1 00:00:06,000 --> 00:00:12,074 -= www.OpenSubtitles.org =- 2 00:01:00,487 --> 00:01:04,082 You might think this orang-utan is washing socks 3 00:01:04,247 --> 00:01:08,525 as some kind of circus trick for which she's been specially trained. 4 00:01:08,687 --> 00:01:13,966 But not so. She is doing this entirely on her own initiative. 5 00:01:14,127 --> 00:01:16,960 She has seen others doing it and she's copying. 6 00:01:17,127 --> 00:01:21,120 That ability to imitate as well as to use tools 7 00:01:21,287 --> 00:01:24,245 is something which started among monkeys 8 00:01:24,407 --> 00:01:28,036 but has been brought to a much greater level among the apes. 9 00:01:28,207 --> 00:01:33,759 Those two talents were ultimately to lead to the transformation of the world. 10 00:01:42,247 --> 00:01:46,923 Camp Leakey in Borneo is home to a special group of orangs 11 00:01:47,087 --> 00:01:50,284 who have been rescued from captivity and returned to the wild. 12 00:01:50,847 --> 00:01:53,998 Because they've lived partly in our world as well as theirs, 13 00:01:54,167 --> 00:01:56,761 they can give us an insight into what we have in common. 14 00:01:57,087 --> 00:02:00,397 This old lady loves DIY. 15 00:02:11,287 --> 00:02:14,404 So does her son, who was born in the wild. 16 00:02:17,047 --> 00:02:20,005 Even her infant is interested. 17 00:02:25,727 --> 00:02:31,836 It's very striking when you sit as close to an orang-utan as this 18 00:02:32,007 --> 00:02:36,364 to see how similar they are to human beings. 19 00:02:36,527 --> 00:02:39,883 We are both, of course, great apes. 20 00:02:40,047 --> 00:02:46,805 But look how human her hand is, the skill with which she picks things up, 21 00:02:47,807 --> 00:02:51,561 the way that she can grasp a tool like that. 22 00:02:51,727 --> 00:02:56,039 The way she uses her brain to imitate what she's seen others doing, 23 00:02:56,207 --> 00:03:00,519 and oddly enough, the fact that she is clearly left-handed. 24 00:03:00,687 --> 00:03:04,839 Great apes share with human beings a predilection to use 25 00:03:05,007 --> 00:03:09,876 either the right hand or the left hand, and she's left-handed. 26 00:03:11,127 --> 00:03:15,757 But the most important thing we share is our big brain. 27 00:03:15,927 --> 00:03:19,556 It's that that has produced so many of the talents and abilities 28 00:03:19,727 --> 00:03:21,718 that we have in common. 29 00:03:26,287 --> 00:03:31,122 All apes have a love of one kind of food - fruit. 30 00:03:37,767 --> 00:03:42,966 But collecting fruit in these south-east Asian forests has its problems. 31 00:03:43,127 --> 00:03:45,118 (DEEP GROWL) 32 00:03:47,167 --> 00:03:49,442 There are powerful predators on the ground, 33 00:03:49,607 --> 00:03:53,520 so orangs seldom come down from the trees. 34 00:03:55,207 --> 00:03:59,041 They're by far the heaviest animal to live up in the branches, 35 00:03:59,207 --> 00:04:03,041 but they've worked out an ingenious way of exploiting their weight. 36 00:04:03,207 --> 00:04:05,198 They pole-vault. 37 00:04:09,447 --> 00:04:12,519 Even so, getting around can be quite tiring, 38 00:04:12,687 --> 00:04:15,360 and as fruiting trees are few and widely scattered, 39 00:04:15,527 --> 00:04:18,564 orangs need to take the most direct path between them. 40 00:04:19,767 --> 00:04:22,565 But they seldom take wrong turns. 41 00:04:23,007 --> 00:04:27,364 It seems they have a map of the forest in their minds. 42 00:04:32,647 --> 00:04:36,606 They must also have a mental calendar, for they miraculously appear in a tree 43 00:04:36,767 --> 00:04:39,565 at exactly the time its fruit is ready for picking. 44 00:04:44,087 --> 00:04:47,875 It requires a lot of skill to travel around in this way, 45 00:04:48,047 --> 00:04:52,165 and youngsters take many years to match their parents' expertise 46 00:04:52,327 --> 00:04:55,399 in route-finding and aerial gymnastics. 47 00:05:04,047 --> 00:05:06,845 Mothers keep a close eye on their young, 48 00:05:07,007 --> 00:05:12,843 ready when needed to provide a helping hand, or an arm, or a leg. 49 00:05:15,087 --> 00:05:17,647 It takes up to thirteen years for a youngster 50 00:05:17,807 --> 00:05:20,526 to match its mother's knowledge of the forest. 51 00:05:22,567 --> 00:05:26,162 This may be why young orangs spend longer with their mothers 52 00:05:26,327 --> 00:05:29,637 than any other ape does, except humans. 53 00:05:32,567 --> 00:05:36,719 But eventually, this close tie has to be broken. 54 00:05:40,087 --> 00:05:44,080 Orang-utan, as adults, are famed as loners. 55 00:05:44,247 --> 00:05:47,717 But this doesn't mean that they're necessarily anti-social. 56 00:05:52,527 --> 00:05:55,883 Back at Camp Leaky...it's feeding time. 57 00:05:56,047 --> 00:06:00,006 There's a lot of food, and here a number of orang-utan assemble 58 00:06:00,167 --> 00:06:04,445 and show that at heart they're really quite sociable animals. 59 00:06:05,287 --> 00:06:09,599 Scenes like these suggest that it's only the scarcity of food 60 00:06:09,767 --> 00:06:12,486 that compels these apes to live apart. 61 00:06:12,647 --> 00:06:18,040 A group as big as this would starve if they tried to live together in the wild. 62 00:06:23,287 --> 00:06:28,566 But just occasionally, the forest creates its own food bonanza. 63 00:06:31,727 --> 00:06:35,686 Every four or five years, many fruit trees ripen simultaneously, 64 00:06:35,847 --> 00:06:41,763 producing a brief glut of food which attracts orangs from miles around. 65 00:06:45,207 --> 00:06:50,076 Now they show just how sociable they can be, 20 of them in just one tree. 66 00:06:50,247 --> 00:06:51,760 The fruit will soon be finished, 67 00:06:51,927 --> 00:06:55,442 so friends have to make the most of their time together. 68 00:06:57,887 --> 00:07:01,084 But some individuals do cause trouble. 69 00:07:01,767 --> 00:07:07,444 The highly-sexed male clambering eagerly up the tree is not after fruit. 70 00:07:07,607 --> 00:07:12,681 He drives off a female's chosen partner and tries to force himself on her. 71 00:07:20,207 --> 00:07:22,596 (SCREECHING) 72 00:07:29,647 --> 00:07:35,165 A bellowing call announces the arrival of the most powerful orang in the whole forest. 73 00:07:36,807 --> 00:07:40,117 He hasn't visited this area for many years. 74 00:07:40,367 --> 00:07:43,245 The others recognise him instantly. 75 00:07:47,527 --> 00:07:51,679 The mere threat of his presence sends the smaller male into retreat. 