1 00:00:10,327 --> 00:00:13,603 ALICE ROBERTS: They say this is where it all began. 2 00:00:16,687 --> 00:00:19,645 That we are all children of Africa. 3 00:00:23,287 --> 00:00:26,757 But if so, why do we look so different? 4 00:00:28,927 --> 00:00:32,476 And how on earth could a handful of African families 5 00:00:32,567 --> 00:00:35,400 become a whole world full of people? 6 00:00:47,847 --> 00:00:52,523 I'm Alice Roberts, medical doctor and anthropologist. 7 00:00:52,607 --> 00:00:57,840 I'm fascinated by what bones, stones 8 00:00:57,927 --> 00:01:02,079 and even our bodies can reveal about the distant past. 9 00:01:04,167 --> 00:01:08,638 I'm going in search of the traces left by our African ancestors 10 00:01:08,727 --> 00:01:11,446 and their journeys to populate the world. 11 00:01:15,087 --> 00:01:19,763 This time, the Americas, seemingly impossible to reach. 12 00:01:21,007 --> 00:01:22,042 Ow! 13 00:01:23,087 --> 00:01:26,841 In one direction, a vast wall of ice. 14 00:01:28,647 --> 00:01:33,084 In the other, thousands of miles of empty ocean. 15 00:01:34,127 --> 00:01:36,482 It just doesn't seem to stack up. 16 00:01:36,567 --> 00:01:40,401 That makes us rethink all of our theories about early Americans. 17 00:01:40,487 --> 00:01:43,957 So how did people reach the Americas? 18 00:01:45,047 --> 00:01:48,119 Come with me in the footsteps of our ancestors 19 00:01:48,207 --> 00:01:51,722 on the most epic adventure ever undertaken. 20 00:02:20,607 --> 00:02:23,679 With a modern population of almost a billion, 21 00:02:23,767 --> 00:02:27,043 it's easy to forget that until quite recently 22 00:02:27,127 --> 00:02:30,244 not a single person lived in the Americas. 23 00:02:39,247 --> 00:02:43,638 For our ancient ancestors, there were two very good reasons for this. 24 00:02:43,727 --> 00:02:47,402 To the south, the vast, uncrossable Pacific Ocean, 25 00:02:47,487 --> 00:02:49,637 and to the north, ice. 26 00:02:54,287 --> 00:02:56,437 At the peak of the last Ice Age 27 00:02:56,527 --> 00:03:01,078 much of North America was swathed in a massive blanket of ice 28 00:03:01,167 --> 00:03:03,362 up to 3 kilometres deep. 29 00:03:07,087 --> 00:03:10,045 I've come to the Ipsuit Glacier in Canada, 30 00:03:10,127 --> 00:03:12,960 a remnant of those ancient ice sheets, 31 00:03:13,047 --> 00:03:16,960 to try to understand the challenge facing our ancestors. 32 00:03:17,847 --> 00:03:20,407 JIM: Just do everything very gently. 33 00:03:21,407 --> 00:03:23,682 ROBERTS: My guide is Jim Orava. 34 00:03:23,767 --> 00:03:26,918 He's climbed some of the world's most formidable peaks. 35 00:03:27,007 --> 00:03:29,157 This is making me somewhat nervous. 36 00:03:29,247 --> 00:03:31,886 Jim is going up a vertical wall of ice 37 00:03:32,367 --> 00:03:36,280 with a couple of ice axes and crampons. 38 00:03:36,367 --> 00:03:38,722 Okay, we're just about to bring you up now, Alice. 39 00:03:38,807 --> 00:03:43,403 Jim's just put an ice screw in up there and he's belaying me with this rope. 40 00:03:43,727 --> 00:03:46,241 So if I do fall, I shouldn't fall too far. 41 00:03:46,327 --> 00:03:47,965 Okay, climbing. 42 00:03:51,367 --> 00:03:52,595 (GROANS) 43 00:03:52,967 --> 00:03:56,676 Ice can be treacherous and deceptive. 44 00:03:56,767 --> 00:03:58,917 I can hear the ice creaking. 45 00:03:59,007 --> 00:04:01,282 It's hard to tell what's solid. 46 00:04:03,327 --> 00:04:04,555 JIM: You're doing very well. 47 00:04:04,647 --> 00:04:06,558 My heart is in my mouth. 48 00:04:08,927 --> 00:04:10,565 JIM: It's steep. 49 00:04:11,127 --> 00:04:14,039 -You got me there, Jim? -I've got you, yeah. 50 00:04:21,567 --> 00:04:22,966 This really is nerve-wracking. 