45,820 --> 00:28:50,540 Hazen says minerals like clays illustrate a fascinating aspect of 322 00:28:50,549 --> 00:28:55,889 chemistry, because the surface where reactions take place can be as important 323 00:28:55,889 --> 00:28:59,000 as the ingredients themselves. 324 00:28:59,000 --> 00:29:03,080 The most exquisite chemistry occurs at surfaces 325 00:29:03,120 --> 00:29:10,180 Your body, your cells are almost entirely surfaces on which chemistry takes place 326 00:29:11,260 --> 00:29:16,540 So when we think about the origin of life, the minerals is where we place surfaces 327 00:29:16,540 --> 00:29:19,540 you have in your body that do that chemical work. 328 00:29:23,879 --> 00:29:28,349 We are finally beginning to understand the secret role minerals could have 329 00:29:28,349 --> 00:29:31,349 played in life's origin. 330 00:29:34,840 --> 00:29:40,930 They provided some of the ingredients. And surfaces, where important chemical 331 00:29:40,930 --> 00:29:43,380 reactions take place. 332 00:29:54,160 --> 00:29:58,220 So, when in Hazen's color phases did all this happen? 333 00:30:03,380 --> 00:30:07,940 One of the best places to figure that out is back in Australia where Hazen and 334 00:30:07,940 --> 00:30:12,320 team are now searching for signs of Earth's earliest life. 335 00:30:12,960 --> 00:30:16,229 I can't believe these rocks are three and a half billion years old. They would maybe 336 00:30:16,229 --> 00:30:17,940 form last week. 337 00:30:19,200 --> 00:30:24,600 Martin Van Kranendonk leads the team to a very unusual rock formation. 338 00:30:25,020 --> 00:30:31,440 You get your eye casting up. You see them all wrinkly, laminated, black and then if 339 00:30:31,440 --> 00:30:34,919 you look a bit further back, you see a very large domical structure. 340 00:30:34,920 --> 00:30:38,540 There is no obvious way that a chemical or physical process would form that. 341 00:30:38,540 --> 00:30:40,140 Exactly. 342 00:30:41,040 --> 00:30:46,740 These strange shapes are fossilized remnants of life, called stromatolites, 343 00:30:46,880 --> 00:30:49,760 beautifully preserved in these ancient rocks. 344 00:30:51,220 --> 00:30:52,760 This is an amazing spot. 345 00:30:52,769 --> 00:30:55,979 We're actually looking down on the surface of the ancient Earth here. 346 00:30:55,980 --> 00:30:59,800 This was the seafloor 3.4 billion years ago. 347 00:30:59,840 --> 00:31:04,400 I can see it in action, it is like a snap frozen in an instant of time. 348 00:31:04,840 --> 00:31:08,360 But billions of years have taken their toll. 349 00:31:12,360 --> 00:31:17,920 To really understand stromatolites, we have to go nearly 800 miles away. 350 00:31:18,960 --> 00:31:24,059 David Flannery, a geologist, has come to Shark Bay in search of their very 351 00:31:24,060 --> 00:31:27,460 distant descendants. 352 00:31:28,840 --> 00:31:30,280 Just below the surface, 353 00:31:30,280 --> 00:31:38,160 he finds a series of round, black mounts - living stromatolites. 354 00:31:41,700 --> 00:31:43,320 Modern environments like these 355 00:31:43,320 --> 00:31:46,919 they're very rare, but they are really the key to interpreting what we see in the 356 00:31:46,920 --> 00:31:49,000 very early fossil record. 357 00:31:51,040 --> 00:31:55,540 Without environments like these, we wouldn't know how stromatolites were built. 358 00:31:55,580 --> 00:31:58,679 Stromatolites are something like coral, a hard mineral 359 00:31:58,680 --> 00:32:02,200 structure that has been built, layer by layer. 