76 00:07:51,967 --> 00:07:54,276 (BELLOWS) 77 00:07:59,927 --> 00:08:04,364 He takes up his dominant position in the group and the rest settle down again. 78 00:08:05,167 --> 00:08:08,955 In the same way that we can take up relationships... 79 00:08:09,127 --> 00:08:13,279 (HE CHUCKLES) ...sometimes after years of separation, 80 00:08:13,447 --> 00:08:18,475 so orang-utans can slot back quickly into their own social circle. 81 00:08:18,647 --> 00:08:23,596 That requires a brain that is able to keep track of different individuals 82 00:08:23,767 --> 00:08:26,918 over long periods of time and distances. 83 00:08:27,087 --> 00:08:32,559 There is one place where interactions happen between orang-utans 84 00:08:32,727 --> 00:08:35,321 more frequently than anywhere else, 85 00:08:35,487 --> 00:08:39,719 and that has produced some extraordinary examples of their intelligence. 86 00:08:41,927 --> 00:08:45,442 The swamp forests of northern Sumatra. 87 00:08:46,687 --> 00:08:50,726 This is a paradise for orang-utan. 88 00:08:51,767 --> 00:08:56,795 It floods regularly, and the waters bring in a rich supply of nutrients, 89 00:08:56,967 --> 00:08:59,527 so there's a great deal of food to be had. 90 00:09:01,247 --> 00:09:06,560 Here orangs can travel and feed together in groups throughout the year. 91 00:09:12,127 --> 00:09:15,164 They eat insects as well as fruit. 92 00:09:18,247 --> 00:09:21,444 Termites are a particular favourite. 93 00:09:22,927 --> 00:09:27,637 Collecting them from a rotten trunk doesn't need much ingenuity. 94 00:09:28,727 --> 00:09:33,517 Extracting something from a hole in a living tree is a different matter, 95 00:09:33,807 --> 00:09:35,877 even for a powerful male like this one. 96 00:09:36,807 --> 00:09:41,676 But the orangs here have solved such problems - they make tools. 97 00:09:41,847 --> 00:09:44,645 First they select a twig. 98 00:09:45,367 --> 00:09:48,245 Next they trim it to length. 99 00:09:49,127 --> 00:09:52,005 Then they whittle it into shape... 100 00:09:53,847 --> 00:09:59,604 ..and carefully insert it into the tree to reach what they want from inside. 101 00:10:02,487 --> 00:10:08,562 This ingenious male is probing into a bees' nest with a double-ended instrument 102 00:10:08,727 --> 00:10:13,243 which enables him to lick honey from one end while collecting more with the other. 103 00:10:21,727 --> 00:10:24,287 Younger members of the group watch and learn. 104 00:10:24,447 --> 00:10:28,565 So a tradition grows that will be passed on to new generations. 105 00:10:32,007 --> 00:10:34,521 If there's an abundance of food, 106 00:10:34,687 --> 00:10:39,203 orang-utan can live in high densities and so form a community. 107 00:10:39,367 --> 00:10:42,837 And within a community, if one individual gets a bright idea, 108 00:10:43,007 --> 00:10:45,885 others will copy it and so form a culture. 109 00:10:46,047 --> 00:10:51,758 To see an ape culture that's even more complex, we have to go to another continent. 110 00:10:54,367 --> 00:10:59,282 This is Africa, a mangrove-covered island near the mouth of the Congo. 111 00:10:59,447 --> 00:11:03,122 It's home to a remarkable and very revealing community 112 00:11:03,287 --> 00:11:06,643 of a different great ape, chimpanzees. 113 00:11:06,807 --> 00:11:08,798 (SCREECHING) 114 00:11:09,207 --> 00:11:12,404 These chimps are orphans. 115 00:11:12,847 --> 00:11:16,920 Their parents were killed for the bush-meat trade, 116 00:11:17,087 --> 00:11:20,762 and many were pets kept in very unsuitable conditions. 117 00:11:21,527 --> 00:11:24,997 Now they're part of an unique experiment 118 00:11:25,167 --> 00:11:27,920 in which they're taught the skills they'll need 119 00:11:28,087 --> 00:11:32,717 in order that they may survive by themselves in the wild. 120 00:11:33,967 --> 00:11:36,765 (SCREECHING AND CALLING) 121 00:11:51,367 --> 00:11:57,124 Several of them, as youngsters, acquired a number of skills by watching humans. 122 00:11:57,967 --> 00:11:59,958 Some know how to crack nuts. 123 00:12:02,047 --> 00:12:04,686 But it takes a chimp a number of years to work out 124 00:12:04,847 --> 00:12:08,556 how to place the nut in a socket and then how to wield a hammer. 125 00:12:09,847 --> 00:12:13,283 This chimp, Balinga, is an expert. 126 00:12:13,447 --> 00:12:16,041 His companion, Flo, watches attentively. 127 00:12:22,127 --> 00:12:24,436 Puck is really struggling. 128 00:12:25,127 --> 00:12:28,164 He only started watching nuts being cracked when he was six. 129 00:12:28,327 --> 00:12:31,797 That's two years too late for a chimp to learn new skills. 130 00:12:31,967 --> 00:12:35,118 You really can't teach an old ape new tricks. 131 00:12:47,647 --> 00:12:50,480 What about this? Do you want one of these? 132 00:12:55,807 --> 00:12:57,525 Mind your fingers! 133 00:13:15,087 --> 00:13:19,603 Of course, there are many different ways of cracking a nut. 134 00:13:21,767 --> 00:13:25,362 And, come to that, there are many different kinds of nuts. 135 00:13:25,527 --> 00:13:31,875 So different groups of chimps have developed different ways of dealing with the problem. 136 00:13:32,047 --> 00:13:35,437 That is the beginning of a culture, 137 00:13:35,607 --> 00:13:41,045 and a culture has many things in it, apart from cracking nuts. 138 00:13:43,167 --> 00:13:48,195 These rainforests lie 1,000 miles away east of the Congo, in Uganda. 139 00:13:48,607 --> 00:13:52,600 There are chimps here, too, but they have a very different culture 140 00:13:52,767 --> 00:13:55,839 and they have never been filmed before. 141 00:13:56,527 --> 00:13:59,087 Their communities are the biggest known 142 00:13:59,247 --> 00:14:02,523 and contain by far the most adult males known anywhere. 143 00:14:04,727 --> 00:14:10,324 As elsewhere, their cultural traditions extend to details of social etiquette. 144 00:14:15,047 --> 00:14:20,838 Here they practice a style of grooming known as the grooming hand-clasp. 145 00:14:22,167 --> 00:14:24,965 Most of the time, life is peaceful. 146 00:14:25,127 --> 00:14:28,915 But the males, although they live alongside one another, are rivals, 147 00:14:29,087 --> 00:14:31,681 and occasionally tempers flare. 148 00:14:31,847 --> 00:14:34,680 (AGGRESSIVE SCREECHING) 149 00:15:01,527 --> 00:15:05,566 These displays are ways by which males establish their dominance 150 00:15:05,727 --> 00:15:07,683 without physically wounding others 151 00:15:07,847 --> 00:15:12,079 who would be needed as comrades-in-arms were the group to be attacked. 