51 00:04:23,047 --> 00:04:28,405 I am standing on the very edge of this precipice-like crevasse. 52 00:04:28,487 --> 00:04:33,163 And I've got to walk up this knife edge. I cannot rely on the snow this side. 53 00:04:33,647 --> 00:04:36,764 I don't wanna be at the bottom of that crevasse. 54 00:04:42,047 --> 00:04:45,517 JIM: Don't stand on the snow, 'cause that could be a trapdoor. 55 00:04:50,127 --> 00:04:51,606 -Okay. -Well done. Tricky bit. 56 00:04:51,687 --> 00:04:53,166 Oh, thank you. 57 00:04:53,807 --> 00:04:59,643 Even with crampons, ice picks and Jim's help, it's been a challenge. 58 00:05:02,007 --> 00:05:08,765 So imagine Stone Age families on a 5,000-kilometre trek across ice 59 00:05:08,847 --> 00:05:14,558 with no guide, no safety gear, and only as much food as they can carry. 60 00:05:16,447 --> 00:05:21,157 Surely every bit as impossible as crossing the oceans. 61 00:05:27,167 --> 00:05:31,001 And that's what's so puzzling about the peopling of the Americas. 62 00:05:31,087 --> 00:05:36,207 Because this was a land that was, to all intents and purposes, unreachable. 63 00:05:36,287 --> 00:05:39,165 And yet we know that people got here. 64 00:05:41,247 --> 00:05:44,364 So just how did our ancestors do it? 65 00:05:45,927 --> 00:05:48,964 My investigation starts in Calgary. 66 00:05:51,687 --> 00:05:53,405 (DRUMS BEATING) 67 00:05:53,487 --> 00:05:55,557 (SINGING) 68 00:05:57,527 --> 00:06:02,078 Every summer, descendants of the first Americans gather together. 69 00:06:05,967 --> 00:06:09,721 I've come to the annual powwow of the Tsuu T'ina Nation. 70 00:06:10,247 --> 00:06:13,398 For them, it's a chance to celebrate their roots. 71 00:06:16,727 --> 00:06:18,638 What a beautiful dress. 72 00:06:18,727 --> 00:06:23,039 And for me, it's a chance to search for some hint of their past. 73 00:06:24,247 --> 00:06:25,646 (SINGING) 74 00:06:26,047 --> 00:06:27,924 ROBERTS: Are those leaders from lots of different tribes? 75 00:06:28,007 --> 00:06:29,122 No, from this tribe. 76 00:06:29,207 --> 00:06:30,925 -From the Tsuu T'ina? -The leaders of this land. 77 00:06:31,007 --> 00:06:33,441 -Right. -Yeah, from the Tsuu T'ina. 78 00:06:35,007 --> 00:06:40,479 Recent scientific discoveries suggest that around 70,000 years ago 79 00:06:40,567 --> 00:06:46,164 a tiny group of us left Africa and went on to populate the rest of the world. 80 00:06:47,807 --> 00:06:50,196 But how we reached the Americas, 81 00:06:50,287 --> 00:06:55,281 whether from the north or across the oceans, is a mystery. 82 00:06:58,567 --> 00:07:03,243 Does Tsuu T'ina folklore say anything about how their ancestors got here? 83 00:07:09,127 --> 00:07:11,721 Chief, I'm very interested in 84 00:07:11,807 --> 00:07:15,720 how the Tsuu T'ina came to be in this place. 85 00:07:16,287 --> 00:07:21,725 Well, what was told to us by our ancestors, the old people, 86 00:07:21,807 --> 00:07:27,006 was that thousands of years ago we were travelling, migrating across the ice 87 00:07:27,087 --> 00:07:29,555 over a disagreement in a huge camp. 88 00:07:29,647 --> 00:07:30,875 So they were going across ice? 89 00:07:30,967 --> 00:07:33,800 They were going across the ice at Slave Lake. 90 00:07:33,887 --> 00:07:37,482 And there was a young child that was on her grandmother's back. 91 00:07:37,567 --> 00:07:40,798 And there was a horn sticking out of the ice. 92 00:07:40,887 --> 00:07:45,165 So the child was asking for that horn, so they had to stop the migration. 93 00:07:45,247 --> 00:07:49,559 So they started to chip away at that ice to get that horn out 94 00:07:49,647 --> 00:07:52,036 and then it cracked and split in two. 95 00:07:52,127 --> 00:07:57,838 So the clans that were already on the south side continued to migrate south, 96 00:07:57,927 --> 00:08:00,566 and the ones in the north stayed up in the north. 