Earth: Making of a Planet

1 00:00:06,000 --> 00:00:12,074 2 00:00:14,563 --> 00:00:16,063 The Earth... 3 00:00:16,168 --> 00:00:18,018 as far as we know 4 00:00:18,038 --> 00:00:21,838 it's the only home to life in the universe. 5 00:00:23,041 --> 00:00:26,391 So what makes our planet so special? 6 00:00:30,249 --> 00:00:34,449 To find answers, we must travel back in time. 7 00:00:36,457 --> 00:00:39,007 See the first humans walk the Earth. 8 00:00:40,528 --> 00:00:43,628 Ride each colliding continent. 9 00:00:44,666 --> 00:00:46,966 Face killer dinosaurs. 10 00:00:50,638 --> 00:00:54,688 Dive into oceans full of bizarre life forms. 11 00:00:56,846 --> 00:00:59,683 Feel the bitter chill of global ice ages. 12 00:01:00,751 --> 00:01:04,901 And experience the fury of cosmic missile attacks. 13 00:01:12,330 --> 00:01:14,532 By travelling back in time, 14 00:01:14,599 --> 00:01:18,434 we can piece together our planet's incredible story. 15 00:01:18,904 --> 00:01:23,374 And discover why all of this, and all of us, 16 00:01:23,441 --> 00:01:24,975 are here. 17 00:01:42,262 --> 00:01:45,997 The journey starts almost five billion years ago. 18 00:01:48,736 --> 00:01:51,286 There's no sign of Earth just yet. 19 00:01:55,310 --> 00:01:56,560 Only the Sun, 20 00:01:56,580 --> 00:01:59,580 a newborn star surrounded by dust. 21 00:02:05,754 --> 00:02:08,054 The Earth hasn't formed yet. 22 00:02:19,102 --> 00:02:20,552 But through time, 23 00:02:20,605 --> 00:02:23,505 gravity pulls the dust into tiny rocks. 24 00:02:38,992 --> 00:02:40,492 To our surprise, 25 00:02:40,595 --> 00:02:42,545 something as complex as a planet 26 00:02:42,565 --> 00:02:46,215 is made from nothing more than dust and rocks. 27 00:02:49,971 --> 00:02:53,006 Over millions of years, gravity pulls these 28 00:02:53,074 --> 00:02:56,642 rocks together to form the Earth, 29 00:02:56,710 --> 00:02:58,511 one of at least a hundred planets 30 00:02:58,578 --> 00:03:01,080 circling the sun. 31 00:03:31,041 --> 00:03:33,742 But four and a half billion years ago, 32 00:03:33,810 --> 00:03:37,813 Earth looks more like hell than home. 33 00:03:41,717 --> 00:03:43,751 Up close the temperature is over 34 00:03:43,819 --> 00:03:46,369 2,000 degrees Fahrenheit. 35 00:03:47,956 --> 00:03:50,906 There's no air, just carbon dioxide, 36 00:03:50,992 --> 00:03:53,442 nitrogen and water vapor. 37 00:03:54,629 --> 00:03:57,164 It's so hot and toxic that if we got any 38 00:03:57,232 --> 00:03:59,700 closer we'd be incinerated and 39 00:03:59,768 --> 00:04:03,638 suffocated in seconds. 40 00:04:13,784 --> 00:04:17,684 This newborn planet is a boiling ball of liquid rock; 41 00:04:24,828 --> 00:04:27,678 an endless ocean of lava. 42 00:04:37,974 --> 00:04:40,242 A young planet called Theia is heading 43 00:04:40,310 --> 00:04:45,115 straight for Earth. 44 00:04:45,383 --> 00:04:48,318 The size of Mars, it travels nearly 10 miles 45 00:04:48,386 --> 00:04:51,255 per second, twenty times faster than a 46 00:04:51,323 --> 00:04:52,924 bullet. 47 00:05:01,366 --> 00:05:04,168 The intruder's gravity distorts the Earth's surface. 48 00:05:33,569 --> 00:05:36,604 The blast wave races around the planet. 49 00:05:37,239 --> 00:05:40,508 It's as though both young planets turn to liquid, 50 00:05:48,720 --> 00:05:52,120 trillions of tons of debris blast out into space. 51 00:06:10,778 --> 00:06:13,345 But over the course of a thousand years, 52 00:06:13,413 --> 00:06:16,181 gravity turns the rubble into a ring of 53 00:06:16,249 --> 00:06:21,886 red hot dust and rock that circles the Earth. 54 00:06:27,024 --> 00:06:29,826 From this ring, a ball forms, 55 00:06:29,894 --> 00:06:34,831 over two thousand miles wide. 56 00:06:39,571 --> 00:06:43,774 It's the birth of our moon. 57 00:06:49,147 --> 00:06:52,751 But it's much closer than the moon today, 58 00:06:52,818 --> 00:06:56,321 just 14,000 miles away instead of a quarter of 59 00:06:56,389 --> 00:06:59,959 a million miles. 60 00:07:15,912 --> 00:07:18,547 The sun rises over a cooling Earth. 61 00:07:18,614 --> 00:07:24,752 And sets just three hours later. 62 00:07:24,887 --> 00:07:27,155 The Earth is spinning so fast that an entire 63 00:07:27,223 --> 00:07:32,193 day lasts six hours. 64 00:07:32,461 --> 00:07:34,762 The days may pass quickly but the Earth 65 00:07:34,830 --> 00:07:38,966 changes slowly. 66 00:07:39,168 --> 00:07:41,736 To understand the making of our planet we 67 00:07:41,804 --> 00:07:46,574 need to fast foard through millions of years. 68 00:08:09,967 --> 00:08:12,579 3.9 billion years ago, 69 00:08:12,603 --> 00:08:16,774 a hail of meteors attack the Earth. 70 00:08:17,242 --> 00:08:19,544 It's debris left over from the solar system's 71 00:08:19,612 --> 00:08:23,048 formation. 72 00:08:30,058 --> 00:08:32,626 Inside the meteors are crystals that look like 73 00:08:32,694 --> 00:08:37,431 grains of salt. 74 00:08:37,699 --> 00:08:41,001 And inside the crystals are minute droplets of 75 00:08:41,069 --> 00:08:42,903 water. 76 00:08:49,843 --> 00:08:52,545 These deadly missiles could contain the vital 77 00:08:52,613 --> 00:08:55,314 ingredient for life on Earth. 78 00:09:09,394 --> 00:09:12,029 Only a small amount of water exists inside 79 00:09:12,097 --> 00:09:15,299 each meteorite, but as they bombard the Earth 80 00:09:15,366 --> 00:09:17,801 for over 20 million years, 81 00:09:17,868 --> 00:09:21,205 pools of water grow. 82 00:09:23,675 --> 00:09:25,910 The Earth's core remains molten, 83 00:09:25,977 --> 00:09:28,079 but its surface has cooled enough to form a 84 00:09:28,146 --> 00:09:29,947 crust. 85 00:09:30,015 --> 00:09:34,418 The air is around 170 degrees. 86 00:09:36,754 --> 00:09:38,689 In the future, there's a chance we could 87 00:09:38,757 --> 00:09:42,259 swallow this very water. 88 00:09:42,327 --> 00:09:44,261 Every sip, every puddle, 89 00:09:44,329 --> 00:09:47,431 every drop of water in every ocean, 90 00:09:47,498 --> 00:09:50,634 is billions of years old. 91 00:09:51,436 --> 00:09:53,303 And it may have travelled millions of 92 00:09:53,370 --> 00:09:56,673 miles to reach us, carried inside a 93 00:09:56,741 --> 00:09:59,576 meteor. 94 00:10:01,579 --> 00:10:03,779 The Earth looks more familiar, 95 00:10:03,847 --> 00:10:09,018 but it's still a dangerous place. 96 00:10:09,186 --> 00:10:11,120 Winds are faster than the most destructive 97 00:10:11,188 --> 00:10:13,589 hurricanes today. 98 00:10:13,657 --> 00:10:15,725 It's a mega storm, whipped up by the 99 00:10:15,793 --> 00:10:19,930 planet's rapid rotation. 100 00:10:29,674 --> 00:10:32,510 The moon is so close to Earth that its gravity 101 00:10:32,577 --> 00:10:35,812 is overwhelmed, creating huge tides 102 00:10:35,880 --> 00:10:39,683 that race across the planet's surface. 103 00:11:11,482 --> 00:11:14,284 But over time, the moon moves away, 104 00:11:14,351 --> 00:11:18,821 the waves calm down and the planet spins slower. 105 00:11:23,826 --> 00:11:27,162 700 million years after the planet's birth, 106 00:11:27,229 --> 00:11:31,366 life-giving water covers its surface. 107 00:11:32,635 --> 00:11:34,903 And scattered throughout are tiny 108 00:11:34,971 --> 00:11:37,706 islands. 109 00:11:43,114 --> 00:11:47,551 They seem to have appeared from nowhere. 110 00:11:49,454 --> 00:11:53,423 So how did they get here? 111 00:11:58,063 --> 00:11:59,930 Molten rock bursts through the Earth's 112 00:11:59,998 --> 00:12:05,268 crust and rises up through the ocean. 113 00:12:06,971 --> 00:12:08,906 Over time the lava cools, 114 00:12:08,974 --> 00:12:12,109 forming a volcanic island. 115 00:12:17,348 --> 00:12:19,616 In the future, these islands will join 116 00:12:19,684 --> 00:12:24,888 together to form the first continents. 117 00:12:25,556 --> 00:12:29,592 Earth now has water and land. 118 00:12:29,660 --> 00:12:32,362 It's beginning to look like the planet we call home. 119 00:12:35,065 --> 00:12:37,666 But the atmosphere is still toxic and the 120 00:12:37,734 --> 00:12:40,668 temperature is scorching. 