152 00:15:12,807 --> 00:15:17,483 After a quarrel, they embrace one another to re-establish their bonds of friendship. 153 00:15:18,887 --> 00:15:22,277 But sometimes rivalries become more serious. 154 00:15:24,127 --> 00:15:27,722 Suddenly, a gang of males will pick on an individual 155 00:15:27,887 --> 00:15:30,321 and attack him with frightening violence. 156 00:15:30,487 --> 00:15:33,957 A young male called Grapelli is being ferociously beaten 157 00:15:34,127 --> 00:15:37,244 by an unusually large gang of adult males. 158 00:15:37,407 --> 00:15:40,319 (DIN OF SCREECHING) 159 00:15:50,927 --> 00:15:54,602 Battles between rival groups from neighbouring communities 160 00:15:54,767 --> 00:15:57,327 have occasionally been seen elsewhere in Africa, 161 00:15:57,487 --> 00:16:02,481 but attacks like this on a single male within the group are very rare indeed. 162 00:16:11,687 --> 00:16:15,396 This is the last that was seen of Grapelli. 163 00:16:16,367 --> 00:16:20,599 He was very seriously wounded and it is almost certain that he died. 164 00:16:26,287 --> 00:16:29,438 His body has not yet been found. 165 00:16:33,127 --> 00:16:36,437 What is happening at Ngogo that causes these savage attacks? 166 00:16:37,807 --> 00:16:41,925 One theory is that young males find it particularly hard 167 00:16:42,087 --> 00:16:46,478 to establish a place within such a large group of powerful adult males, 168 00:16:46,647 --> 00:16:51,596 whose lives are regulated by social relationships we have yet to understand. 169 00:16:54,967 --> 00:16:57,959 Even these apparently simple acts of grooming 170 00:16:58,127 --> 00:17:00,641 can have great social significance. 171 00:17:02,567 --> 00:17:05,365 Grooming, of course, is important for health. 172 00:17:05,527 --> 00:17:08,360 It's a service that males often perform for their relatives, 173 00:17:08,527 --> 00:17:10,722 as these two brothers are doing. 174 00:17:12,607 --> 00:17:17,556 It's also a way of creating and maintaining good social relationships 175 00:17:17,727 --> 00:17:20,958 between allies and males in the same peer group. 176 00:17:26,487 --> 00:17:28,955 This young male, Pork Pie, 177 00:17:29,127 --> 00:17:32,483 seems to be more successful socially than Grapelli was. 178 00:17:36,807 --> 00:17:41,562 But these males have other things than grooming on their mind. 179 00:17:43,007 --> 00:17:48,445 Their attention has turned to the tree tops. It's time to hunt. 180 00:17:49,527 --> 00:17:53,076 A large group of like-minded males are assembling. 181 00:17:54,927 --> 00:18:01,002 One of them drums, a signal telling others nearby that the hunt is about to start. 182 00:18:04,687 --> 00:18:08,362 Chimps elsewhere hunt when they see a good opportunity, 183 00:18:08,527 --> 00:18:11,405 but here in Ngogo, hunts often start 184 00:18:11,567 --> 00:18:14,365 whether or not suitable prey has been spotted. 185 00:18:17,287 --> 00:18:19,847 The males set off through the forest. 186 00:18:20,007 --> 00:18:25,035 They travel for up to four hours at a time, searching for likely victims. 187 00:18:25,687 --> 00:18:27,962 Pork Pie tags along. 188 00:18:28,127 --> 00:18:31,358 He's not yet an accepted member of the hunting group. 189 00:18:34,327 --> 00:18:38,798 This is what they're looking for, a troop of red colobus monkeys. 190 00:18:47,087 --> 00:18:50,716 The hunters take up their positions in the surrounding trees, 191 00:18:50,887 --> 00:18:54,197 ready to pounce on any monkeys that try to escape. 192 00:19:11,527 --> 00:19:16,555 They're closing in on the most vulnerable, a female with her young. 193 00:19:30,607 --> 00:19:34,395 (WILD SCREECHING FROM BOTH SIDES) 194 00:19:47,527 --> 00:19:50,360 The colobus males do their best to fight back, 195 00:19:50,527 --> 00:19:53,087 but the chimps are much bigger and stronger. 196 00:20:14,487 --> 00:20:18,116 Some of the infants have been separated from their mothers. 197 00:20:20,847 --> 00:20:22,838 They're now easy prey. 198 00:20:26,087 --> 00:20:29,124 (DIN OF SCREECHING AND SQUEALING) 199 00:20:31,447 --> 00:20:36,840 But it's not over yet. The male colobus fight to defend their families. 200 00:20:42,167 --> 00:20:45,398 But they couldn't save this infant. 201 00:20:48,127 --> 00:20:53,155 The hunters crowd round the kill. The rest of the group join them. 202 00:20:56,887 --> 00:20:59,879 The males are the first to eat. 203 00:21:00,047 --> 00:21:05,485 They supplement the flesh with a few leaves, just as humans take vegetables with their meat. 204 00:21:08,647 --> 00:21:11,878 Some of the male hunters now share their kill 205 00:21:12,047 --> 00:21:15,084 with other members of the group, including the females. 206 00:21:17,887 --> 00:21:21,846 Do they get anything in exchange? Sex, for example? 207 00:21:22,727 --> 00:21:26,561 This male is certainly mating with one of the females. 208 00:21:30,727 --> 00:21:35,482 But then he allows a different female to take some of his meat. 209 00:21:40,927 --> 00:21:44,761 Perhaps the meat is given to those who beg the hardest. 210 00:21:45,887 --> 00:21:51,325 Pork Pie is certainly trying his luck with one hunter after another. 211 00:21:51,887 --> 00:21:54,685 Time after time he's spurned. 212 00:21:56,447 --> 00:21:59,917 Eventually his persistence pays off. 213 00:22:02,647 --> 00:22:07,562 But the Ngogo chimps have another possible motive for meat-sharing. 214 00:22:07,887 --> 00:22:11,960 Males give meat more frequently to their allies than to others. 215 00:22:12,127 --> 00:22:16,598 It seems they're using meat as a way of strengthening such bonds. 216 00:22:17,167 --> 00:22:19,362 The hope of collecting a share of meat 217 00:22:19,527 --> 00:22:23,600 may well be a reason for others joining in the hunt in the first place. 218 00:22:25,367 --> 00:22:29,076 Chimpanzees have much in common with humans. 219 00:22:29,247 --> 00:22:33,126 They are, after all, thought to be our closest living relatives. 220 00:22:35,087 --> 00:22:38,204 They're clever, social, political creatures, 221 00:22:38,527 --> 00:22:41,678 and apparently they even dream. 222 00:22:43,807 --> 00:22:48,483 Way back in prehistory, the dreams and ambitions of the ape 223 00:22:48,647 --> 00:22:51,366 whose descendants would eventually take over the planet 224 00:22:51,527 --> 00:22:54,519 must have taken a very different direction. 