360 00:32:02,800 --> 00:32:06,900 A closer look reveals the builders: 361 00:32:07,320 --> 00:32:10,400 Microbes - single-celled life. 362 00:32:10,500 --> 00:32:13,440 The living part of a stromatolite is only the surface. 363 00:32:13,440 --> 00:32:17,070 With a living microbial mat that is building up the structure layer by layer, 364 00:32:17,070 --> 00:32:19,180 less than a millimeter per year. 365 00:32:19,260 --> 00:32:26,280 The top layer of these stromatolites is alive with microbes that perform a remarkable trick. 366 00:32:26,460 --> 00:32:30,120 They capture minerals and sand in the water and biologically 367 00:32:30,120 --> 00:32:35,000 cement them, layer by layer, into the solid mounds. 368 00:32:38,580 --> 00:32:44,880 The results can be seen in Shark Bay today and in the ancient fossils. 369 00:32:45,980 --> 00:32:49,140 Let me introduce you to this outcrop. It's just spectacular 370 00:32:49,140 --> 00:32:51,020 to be able to see this. 371 00:32:51,020 --> 00:32:53,020 And this outcrop is unique. 372 00:32:54,540 --> 00:32:58,659 Van Kranendonk has dated this stromatolite to 3.5 373 00:32:58,660 --> 00:33:00,700 billion years ago. 374 00:33:02,000 --> 00:33:06,960 This is the very oldest fossil of life on Earth. 375 00:33:09,240 --> 00:33:13,660 We all want to know where we come from, where life originated, how long ago in 376 00:33:13,660 --> 00:33:19,260 what form and this is the oldest direct evidence we have for life on Earth. 377 00:33:27,960 --> 00:33:32,370 But while stromatolites are the earliest fossil of life we've found that does not 378 00:33:32,370 --> 00:33:35,680 make them the very first living thing. 379 00:33:37,140 --> 00:33:39,460 In fact, Van Kranendonk thinks that by the 380 00:33:39,460 --> 00:33:44,520 time stromatolite appeared, life's party was already in full swing. 381 00:33:44,580 --> 00:33:49,460 There are whole communities and colonies that are building fantastically complex structures. 382 00:33:49,460 --> 00:33:52,740 So, we've actually come in pretty late to the game, there's a lot that's gone on 383 00:33:52,740 --> 00:33:57,180 before us to get to this stage. And it's this complexity that tells us that life 384 00:33:57,180 --> 00:34:00,180 probably originated on Earth very early. 385 00:34:05,180 --> 00:34:11,260 So if these very early fossils are too complex to be the oldest form of life, 386 00:34:11,260 --> 00:34:14,419 is it possible to find something earlier? 387 00:34:16,460 --> 00:34:21,760 That is what Ruth Blake, a geologist at Yale University, is trying to figure out. 388 00:34:22,060 --> 00:34:25,880 By turning to the geological equivalent of a crime scene investigation. 389 00:34:28,880 --> 00:34:33,340 The crime has been committed, the criminals gone, but they've left behind 390 00:34:33,340 --> 00:34:36,000 some indicators, because they've changed their environment. 391 00:34:36,000 --> 00:34:41,429 Blake is analyzing some of the oldest rocks on Earth, like this ground up one 392 00:34:41,429 --> 00:34:45,460 from Greenland that formed at the bottom of an ocean 393 00:34:46,600 --> 00:34:52,800 She's looking for a chemical signature of life, left by microbes, including bacteria. 394 00:34:52,940 --> 00:34:58,680 What we start with is our ocean, trapped in a rock, and our file signature is 395 00:34:58,680 --> 00:35:01,800 somewhere in here. We have to get it out. 396 00:35:02,360 --> 00:35:04,560 In the lab, Blake and her team dissolve 397 00:35:04,560 --> 00:35:09,300 these rocks and extract molecules that are the chemical signature left behind 398 00:35:09,300 --> 00:35:12,300 by ancient microbes. 