121 00:12:40,736 --> 00:12:42,637 Life here is impossible. 122 00:12:53,291 --> 00:12:55,359 Since the planet's formation, 123 00:12:55,427 --> 00:12:59,363 meteors have been pummeling Earth. 124 00:12:59,965 --> 00:13:04,268 But now, 3.8 billion years ago, 125 00:13:04,335 --> 00:13:07,504 the assault enters a violent new phase. 126 00:13:07,572 --> 00:13:09,639 Something's disturbed the orbits of these 127 00:13:09,706 --> 00:13:13,642 meteorites. 128 00:13:15,678 --> 00:13:17,913 In addition to water, the meteors carry 129 00:13:17,981 --> 00:13:21,182 something else. 130 00:13:30,091 --> 00:13:32,626 As they dissolve, the meteorites release 131 00:13:32,694 --> 00:13:34,061 minerals. 132 00:13:34,129 --> 00:13:36,630 Carbon and primitive proteins made of amino 133 00:13:36,698 --> 00:13:40,000 acids are transported from outer space to the 134 00:13:40,068 --> 00:13:42,936 bottom of the ocean. 135 00:13:48,075 --> 00:13:51,811 Thousands of feet below the waves, it is dark, 136 00:13:51,878 --> 00:13:55,547 and close to freezing. 137 00:14:10,631 --> 00:14:15,368 But a dramatic illusion is taking shape. 138 00:14:17,038 --> 00:14:22,610 Underwater chimneys, spewing hot liquid. 139 00:14:26,047 --> 00:14:28,682 Seawater seeps down into the Earth through 140 00:14:28,750 --> 00:14:31,452 cracks in the crust, collecting minerals and 141 00:14:31,520 --> 00:14:34,188 gases along the way. 142 00:14:34,256 --> 00:14:36,923 This potent mixture is released back out into 143 00:14:36,991 --> 00:14:41,627 the ocean, building these towers. 144 00:14:45,999 --> 00:14:47,710 Combined with the minerals and chemicals 145 00:14:47,734 --> 00:14:50,202 from the meteorites, the water becom a 146 00:14:50,270 --> 00:14:52,404 chemical soup. 147 00:14:54,608 --> 00:14:57,443 It's impossible to know how or when, 148 00:14:57,511 --> 00:14:59,879 but somehow these chemicals come together 149 00:14:59,947 --> 00:15:03,884 to create life. 150 00:15:05,119 --> 00:15:07,121 The water is now full of microscopic 151 00:15:07,188 --> 00:15:08,889 organisms. 152 00:15:08,957 --> 00:15:11,459 These single-celled bacteria are the 153 00:15:11,526 --> 00:15:16,031 earliest forms of life on Earth. 154 00:15:19,703 --> 00:15:22,938 This is a defining moment in the making of 155 00:15:23,006 --> 00:15:24,940 the planet. 156 00:15:26,910 --> 00:15:30,613 Microscopic life is underway. 157 00:15:40,991 --> 00:15:43,293 For hundreds of millions of years 158 00:15:43,361 --> 00:15:45,262 nothing changes. 159 00:15:48,500 --> 00:15:53,505 The only life is single-celled bacteria. 160 00:16:01,947 --> 00:16:04,082 To find more complex life, 161 00:16:04,150 --> 00:16:09,320 we need to fast forward to 3.5 billion years ago, 162 00:16:12,758 --> 00:16:16,561 and a shallow ocean. 163 00:16:22,668 --> 00:16:26,738 These look like rocks, or even plants, 164 00:16:26,806 --> 00:16:31,409 growing out of the sea bed. 165 00:16:32,244 --> 00:16:35,447 Each mound is a colony of living bacteria 166 00:16:35,515 --> 00:16:38,283 called a stromatolite. 167 00:16:42,922 --> 00:16:46,190 These bacteria turn sunlight into food, 168 00:16:46,258 --> 00:16:49,493 a process called photosynthesis. 169 00:16:49,561 --> 00:16:52,429 It uses the power of sunlight to traform 170 00:16:52,497 --> 00:16:55,999 carbon dioxide and water into glucose, 171 00:16:56,067 --> 00:16:58,502 a simple form of sugar. 172 00:17:12,986 --> 00:17:16,288 And this magical transformation releases 173 00:17:16,356 --> 00:17:20,961 a by-product, a gas called oxygen. 174 00:17:24,999 --> 00:17:27,634 Underwater, the stromatolites slowly 175 00:17:27,702 --> 00:17:31,771 fill the oceans with oxygen. 176 00:17:35,042 --> 00:17:38,243 The oxygen then turns traces of iron into 177 00:17:38,311 --> 00:17:41,446 rust, which fall to the ocean floor, 178 00:17:41,514 --> 00:17:45,317 to form deposits of iron rich rock. 179 00:17:45,385 --> 00:17:47,820 It's this mineral that will one day be used to 180 00:17:47,887 --> 00:17:52,726 build bridges, ships, and skyscrapers. 181 00:18:03,039 --> 00:18:05,974 Above the waves, the oxygen transforms the 182 00:18:06,042 --> 00:18:08,177 atmosphere. 183 00:18:08,244 --> 00:18:10,412 These stromatolites are creating the most 184 00:18:10,480 --> 00:18:14,483 important element for life on earth. 185 00:18:14,550 --> 00:18:17,453 Without them, virtually every living thing 186 00:18:17,520 --> 00:18:19,722 wouldn't exist. 187 00:18:27,865 --> 00:18:30,200 Over the next two billion years oxygen 188 00:18:30,268 --> 00:18:32,804 levels continue to rise, 189 00:18:32,871 --> 00:18:35,340 and as the planet's spin slows, 190 00:18:35,408 --> 00:18:41,480 the days get longer, lasting at least 16 hours. 191 00:18:51,157 --> 00:18:54,325 3 billion years after the planet's birth, 192 00:18:54,392 --> 00:18:56,760 there's still no complex life, 193 00:18:56,828 --> 00:19:03,066 no plants, no dinosaurs, no humans. 194 00:19:03,834 --> 00:19:06,269 But the Earth has something unlike any 195 00:19:06,337 --> 00:19:09,039 other planet in this solar system, 196 00:19:09,107 --> 00:19:12,543 a force with the power to change everything. 197 00:19:20,916 --> 00:19:22,250 One and a half billion 198 00:19:22,317 --> 00:19:26,855 years ago, the Earth is a beautiful blue ball, 199 00:19:26,923 --> 00:19:31,159 dotted with volcanic islands. 200 00:19:31,427 --> 00:19:34,663 Over millions of years, a mysterious force 201 00:19:34,731 --> 00:19:37,699 rearranges these islands. 202 00:19:37,767 --> 00:19:39,300 Hidden beneath the ocean, 203 00:19:39,368 --> 00:19:41,969 the Earth's crust breaks into vast 204 00:19:42,037 --> 00:19:44,038 plates. 205 00:19:44,306 --> 00:19:48,174 But even deeper, the Earth's core is so hot 206 00:19:48,242 --> 00:19:50,577 that it generates movement in the rock 207 00:19:50,644 --> 00:19:54,246 beneath the crust. 208 00:19:54,614 --> 00:19:57,082 These movements push and pull the plates 209 00:19:57,150 --> 00:20:00,486 around the globe, carrying the oceans and 210 00:20:00,554 --> 00:20:03,456 islands with them. 211 00:20:04,225 --> 00:20:07,427 Millions of years race by, 212 00:20:07,495 --> 00:20:11,665 our planet is alive, and changing. 213 00:20:13,568 --> 00:20:16,769 Over 400 million years a vast new super 214 00:20:16,837 --> 00:20:18,972 continent takes shape. 215 00:20:19,039 --> 00:20:23,143 It's called Rodinia. 216 00:20:27,348 --> 00:20:30,183 In the shallow waters surrounding Rodinia, 217 00:20:30,251 --> 00:20:32,452 stromatolites work their magic for more 218 00:20:32,520 --> 00:20:36,389 than two billion years, pumping oxygen into the 219 00:20:36,457 --> 00:20:38,557 atmosphere. 220 00:20:39,727 --> 00:20:42,795 The temperature is 85 degrees. 221 00:20:43,130 --> 00:20:47,067 And the days are 18 hours long. 222 00:20:54,442 --> 00:20:57,979 But this planet looks more like Mars than Earth. 223 00:21:03,152 --> 00:21:06,656 To find life, we must fast forward through time. 224 00:21:19,568 --> 00:21:25,372 Washington State: 750 million years ago. 225 00:21:25,440 --> 00:21:28,509 A force deep inside the planet rips the crust 226 00:21:28,576 --> 00:21:30,910 to pieces. 227 00:21:30,978 --> 00:21:32,479 It's as though the world is breaking 228 00:21:32,546 --> 00:21:34,447 apart. 229 00:21:36,117 --> 00:21:37,818 And there's only one force powerful enough 230 00:21:37,885 --> 00:21:41,989 to do this, heat. 231 00:21:42,757 --> 00:21:45,526 It escapes from the Earth's molten core, 232 00:21:45,593 --> 00:21:50,063 stretching and weakening the crust. 233 00:21:50,131 --> 00:21:53,166 Inch by inch, year by year, 234 00:21:53,234 --> 00:21:54,467 the great super-continent is 235 00:21:54,535 --> 00:21:58,271 splitting in two. 236 00:22:35,646 --> 00:22:38,614 The intense geological activity spawns a mass 237 00:22:38,682 --> 00:22:41,017 of volcanoes. 238 00:22:41,285 --> 00:22:42,785 They pump carbon dioxide into the 239 00:22:42,853 --> 00:22:45,588 atmosphere. 