225 00:22:56,087 --> 00:23:01,445 More discoveries about that creature have been made here at Olduvai Gorge, Tanzania, 226 00:23:01,607 --> 00:23:03,598 than anywhere else in the world. 227 00:23:03,767 --> 00:23:08,636 Perhaps here we can find clues as to why our ancestors took such a different path. 228 00:23:10,407 --> 00:23:12,398 Three and a half million years ago, 229 00:23:12,447 --> 00:23:18,841 the volcano behind me was belching out ash which covered the entire landscape, 230 00:23:18,927 --> 00:23:23,364 and it was in that ash that the most evocative discovery of all was made. 231 00:23:24,687 --> 00:23:29,124 These are the fossilised tracks of ancient rhino and antelope, 232 00:23:29,287 --> 00:23:31,403 here at Laetoli in Tanzania. 233 00:23:31,567 --> 00:23:37,244 Among them are the footprints of an ape, a very remarkable ape. 234 00:23:39,847 --> 00:23:43,840 Scientists maintain that they can deduce from the shape of bones 235 00:23:44,007 --> 00:23:47,761 the posture of the living animal, but there will always be arguments. 236 00:23:47,927 --> 00:23:52,762 Here, however, is proof positive that three and a half million years ago 237 00:23:52,927 --> 00:23:56,966 mankind's ancestors were walking on two feet, upright. 238 00:23:57,127 --> 00:24:01,917 Here's the dent made by the heel as it hit the ground, the raised instep, 239 00:24:02,087 --> 00:24:05,966 and the big toe, instead of pointing outwards from the foot 240 00:24:06,127 --> 00:24:12,077 as is needed to climb trees, is aligned forward to give the final push-off. 241 00:24:12,487 --> 00:24:15,763 But the exciting thing about Laetoli 242 00:24:15,927 --> 00:24:21,081 is that there is a whole track way of prints and they have fossilised behaviour 243 00:24:21,247 --> 00:24:26,241 and revealed family life in a way that is almost disturbingly familiar. 244 00:24:29,607 --> 00:24:32,883 Two individuals, one slightly larger than the other, 245 00:24:33,047 --> 00:24:34,605 perhaps male and female, 246 00:24:34,767 --> 00:24:38,555 appear to have been walking beside one another, maybe even arm in arm. 247 00:24:38,727 --> 00:24:42,766 The male's footprints are scuffed by a smaller set of prints, 248 00:24:42,927 --> 00:24:47,045 perhaps made by a child walking through the newly-fallen volcanic ash 249 00:24:47,207 --> 00:24:49,926 and treading in the steps of its father. 250 00:24:51,607 --> 00:24:55,316 The big question is why did they stand upright? 251 00:24:55,487 --> 00:24:57,557 There have been a number of suggestions. 252 00:24:57,727 --> 00:25:00,719 One is that it was to get a better view of the surroundings, 253 00:25:00,887 --> 00:25:02,878 to spot for danger or for prey. 254 00:25:03,047 --> 00:25:06,517 Maybe it was to release the hands to use tools, 255 00:25:06,687 --> 00:25:09,076 or pick up food or hold a baby. 256 00:25:09,247 --> 00:25:13,035 And there's a third, rather more controversial suggestion. 257 00:25:13,567 --> 00:25:19,403 Six million years ago, the climate of the earth became very erratic. 258 00:25:23,607 --> 00:25:26,405 The great African forests began to die back. 259 00:25:26,727 --> 00:25:30,720 The blanket of trees became broken by patches of scrub and grassland. 260 00:25:30,887 --> 00:25:34,197 There's some evidence too that slow movements in the earth's crust 261 00:25:34,367 --> 00:25:37,120 caused areas of East Africa to flood. 262 00:25:37,287 --> 00:25:40,165 A new habitat had appeared for the apes. 263 00:25:40,807 --> 00:25:43,605 Using their long chimp-like arms, 264 00:25:43,767 --> 00:25:47,760 these early creatures were still climbing trees in order to find their food. 265 00:25:47,927 --> 00:25:49,918 But as the forests diminished, 266 00:25:50,087 --> 00:25:52,965 so they had to travel farther from one tree to the next, 267 00:25:53,127 --> 00:25:58,565 and that involved crossing open spaces covered with grass or even water. 268 00:25:58,727 --> 00:26:03,278 To do that, they travelled upright on two feet, as I am doing. 269 00:26:55,527 --> 00:27:01,363 Suddenly, an image from our remote past comes vividly to light - 270 00:27:01,527 --> 00:27:05,884 the time when our distant ancestors, in order to keep up with the changing environment, 271 00:27:06,047 --> 00:27:11,519 had to wade and keep their heads above water in order to find food; 272 00:27:11,687 --> 00:27:15,885 that crucial moment when our far distant ancestors 273 00:27:16,047 --> 00:27:21,246 took a step away from being apes and a step towards humanity. 274 00:27:25,447 --> 00:27:29,076 Apes are primarily adapted for a life in the trees, 275 00:27:29,247 --> 00:27:32,205 which is why they waddle if they try to walk upright. 276 00:27:32,367 --> 00:27:36,360 It's tiring for them to stand on two feet for any length of time. 277 00:27:37,087 --> 00:27:39,840 But when they wade, the water supports their bodies 278 00:27:40,007 --> 00:27:42,475 and takes some of the strain off their leg muscles, 279 00:27:42,647 --> 00:27:45,559 so that they can stay upright for much longer. 280 00:27:56,807 --> 00:28:01,244 Maybe a life at the water's edge encouraged anatomical change. 281 00:28:01,407 --> 00:28:05,719 At about this time, the hip bones of these early ape-men altered 282 00:28:05,887 --> 00:28:09,436 and our ancestors adopted an upright existence. 283 00:28:15,207 --> 00:28:19,405 There are places in the forest of the Congo which can give us a clue 284 00:28:19,567 --> 00:28:23,719 as to the sort of thing that ape-men might have found to eat in the swamps. 285 00:28:26,687 --> 00:28:29,838 These are lowland gorillas. 286 00:28:37,807 --> 00:28:40,685 They're collecting marsh plants. 287 00:28:42,007 --> 00:28:46,717 Our ancestors might have come to such places to feed in a similar way. 288 00:28:48,167 --> 00:28:52,206 We know from other evidence that nutritious roots and tubers 289 00:28:52,367 --> 00:28:55,120 were indeed eaten by early humans. 290 00:28:59,887 --> 00:29:04,563 There was another kind of food that our ancestors might have found here. 291 00:29:04,727 --> 00:29:09,243 Gorillas today are exclusively vegetarian, but our ancestors, 292 00:29:09,407 --> 00:29:13,559 judging from their teeth, also ate meat, as chimps do. 293 00:29:15,847 --> 00:29:21,001 Although gorillas ignore other animals visiting these swamps, 294 00:29:21,167 --> 00:29:26,116 the presence of such creatures might not have gone unnoticed by early ape-men. 295 00:29:28,807 --> 00:29:32,436 But to kill such fast and wary prey, which so easily take to flight 296 00:29:32,607 --> 00:29:36,964 and can run faster than any ape, would require the skill to follow their tracks. 