1 00:02:03,156 --> 00:02:05,647 It was once the heart of the Mayan civilization 2 00:02:05,792 --> 00:02:07,987 that stretched across Central America - 3 00:02:08,128 --> 00:02:10,961 a great city known as Tikal. 4 00:02:12,832 --> 00:02:15,357 Its temples were the tallest in the Western world... 5 00:02:15,502 --> 00:02:18,164 monuments to its kings and architects. 6 00:02:21,674 --> 00:02:24,165 For centuries, Tikal grew larger... 7 00:02:24,310 --> 00:02:26,938 its arts and sciences flourished. 8 00:02:27,080 --> 00:02:30,607 Then, a thousand years ago, at the height of its power, 9 00:02:30,750 --> 00:02:33,548 the city was suddenly abandoned. 10 00:02:37,590 --> 00:02:40,320 What happened in this lost world? 11 00:02:46,566 --> 00:02:53,768 What keeps all cities, all civilizations, alive... then and now? 12 00:03:29,108 --> 00:03:32,475 Cities like New York are triumphs of human technology - 13 00:03:32,612 --> 00:03:35,308 they feel as if they will last forever. 14 00:03:35,448 --> 00:03:38,906 And they give us the sense that we're somehow apart 15 00:03:39,052 --> 00:03:40,917 from the rest of nature. 16 00:03:47,961 --> 00:03:51,397 In big cities, it's easy to take a lot of things for granted: 17 00:03:51,531 --> 00:03:53,829 Food comes from the supermarket... 18 00:03:53,967 --> 00:03:57,562 water comes from the faucet... or does it? 19 00:04:56,996 --> 00:05:00,762 Eight million New Yorkers drink clean water from the Catskill mountains, 20 00:05:00,900 --> 00:05:03,095 a hundred miles away. 21 00:05:03,236 --> 00:05:05,966 If New York had to build water - purification plants, 22 00:05:06,105 --> 00:05:08,335 it would cost billions. 23 00:05:08,474 --> 00:05:12,410 Here, nature provides that service, free of charge. 24 00:05:30,930 --> 00:05:34,798 If we could follow the rainfall down through the leaf litter, 25 00:05:34,934 --> 00:05:37,960 we'd find that what we think of as "dirt" 26 00:05:38,104 --> 00:05:41,232 is a world teeming with life - 27 00:05:41,374 --> 00:05:46,038 a metropolis much more densely populated than the city it serves. 28 00:06:03,262 --> 00:06:04,593 In every square inch, 29 00:06:04,731 --> 00:06:08,223 billions of microbes and other organisms go about their business, 30 00:06:08,368 --> 00:06:11,565 building and enriching the soil we grow our food in... 31 00:06:11,704 --> 00:06:14,036 helping condition the air we breathe... 32 00:06:14,173 --> 00:06:18,234 and cleaning the rainwater on its way downhill to the reservoirs. 33 00:06:19,445 --> 00:06:24,246 It's just one example of what scientists call biological diversity - 34 00:06:24,384 --> 00:06:28,514 the variety of interconnecting life that keeps things healthy... 35 00:06:28,654 --> 00:06:30,349 all over the planet 36 00:06:42,668 --> 00:06:46,331 Everywhere, natural has found ways to thrive. 37 00:06:46,472 --> 00:06:48,736 Each place... each ecosystem... 38 00:06:48,875 --> 00:06:52,174 shapes its own community of plants and animals. 39 00:07:00,353 --> 00:07:05,950 In every ecosystem, there is a balance of relationships that keeps it working. 40 00:07:13,833 --> 00:07:18,634 The giant seaweed called kelp... is many things to many creatures. 41 00:07:18,771 --> 00:07:20,705 It's a hiding place... 42 00:07:28,681 --> 00:07:31,206 It's a nursery for spawning fish... 43 00:07:35,021 --> 00:07:38,047 and it's a food supply for the sea urchin, 44 00:07:38,191 --> 00:07:41,217 a spiny creature with a big appetite. 