399 00:35:14,880 --> 00:35:21,200 Old life, like these microbes, consumes nutrients to produce energy. 400 00:35:23,960 --> 00:35:28,360 The leftovers carry the chemical footprint of life. 401 00:35:32,300 --> 00:35:36,800 Even today, we humans leave behind chemical footprints. 402 00:35:39,720 --> 00:35:46,620 When we breathe, for example, we're taking in oxygen and we are exhaling CO2 and water vapor 403 00:35:47,460 --> 00:35:51,640 And water vapor interacts with your environment. 404 00:35:53,240 --> 00:36:01,180 Amazingly, rocks from 3.5 billion years ago, at the time of the stromatolites in Australia, 405 00:36:01,180 --> 00:36:04,980 also carry a strong chemical footprint of life. 406 00:36:06,420 --> 00:36:11,160 But when Blake analyzes the Greenland rocks from 300 million years earlier, 407 00:36:11,160 --> 00:36:14,060 she makes a tantalizing discovery. 408 00:36:14,060 --> 00:36:18,520 As far back as 3.5 billion years, we see a strong biological signature and the 409 00:36:18,520 --> 00:36:22,800 older rocks are approaching that, but not quite there, 410 00:36:22,800 --> 00:36:27,100 but we do believe that we see something there. 411 00:36:27,100 --> 00:36:33,340 Blake believes she has detected the faint signal of life at 3.8 billion years ago, 412 00:36:33,980 --> 00:36:38,340 only 700 million years after Earth was created, 413 00:36:38,500 --> 00:36:41,500 early in the blue phase. 414 00:36:45,160 --> 00:36:49,260 There is still much that we don't know about our early planet, 415 00:36:49,260 --> 00:36:52,980 but some things are becoming clearer. 416 00:36:54,200 --> 00:36:56,860 If you could transport yourself back in time, 417 00:36:56,860 --> 00:37:01,720 about 4 billion years, parts of our earth might not look too different than this 418 00:37:01,720 --> 00:37:08,000 Southern California beach minus the surfers and Google. 419 00:37:09,520 --> 00:37:16,120 You could stand on cliffs, probably of granite, overlooking oceans that were increasingly rich with 420 00:37:16,120 --> 00:37:19,060 minerals and early microbial life. 421 00:37:20,660 --> 00:37:24,440 But you would quickly die in a great deal of pain, 422 00:37:24,440 --> 00:37:31,000 suffocating in the heavy atmosphere, rich in nitrogen and carbon dioxide, but 423 00:37:31,000 --> 00:37:34,820 lacking in life-giving free oxygen. 424 00:37:39,040 --> 00:37:42,840 Then, something truly astonishing happened. 425 00:37:42,900 --> 00:37:47,700 Those harmless-looking microbes, floating in the water or on stromatolites, 426 00:37:47,700 --> 00:37:52,660 started to change everything, turning Earth red. 427 00:38:04,000 --> 00:38:09,620 Wow! Oh my god, this is amazing! 428 00:38:09,880 --> 00:38:13,940 There aren't many places on Earth you can see something like this. 429 00:38:14,620 --> 00:38:21,580 A remnant of red Earth can be seen in Australia at the Hammersley Basin in Karijini national park. 430 00:38:22,620 --> 00:38:27,940 In these rocks, Hazen finds a startling consequence of early life as 431 00:38:27,950 --> 00:38:30,800 it began to thrive and evolve. 432 00:38:30,800 --> 00:38:35,270 What we're seeing here is one of the greatest tricks that life ever figured out. 433 00:38:35,270 --> 00:38:39,740 And that was how to take sunlight and convert it to energy. 434 00:38:40,240 --> 00:38:46,720 Microbes, like those in the stromatolites at Shark Bay, eventually began to live off the Sun's energy 435 00:38:46,720 --> 00:38:48,940 through photosynthesis. 