297 00:29:40,207 --> 00:29:46,442 Linking marks in the earth with an animal that may have passed hours, if not days before, 298 00:29:46,607 --> 00:29:50,566 requires a profound leap of the imagination, and as far as we know, 299 00:29:50,727 --> 00:29:53,480 only human beings have ever done that. 300 00:29:53,647 --> 00:29:55,558 But once it's been done, 301 00:29:55,727 --> 00:29:58,958 identifying the tracks, in the simplest terms, is not difficult. 302 00:29:59,167 --> 00:30:02,557 Even I know that those are the tracks of an eland. 303 00:30:02,767 --> 00:30:07,966 There are some people who can interpret even the faintest of marks on the ground. 304 00:30:10,367 --> 00:30:12,722 They hunt in silence. 305 00:30:12,887 --> 00:30:17,722 The hand-sign indicates that one of them has found the track of a group of kudu. 306 00:30:18,607 --> 00:30:22,077 These are the San people of the Kalahari Desert, 307 00:30:22,247 --> 00:30:25,284 the last tribe on Earth to use what some believe 308 00:30:25,447 --> 00:30:30,316 is the most ancient hunting technique of all, the ''persistence hunt''. 309 00:30:30,487 --> 00:30:33,524 They run down their prey. 310 00:30:39,607 --> 00:30:42,724 They start to feel the rhythm of the animal's movements 311 00:30:42,887 --> 00:30:46,926 from the spacing of the tracks. The group is not moving fast. 312 00:30:56,447 --> 00:30:58,915 The animals have taken fright. 313 00:31:03,607 --> 00:31:05,598 They will concentrate on the bull. 314 00:31:05,847 --> 00:31:10,875 He will be carrying a heavy set of horns and will tire more quickly. 315 00:31:12,487 --> 00:31:15,604 To do that, they must separate him from the herd 316 00:31:15,767 --> 00:31:19,442 so that his tracks won't be confused by those of others. 317 00:31:23,847 --> 00:31:26,486 The sun is directly overhead 318 00:31:26,647 --> 00:31:31,038 and the men sense a change in the kudu's pace - he's slowing. 319 00:31:34,367 --> 00:31:36,358 After hours of tracking, 320 00:31:36,527 --> 00:31:40,202 they've entered an almost trance-like state of concentration. 321 00:31:45,367 --> 00:31:49,042 At times it's impossible to see any sign of the kudu's tracks, 322 00:31:49,207 --> 00:31:52,597 and the hunters must imagine the path it will have taken. 323 00:32:01,607 --> 00:32:05,202 The heat is hard on the hunters, but they're now close enough 324 00:32:05,367 --> 00:32:08,564 for the next stage in the hunt, the chase. 325 00:32:16,607 --> 00:32:19,440 This is the signal for it to begin. 326 00:32:26,607 --> 00:32:31,397 Only one man will undertake it, Karohe, the runner. 327 00:32:45,887 --> 00:32:48,321 He must be relentless. 328 00:32:54,247 --> 00:32:57,000 It's now a test of endurance. 329 00:32:57,167 --> 00:33:00,716 Who will collapse first, the man or the animal? 330 00:33:05,087 --> 00:33:08,204 This was how men hunted before they had weapons, 331 00:33:08,367 --> 00:33:12,326 when a hunter had nothing more than his own physical endurance 332 00:33:12,487 --> 00:33:14,921 with which to gain his prize. 333 00:33:16,567 --> 00:33:22,324 Running on two feet is more efficient over long distances than running on four. 334 00:33:25,007 --> 00:33:29,285 A man sweats from glands all over his body and so cools himself. 335 00:33:29,847 --> 00:33:34,841 A kudu sweats much less and has to find shade if it's to cool down. 336 00:33:39,847 --> 00:33:43,157 A man has hands with which to carry water, 337 00:33:43,327 --> 00:33:48,196 so, during the chase, he can replenish the liquid he loses as sweat. 338 00:34:13,447 --> 00:34:17,076 Hours pass and Karohe is getting closer. 339 00:34:18,207 --> 00:34:21,279 But then the kudu runs into thick cover. 340 00:34:25,887 --> 00:34:28,276 The tracks have disappeared. 341 00:34:33,607 --> 00:34:37,646 Karohe tries to put himself into the mind of the kudu, 342 00:34:37,807 --> 00:34:41,402 and re-enacts the moment when it heard him approaching 343 00:34:41,567 --> 00:34:44,206 as it tried to rest in the shade. 344 00:34:50,527 --> 00:34:56,602 He deduces the direction in which it must have fled. It's close by. 345 00:35:10,287 --> 00:35:12,676 The chase has lasted eight hours. 346 00:35:12,847 --> 00:35:15,998 Hunter and hunted are both at the end of their strength. 347 00:35:16,167 --> 00:35:18,556 Neither can go on much longer. 348 00:35:32,847 --> 00:35:38,877 Then the kudu collapses... from sheer exhaustion. 349 00:35:45,207 --> 00:35:47,516 It's close to death. 350 00:35:53,607 --> 00:35:59,204 Karohe's spear-throw now is scarcely more than a symbolic gesture. 351 00:36:25,887 --> 00:36:30,802 The hunter pays tribute to his quarry's courage and strength 352 00:36:30,967 --> 00:36:35,404 with ceremonial gestures that ensure its spirit returns 353 00:36:35,567 --> 00:36:37,956 to the desert sands from which it came. 354 00:36:42,727 --> 00:36:45,241 While it was alive, he lived and breathed with it 355 00:36:45,407 --> 00:36:48,843 and felt its every movement in his own body. 356 00:36:51,927 --> 00:36:55,840 At the moment of its death, he shared its pain. 357 00:36:59,167 --> 00:37:04,241 He rubs its saliva into his own legs to relieve the agony of his burning muscles. 358 00:37:04,407 --> 00:37:07,558 He gives thanks for the life he has taken, 359 00:37:07,727 --> 00:37:10,924 so that he may sustain the lives of his family 360 00:37:11,087 --> 00:37:13,726 waiting for him back in their settlement. 361 00:37:17,687 --> 00:37:22,283 While the men were away, the women have collected tubers and roots. 362 00:37:22,447 --> 00:37:28,397 Now Karohe has brought them the much more nutritious and energy-giving meat. 363 00:37:28,567 --> 00:37:30,797 (TALK IN DIALECT) 364 00:37:36,487 --> 00:37:39,160 The dogs are given a share. 365 00:37:39,327 --> 00:37:44,321 Wild dogs must have followed human hunters for scraps since prehistory. 366 00:37:44,487 --> 00:37:48,685 Men selected pups that were the least savage to help with tracking. 367 00:37:48,847 --> 00:37:51,919 The character of their dogs began to change. 368 00:37:53,247 --> 00:37:57,001 Cattle were domesticated by a similar process, 369 00:37:57,167 --> 00:38:00,364 choosing the most docile calves and hand-rearing them. 370 00:38:01,287 --> 00:38:05,599 The Fulani people of Mali lay claim to the half-wild herds 371 00:38:05,767 --> 00:38:09,362 that roam the savannahs, and mark them accordingly. 