45 00:07:47,099 --> 00:07:48,999 If there are too many of them, 46 00:07:49,135 --> 00:07:53,401 urchins can virtually clear-cut the underwater forest 47 00:07:57,577 --> 00:08:02,708 Until the 1970s, this was happening along the California coast, 48 00:08:02,849 --> 00:08:07,218 all because an animal that belongs here was missing... 49 00:08:08,821 --> 00:08:13,155 an animal that loves to eat urchins - the sea otter. 50 00:08:13,292 --> 00:08:17,524 It had been hunted almost to extinction for its thick coat of fur. 51 00:08:19,799 --> 00:08:23,462 Then, people decided to protect the sea otter by law, 52 00:08:23,603 --> 00:08:25,468 and their numbers grew... 53 00:08:31,010 --> 00:08:34,844 the balance of life began to re-establish itself. 54 00:08:37,950 --> 00:08:40,510 Now, wherever there are otters, 55 00:08:40,653 --> 00:08:44,248 the kelp forest flourishes and so does everything in it 56 00:08:59,338 --> 00:09:04,833 In the tropical forest, biological diversity reaches its peak. 57 00:09:04,977 --> 00:09:09,073 There are countless opportunities and life seems to seize them all. 58 00:09:21,661 --> 00:09:24,892 Like the kelp forest, the health of the rain forest 59 00:09:25,031 --> 00:09:28,364 is maintained by the variety of its inhabitants - 60 00:09:28,501 --> 00:09:31,902 as long as the natural balance is undisturbed. 61 00:09:57,563 --> 00:10:01,465 Animals can't live without the habitats they're adapted to. 62 00:10:04,370 --> 00:10:08,170 Many, like the South American tapir, are now threatened or endangered 63 00:10:08,307 --> 00:10:11,242 because they're losing the places they live. 64 00:10:11,978 --> 00:10:14,139 The forests are shrinking. 65 00:10:21,387 --> 00:10:24,754 For thousands of years, more than a third of Earth's land mass was 66 00:10:24,890 --> 00:10:28,257 covered with pristine forests, full of life. 67 00:10:32,465 --> 00:10:35,263 The forests of China and lands around the Mediterranean 68 00:10:35,401 --> 00:10:40,634 were first to be cut... as towns became cities and nations. 69 00:10:42,608 --> 00:10:45,907 The rate of loss speeded up with the Industrial Revolution. 70 00:10:46,045 --> 00:10:49,037 But in the last 50 years, we've cleared more forest 71 00:10:49,181 --> 00:10:53,743 than in our previous history. Less than half is left 72 00:10:58,557 --> 00:11:03,426 Scientists estimate that thousands of species of animals, plants, insects, 73 00:11:03,562 --> 00:11:08,625 and other organisms are being driven to extinction each year, 74 00:11:08,768 --> 00:11:11,293 with unknown consequences. 75 00:11:13,706 --> 00:11:15,799 We are changing the world too quickly for animals 76 00:11:15,941 --> 00:11:18,102 to be able to change with it 77 00:11:25,084 --> 00:11:30,078 In major institutions around the world, scientists are now working against time, 78 00:11:30,222 --> 00:11:34,124 to find and understand all the diversity of life that remains. 79 00:12:06,425 --> 00:12:10,953 Nearly two million species from beetles to blue whales, have been classified, 80 00:12:11,097 --> 00:12:15,124 but there could be ten times that many, still undiscovered. 81 00:12:32,051 --> 00:12:34,246 The priority now is to explore the places 82 00:12:34,386 --> 00:12:36,377 with the most unique biodivercity... 