436 00:38:48,940 --> 00:38:54,500 That led to a dramatic rise in a gas that Earth was not accustomed to. 437 00:38:54,500 --> 00:38:56,940 Oxygen. 438 00:38:57,000 --> 00:39:02,460 While to us, oxygen is a life-giving benign gas, to a world not accustomed to it, 439 00:39:02,960 --> 00:39:08,160 oxygen created a dangerously corrosive cocktail. 440 00:39:09,500 --> 00:39:18,020 The early oceans were filled with dissolved iron. The new oxygen reacted with that iron and it began to 441 00:39:18,020 --> 00:39:21,500 rust and sank to the bottom of the sea. 442 00:39:22,280 --> 00:39:24,960 These little microbes they're microscopic things and you wouldn't think 443 00:39:24,960 --> 00:39:29,100 they could do all that much, but when they produce that oxygen, the oxygen 444 00:39:29,100 --> 00:39:33,030 reacts with the iron in the oceans. You get the world's largest deposits of iron, 445 00:39:33,030 --> 00:39:36,600 thousands of feet, covering hundreds of square miles. 446 00:39:38,360 --> 00:39:44,920 these formations cover a vast area with trillions of tons of iron ore. 447 00:39:46,140 --> 00:39:52,460 That is an unimaginable consequence of trillions upon trillions of microbes breathing. 448 00:39:54,640 --> 00:39:57,440 it's a fundamental change in the chemistry of Earth. 449 00:39:57,440 --> 00:40:01,040 It's the consequence of the rise of oxygen. 450 00:40:02,200 --> 00:40:11,580 The rise in oxygen that rusted iron and sent Earth into the red phase also created many new minerals 451 00:40:12,500 --> 00:40:16,340 As a mineralogist, when I look at Earth's history, I see big transitions. 452 00:40:16,340 --> 00:40:21,500 I see the moon-forming impact, I see the formation of oceans and so forth. Then nothing, 453 00:40:21,500 --> 00:40:27,580 nothing matches what life and oxygen did to create new minerals. 454 00:40:29,160 --> 00:40:35,740 Some estimate that the meteorites that formed Earth began with only about 250 minerals. 455 00:40:41,800 --> 00:40:42,779 Today, 456 00:40:42,779 --> 00:40:45,779 there are more than 5,000. 457 00:40:49,110 --> 00:40:53,100 Hazen believes that two-thirds of all the minerals that now make up our planet, 458 00:40:53,100 --> 00:40:59,850 were created by the introduction of oxygen and most of that was in turn 459 00:40:59,850 --> 00:41:02,850 created by life. 460 00:41:05,170 --> 00:41:12,220 It's mind-boggling. Rocks create life, life creates rocks, they're intertwined 461 00:41:12,220 --> 00:41:15,220 in ways that are just now coming into focus. 462 00:41:15,800 --> 00:41:21,640 But the road ahead for life and for rocks would not be easy 463 00:41:24,720 --> 00:41:30,030 As we head into the next phase of Earth, new continents formed and broke apart 464 00:41:30,030 --> 00:41:34,000 which may have created dramatic extremes in the climate. 465 00:41:34,720 --> 00:41:40,540 Earth plunged into an icy freeze, turning it white. 466 00:41:43,740 --> 00:41:49,360 In these frozen conditions, life was nearly wiped out. 467 00:41:51,440 --> 00:41:57,140 Fortunately, active volcanoes still poke through the icy veneer, billowing out 468 00:41:57,140 --> 00:42:00,600 carbon dioxide, or CO2. 469 00:42:04,420 --> 00:42:11,020 Like a thermal blanket around our Earth, this kept heat in and rescued life. 470 00:42:13,360 --> 00:42:19,460 Life all but shut down and then the CO2 rises and rises and the greenhouse effect 471 00:42:19,460 --> 00:42:24,000 gets hotter and hotter and suddenly the planet melts. 