240 00:23:02,741 --> 00:23:05,176 The carbon dioxide mixes with water, 241 00:23:05,244 --> 00:23:08,746 and creates acid rain. 242 00:23:18,957 --> 00:23:21,024 When the continent tore apart, 243 00:23:21,092 --> 00:23:27,063 many rocks were exposed. 244 00:23:27,665 --> 00:23:30,800 These rocks absorb the acid rain, 245 00:23:30,868 --> 00:23:33,536 including its carbon dioxide. 246 00:23:33,604 --> 00:23:36,806 Vast quantities of CO 2 are absorbed out of the 247 00:23:36,874 --> 00:23:39,309 atmosphere. 248 00:23:46,585 --> 00:23:49,221 Now, there's not enough carbon dioxide in the 249 00:23:49,288 --> 00:23:54,426 air to trap the sun's heat around the planet. 250 00:23:55,061 --> 00:23:57,129 In just a few thousand years, 251 00:23:57,197 --> 00:23:59,565 the temperature plummets to around 252 00:23:59,632 --> 00:24:03,601 minus 60 degrees. 253 00:24:03,836 --> 00:24:06,837 This frozen wasteland is Southern Australia, 254 00:24:06,905 --> 00:24:11,675 650 million years ago. 255 00:24:11,743 --> 00:24:14,978 It's the start of what some scientists call 256 00:24:15,046 --> 00:24:18,682 Snowball Earth, a period they believe to 257 00:24:18,750 --> 00:24:22,353 be the longest, coldest ice age ever to grip 258 00:24:22,421 --> 00:24:24,101 the planet. 259 00:24:28,495 --> 00:24:31,397 A vast wall of ice looms thousands of feet 260 00:24:31,465 --> 00:24:33,066 high. 261 00:24:35,002 --> 00:24:38,805 And it's unstoppable. 262 00:24:39,073 --> 00:24:41,541 The more ice there is the more sunlight it 263 00:24:41,608 --> 00:24:43,776 reflects away from the planet, 264 00:24:43,844 --> 00:24:47,579 and the faster the ice spreads. 265 00:24:48,447 --> 00:24:53,617 Nearby is a second ice sheet just as high. 266 00:24:53,685 --> 00:24:56,220 The two sheets spread away from the poles, 267 00:24:56,288 --> 00:24:58,789 toward each other to meet at the Equator. 268 00:25:22,714 --> 00:25:25,082 Now an ice sheet up to 10,000 269 00:25:25,150 --> 00:25:31,056 feet thick covers the entire planet. 270 00:25:32,525 --> 00:25:36,339 Earth first began as a molten ball of fire, 271 00:25:36,363 --> 00:25:40,499 now it's a frozen ball of ice. 272 00:25:43,970 --> 00:25:47,073 Virtually all the sun's light, and warmth, 273 00:25:47,140 --> 00:25:52,245 reflects back into space. 274 00:25:59,320 --> 00:26:01,221 And it seems as though nothing, 275 00:26:01,289 --> 00:26:04,625 not even the Sun can rescue the planet now. 276 00:26:17,393 --> 00:26:20,094 650 million years ago, 277 00:26:20,162 --> 00:26:23,432 ice entombs the planet. 278 00:26:23,499 --> 00:26:26,302 For 15 million years, the Earth is a vast 279 00:26:26,369 --> 00:26:29,171 frozen snowball. 280 00:26:31,275 --> 00:26:33,243 But it can't last forever; 281 00:26:33,311 --> 00:26:35,646 something must release the Earth from this 282 00:26:35,713 --> 00:26:39,250 frozen prison. 283 00:26:39,318 --> 00:26:41,653 And when it does, who knows whether life has 284 00:26:41,720 --> 00:26:44,956 survived beneath the ice. 285 00:26:45,024 --> 00:26:47,993 The surface is frozen but the core is still 286 00:26:48,060 --> 00:26:51,962 hotter than the sun's surface. 287 00:26:57,568 --> 00:26:59,235 Volcanoes have been erupting since the 288 00:26:59,302 --> 00:27:01,837 world began to freeze. 289 00:27:01,905 --> 00:27:05,373 But up until now even their heat and power 290 00:27:05,441 --> 00:27:09,344 made no impact on the ice. 291 00:27:11,648 --> 00:27:14,016 Volcanoes pump out billions of tons of 292 00:27:14,084 --> 00:27:17,687 carbon dioxide. 293 00:27:17,954 --> 00:27:20,590 Before the big freeze, the Earth's rocks 294 00:27:20,657 --> 00:27:25,195 absorbed most of the CO2. 295 00:27:25,530 --> 00:27:28,632 But now, with the rocks smothered in ice, 296 00:27:28,700 --> 00:27:31,168 there's nothing to absorb the gas. 297 00:27:31,236 --> 00:27:34,639 So it fills the atmosphere. 298 00:27:41,447 --> 00:27:44,149 Like a blanket, it traps the sun's warmth 299 00:27:44,217 --> 00:27:45,884 around the planet, allowing the 300 00:27:45,952 --> 00:27:49,921 temperatures to rise. 301 00:27:50,223 --> 00:27:53,725 Now, after 15 million years, 302 00:27:53,793 --> 00:27:56,861 the ice begins to melt. 303 00:28:19,321 --> 00:28:21,822 It's thought that during Snowball Earth 304 00:28:21,890 --> 00:28:24,524 the ice pushed the crust down. 305 00:28:24,592 --> 00:28:29,029 But now, as it melts, the crust bounces up, 306 00:28:29,097 --> 00:28:33,099 creating fissures and weak spots, 307 00:28:33,167 --> 00:28:35,769 and more volcanoes. 308 00:28:40,742 --> 00:28:43,844 The volcanoes release more carbon dioxide and 309 00:28:43,912 --> 00:28:48,049 push the temperature up even higher. 310 00:28:48,450 --> 00:28:52,887 The melt gathers momentum. 311 00:28:52,955 --> 00:28:56,859 And oxygen levels rise. 312 00:28:57,628 --> 00:29:00,363 Through a series of chemical reactions the 313 00:29:00,431 --> 00:29:03,867 ice has created oxygen. 314 00:29:04,168 --> 00:29:06,002 While the planet was frozen, 315 00:29:06,070 --> 00:29:09,439 the Sun's ultraviolet rays reacted with water 316 00:29:09,506 --> 00:29:12,709 molecules in the ice, to produce hydrogen 317 00:29:12,777 --> 00:29:16,679 peroxide, a chemical rich in oxygen. 318 00:29:28,726 --> 00:29:32,262 Now, as the ice melts, the hydrogen peroxide 319 00:29:32,330 --> 00:29:34,398 breaks down and releases massive 320 00:29:34,465 --> 00:29:39,102 amounts of oxygen. 321 00:29:45,176 --> 00:29:49,046 The Earth is waking up, and it's a very 322 00:29:49,114 --> 00:29:51,215 different place. 323 00:30:28,985 --> 00:30:31,919 600 million years ago, the atmosphere is 324 00:30:31,987 --> 00:30:35,857 warmer, like a summer day. 325 00:30:37,926 --> 00:30:43,163 And the days are about 22 hours long. 326 00:30:48,203 --> 00:30:52,140 Add all this water and it's the perfect recipe 327 00:30:52,208 --> 00:30:54,142 for life. 328 00:30:58,448 --> 00:31:01,050 Before Snowball Earth, primitive bacteria 329 00:31:01,118 --> 00:31:04,387 emerged in the oceans. 330 00:31:04,455 --> 00:31:06,623 But surely they couldn't have survived 331 00:31:06,691 --> 00:31:10,593 an ice age 75 times longer than the entire 332 00:31:10,661 --> 00:31:13,995 span of human history. 333 00:31:14,197 --> 00:31:16,131 If something has survived, 334 00:31:16,198 --> 00:31:19,600 then life may be found where it was last seen, 335 00:31:19,668 --> 00:31:22,069 in the oceans. 336 00:31:26,308 --> 00:31:29,677 Now, 540 million years ago, 337 00:31:29,745 --> 00:31:31,913 in an ocean full of oxygen, 338 00:31:31,981 --> 00:31:36,551 those primitive bacteria have evolved. 339 00:31:36,853 --> 00:31:38,413 A handful must have clung on through the 340 00:31:38,455 --> 00:31:41,490 big freeze. 341 00:31:41,557 --> 00:31:43,192 There are plants scattered on the sea 342 00:31:43,260 --> 00:31:47,663 floor. 343 00:31:47,998 --> 00:31:52,868 And something else. 344 00:31:53,103 --> 00:31:55,771 What looks like an armored slug takes up 345 00:31:55,839 --> 00:31:57,873 residence. 346 00:31:57,941 --> 00:32:02,077 It's called Wiwaxia, a new generation of 347 00:32:02,145 --> 00:32:06,781 complex multi-celled organisms. 348 00:32:07,016 --> 00:32:08,661 The Earth enters one of the most dynamic 349 00:32:08,685 --> 00:32:15,691 periods in its history, the Cambrian explosion. 350 00:32:15,758 --> 00:32:18,460 Increased oxygen levels allow creatures to grow 351 00:32:18,528 --> 00:32:24,867 larger and develop bony skeletons. 352 00:32:25,035 --> 00:32:31,840 There are worms, sponges, 353 00:32:31,908 --> 00:32:35,810 and these trilobites: distant relatives of 354 00:32:35,878 --> 00:32:40,681 insects, lobsters, even scorpions. 355 00:32:49,090 --> 00:32:53,760 Life in the oceans blossoms. 356 00:32:54,696 --> 00:33:00,834 From microscopic bacteria, to monsters. 357 00:33:10,410 --> 00:33:13,946 This is Anomalocaris. 358 00:33:14,013 --> 00:33:18,850 Nearly two feet long, it has large eyes, 359 00:33:18,918 --> 00:33:23,588 razor sharp teeth and grasping limbs. 360 00:33:41,409 --> 00:33:46,046 All it has to do, is take its pick. 361 00:33:54,322 --> 00:33:56,556 The trilobite can't right itself, 362 00:33:56,624 --> 00:34:00,861 its soft belly is exposed. 