83 00:12:36,522 --> 00:12:39,184 where the web of life is still intact 84 00:12:40,359 --> 00:12:44,090 Fabian Michelangeli of the American Museum of Natural History 85 00:12:44,230 --> 00:12:46,892 is going back to his native Venezuela 86 00:12:47,032 --> 00:12:50,627 to join a Rapid Assessment Team on an expedition... 87 00:12:50,770 --> 00:12:56,572 to the fabled "Lost World" that inspired the novel by Sir Arthur Conan Doyle. 88 00:12:59,712 --> 00:13:02,806 I don't think we'll find a dinosaur on this trip, 89 00:13:02,948 --> 00:13:07,078 but in all of South America, there's no place more incredible 90 00:13:07,219 --> 00:13:10,586 than the table mountains of Southern Venezuela. 91 00:13:14,093 --> 00:13:18,962 The expedition is being organized in the capital of Venezuela - Caracas. 92 00:13:40,286 --> 00:13:44,154 Leader of the Rapid Assessment Team is biologist Margarita Lampo, 93 00:13:44,290 --> 00:13:46,656 whose specialty is amphibians. 94 00:13:47,459 --> 00:13:51,589 I always had a passion for animals, ever since I was a little kid, 95 00:13:52,498 --> 00:13:55,058 I liked the idea that everything in nature 96 00:13:55,201 --> 00:13:57,669 was connected to something else. 97 00:13:59,171 --> 00:14:02,663 For ten years now, I've been studying frogs and toads. 98 00:14:02,808 --> 00:14:04,435 These creatures can tell us so much 99 00:14:04,577 --> 00:14:07,307 about the health of the places where they live. 100 00:14:10,649 --> 00:14:14,517 My colleague Celsi Senaris and I are concerned by evidence that 101 00:14:14,653 --> 00:14:18,453 frog populations are declining all over the world. 102 00:14:18,591 --> 00:14:20,115 Now we have the chance to search for them 103 00:14:20,259 --> 00:14:23,285 in a place few people have ever been. 104 00:14:26,498 --> 00:14:30,935 For the next few weeks, we'll be living in very different conditions. 105 00:14:51,790 --> 00:14:54,657 We're heading southeast towards Canaima. 106 00:14:55,694 --> 00:14:57,958 The plan is to meet our guide at the airstrip, 107 00:14:58,097 --> 00:14:59,758 go upriver by canoe, 108 00:14:59,899 --> 00:15:04,097 and hopefully to the top of Mount Roraima by helicopter. 109 00:15:05,804 --> 00:15:09,399 Beneath us is the watershed of the great Orinoco River. 110 00:16:13,706 --> 00:16:16,072 Tonight we'll stay in a Pemon Indian village 111 00:16:16,208 --> 00:16:18,642 where we've hired a local boatman. 112 00:16:18,777 --> 00:16:21,211 The table mountains are a lot closer now. 113 00:16:22,614 --> 00:16:25,708 I like the Pemon word for them - tepuy. 114 00:16:25,851 --> 00:16:29,719 But I can see why others have called them the Lost World. 115 00:18:33,679 --> 00:18:36,443 Now the river is too shallow for the boat 116 00:18:37,316 --> 00:18:42,253 We'll hike the rest of the way and explore the rainforest on our way... 117 00:18:44,656 --> 00:18:47,682 I can't believe the beauty of this place. 118 00:18:54,800 --> 00:18:57,769 On the riverbank, we found some fresh tracks. 119 00:18:57,903 --> 00:19:01,669 Only hours ago, a jaguar was here. 120 00:19:01,807 --> 00:19:06,369 This tells us that the ecosystem still has a full range of biodiversity. 121 00:19:08,480 --> 00:19:12,746 Large predators control the number of mammals like the coatimundi, 122 00:19:12,885 --> 00:19:15,877 so they don't overgraze the fruits and seedlings, 123 00:19:16,021 --> 00:19:18,455 or eat too many birds eggs. 124 00:19:21,460 --> 00:19:24,861 This balance helps to ensure the health of the forest 125 00:20:29,127 --> 00:20:31,186 Now, this is it... 126 00:20:31,330 --> 00:20:34,060 the moment I've been thinking about for weeks. 