372 00:38:19,567 --> 00:38:22,604 But grazing animals, wild or tame, 373 00:38:22,767 --> 00:38:27,124 may have to migrate with the seasons to find pasture. 374 00:38:27,287 --> 00:38:30,199 And then the people must follow. 375 00:38:36,767 --> 00:38:40,203 People all over the world have tried to domesticate animals. 376 00:38:40,367 --> 00:38:43,962 In fact, very few species are actually suitable. 377 00:38:44,127 --> 00:38:47,517 To be any good, an animal has, first of all, to be docile. 378 00:38:47,687 --> 00:38:50,565 Secondly, to eat a food that's easily available. 379 00:38:50,727 --> 00:38:54,242 Thirdly, to breed easily in captivity. 380 00:38:54,407 --> 00:38:59,276 Fourthly, to live in packs or herds, groups in which individuals recognise 381 00:38:59,447 --> 00:39:03,565 that just one is the dominant animal to which all the rest are submissive. 382 00:39:03,727 --> 00:39:07,845 Then a human being can take over the place of that dominant animal 383 00:39:08,007 --> 00:39:10,680 and so control his flocks and herds. 384 00:39:10,847 --> 00:39:12,838 (LOUD BANG) 385 00:39:13,007 --> 00:39:15,885 A gunshot drives the cattle forward. 386 00:39:20,727 --> 00:39:24,037 The herds must be guided if they're to survive this, 387 00:39:24,207 --> 00:39:27,005 the most challenging part of their long annual journey. 388 00:39:28,807 --> 00:39:33,244 Every year grazing animals, both domesticated and wild, 389 00:39:33,407 --> 00:39:38,197 have to risk their lives in treacherous waters to reach food on the other side. 390 00:39:41,047 --> 00:39:43,356 (CATTLE BELLOW) 391 00:39:52,127 --> 00:39:54,925 The tamed and subservient cattle, however, 392 00:39:55,087 --> 00:39:57,521 are guided and protected by the men. 393 00:40:02,767 --> 00:40:06,885 If the animals don't stay together, they may be swept away by currents. 394 00:40:11,527 --> 00:40:14,678 Herding cattle is by no means the easy option. 395 00:40:14,847 --> 00:40:18,237 Just keeping them alive is full of difficulties. 396 00:40:18,407 --> 00:40:20,523 But in spite of all the problems, 397 00:40:20,687 --> 00:40:23,679 human beings have become so good at it that today 398 00:40:23,847 --> 00:40:28,318 domesticated cattle far outnumber their wild relatives. 399 00:40:42,007 --> 00:40:45,682 Relying on herds that must migrate in search of pasture 400 00:40:45,847 --> 00:40:50,045 makes it impossible for people to settle permanently in one place. 401 00:40:50,487 --> 00:40:54,878 But in more fertile areas, cattle can be confined, 402 00:40:55,047 --> 00:40:59,325 and then they can provide not only milk and meat but power. 403 00:40:59,487 --> 00:41:03,321 Once people settle down, they can plant crops. 404 00:41:03,487 --> 00:41:05,478 They can become farmers. 405 00:41:06,487 --> 00:41:10,685 All over the world, woodlands and grasslands began to disappear, 406 00:41:10,847 --> 00:41:15,762 to be replaced by fields in which to grow crops of domesticated plants. 407 00:41:17,647 --> 00:41:21,003 People began to select those plants that gave good yields, 408 00:41:21,167 --> 00:41:25,524 and so plants also changed, just as animals have done. 409 00:41:27,247 --> 00:41:33,243 In Africa, in Europe, in Asia, people started to settle down in villages. 410 00:41:33,927 --> 00:41:37,363 Hitherto, the population of every species of animal on Earth 411 00:41:37,527 --> 00:41:40,837 was limited by the amount of food available to it. 412 00:41:41,687 --> 00:41:44,759 But human beings now changed that. 413 00:41:44,927 --> 00:41:47,236 They'd learned how to increase the supply of food 414 00:41:47,407 --> 00:41:50,604 far beyond that which occurred naturally. 415 00:41:52,967 --> 00:41:57,199 It was a crucial moment in the history of this planet. 416 00:41:57,367 --> 00:42:00,882 The number of human beings began to increase. 417 00:42:05,527 --> 00:42:08,439 This strange miniature house 418 00:42:08,607 --> 00:42:11,679 wasn't built for occupation by human beings. 419 00:42:11,847 --> 00:42:15,556 Instead it shelters the commodity that is most important 420 00:42:15,727 --> 00:42:18,161 in this Dogon village in Mali, West Africa. 421 00:42:18,327 --> 00:42:21,364 It's a granary. It contains millet. 422 00:42:23,727 --> 00:42:26,958 Millet is the most important thing in Dogon life. 423 00:42:27,127 --> 00:42:30,756 The year revolves around planting it and harvesting it. 424 00:42:30,927 --> 00:42:36,877 There are more houses to contain it in a village than there are houses for human beings. 425 00:42:37,047 --> 00:42:41,245 The first music a baby in Dogonland is likely to hear 426 00:42:41,407 --> 00:42:44,160 is the sound of its mother pounding millet. 427 00:42:44,327 --> 00:42:46,318 (THUDDING) 428 00:42:54,727 --> 00:42:59,198 Now that people were no longer compelled to be permanently on the move 429 00:42:59,367 --> 00:43:03,565 in order to find food, they had more time to spend on other things. 430 00:43:03,727 --> 00:43:07,197 Ritual and the arts flourished as never before. 431 00:43:07,367 --> 00:43:09,801 (THUDDING, BANGING, CLAPPING) 432 00:43:22,927 --> 00:43:26,966 For the Dogon, harvest is finished. The granaries are full. 433 00:43:27,367 --> 00:43:29,642 It's time to celebrate. 434 00:43:44,527 --> 00:43:50,045 As more food became more easily available, so the human population continued to increase. 435 00:43:50,207 --> 00:43:56,123 Villages grew into towns. Towns became cities. 436 00:44:08,047 --> 00:44:12,916 This immense low mound may look as though it's covered with gravel, 437 00:44:13,087 --> 00:44:19,435 but if you look closely, you'll see it's composed of tiny fragments of pottery. 438 00:44:19,607 --> 00:44:23,566 I'm standing on the site of the oldest city in Africa below the Sahara, 439 00:44:23,727 --> 00:44:30,599 and this is the remains of 2,000 years of continuous human occupation. 440 00:44:30,767 --> 00:44:36,603 Even more remarkable, the city itself is still flourishing over there. 441 00:44:37,967 --> 00:44:40,435 This is Djenne. 442 00:44:40,607 --> 00:44:46,398 In its heart stands the mosque, the oldest and largest mud building in the world. 443 00:44:49,567 --> 00:44:54,561 Around it, a market that has been held here since medieval times. 444 00:44:56,967 --> 00:45:01,961 Djenne's growth was closely tied to that of a neighbouring city, 445 00:45:02,127 --> 00:45:06,359 the fabulous Timbuktu that lay further up the Niger. 