363 00:34:14,978 --> 00:34:17,813 Also found in the sea is Pikaia. 364 00:34:17,881 --> 00:34:20,116 Only an inch and a half long, 365 00:34:20,183 --> 00:34:25,621 they may be the first organism with a spine. 366 00:34:29,559 --> 00:34:32,795 Over millions of years, this simple structure 367 00:34:32,863 --> 00:34:35,965 will evolve into the spine that keeps us 368 00:34:36,033 --> 00:34:38,468 standing. 369 00:34:55,319 --> 00:34:57,854 Expecting to find life in ruins, 370 00:34:57,922 --> 00:35:03,093 the oceans are in fact full of life. 371 00:35:04,028 --> 00:35:07,797 Where trilobites scavenge and monsters 372 00:35:07,865 --> 00:35:10,366 prowl. 373 00:35:10,434 --> 00:35:12,235 And where creatures begin to take on 374 00:35:12,302 --> 00:35:14,537 familiar forms. 375 00:35:17,441 --> 00:35:20,376 Beneath the waves there are already tens of 376 00:35:20,444 --> 00:35:25,314 thousands of plant and animal species. 377 00:35:25,382 --> 00:35:28,718 The advance of life seems unstoppable. 378 00:35:45,265 --> 00:35:47,867 460 million years ago, 379 00:35:47,934 --> 00:35:51,537 the plates have been moving, again. 380 00:35:51,772 --> 00:35:57,143 A new continent now exists, Gondwana. 381 00:35:58,979 --> 00:36:01,648 It's 90 degrees and oxygen levels are close 382 00:36:01,715 --> 00:36:04,684 to what they are today. 383 00:36:06,587 --> 00:36:08,888 The land should be covered with plants and 384 00:36:08,955 --> 00:36:11,557 crawling with creatures. 385 00:36:11,625 --> 00:36:13,592 But there's not much here, 386 00:36:13,660 --> 00:36:16,796 besides a few patches of algae. 387 00:36:25,238 --> 00:36:33,238 There's only one explanation, the Sun. 388 00:36:38,085 --> 00:36:44,391 It blasts the surface with deadly radiation, 389 00:36:44,459 --> 00:36:46,494 so the complex life in the ocean doesn't stand 390 00:36:46,562 --> 00:36:48,796 a chance on land. 391 00:36:52,668 --> 00:36:55,136 But 30 miles up, where the rays enter the 392 00:36:55,204 --> 00:37:00,074 Earth's atmosphere, something is happening. 393 00:37:02,177 --> 00:37:04,813 When oxygen meets the sun's radiation, 394 00:37:04,880 --> 00:37:07,081 it turns into another kind of gas, 395 00:37:07,149 --> 00:37:09,951 call ozone. 396 00:37:11,754 --> 00:37:13,689 This gas forms a blanket around the 397 00:37:13,756 --> 00:37:17,392 planet and absorbs the lethal radiation. 398 00:37:20,163 --> 00:37:23,699 Over 120 million years, the ozone layer gets 399 00:37:23,767 --> 00:37:26,936 thicker and prevents more and more radiation 400 00:37:27,003 --> 00:37:30,105 from reaching the Earth's surface. 401 00:37:30,173 --> 00:37:32,942 Without this layer, life on land simply 402 00:37:33,009 --> 00:37:35,110 wouldn't exist. 403 00:37:35,511 --> 00:37:37,946 Now, shielded from radiation, 404 00:37:38,013 --> 00:37:41,082 life takes off. 405 00:37:44,519 --> 00:37:50,224 Small mossy lumps are the first land plants. 406 00:37:50,759 --> 00:37:54,261 They pump out even more oxygen. 407 00:37:54,329 --> 00:37:58,766 Levels soar. 408 00:38:04,941 --> 00:38:09,011 375 million years ago, a new species lives in 409 00:38:09,079 --> 00:38:12,648 the water, swimming. 410 00:38:24,395 --> 00:38:29,566 It's a strange fish called a Tiktaalik. 411 00:38:51,622 --> 00:38:56,192 It uses its neck to raise itself up. 412 00:39:10,374 --> 00:39:12,442 And its fins function as legs, 413 00:39:16,780 --> 00:39:20,049 allowing it to move out of the water. 414 00:39:32,063 --> 00:39:34,598 This is one of the most important moments in 415 00:39:34,666 --> 00:39:37,567 the making of our planet. 416 00:39:38,269 --> 00:39:41,605 Over 15 million years, creatures like these 417 00:39:41,673 --> 00:39:43,374 evolve. 418 00:39:44,843 --> 00:39:47,145 They grow stronger limbs and spend more 419 00:39:47,213 --> 00:39:50,214 time out of the water, where plant life is 420 00:39:50,282 --> 00:39:52,650 exploding. 421 00:39:53,018 --> 00:39:56,587 Until, 360 million years ago, 422 00:39:56,655 --> 00:39:59,456 their relatives, called tetrapods, 423 00:39:59,524 --> 00:40:02,660 make the land their home. 424 00:40:02,828 --> 00:40:05,429 From tetrapods, four legged vertebrates 425 00:40:05,497 --> 00:40:08,399 evolve into dinosaurs, birds, 426 00:40:08,467 --> 00:40:13,504 mammals and eventually humans. 427 00:40:16,875 --> 00:40:20,011 There are mosses and ferns everywhere, 428 00:40:20,079 --> 00:40:24,582 some at least a hundred feet tall. 429 00:40:24,984 --> 00:40:27,285 A seed is carried by the wind. 430 00:40:33,326 --> 00:40:34,626 Until now, 431 00:40:34,694 --> 00:40:37,395 plants reproduced using spores, 432 00:40:37,463 --> 00:40:39,831 single-celled particles that need plenty of 433 00:40:39,899 --> 00:40:42,800 water to grow. 434 00:40:44,236 --> 00:40:48,339 But this seed is miles from water. 435 00:40:50,776 --> 00:40:53,344 This embryonic plant has its own food and 436 00:40:53,411 --> 00:40:56,780 water supply. 437 00:40:56,848 --> 00:41:00,083 Unlike a spore, this seed can survive far 438 00:41:00,151 --> 00:41:04,620 from water for months, even years. 439 00:41:17,165 --> 00:41:20,501 The humble seed spreads life across the planet. 440 00:41:20,569 --> 00:41:23,437 And each tree and plant pumps out even more 441 00:41:23,505 --> 00:41:25,706 oxygen. 442 00:41:39,589 --> 00:41:43,692 It's an environment very much like today. 443 00:42:00,675 --> 00:42:03,343 The planet has come a long way, 444 00:42:03,411 --> 00:42:06,479 from a lump of burning rock and dust, 445 00:42:06,547 --> 00:42:09,315 to a blue and green world bursting with 446 00:42:09,382 --> 00:42:11,017 life. 447 00:42:17,023 --> 00:42:25,023 There are now fish, plants, and this, 448 00:42:27,301 --> 00:42:29,402 the dragonfly. 449 00:42:32,272 --> 00:42:35,008 It's called Meganeura. 450 00:42:35,710 --> 00:42:39,812 This insect is the size of an eagle. 451 00:42:39,879 --> 00:42:41,948 What were once legs have evolved into 452 00:42:42,015 --> 00:42:45,051 wings, extending the dragonfly's hunting 453 00:42:45,119 --> 00:42:49,089 territory over a vast area. 454 00:42:52,860 --> 00:42:54,894 There are also millipedes, 455 00:42:54,962 --> 00:42:58,732 and spiders down there. 456 00:43:02,937 --> 00:43:06,173 These creatures, called arthropod, 457 00:43:06,240 --> 00:43:08,541 were among the first to set foot on land 458 00:43:08,609 --> 00:43:11,277 hundreds of millions of years ago. 459 00:43:11,612 --> 00:43:14,080 They look almost identical to the bugs 460 00:43:14,148 --> 00:43:16,883 that invade our homes today. 461 00:43:16,951 --> 00:43:19,418 Except for one big difference. 462 00:43:19,486 --> 00:43:23,823 Like the Meganeura, they're monsters. 463 00:43:23,991 --> 00:43:26,058 It's a world full of giants, 464 00:43:26,126 --> 00:43:29,028 where millipedes are 6 feet long, 465 00:43:29,095 --> 00:43:34,867 andcorpions are the size of wolves. 466 00:43:36,336 --> 00:43:38,637 This is because the oxygen level is much 467 00:43:38,705 --> 00:43:40,705 higher than it is today, 468 00:43:40,773 --> 00:43:43,041 which allows their respiratory systems to 469 00:43:43,108 --> 00:43:45,676 be more efficient, fueling thier bodies to 470 00:43:45,744 --> 00:43:48,179 grow larger. 471 00:43:57,788 --> 00:44:00,256 So far, animals have been laying their eggs 472 00:44:00,324 --> 00:44:03,993 in the water. 473 00:44:04,194 --> 00:44:05,928 But a lizard-like creature, 474 00:44:05,996 --> 00:44:09,832 called the hylonomus, prefers land. 475 00:44:10,601 --> 00:44:13,737 Its eggs contain all the water and nutrients 476 00:44:13,804 --> 00:44:16,973 that the developing fetus needs. 477 00:44:17,041 --> 00:44:18,342 The babies grow in their own 478 00:44:18,409 --> 00:44:21,011 self-contained pond. 479 00:44:21,079 --> 00:44:23,147 The egg is a major evolutionary 480 00:44:23,215 --> 00:44:25,517 breakthrough. 