127 00:20:34,199 --> 00:20:38,260 Our guide Nadim sayss these pilots know the mountains better than anyone. 128 00:20:39,972 --> 00:20:43,408 Next stop, the summit of Mount Roraima. 129 00:22:39,291 --> 00:22:44,228 Mount Roraima is a biological island, lost in time... 130 00:22:45,764 --> 00:22:48,858 eroded by eons of wind and rain. 131 00:23:33,512 --> 00:23:37,073 The pilots can't shut off the engine up here. 132 00:23:38,750 --> 00:23:41,344 The weather changes too fast 133 00:23:43,321 --> 00:23:45,186 They have to get out before the next storm, 134 00:23:45,323 --> 00:23:47,757 and one is coming in fast now. 135 00:23:50,796 --> 00:23:55,062 They'll be back with supplies in three days, if they can. 136 00:24:02,140 --> 00:24:06,236 I had mixed feelings watching the helicopter leave. 137 00:24:06,378 --> 00:24:09,541 It was like being left alone on another planet... 138 00:24:10,315 --> 00:24:13,807 surrounded by images from the dawn of time. 139 00:24:42,013 --> 00:24:45,278 In these conditions, shelter is the priority. 140 00:24:46,218 --> 00:24:48,277 Science will have to wait 141 00:25:16,915 --> 00:25:20,681 Roraima is a natural laboratory for studying the adaptation 142 00:25:20,819 --> 00:25:23,652 of species to harsh environments. 143 00:25:31,229 --> 00:25:34,096 Fabian is the team's plant specialist 144 00:25:36,434 --> 00:25:41,371 All over Roraima, there are these beautiful miniature gardens. 145 00:25:44,809 --> 00:25:49,940 Most of the summit is bare rock, so the rain runs off quickly. 146 00:25:50,081 --> 00:25:55,018 Plants only grow in depressions where water and soil can accumulate. 147 00:25:56,354 --> 00:25:59,050 If we carefully examine these little islands, 148 00:25:59,190 --> 00:26:03,854 we see that they are just lying like rugs on top of the rock. 149 00:26:04,729 --> 00:26:08,688 The soil is mostly sand, with very few nutrients. 150 00:26:08,833 --> 00:26:12,496 But it still supports an incredible amount of life, 151 00:26:12,637 --> 00:26:18,269 probably most of it exists only on this mountain, and no where else. 152 00:26:29,554 --> 00:26:31,886 In this nutrient-poor environment, 153 00:26:32,023 --> 00:26:35,720 plants have evolved different strategies for survival... 154 00:26:38,964 --> 00:26:44,061 Some have become carnivorous, trapping and consuming insects. 155 00:27:17,936 --> 00:27:22,703 Other carnivorous plants lure insects with vivid color and attractive scent 156 00:27:22,841 --> 00:27:26,402 And their pitcher-shape is also a perfect trap. 157 00:27:33,618 --> 00:27:37,179 Thousands of slippery hairs cover the inside of the pitcher. 158 00:27:41,393 --> 00:27:43,520 It's only a matter of time before the victim 159 00:27:43,662 --> 00:27:46,358 slips into the bowl of rainwater where... 160 00:27:46,498 --> 00:27:49,990 larvae and other organisms break down the insect, 161 00:27:50,602 --> 00:27:53,537 the plant absorbs the nutrients in the water. 162 00:27:57,575 --> 00:28:00,043 Roraima seems like a great place for amphibians, 163 00:28:00,178 --> 00:28:05,047 with ponds and streams everywhere. But at first we saw nothing at all. 164 00:28:06,384 --> 00:28:10,878 And our tests showed that the water is as poor a food source as the soil. 165 00:28:11,823 --> 00:28:15,088 Any creatures living here have to be very resourceful. 