446 00:45:06,527 --> 00:45:10,805 Between them, the two dominated the trade across the Sahara. 447 00:45:10,967 --> 00:45:14,516 Into these markets came traders from North Africa 448 00:45:14,687 --> 00:45:20,603 who crossed the Sahara by camel caravan to look for slaves, gold and ivory. 449 00:45:20,767 --> 00:45:23,679 And trade still dominates this city. 450 00:45:28,487 --> 00:45:31,285 (BARTERING IN DIALECT) 451 00:45:34,927 --> 00:45:38,840 Great numbers living together made it possible for some of them 452 00:45:39,007 --> 00:45:42,795 to avoid the daily chore of having to produce food. 453 00:45:43,527 --> 00:45:48,043 They could become craftsmen and exchange what they made for food. 454 00:45:48,207 --> 00:45:51,517 So it became possible for technologies to develop, 455 00:45:51,687 --> 00:45:58,081 for arts and sciences to flourish and for people to put up huge buildings. 456 00:46:07,887 --> 00:46:12,836 This is Tikal, the capital of the Maya people 457 00:46:13,007 --> 00:46:17,159 who built the tallest constructions in the whole of the New World, 458 00:46:17,327 --> 00:46:22,117 until skyscrapers were put up in New York at the beginning of the 20th century. 459 00:46:27,567 --> 00:46:32,357 At the height of Tikal's glory, about 1,300 years ago, 460 00:46:32,527 --> 00:46:34,961 the city covered a vast area. 461 00:46:35,127 --> 00:46:38,722 It was at least double the size of ancient Rome. 462 00:46:40,087 --> 00:46:44,842 The city centre was filled by thousands of temples and houses, 463 00:46:45,007 --> 00:46:47,646 only a fraction of which can be seen today. 464 00:46:50,687 --> 00:46:54,999 The inhabitants excelled at every form of civilised activity. 465 00:46:55,167 --> 00:47:00,366 Not only accomplished builders, they were superb sculptors and painters. 466 00:47:00,527 --> 00:47:05,647 They were expert astronomers and measured the solar cycle with great precision. 467 00:47:10,207 --> 00:47:15,884 They constructed complex calendars to which their religious beliefs were closely tied. 468 00:47:16,047 --> 00:47:18,197 And they devised a system of writing 469 00:47:18,367 --> 00:47:22,326 that was, in its time, the most advanced in all the Americas. 470 00:47:24,767 --> 00:47:27,156 Having achieved such skills and knowledge, 471 00:47:27,327 --> 00:47:30,876 when and why were their cities abandoned? 472 00:47:32,207 --> 00:47:37,361 Fortunately, we do have some clues, certainly as to date. 473 00:47:37,527 --> 00:47:43,238 The Maya recorded their history in great detail on stones like this one. 474 00:47:43,407 --> 00:47:47,002 The latest inscription to be found in the ruins of the city 475 00:47:50,687 --> 00:47:55,522 After that, the city falls silent, the inhabitants disappear, 476 00:47:55,687 --> 00:47:59,282 and classic Maya civilisation is coming to an end. 477 00:48:01,007 --> 00:48:05,637 The explanation of why Tikal and all the other Maya cities collapsed 478 00:48:05,807 --> 00:48:07,877 is the subject of hot debate. 479 00:48:08,047 --> 00:48:10,402 But now new evidence has been found. 480 00:48:10,767 --> 00:48:14,396 To see it, you need to get above the city. 481 00:48:25,767 --> 00:48:28,679 From there, you can see hints of occupation 482 00:48:28,847 --> 00:48:33,398 that extend far beyond the jungle-covered ruins that survive today. 483 00:48:33,567 --> 00:48:37,355 Cameras in space have revealed aqueducts, canals 484 00:48:37,527 --> 00:48:40,564 and a dense network of fields buried under the soil - 485 00:48:40,727 --> 00:48:43,844 evidence that by the time the temples were built, 486 00:48:44,007 --> 00:48:46,396 the surrounding forest had already been felled 487 00:48:46,567 --> 00:48:50,242 and replaced by a great expanse of cultivated fields. 488 00:48:52,127 --> 00:48:57,121 As the population of the city grew, probably to about 60,000, 489 00:48:57,287 --> 00:49:00,120 the farmers struggled to produce enough food. 490 00:49:00,287 --> 00:49:05,964 The fertility of the fields was exhausted. Soon the people were starving. 491 00:49:06,127 --> 00:49:10,245 They drifted away from the city and gradually the jungle returned. 492 00:49:11,647 --> 00:49:15,606 But how is the fate of Tikal relevant to us today? 493 00:49:18,207 --> 00:49:20,437 When the Maya built their cities, 494 00:49:20,607 --> 00:49:24,202 there were only about 50 million people on the entire planet. 495 00:49:26,607 --> 00:49:30,441 But the Maya were unable to sustain their population 496 00:49:30,607 --> 00:49:35,601 with the technology that they had developed, sophisticated though it was. 497 00:49:37,167 --> 00:49:39,681 Then, a few centuries later, 498 00:49:39,847 --> 00:49:43,681 human beings elsewhere, with newly-developed techniques, 499 00:49:43,847 --> 00:49:49,444 began to build on a scale that dwarfed even the skyscrapers of Tikal. 500 00:50:07,767 --> 00:50:15,117 Today, there are not just 50 million, but 6,000 million people on Earth. 501 00:50:15,287 --> 00:50:20,759 Nearly half of that vast number live in cities which are still growing fast. 502 00:50:20,927 --> 00:50:23,885 And all these people need food. 503 00:50:24,807 --> 00:50:26,877 We have long since utilised 504 00:50:27,047 --> 00:50:30,676 the most suitable fertile places on the earth to grow our food. 505 00:50:30,847 --> 00:50:34,396 Now we are having to try to do so elsewhere. 506 00:50:41,047 --> 00:50:44,084 In a desert like this one in Arizona, 507 00:50:44,247 --> 00:50:47,364 trying to cultivate anything would seem to be futile. 508 00:50:47,527 --> 00:50:53,045 With just a few centimetres of rain a year, there is no use for a thing like this 509 00:50:53,207 --> 00:50:58,725 and little enough water for thirsty plants, but appearances can be deceptive. 510 00:50:59,807 --> 00:51:04,642 With the right technology, even the desert can yield edible crops. 511 00:51:06,047 --> 00:51:09,244 These lush fields can only exist 512 00:51:09,407 --> 00:51:14,197 because of humanity's unique capacity to innovate and to learn. 513 00:51:14,367 --> 00:51:20,078 Our big brains have enabled us to discover how to add fertiliser to poor soil, 514 00:51:20,247 --> 00:51:25,844 to deal with pests with insecticides and even bring rain to the desert. 515 00:51:30,087 --> 00:51:34,319 This ''rain'' has been pumped along hundreds of miles of pipes 516 00:51:34,487 --> 00:51:37,047 from a far distant water supply. 517 00:51:37,407 --> 00:51:42,401 Every year, human beings displace the equivalent of entire rivers 518 00:51:42,567 --> 00:51:44,876 in order to water their crops. 