481 00:44:26,252 --> 00:44:29,387 Allowing animals to leave the water behind, 482 00:44:29,455 --> 00:44:32,190 and conquer land. 483 00:44:44,168 --> 00:44:49,305 This baby hylonomus leads the advance, 484 00:44:50,807 --> 00:44:54,577 as a new creature, the reptile. 485 00:45:08,493 --> 00:45:12,997 Inevitably, with life, comes death. 486 00:45:13,598 --> 00:45:16,233 Dead plant matter builds up and decays 487 00:45:16,301 --> 00:45:20,370 into dense soggy layers. 488 00:45:20,438 --> 00:45:22,072 Over hundreds of millions of years, 489 00:45:22,140 --> 00:45:24,441 rocks cover these layers. 490 00:45:24,508 --> 00:45:25,942 And heat from the Earth's core and 491 00:45:26,010 --> 00:45:28,144 pressure from the overlying rocks 492 00:45:28,212 --> 00:45:32,783 transform these layers into seams of coal. 493 00:45:34,385 --> 00:45:37,221 Each lump of coal burned today is made of 494 00:45:37,289 --> 00:45:42,294 plants that died 300 million years ago. 495 00:45:53,774 --> 00:45:56,475 Amidst the decay, hidden from sight, 496 00:45:56,542 --> 00:45:59,077 life is stirring. 497 00:45:59,412 --> 00:46:01,713 Soon seeds will germinate, 498 00:46:01,781 --> 00:46:04,349 plants will grow, and this wasteland will 499 00:46:04,417 --> 00:46:06,552 live again. 500 00:46:06,620 --> 00:46:10,322 Life seems to have conquered the planet. 501 00:46:10,389 --> 00:46:11,823 But will it last? 502 00:46:27,703 --> 00:46:29,304 A herd of creatures graze 503 00:46:29,371 --> 00:46:35,743 the Siberian plains, and they are big. 504 00:46:42,952 --> 00:46:46,521 Evolution takes a huge leap forward, 505 00:46:46,589 --> 00:46:51,426 small lizards are now giant reptiles. 506 00:46:52,061 --> 00:46:55,630 These scutosaurs are distant relatives of 507 00:46:55,698 --> 00:46:59,234 turtles. 508 00:47:01,871 --> 00:47:04,806 If these plant eaters look this tough, 509 00:47:04,873 --> 00:47:09,777 the carnivores must be seriously mean. 510 00:47:13,849 --> 00:47:17,184 Like this gorgonopsid. 511 00:47:17,252 --> 00:47:19,754 A perfectly engineered pre-historic killing 512 00:47:19,821 --> 00:47:21,389 machine. 513 00:47:39,677 --> 00:47:42,579 The gorgonopsid's sabre-teeth wound the scutosaur. 514 00:47:54,457 --> 00:47:56,124 The predator watches, 515 00:47:56,192 --> 00:47:59,661 as its prey grows weak from blood loss. 516 00:48:01,264 --> 00:48:07,570 But before it can make its final move, 517 00:48:07,638 --> 00:48:10,841 something strange happens. 518 00:48:10,908 --> 00:48:15,046 The ground gets hot. 519 00:48:20,787 --> 00:48:23,488 Enormous pressure builds beneath the surface, 520 00:48:23,556 --> 00:48:26,524 and lava spews into the air. 521 00:48:55,858 --> 00:48:59,861 But the lava isn't from one single volcano, 522 00:48:59,929 --> 00:49:03,264 the entire landscape is erupting. 523 00:49:05,467 --> 00:49:07,868 It's a flood basalt eruption. 524 00:49:07,936 --> 00:49:10,704 A massive plume of mantle rises up from 525 00:49:10,772 --> 00:49:14,007 deep inside the Earth, and pushes molten rock 526 00:49:14,074 --> 00:49:19,812 out through fissures in the Earth's crust. 527 00:49:22,249 --> 00:49:26,152 The lush paradise is now a lifeless hell. 528 00:49:26,220 --> 00:49:31,125 The scutosaurs and the gorgonopsids are dead. 529 00:49:31,560 --> 00:49:33,561 They're the first casualties in the 530 00:49:33,629 --> 00:49:35,830 greatest mass extinction the world 531 00:49:35,898 --> 00:49:40,603 has ever seen, the Permian Extinction. 532 00:49:51,480 --> 00:49:54,215 On the other side of the continent Gondwana, 533 00:49:54,282 --> 00:49:58,885 nothing's changed, yet. 534 00:50:07,796 --> 00:50:09,997 It appears to be snowing, 535 00:50:10,065 --> 00:50:15,169 but the temperature is about 70 degrees. 536 00:50:15,237 --> 00:50:17,372 It's actually ash, fallout from the 537 00:50:17,440 --> 00:50:21,543 eruptions some 10,000 miles away. 538 00:50:26,384 --> 00:50:29,185 The ash burns and suffocates the animals, 539 00:50:29,253 --> 00:50:32,055 killing them around the world. 540 00:50:43,934 --> 00:50:46,769 Sulphur dioxide from the eruptions fills the 541 00:50:46,837 --> 00:50:49,505 atmosphere. 542 00:50:50,040 --> 00:50:53,141 As it rains, the gas turns to sulphuric 543 00:50:53,209 --> 00:50:57,211 acid, and burns everything it falls on. 544 00:51:00,917 --> 00:51:04,486 What was a local disaster has now turned 545 00:51:04,554 --> 00:51:06,355 global. 546 00:51:18,570 --> 00:51:20,972 The Siberian eruptions increase the Earth's 547 00:51:21,040 --> 00:51:24,042 carbon dioxide levels. 548 00:51:24,110 --> 00:51:26,878 The atmosphere gets hotter. 549 00:51:26,946 --> 00:51:30,849 Water evaporates. 550 00:51:30,917 --> 00:51:32,985 And vegetation dies. 551 00:51:43,664 --> 00:51:50,269 Around the world, life on land is being wiped out. 552 00:51:50,337 --> 00:51:52,104 And life in the oceans, 553 00:51:52,172 --> 00:51:54,574 has also been compromised. 554 00:51:56,510 --> 00:52:01,948 The waters turn pink. 555 00:52:05,286 --> 00:52:09,656 Plants, trilobites, and predators, disappear. 556 00:52:18,831 --> 00:52:20,999 The new, hotter atmosphere heated the 557 00:52:21,067 --> 00:52:25,170 oceans and stripped them of oxygen. 558 00:52:25,438 --> 00:52:27,973 Now, this pink algae is one of the few life 559 00:52:28,041 --> 00:52:32,745 forms that can survive in the stagnant water. 560 00:52:32,913 --> 00:52:35,848 The Siberian eruptions transform the entire 561 00:52:35,916 --> 00:52:38,918 planet, nothing, not even the deepest ocean 562 00:52:38,986 --> 00:52:43,623 floor, is beyond their reach. 563 00:52:50,564 --> 00:52:53,132 Bubbles of methane gas escape from beneath the 564 00:52:53,200 --> 00:52:55,401 sea bed. 565 00:52:59,506 --> 00:53:02,108 Methane is a greenhouse gas, 566 00:53:02,175 --> 00:53:05,679 at least twenty times deadlier than carbon dioxide. 567 00:53:07,782 --> 00:53:10,817 Until now, the gas has been frozen. 568 00:53:10,885 --> 00:53:13,220 But as the sea temperature rises, 569 00:53:13,288 --> 00:53:16,123 it begins to melt. 570 00:53:29,570 --> 00:53:31,405 Released into the atmosphere, 571 00:53:31,472 --> 00:53:34,040 this powerful gas pushes up temperatures 572 00:53:34,108 --> 00:53:37,743 even further. 573 00:53:37,978 --> 00:53:40,980 It's now almost 105 degrees, 574 00:53:41,048 --> 00:53:43,382 11 degrees hotter than before the Siberian 575 00:53:43,450 --> 00:53:45,418 eruptions. 576 00:53:50,024 --> 00:53:52,893 Creatures that survive the initial destruction 577 00:53:52,961 --> 00:53:56,564 now face a new and deadly environment. 578 00:53:56,632 --> 00:54:00,535 Few will live. 579 00:54:00,970 --> 00:54:03,571 It's been five hundred thousand years since 580 00:54:03,639 --> 00:54:05,840 the eruptions first began, 581 00:54:05,908 --> 00:54:09,477 And all this time, the lava's been pouring out. 582 00:54:11,380 --> 00:54:14,182 By now, it covers an area the size of the 583 00:54:14,250 --> 00:54:16,885 United States with a layer of molten rock 584 00:54:16,952 --> 00:54:22,256 nearly 4 miles deep. 585 00:54:24,492 --> 00:54:30,130 95 per cent of the species are gone. 586 00:54:30,765 --> 00:54:34,267 A few survive by eating anything they can find 587 00:54:34,335 --> 00:54:39,272 and living in burrows underground. 588 00:54:42,444 --> 00:54:47,749 But everything else, is dead. 589 00:54:47,816 --> 00:54:51,653 250 million years ago, the Earth reverts back 590 00:54:51,721 --> 00:54:54,990 to an almost lifeless planet. 591 00:54:55,058 --> 00:54:58,193 But that's about to change, again. 592 00:55:04,536 --> 00:55:06,136 It's been fifty million 593 00:55:06,204 --> 00:55:08,839 years since virtually all life on Earth was 594 00:55:08,906 --> 00:55:11,675 wiped out. 595 00:55:11,876 --> 00:55:14,777 And the planet has been transformed. 596 00:55:17,848 --> 00:55:21,317 It's now 200 million years ago, 597 00:55:21,385 --> 00:55:24,387 and just one supercontinent, Pangea, 598 00:55:24,454 --> 00:55:28,157 stretches from pole to pole. 599 00:55:33,965 --> 00:55:36,533 After the trauma of the mass extinction, 600 00:55:36,601 --> 00:55:39,403 the planet heals. 