166 00:28:19,831 --> 00:28:22,664 Then we found our first amphibians: 167 00:28:22,801 --> 00:28:26,794 Tadpoles feeding on clusters of unhatched eggs. 168 00:28:27,906 --> 00:28:30,340 The mother frog apparently produced extra eggs, 169 00:28:30,475 --> 00:28:33,342 so her offspring would have plenty to eat! 170 00:28:38,349 --> 00:28:42,410 Nearby, we saw a frog laying eggs in a plant - 171 00:28:42,554 --> 00:28:45,921 the only carnivorous bromeliad known to science. 172 00:28:47,058 --> 00:28:50,050 The water below is full of captured insects. 173 00:28:50,195 --> 00:28:54,564 Once her eggs hatch, the tadpoles can make a feast of this soup... 174 00:28:55,567 --> 00:28:58,127 and maybe the plant gets something too - 175 00:28:58,269 --> 00:29:01,295 like nitrogen from their waste products. 176 00:29:09,547 --> 00:29:13,278 At dusk, we heard a sound we never heard before... 177 00:29:14,819 --> 00:29:18,050 definitely amphibian, but strange... 178 00:29:21,926 --> 00:29:25,362 We look for it until the sound stop. 179 00:29:35,206 --> 00:29:37,766 In the morning we heard it again. 180 00:29:40,011 --> 00:29:42,309 Celsi recorded the sound, 181 00:29:42,447 --> 00:29:44,915 but we never saw the creature that made it... 182 00:29:48,186 --> 00:29:51,952 Later, we did come across something truly unique. 183 00:29:54,425 --> 00:29:58,862 A tiny black toad, threatened by a tarantula. 184 00:29:59,831 --> 00:30:03,528 It didn't jump... it just walked away... 185 00:30:03,668 --> 00:30:06,102 and climbed the rock. 186 00:30:12,477 --> 00:30:19,747 When the tarantula moved on, the toad curled itself up and rolled down again. 187 00:30:20,919 --> 00:30:23,752 Now, that I've never seen before! 188 00:30:29,727 --> 00:30:31,922 Why would nature produce a tiny toad 189 00:30:32,063 --> 00:30:35,396 that walks and rolls instead of jumping? 190 00:30:36,467 --> 00:30:39,231 No doubt, we still have a lot to learn... 191 00:30:41,406 --> 00:30:45,035 People often ask me why we should care about creatures like this. 192 00:30:46,077 --> 00:30:51,982 Well, it may have something we need - like chemicals or medicines. 193 00:30:52,116 --> 00:30:55,142 Or maybe because it's living proof of nature's ability 194 00:30:55,286 --> 00:31:01,225 to diversify and survive... in ways we never even imagined. 195 00:31:21,913 --> 00:31:24,279 It's a long way from the Lost World of Venezuela 196 00:31:24,415 --> 00:31:26,713 to the suburbs of New York, 197 00:31:26,851 --> 00:31:31,550 but the diversity of life here is just as fragile and just as important 198 00:31:42,834 --> 00:31:46,201 Like the life of remote rain forests and mountains, 199 00:31:46,337 --> 00:31:49,465 the creatures in our backyard all play their part in the balance 200 00:31:49,607 --> 00:31:52,735 of relationships that keeps the world healthy. 201 00:31:54,712 --> 00:31:59,149 Insects need flowers, flowers need insects, 202 00:32:00,018 --> 00:32:03,454 and we need the food that pollination produces. 203 00:32:05,924 --> 00:32:07,289 In just one square meter, 204 00:32:07,425 --> 00:32:11,452 young explorers on a field trip can find a lot of life. 205 00:32:11,596 --> 00:32:12,620 If they look hard enough, 206 00:32:12,764 --> 00:32:15,995 they'll find things even scientists haven't seen before. 