472 00:42:25,240 --> 00:42:30,900 Cycles of these snowball hothouse conditions had profound consequences for life 473 00:42:32,160 --> 00:42:38,120 One result was more oxygen, which eventually allowed for bigger animals 474 00:42:43,320 --> 00:42:47,940 The dramatic changes during white Earth would bring us to the present phase, 475 00:42:48,000 --> 00:42:52,520 starting about 540 million years ago. 476 00:42:53,220 --> 00:42:55,220 A living planet. 477 00:42:55,940 --> 00:43:01,100 Filled with diverse plants and spectacular creatures. 478 00:43:04,700 --> 00:43:09,460 But those life forms are pitted against each other in a survival of the fittest. 479 00:43:10,420 --> 00:43:15,040 And rocks can make the difference between life and death. 480 00:43:19,560 --> 00:43:25,860 That struggle can be seen back in Morocco at the edge of the anti Atlas Mountains. 481 00:43:28,140 --> 00:43:32,970 Here, Bob Hazen and Adam Aaronsen are looking for evidence of an evolutionary 482 00:43:32,970 --> 00:43:40,040 trick that shows, once again, how life and rocks took a big leap forward together. 483 00:43:45,800 --> 00:43:50,840 520 million years ago, this valley was a shallow ocean, 484 00:43:52,680 --> 00:43:55,680 filled with new forms of life. 485 00:43:58,940 --> 00:44:06,320 This is when the diversity of life on Earth exploded, all thriving in a living sea. 486 00:44:08,540 --> 00:44:12,619 So, if you were a scuba diver, and you dove down to this reef, you'd see all kinds of 487 00:44:12,619 --> 00:44:13,549 life swimming around. 488 00:44:13,549 --> 00:44:16,549 It would be really amazing, probably very colorful too. 489 00:44:20,180 --> 00:44:25,940 There is one creature that dominates this ancient reef that Hazen wants to find. 490 00:44:27,320 --> 00:44:32,300 Nothing there, nothing there, and nothing there. 491 00:44:32,839 --> 00:44:39,290 Fossil hunting is a game of luck and persistence but it doesn't take long for 492 00:44:39,290 --> 00:44:42,319 Hazen to strike geologic gold. 493 00:44:42,320 --> 00:44:45,650 Whoa! Geez, look at that! 494 00:44:46,760 --> 00:44:48,720 That is amazing. 495 00:44:49,520 --> 00:44:50,860 The trilobite. 496 00:44:51,220 --> 00:44:54,800 Hey look, there's another head there, and a head there. Two more. 497 00:44:54,800 --> 00:44:56,440 Boy, this is rich rock. 498 00:44:56,440 --> 00:44:58,600 The trilobites here are amazing because these 499 00:44:58,600 --> 00:45:01,160 are the oldest animals that you can find. 500 00:45:01,160 --> 00:45:04,300 They're preserved as what you think of as a fossil 501 00:45:04,300 --> 00:45:06,440 that you can hold in your hand. 502 00:45:07,800 --> 00:45:13,339 Some trilobites were like horseshoe crabs, scurrying about the ocean floor. 503 00:45:14,480 --> 00:45:18,460 The reason they are found as fossils today, is because they developed an 504 00:45:18,460 --> 00:45:23,420 astonishing evolutionary trick: Shells. 505 00:45:27,780 --> 00:45:32,520 Trilobite shells were made of calcium carbonate, the same mineral found in 506 00:45:32,520 --> 00:45:36,040 limestone, the rock that built the pyramids. 507 00:45:37,460 --> 00:45:42,900 In effect, life itself began to make rocks for its own advantage. 508 00:45:44,020 --> 00:45:47,020 And the idea went viral. 509 00:45:49,300 --> 00:45:53,120 If you had a shell, you're gonna survive a lot longer than that soft body animal 510 00:45:53,120 --> 00:45:56,120 that doesn't have a shell. 511 00:45:57,040 --> 00:46:01,560 The trilobite had an advantage. It's survival of the fittest. 512 00:46:02,120 --> 00:46:07,440 The trilobites' mineral shell heralded a new phase in the evolution of animals, 513 00:46:07,700 --> 00:46:12,540 catapulting our planet into the present stage: Green Earth. 