601 00:55:39,471 --> 00:55:42,840 Temperatures stabilize; the acid rain 602 00:55:42,907 --> 00:55:46,310 neutralizes and vegetation returns. 603 00:55:48,180 --> 00:55:50,548 With 95 per cent of all life on Earth wiped 604 00:55:50,616 --> 00:55:54,519 out, the field opens for a new species to 605 00:55:54,587 --> 00:55:56,388 emerge. 606 00:55:56,622 --> 00:55:58,890 One that will dominate the planet like no 607 00:55:58,958 --> 00:56:00,825 other. 608 00:56:07,498 --> 00:56:11,567 The dinosaurs. 609 00:56:11,702 --> 00:56:15,205 These are called Ammosaurs. 610 00:56:15,272 --> 00:56:17,441 Like all dinos, they evolved from the 611 00:56:17,508 --> 00:56:23,980 reptiles that survived the Permian Extinction. 612 00:56:24,449 --> 00:56:28,251 At 15 feet tall, their size makes them slow, 613 00:56:28,319 --> 00:56:31,288 and vulnerable. 614 00:56:38,094 --> 00:56:44,699 Nearby is the dilophosaurus. 615 00:56:47,602 --> 00:56:52,639 It's small, 616 00:56:52,707 --> 00:56:54,842 and fast. 617 00:57:15,867 --> 00:57:17,934 The ammosaurus is too big a meal for one 618 00:57:18,001 --> 00:57:20,603 dilophosaurus. 619 00:57:20,671 --> 00:57:22,638 But not for two. 620 00:57:37,355 --> 00:57:40,391 The dinosaurs have repopulated the Earth. 621 00:57:41,026 --> 00:57:44,162 But no species can tame this restless, 622 00:57:44,229 --> 00:57:46,397 volatile planet. 623 00:57:52,305 --> 00:57:54,273 The earth's crust is thinning. 624 00:57:54,340 --> 00:57:56,241 It's releasing lava and shaking with 625 00:57:56,309 --> 00:57:59,344 earthquakes, as if being stretched by some 626 00:57:59,412 --> 00:58:01,613 unseen force. 627 00:58:07,785 --> 00:58:10,120 It's also happening near what will become 628 00:58:10,188 --> 00:58:14,424 North America's eastern seaboard. 629 00:58:22,599 --> 00:58:26,502 The Earth's plates are on the move again. 630 00:58:26,570 --> 00:58:28,571 190 million years ago, the great 631 00:58:28,639 --> 00:58:32,374 super-continent of Pangea tears apart. 632 00:58:37,314 --> 00:58:39,281 A vast slab of land breaks away, 633 00:58:39,349 --> 00:58:42,484 creating a chasm. 634 00:58:42,552 --> 00:58:45,820 It fills with a new ocean called the Tethys 635 00:58:45,888 --> 00:58:49,991 over what will one day be the Middle East. 636 00:58:55,597 --> 00:58:57,565 Currents push nutrients up into 637 00:58:57,633 --> 00:59:03,038 the coastal waters. 638 00:59:03,105 --> 00:59:05,607 And the nutrients attract fish, 639 00:59:05,675 --> 00:59:12,548 in the millions. 640 00:59:12,615 --> 00:59:17,422 But again, with so much life, also comes death. 641 00:59:20,790 --> 00:59:26,394 Dead fish and plankton carpet the ocean floor. 642 00:59:26,461 --> 00:59:28,696 Over the next 10 million years, 643 00:59:28,764 --> 00:59:31,432 layers of rock will bury and heat 644 00:59:31,499 --> 00:59:34,167 the dead creatures. 645 00:59:34,235 --> 00:59:35,569 Ancient fish and 646 00:59:35,636 --> 00:59:41,609 plankton will become oil. 647 00:59:54,023 --> 00:59:57,126 Every gallon of gas in our cars, 648 00:59:57,193 --> 01:00:00,096 every piece of plastic on the planet, 649 01:00:00,163 --> 01:00:02,665 the paint on our walls, the carpet under our 650 01:00:02,733 --> 01:00:06,403 feet, even the soap we wash with, 651 01:00:06,471 --> 01:00:09,671 almost all originated in this way. 652 01:00:22,520 --> 01:00:26,455 180 million years ago, the North American plate 653 01:00:26,505 --> 01:00:30,305 is still moving away from the European and Asian plate. 654 01:00:38,001 --> 01:00:40,770 It's shifting about one inch each year, 655 01:00:40,838 --> 01:00:47,644 the same speed at which our fingernails grow. 656 01:00:47,712 --> 01:00:50,915 But fast forward 35 million years and a new 657 01:00:50,983 --> 01:00:57,154 ocean forms, as well as new continents. 658 01:00:57,222 --> 01:01:00,272 The United States breaks away from Africa. 659 01:01:03,928 --> 01:01:07,163 The world as we know it takes shape. 660 01:01:07,230 --> 01:01:10,165 The chasm between the two continents fills, 661 01:01:10,233 --> 01:01:12,433 creating the Atlantic Ocean. 662 01:01:21,043 --> 01:01:24,193 And in the middle, lies a volcano. 663 01:01:28,217 --> 01:01:30,985 Like before, currents deep beneath the 664 01:01:31,052 --> 01:01:33,802 Earth's crust move the plates again. 665 01:01:53,140 --> 01:01:56,409 The entire sea floor tears in two and is 666 01:01:56,477 --> 01:01:58,145 pushed up into a ridge of 667 01:01:58,212 --> 01:02:03,351 mountains and volcanoes. 668 01:02:03,419 --> 01:02:05,587 It grows higher than the Himalayas, 669 01:02:05,654 --> 01:02:08,591 and longer than the Rockies. 670 01:02:08,658 --> 01:02:13,530 The water here is hot, as molten lava forces 671 01:02:13,598 --> 01:02:20,404 its way out from deep inside the earth. 672 01:02:20,471 --> 01:02:23,474 As the lava cools, it creates a new range of 673 01:02:23,542 --> 01:02:30,414 volcanic mountains, and a new ocean floor. 674 01:02:30,482 --> 01:02:33,851 Pangea breaks apart, and our world 675 01:02:33,919 --> 01:02:36,869 rearranges again. 676 01:02:54,542 --> 01:02:57,443 It's this geological activity that makes the 677 01:02:57,511 --> 01:03:03,182 Earth restless, creative and unique. 678 01:03:03,250 --> 01:03:05,284 And every time the planet reinvents 679 01:03:05,352 --> 01:03:09,552 itself, its inhabitants adapt and evolve. 680 01:03:17,998 --> 01:03:23,304 Like the ichthyosaurs. 681 01:03:23,371 --> 01:03:26,240 Their reptile ancestors lived on land, 682 01:03:26,308 --> 01:03:28,376 but as the planet changed, 683 01:03:28,444 --> 01:03:30,712 so did these animals. 684 01:03:30,780 --> 01:03:32,381 They grew fins and moved into the newly 685 01:03:32,448 --> 01:03:34,648 formed Atlantic Ocean. 686 01:03:40,357 --> 01:03:42,692 This one is 20 feet long, 687 01:03:42,759 --> 01:03:46,259 and can travel at a quick 25 miles an hour. 688 01:03:53,737 --> 01:03:56,172 It's the ocean's fastest creature and 689 01:03:56,240 --> 01:03:58,107 most efficient predator. 690 01:03:58,175 --> 01:04:01,975 It rules the oceans for 50 million years. 691 01:04:17,829 --> 01:04:20,529 But now, there's a new contender. 692 01:04:35,713 --> 01:04:41,384 The pliosaur. 693 01:04:41,452 --> 01:04:44,921 Longer than a bus, and as heavy as a truck, 694 01:04:44,989 --> 01:04:47,924 its jaws are eight times more powerful 695 01:04:47,992 --> 01:04:50,494 than a great white sharks', 696 01:04:50,561 --> 01:04:53,111 with teeth 12 inches long. 697 01:05:06,912 --> 01:05:09,347 The Earth, and its inhabitants, 698 01:05:09,414 --> 01:05:12,283 have changed beyond recognition. 699 01:05:12,351 --> 01:05:15,185 This was once solid ground, 700 01:05:15,253 --> 01:05:18,856 now it's the Atlantic Ocean. 701 01:05:18,924 --> 01:05:21,726 The very spot where ammosaurs grazed and 702 01:05:21,794 --> 01:05:25,229 dilophosaurs stalked their prey. 703 01:05:25,297 --> 01:05:27,832 The dinosaurs' world may be different, 704 01:05:27,900 --> 01:05:30,501 but they're as dominant as ever. 705 01:05:30,569 --> 01:05:33,471 They appear invincible. 706 01:05:43,680 --> 01:05:44,980 They're one of the planet's most 707 01:05:45,048 --> 01:05:47,616 successful species. 708 01:05:47,684 --> 01:05:51,085 They've survived volcanic eruptions, 709 01:05:51,153 --> 01:05:53,554 earthquakes, and entire continents splitting 710 01:05:53,622 --> 01:05:59,893 apart, The dinosaurs have thrived for 165 711 01:05:59,961 --> 01:06:07,961 million years. 712 01:06:08,402 --> 01:06:11,070 A number of mammals have also survived, 713 01:06:11,138 --> 01:06:19,138 like this shrew-like animal. 714 01:06:19,713 --> 01:06:22,415 They're prey to the dinosaurs. 715 01:06:22,483 --> 01:06:24,951 So they live in trees or underground, 716 01:06:25,018 --> 01:06:29,255 and venture out only at night. 717 01:06:29,322 --> 01:06:37,322 Mammals pose no threat to the dinosaurs. 718 01:06:39,665 --> 01:06:41,633 Nothing on Earth can challenge their 719 01:06:41,700 --> 01:06:49,700 dominance. 720 01:06:54,781 --> 01:07:01,588 Nothing, on Earth. 721 01:07:01,655 --> 01:07:04,824 A large piece of space rock heads toward Earth. 