519 00:51:46,047 --> 00:51:50,245 In just a few thousand years, the revolution of agriculture 520 00:51:50,407 --> 00:51:53,479 has spread to virtually all human societies. 521 00:51:53,647 --> 00:51:56,878 Today, over a third of the surface of the land 522 00:51:57,047 --> 00:52:00,562 is devoted to producing food for human beings. 523 00:52:00,727 --> 00:52:04,925 That has changed some landscapes in the most dramatic way. 524 00:52:14,407 --> 00:52:17,319 The rich variety of the world's natural ecosystems 525 00:52:17,487 --> 00:52:19,921 has been replaced by uniformity. 526 00:52:20,727 --> 00:52:25,243 Complex communities have been eliminated and changed to monocultures. 527 00:52:25,407 --> 00:52:27,716 The intricate embroideries of nature 528 00:52:27,887 --> 00:52:32,483 have been replaced by a geometric landscape of straight lines. 529 00:52:34,087 --> 00:52:38,205 All this was made possible by the technological revolution 530 00:52:38,367 --> 00:52:44,397 which started when our hands were freed and we could manipulate our surroundings. 531 00:52:47,087 --> 00:52:50,841 Our ingenuity has now enabled us to utilise 532 00:52:51,007 --> 00:52:54,477 the most unlikely and unpromising corners of the earth. 533 00:52:54,647 --> 00:52:57,764 We're even beginning to farm the oceans. 534 00:53:05,207 --> 00:53:08,483 The changes we have wrought on the surface of our planet 535 00:53:08,647 --> 00:53:12,162 are so wholesale that they are now visible from space. 536 00:53:12,327 --> 00:53:18,163 As our numbers increase, there is less land for other animals and plants. 537 00:53:18,327 --> 00:53:22,206 But humanity can't expand its numbers indefinitely. 538 00:53:22,367 --> 00:53:26,519 Will our civilisation then crumble, as did that of the Maya? 539 00:53:29,527 --> 00:53:33,964 This has been the launch pad for humanity's greatest, 540 00:53:34,127 --> 00:53:37,676 most complex achievements and highest hopes, 541 00:53:37,847 --> 00:53:40,680 from space shuttles to space stations. 542 00:53:40,847 --> 00:53:48,322 It's from here, in 2020, our species may launch its most ambitious project yet - 543 00:53:48,487 --> 00:53:53,561 to settle on another planet, to send a mission to Mars. 544 00:53:54,567 --> 00:54:00,676 6 - 5 - 4 - 3 - 2 - 1. 545 00:54:00,847 --> 00:54:04,283 - (EXPLOSION) - Lift off. 546 00:54:11,567 --> 00:54:17,756 The ape that stood up on its two hind legs now seems to have outgrown its planet. 547 00:54:17,967 --> 00:54:22,882 Now it seeks to travel through space, to look for another. 548 00:54:29,087 --> 00:54:32,477 Could it really add Mars to its empire? 549 00:54:33,767 --> 00:54:38,716 Conditions there could hardly be more hostile for forms of life that evolved on Earth. 550 00:54:38,887 --> 00:54:42,675 There the energy-giving sunlight is only half as intense, 551 00:54:42,847 --> 00:54:47,284 and the temperatures fall to more than 100 degrees below freezing. 552 00:54:49,087 --> 00:54:53,205 Will our technology be able to meet this challenge? 553 00:55:00,007 --> 00:55:04,922 Colonising another planet might sound like science fiction. 554 00:55:05,087 --> 00:55:09,205 But in fact, work on solving the problems of living on Mars 555 00:55:09,367 --> 00:55:13,440 is going on right now, here on Earth. 556 00:55:18,287 --> 00:55:20,926 The first problem for those that seek to settle there 557 00:55:21,087 --> 00:55:23,965 will be, as always, to find food. 558 00:55:24,127 --> 00:55:29,076 To do that, they will have to grow plants, the basis of all our food. 559 00:55:30,127 --> 00:55:34,678 On Earth, we're beginning to realise that we may now be over-reliant 560 00:55:34,847 --> 00:55:38,806 on the few species of plant which have provided us with food 561 00:55:38,967 --> 00:55:40,958 for the past 10,000 years. 562 00:55:41,127 --> 00:55:44,915 We are at last taking steps to conserve the wild species 563 00:55:45,087 --> 00:55:48,875 that we have been destroying so carelessly for centuries. 564 00:55:51,887 --> 00:55:57,041 Giant greenhouses like this are astonishing technical achievements, 565 00:55:57,207 --> 00:56:01,519 but they are also proof that we have the skill and the knowledge 566 00:56:01,687 --> 00:56:04,281 to create artificial environments almost anywhere, 567 00:56:04,447 --> 00:56:06,324 even on the surface of Mars. 568 00:56:08,887 --> 00:56:12,516 If we did build such structures on another planet, 569 00:56:12,687 --> 00:56:16,362 might we then contemplate spreading our species still further, 570 00:56:16,527 --> 00:56:19,405 to other more distant worlds? 571 00:56:24,047 --> 00:56:29,679 This new era of exploration began when human beings landed on the moon. 572 00:56:30,007 --> 00:56:33,920 Will that be as far as our species will ever reach or should reach? 573 00:56:34,087 --> 00:56:39,286 Or will our incurable urge to explore, and our still growing numbers, 574 00:56:39,447 --> 00:56:43,520 lead us to print our feet on yet more new worlds? 575 00:56:47,007 --> 00:56:50,317 - ..the eagle has landed. - (BEEP) 576 00:56:52,047 --> 00:56:59,237 That's one small step for man, one giant leap for mankind. 577 00:57:03,087 --> 00:57:07,080 Three and a half million years separate the individual 578 00:57:07,247 --> 00:57:11,035 who left these footprints in the sands of Africa 579 00:57:11,207 --> 00:57:13,675 form the one who left them on the moon. 580 00:57:13,847 --> 00:57:16,759 A mere blink in the eye of evolution. 581 00:57:17,087 --> 00:57:21,478 Using his burgeoning intelligence, this most successful of all mammals 582 00:57:21,647 --> 00:57:26,562 has exploited the environment to produce food for an ever-increasing population. 583 00:57:26,727 --> 00:57:31,278 In spite of disasters when civilisations have over-reached themselves, 584 00:57:31,447 --> 00:57:35,838 that process has continued, indeed accelerated, even today. 585 00:57:36,007 --> 00:57:41,127 Now mankind is looking for food, not just on this planet but on others. 586 00:57:41,287 --> 00:57:45,644 Perhaps the time has come to put that process into reverse. 587 00:57:45,807 --> 00:57:50,278 Instead of controlling the environment for the benefit of the population, 588 00:57:50,447 --> 00:57:56,397 perhaps it's time we control the population to allow the survival of the environment. 589 00:57:57,305 --> 00:58:03,480 Support us and become VIP member to remove all ads from www.OpenSubtitles.org