514 00:46:12,660 --> 00:46:15,960 One that is rich in diverse life. 515 00:46:20,320 --> 00:46:23,920 From humans back to trilobites, 516 00:46:23,920 --> 00:46:29,160 we owe our evolution and survival to the world of minerals. 517 00:46:29,880 --> 00:46:36,660 With shells, then eventually with bones and teeth that paved the way for life to grow taller 518 00:46:36,660 --> 00:46:38,180 and stronger. 519 00:46:39,360 --> 00:46:41,360 All are evidence of life 520 00:46:41,360 --> 00:46:46,160 co-opting minerals for its own evolutionary advantage. 521 00:46:47,840 --> 00:46:52,480 We've thought for centuries animals, minerals, they're separate kingdoms, right? 522 00:46:52,480 --> 00:46:56,500 But it turns out they overlap, they're intertwined, they co-evolved, 523 00:46:56,500 --> 00:47:01,520 that life makes minerals and minerals has led to new life forms. 524 00:47:02,120 --> 00:47:05,120 You can't separate the two. 525 00:47:07,180 --> 00:47:12,420 Life and rocks are totally intertwined through billions of years of Earth history. 526 00:47:21,020 --> 00:47:25,020 One of Hazen's favorite places to see this intertwined history of life and 527 00:47:25,020 --> 00:47:29,140 minerals is at the Calvert cliffs along the Chesapeake Bay 528 00:47:30,580 --> 00:47:35,460 He and his wife Margy pick up shells and sharp teeth from a time 18 million 529 00:47:35,470 --> 00:47:39,099 years ago, when massive sea creatures swam here. 530 00:47:39,099 --> 00:47:44,559 That's nice. You find teeth along the beach that are five, six, 531 00:47:44,560 --> 00:47:51,200 sometimes seven inches long with serrated edges, razor-sharp teeth. 532 00:47:54,220 --> 00:48:01,700 These were immense creatures. Sharks that may have been 50 or 60 feet long. 533 00:48:04,180 --> 00:48:09,740 These giants of the sea would have dwarfed today's great whites and it was 534 00:48:09,740 --> 00:48:16,880 the bones and teeth, created with minerals, that enabled them to grow so large and powerful. 535 00:48:19,660 --> 00:48:23,900 They were feeding on whales. Dolphins would have been a snack. 536 00:48:24,680 --> 00:48:31,620 They are just one small part of a story of coevolution, stretching back to Earth's beginning. 537 00:48:35,940 --> 00:48:40,380 The life, the rocks. It's all part of the same story. 538 00:48:42,100 --> 00:48:47,859 Step by step throughout Earth's evolution, minerals and life have sparked 539 00:48:47,860 --> 00:48:54,000 chemical reactions that sculpted the planet into what we see today. 540 00:48:54,020 --> 00:48:57,120 And helped create the life we know. 541 00:48:57,140 --> 00:49:04,840 At this place you get a sense of the immensity of time and the constancy of change. 542 00:49:05,020 --> 00:49:10,140 Life is creating and sculpting our surroundings in ways that are quite wonderful, 543 00:49:10,930 --> 00:49:15,519 and just to recognize the power of life to transform a planet. 544 00:49:21,050 --> 00:49:26,480 Of course, humans transform the planet too. We build cities, we build roads, we change 545 00:49:26,480 --> 00:49:30,360 the composition of the atmosphere and change the composition of the oceans. 546 00:49:32,340 --> 00:49:35,100 There are going to be global changes. 547 00:49:35,720 --> 00:49:40,100 These changes, whose consequences are now beginning to unfold, 548 00:49:40,100 --> 00:49:48,780 are the latest chapter in Earth's epic story. A story that began four and a half billion years ago 549 00:49:48,980 --> 00:00:00,000 with a rock.