722 01:07:12,467 --> 01:07:15,970 This asteroid is at least 6 miles across, 723 01:07:16,037 --> 01:07:20,308 and travelling over 40,000 miles an hour. 724 01:07:20,376 --> 01:07:22,476 It's bigger than Mount Everest, 725 01:07:30,352 --> 01:07:33,202 and heads straight for the Gulf of Mexico. 726 01:07:44,600 --> 01:07:47,735 It travels so fast that its impact would be 727 01:07:47,803 --> 01:07:54,675 missed in a blink of an eye. 728 01:07:54,743 --> 01:07:58,743 A split second changes the world forever. 729 01:08:05,987 --> 01:08:08,355 At impact, the asteroid's back edge 730 01:08:08,423 --> 01:08:11,423 stands at 35,000 feet. 731 01:08:28,709 --> 01:08:31,577 It strikes with such immense force that it 732 01:08:31,645 --> 01:08:34,445 destroys everything it hits. 733 01:08:51,601 --> 01:08:54,951 The asteroid itself instantly vaporizes, 734 01:09:00,144 --> 01:09:02,178 unleashing the energy of millions 735 01:09:02,246 --> 01:09:04,296 of nuclear weapons. 736 01:09:10,087 --> 01:09:11,688 Nowhere is safe, 737 01:09:11,756 --> 01:09:14,306 with debris flying everywhere. 738 01:09:19,231 --> 01:09:21,899 Debris as big as entire city blocks 739 01:09:21,967 --> 01:09:24,117 circle the Earth. 740 01:09:39,351 --> 01:09:42,486 The blastwave races out from the impact zone 741 01:09:42,554 --> 01:09:45,954 like shrapnel from an exploding bomb. 742 01:10:21,293 --> 01:10:23,727 Minutes after impact, hundreds of miles 743 01:10:23,795 --> 01:10:26,063 from where the asteroid struck, 744 01:10:26,130 --> 01:10:28,080 the earth is under attack. 745 01:10:34,640 --> 01:10:37,090 Boulders rain down. 746 01:10:43,116 --> 01:10:45,716 Earthquakes shake the ground. 747 01:10:50,390 --> 01:10:52,890 And tsunamis batter the coasts. 748 01:11:06,471 --> 01:11:10,674 But the onslaught has only just begun. 749 01:11:10,742 --> 01:11:13,277 The plume of molten rock and dust spreads 750 01:11:13,345 --> 01:11:17,715 out, and engulfs the planet. 751 01:11:17,783 --> 01:11:21,533 The entire sky acts like a giant lamp, 752 01:11:26,225 --> 01:11:27,335 heating the Earth's surface to 753 01:11:27,359 --> 01:11:30,962 over 500 degrees. 754 01:11:31,030 --> 01:11:34,980 Vegetation spontaneously ignites. 755 01:11:46,114 --> 01:11:48,282 Even months after the impact, 756 01:11:48,350 --> 01:11:50,217 smoke and ash still block out 757 01:11:50,285 --> 01:11:53,687 the sun's rays. 758 01:11:53,755 --> 01:11:55,905 And with less sunlight, 759 01:11:55,975 --> 01:11:59,175 plants die and the animals starve. 760 01:12:14,710 --> 01:12:16,911 65 million years ago, 761 01:12:16,978 --> 01:12:19,247 the impact has blasted, 762 01:12:19,314 --> 01:12:22,364 stoned and burnt the dinosaurs. 763 01:12:29,824 --> 01:12:34,974 Their 165 million year reign is over. 764 01:12:42,671 --> 01:12:44,839 But the dinosaur's demise brings 765 01:12:44,906 --> 01:12:48,156 opportunity for another species. 766 01:12:52,413 --> 01:12:57,350 A mammal. 767 01:12:57,418 --> 01:13:00,187 By living underground, mammals have avoided 768 01:13:00,254 --> 01:13:03,090 the heat and fires. 769 01:13:03,158 --> 01:13:06,461 And by eating anything, they thrive while more 770 01:13:06,529 --> 01:13:13,269 selective eaters die. 771 01:13:13,336 --> 01:13:17,571 They're the unlikely inheritors of the dinosaurs' crown. 772 01:13:26,150 --> 01:13:28,418 And as one story ends. 773 01:13:28,486 --> 01:13:30,487 Another begins. 774 01:13:30,554 --> 01:13:33,022 With the dinosaurs out of the way, 775 01:13:33,090 --> 01:13:37,259 our ancestors' may now have a chance, at life. 776 01:13:55,237 --> 01:13:58,805 The dinosaurs are long dead. 777 01:13:59,207 --> 01:14:05,411 The planet is peaceful. 778 01:14:05,479 --> 01:14:07,679 In this new world, 779 01:14:07,747 --> 01:14:11,747 our mammal ancestors are evolving. 780 01:14:21,463 --> 01:14:24,598 47 million years ago, this lake, 781 01:14:24,666 --> 01:14:27,035 in what will one day be Germany, 782 01:14:27,102 --> 01:14:30,302 is the perfect place to spot them. 783 01:14:45,887 --> 01:14:48,388 Unlike earlier mammals, its eyes and 784 01:14:48,456 --> 01:14:52,859 brain are bigger. 785 01:14:52,927 --> 01:14:58,165 This is Darwinius Massilae, or Ida. 786 01:14:58,233 --> 01:15:00,701 She looks nothing like humans, 787 01:15:00,769 --> 01:15:03,337 but fossil evidence today indicates that 788 01:15:03,405 --> 01:15:06,608 these creatures might evolve into monkeys, 789 01:15:06,676 --> 01:15:10,876 apes, and eventually humans. 790 01:15:14,251 --> 01:15:16,953 Looking back through 47 million years of 791 01:15:17,020 --> 01:15:19,989 evolution might reveal one of our earliest 792 01:15:20,057 --> 01:15:25,029 known ancestors. 793 01:15:25,096 --> 01:15:28,666 The lake sits on a volcanic crater. 794 01:15:28,734 --> 01:15:33,805 It belches out noxious gas, 795 01:15:33,873 --> 01:15:41,873 that eventually kills Ida. 796 01:15:45,451 --> 01:15:46,951 The lake preserves her in its 797 01:15:47,019 --> 01:15:53,024 oxygen depleted depths. 798 01:15:53,091 --> 01:15:56,360 One day, when the water is gone and Ida's 799 01:15:56,428 --> 01:16:02,366 fossil is found, this primitive primate could 800 01:16:02,434 --> 01:16:05,402 help piece together the beginning of our own 801 01:16:05,470 --> 01:16:13,470 story, the story of human life. 802 01:16:14,111 --> 01:16:16,013 We're closer to understanding how 803 01:16:16,080 --> 01:16:19,050 everything we've seen, from ocean bacteria, 804 01:16:19,117 --> 01:16:21,586 through walking fish and subterranean 805 01:16:21,654 --> 01:16:26,058 rodents, leads to us. 806 01:16:26,126 --> 01:16:27,827 And to understanding how our 807 01:16:27,894 --> 01:16:33,667 planet was made. 808 01:16:33,735 --> 01:16:36,770 47 million years ago, the atmosphere 809 01:16:36,838 --> 01:16:43,577 is much like today. 810 01:16:43,645 --> 01:16:47,080 The temperature is 75 degrees. 811 01:16:47,148 --> 01:16:49,116 And a day lasts just under 812 01:16:49,184 --> 01:16:52,052 twenty four hours. 813 01:16:52,120 --> 01:16:54,688 The Earth is now almost identical to 814 01:16:54,756 --> 01:16:57,724 the planet we call home. 815 01:16:58,401 --> 01:16:59,942 Almost. 816 01:17:15,410 --> 01:17:18,510 The Earth's plates are on the move again. 817 01:17:22,084 --> 01:17:25,234 India moves north toward Asia. 818 01:17:38,801 --> 01:17:41,202 The Indian and Asian plates are locked 819 01:17:41,270 --> 01:17:43,970 in a titanic struggle, 820 01:17:52,183 --> 01:17:56,920 and neither plate is winning. 821 01:17:56,988 --> 01:17:59,457 As they buckle, the ocean floor contorts 822 01:17:59,524 --> 01:18:03,524 upward along a 1,500 mile line. 823 01:18:10,637 --> 01:18:12,671 A vast mountain range rises up 824 01:18:12,739 --> 01:18:20,739 over 27,000 feet. 825 01:18:36,696 --> 01:18:44,696 These are the Himalayas. 826 01:18:49,108 --> 01:18:51,609 And the highest mountain of all, 827 01:18:51,677 --> 01:18:59,677 Mount Everest. 828 01:19:00,419 --> 01:19:02,320 Its summit reaches up into the 829 01:19:02,388 --> 01:19:04,923 Earth's jet stream, the same altitude 830 01:19:04,991 --> 01:19:12,991 where planes fly. 831 01:19:31,014 --> 01:19:33,281 When the snow on the peaks melts, 832 01:19:33,349 --> 01:19:36,685 it feeds rivers like the Ganges, Indus, 833 01:19:36,753 --> 01:19:44,753 Yellow and Yangtze. 834 01:19:45,027 --> 01:19:48,230 The Himalayas are like a vast water tower. 835 01:19:48,298 --> 01:19:50,933 One day, their rivers will supply water for 836 01:19:51,000 --> 01:19:59,000 almost half the world's population. 837 01:20:09,021 --> 01:20:14,760 20 million years ago, this is our planet, 838 01:20:14,827 --> 01:20:16,862 with every continent, and every ocean 839 01:20:16,929 --> 01:20:24,035 as we know it. 840 01:20:24,103 --> 01:20:27,272 Except one thing is still missing, 841 01:20:27,339 --> 01:20:33,912 the human race. 842 01:20:33,980 --> 01:20:36,215 And for humans to evolve, 843 01:20:36,282 --> 01:20:39,818 something needs to change. 