207 00:32:20,204 --> 00:32:23,867 We all need to know what lives here... what it does... 208 00:32:24,008 --> 00:32:25,976 and what it means to us. 209 00:32:31,416 --> 00:32:34,317 But as we take up more and more space on the Earth, 210 00:32:34,452 --> 00:32:38,445 we may tip the balance of life... without even knowing it 211 00:32:38,856 --> 00:32:41,222 It wouldn't be the first time. 212 00:32:57,308 --> 00:33:02,371 The lost city of Tikal was discovered just over a century ago, 213 00:33:02,513 --> 00:33:05,414 buried in the tropical forest of Guatemala. 214 00:33:09,287 --> 00:33:13,417 Experts still debate what happened to this metropolis of kings and priests, 215 00:33:13,558 --> 00:33:15,526 warriors and farmers... 216 00:33:15,660 --> 00:33:19,528 where the rare black jaguar, sacred to the Mayans, 217 00:33:19,664 --> 00:33:22,758 can sometimes be seen at dawn. 218 00:33:39,017 --> 00:33:43,351 New studies suggest that, if we could imagine Tikal as it was, 219 00:33:43,488 --> 00:33:45,820 we might see that its expanding population 220 00:33:45,957 --> 00:33:49,393 had stripped away the forest for miles around... 221 00:33:49,527 --> 00:33:53,657 exhausted the soil, water, and food supply... 222 00:33:53,798 --> 00:33:58,861 with famine, warfare... and collapse not far behind. 223 00:34:17,555 --> 00:34:20,490 Over a thousand years, the forest has returned... 224 00:34:20,625 --> 00:34:24,584 but the high civilization of the Mayans is no more. 225 00:34:28,733 --> 00:34:32,669 Did the people of Tikal lose their life-support system... 226 00:34:32,804 --> 00:34:35,364 without ever understanding it? 227 00:34:59,430 --> 00:35:02,888 Surrounded by the marvels of a modern city, 228 00:35:03,034 --> 00:35:06,003 we believe we are masters of our destiny. 229 00:35:07,438 --> 00:35:13,001 But everything in our homes, everything that keeps us alive, comes from nature. 230 00:35:19,484 --> 00:35:21,111 A hundred years ago, the people of New York 231 00:35:21,252 --> 00:35:23,618 had the foresight to preserve a critical part 232 00:35:23,754 --> 00:35:25,915 of its life-support system... 233 00:35:26,057 --> 00:35:29,754 the mountain forests and soil that clean its drinking water. 234 00:35:37,735 --> 00:35:40,329 Thirty years ago, the marine ecosystem 235 00:35:40,471 --> 00:35:44,032 off the California coast began to restore itself... 236 00:35:44,175 --> 00:35:47,633 because we had the wisdom to protect the sea otter. 237 00:35:51,115 --> 00:35:54,642 When we protect nature, we protect ourselves. 238 00:36:19,343 --> 00:36:22,540 After more than a week on Roraima, soaked by the rain, 239 00:36:22,680 --> 00:36:25,979 we've flown to another tepuy for a few days work on its summit 240 00:36:28,019 --> 00:36:30,010 We'll be on our way home soon... 241 00:36:31,722 --> 00:36:34,452 But in a sense, this is our home. 242 00:36:37,028 --> 00:36:41,397 The air is fresh... and the waters flow endlessly. 243 00:36:42,700 --> 00:36:45,294 These places give us life... 244 00:36:45,436 --> 00:36:49,031 and remind us that we are just a small part of nature. 245 00:36:52,743 --> 00:36:54,802 Could frogs be a kind of bellweather 246 00:36:54,946 --> 00:36:57,346 for the health of the planet? 247 00:36:57,481 --> 00:37:00,609 If so, things are okay up here. 248 00:37:02,587 --> 00:37:05,283 Will it stay this way? 249 00:37:06,057 --> 00:37:07,388 I'd like to think that places like this 250 00:37:07,525 --> 00:37:10,016 to be here for my children. 251 00:37:12,230 --> 00:37:16,098 Maybe our work here will help us to understand the world we have... 252 00:37:16,867 --> 00:37:19,358 and the world we have to lose.