844 01:20:56,398 --> 01:20:57,666 Along the African 845 01:20:57,733 --> 01:21:05,341 coast, a great rift opens up. 846 01:21:08,145 --> 01:21:16,145 It stretches nearly 4,000 miles, 847 01:21:17,455 --> 01:21:25,455 with mountains growing along its edge. 848 01:21:38,876 --> 01:21:41,878 This ape-like creature may stay in these trees 849 01:21:41,946 --> 01:21:48,753 forever, but its world is changing. 850 01:21:48,821 --> 01:21:51,823 The growing mountains act like a wall, 851 01:21:51,891 --> 01:21:54,192 prohibiting moisture from the Indian Ocean 852 01:21:54,260 --> 01:21:57,796 from passing over the land. 853 01:21:57,863 --> 01:22:01,699 It's getting hotter, and drier. 854 01:22:01,767 --> 01:22:04,201 The lush rainforest becomes an arid 855 01:22:04,269 --> 01:22:08,272 savannah. 856 01:22:08,339 --> 01:22:10,974 The new hotter climate changes the creatures' 857 01:22:11,042 --> 01:22:13,810 habitat, forcing them to search further for 858 01:22:13,878 --> 01:22:18,115 food, soon, they stop dragging their knuckles 859 01:22:18,183 --> 01:22:19,893 like apes. 860 01:22:19,917 --> 01:22:25,589 And begin to stand, and walk on two feet. 861 01:22:25,656 --> 01:22:27,357 It's the most important step in 862 01:22:27,425 --> 01:22:34,566 the human story. 863 01:22:34,633 --> 01:22:37,168 This mountain range could be the reason 864 01:22:37,236 --> 01:22:45,236 humans walk on two feet. 865 01:22:46,811 --> 01:22:49,980 The random movement of two plates may have 866 01:22:50,048 --> 01:22:52,549 kick-started a chain of events that leads to 867 01:22:52,617 --> 01:22:58,354 the first humans. 868 01:23:10,101 --> 01:23:11,868 A man and child. 869 01:23:11,936 --> 01:23:14,637 A scene very much like today. 870 01:23:14,705 --> 01:23:19,376 But it's one and a half million years ago. 871 01:23:19,443 --> 01:23:22,479 They are an early species of human called 872 01:23:22,546 --> 01:23:26,549 Homo Erectus. 873 01:23:26,617 --> 01:23:29,252 And these are the first footprints like our 874 01:23:29,319 --> 01:23:36,659 own; civilizations past and present, 875 01:23:36,726 --> 01:23:39,461 everyone that's ever lived, 876 01:23:39,529 --> 01:23:41,665 the greatest inventions, 877 01:23:41,733 --> 01:23:44,234 the most brilliant ideas. 878 01:23:44,302 --> 01:23:47,672 Human history, in all its complexity and 879 01:23:47,739 --> 01:23:55,739 splendor, begins here and now. 880 01:24:09,094 --> 01:24:11,462 The climate changes again. 881 01:24:11,530 --> 01:24:16,167 70,000 years ago sea levels fall. 882 01:24:16,235 --> 01:24:18,603 And the gap between Africa and Arabia 883 01:24:18,671 --> 01:24:26,671 shrinks to just eight miles. 884 01:24:27,147 --> 01:24:29,781 The Red Sea is now narrow and shallow 885 01:24:29,849 --> 01:24:32,718 enough for a small group to cross, 886 01:24:32,785 --> 01:24:36,856 out of Africa. 887 01:24:36,923 --> 01:24:39,659 They're another later species of human, 888 01:24:39,726 --> 01:24:47,726 called Homo Sapiens. 889 01:24:57,809 --> 01:25:01,111 Scientists believe that the entire world beyond 890 01:25:01,179 --> 01:25:04,281 Africa was populated from descendants of 891 01:25:04,349 --> 01:25:10,553 these two hundred individuals. 892 01:25:10,621 --> 01:25:13,857 Over time our ancestors multiply and spread 893 01:25:13,924 --> 01:25:21,924 out; to India, onto Asia and into Europe. 894 01:25:34,447 --> 01:25:36,648 But while humans head north, 895 01:25:36,715 --> 01:25:44,715 a giant wall of ice travels south. 896 01:25:45,991 --> 01:25:49,694 Europe, 40,000 years ago. 897 01:25:49,762 --> 01:25:53,231 Homo sapiens arrive, only to find a world 898 01:25:53,299 --> 01:25:56,300 that's quickly changing. 899 01:25:56,368 --> 01:25:58,436 It should be the height of summer, 900 01:25:58,504 --> 01:26:00,539 but it's getting colder. 901 01:26:00,606 --> 01:26:02,374 The plants are frostbitten, 902 01:26:02,442 --> 01:26:06,579 and the rivers are frozen. 903 01:26:06,647 --> 01:26:08,982 Natural changes in the Earth's orbit, 904 01:26:09,049 --> 01:26:12,152 CO2 levels, and the flow of warm water 905 01:26:12,219 --> 01:26:14,588 around the planet conspire to lower the 906 01:26:14,656 --> 01:26:17,024 Earth's temperature. 907 01:26:17,092 --> 01:26:19,260 The Earth, and its inhabitants, 908 01:26:19,327 --> 01:26:22,363 enter an ice age. 909 01:26:22,431 --> 01:26:25,733 Glaciers as high as skyscrapers creep over 910 01:26:25,801 --> 01:26:31,138 the northern hemisphere about a foot every day, 911 01:26:31,206 --> 01:26:34,141 Slow, and powerful, they sculpt the 912 01:26:34,209 --> 01:26:39,647 landscape, gouging out great depressions. 913 01:26:39,715 --> 01:26:47,256 The planet will never look the same again. 914 01:26:47,324 --> 01:26:50,226 Now, around twenty thousand years ago, 915 01:26:50,293 --> 01:26:53,896 they grind to a halt. 916 01:26:53,964 --> 01:26:56,365 Much of the northern hemisphere is covered 917 01:26:56,433 --> 01:27:04,433 by ice sheets up to one and a half miles thick. 918 01:27:08,144 --> 01:27:10,446 With trillions of gallons of water locked 919 01:27:10,514 --> 01:27:17,019 up as ice, sea levels fall. 920 01:27:17,087 --> 01:27:19,655 A strip of land emerges from the ocean between 921 01:27:19,723 --> 01:27:27,723 Siberia and Alaska. 922 01:27:28,299 --> 01:27:33,004 It's a bridge between two vast continents, 923 01:27:33,072 --> 01:27:36,507 a gateway that takes humans from Asia to a 924 01:27:36,575 --> 01:27:41,645 new world, the Americas. 925 01:27:41,713 --> 01:27:43,781 They're the last great continents to be 926 01:27:43,848 --> 01:27:48,385 colonized, the last great human migration, 927 01:27:48,453 --> 01:27:56,226 and the first Americans. 928 01:28:02,634 --> 01:28:06,103 Now, 14,000 years ago, the changes that 929 01:28:06,171 --> 01:28:10,941 triggered the ice age reverse. 930 01:28:11,009 --> 01:28:13,744 As the ice retreats, it reveals a very 931 01:28:13,812 --> 01:28:17,548 different northern hemisphere. 932 01:28:17,615 --> 01:28:19,660 The huge depressions that the glaciers 933 01:28:19,684 --> 01:28:22,386 create fill with water to become North 934 01:28:22,454 --> 01:28:30,454 America's Great Lakes. 935 01:28:38,738 --> 01:28:41,940 6,000 years ago, the ice retreats back to 936 01:28:42,008 --> 01:28:50,008 the poles, toward the Arctic and Antarctic. 937 01:29:03,430 --> 01:29:06,499 After a four and a half billion year journey, 938 01:29:06,567 --> 01:29:10,838 we're, finally home. 939 01:29:10,905 --> 01:29:17,244 This is our world, our time. 940 01:29:17,312 --> 01:29:19,847 The planet's incredible story helps us 941 01:29:19,914 --> 01:29:23,450 understand how and why everything around us is 942 01:29:23,518 --> 01:29:31,090 here today. 943 01:29:31,157 --> 01:29:38,397 From the skies above. 944 01:29:38,465 --> 01:29:46,040 To water, the essential ingredient for life. 945 01:29:46,107 --> 01:29:54,107 To the ground beneath our feet. 946 01:29:54,850 --> 01:30:02,256 And finally life, a chain of catastrophes 947 01:30:02,324 --> 01:30:04,691 and coincidences, creating a 948 01:30:04,759 --> 01:30:08,795 spectacular result. 949 01:30:08,863 --> 01:30:11,664 Each triumph and disaster is a step 950 01:30:11,732 --> 01:30:17,035 leading to here, each and every one of 951 01:30:17,103 --> 01:30:21,807 us, right now. 952 01:30:21,875 --> 01:30:27,680 But the Earth's story isn't over. 953 01:30:27,748 --> 01:30:31,418 This journey is only half the story. 954 01:30:31,486 --> 01:30:36,423 A lot more is yet to come. 955 01:30:36,491 --> 01:30:39,860 The Earth will live for at least another 4.5 956 01:30:39,928 --> 01:30:41,428 billion years. 957 01:30:51,672 --> 01:30:56,376 More wonders, more terrors, 958 01:30:56,444 --> 01:30:58,978 and more strange creatures lie ahead for 959 01:30:59,046 --> 01:31:02,346 our restless and creative planet. 960 01:31:06,587 --> 01:31:08,937 The next chapter of Earth's story 961 01:31:09,123 --> 01:31:11,473 is still to be written. 962 01:31:16,254 --> 01:31:20,254 -- sync, corrected by <font color=#00ff00>elderman</font> -- 962 01:31:21,305 --> 01:32:21,208