97 00:08:00,647 --> 00:08:03,115 That's what we've been told through history. 98 00:08:03,207 --> 00:08:04,322 That's fascinating. 99 00:08:07,847 --> 00:08:12,238 It's really intriguing that this story of the first Tsuu T'ina 100 00:08:12,327 --> 00:08:15,046 hints at a journey across the ice. 101 00:08:16,967 --> 00:08:21,404 But it's how these people look that might be a more important clue. 102 00:08:25,727 --> 00:08:31,279 I visited a tribe in Siberia and I think that there are some similarities 103 00:08:31,367 --> 00:08:34,006 between your people and those people in Siberia. 104 00:08:34,087 --> 00:08:35,600 And it might just be quite interesting 105 00:08:35,687 --> 00:08:38,485 to look at these pictures of Evenki faces. 106 00:08:38,807 --> 00:08:40,923 So there's an old lady... 107 00:08:43,127 --> 00:08:45,846 And a mum and a child. 108 00:08:45,927 --> 00:08:47,406 Do you think these faces look similar? 109 00:08:47,487 --> 00:08:51,116 The eyes are similar to the real far-northern Dene 110 00:08:51,207 --> 00:08:52,799 up in the Yukon and that. 111 00:08:52,887 --> 00:08:54,081 -Yeah. -very similar. 112 00:08:54,167 --> 00:08:56,317 -These almond-shaped eyes. -Yes. 113 00:08:56,407 --> 00:08:57,920 And high, wide cheekbones. 114 00:08:58,007 --> 00:08:59,804 very wide cheekbones, yeah. 115 00:09:00,287 --> 00:09:01,561 CHIEF: Prominent noses. 116 00:09:01,647 --> 00:09:02,716 Yeah. 117 00:09:04,847 --> 00:09:07,884 And it's not just facial similarities. 118 00:09:07,967 --> 00:09:13,280 This teepee is almost identical to the tchum of the Siberian Evenki. 119 00:09:15,247 --> 00:09:17,078 Could this be more evidence 120 00:09:17,167 --> 00:09:20,443 that the first American families came from Siberia? 121 00:09:21,247 --> 00:09:23,397 Or is it just coincidence? 122 00:09:24,607 --> 00:09:28,122 If the ancestors of the Tsuu T'ina did come from the north, 123 00:09:28,207 --> 00:09:30,960 they could have made it as far as Alaska. 124 00:09:31,687 --> 00:09:34,076 Because instead of the Bering Straits, 125 00:09:34,167 --> 00:09:39,844 20,000 years ago there was a vast swath of land, Beringia. 126 00:09:45,487 --> 00:09:49,526 But a huge eXpanse of ice still blocks the way 127 00:09:49,607 --> 00:09:51,802 to the rest of the Americas. 128 00:10:04,887 --> 00:10:08,482 It's time to look at those ice sheets in more detail. 129 00:10:15,967 --> 00:10:19,164 Well, climate scientists can now do something rather wonderful. 130 00:10:19,247 --> 00:10:25,197 They can let us peer back in time and give us an ancient weather report. 131 00:10:25,287 --> 00:10:27,642 I'm looking here at a map of North America 132 00:10:27,727 --> 00:10:30,719 as it was 22,000 years ago. 133 00:10:30,807 --> 00:10:33,526 So actually before the peak of the last Ice Age. 134 00:10:33,607 --> 00:10:38,920 And you can see this massive sheet of ice right across the top here. 135 00:10:39,007 --> 00:10:42,716 Well, I'm gonna run this through time... 136 00:10:43,527 --> 00:10:46,200 and we'll see what happens to that ice sheet. 137 00:10:47,127 --> 00:10:49,118 It's moving at the edges. 138 00:10:49,767 --> 00:10:51,644 And in fact it's splitting in two. 139 00:10:51,727 --> 00:10:56,562 It parts into two separate ice sheets and a corridor appears. 140 00:10:58,407 --> 00:11:03,720 So there was a way down at about 1 3,500 years ago. 141 00:11:06,687 --> 00:11:10,441 Was this corridor the gateway to the Americas? 142 00:11:18,167 --> 00:11:19,646 Hello. Are you Bert? 143 00:11:19,727 --> 00:11:21,240 BERT: I'm Bert. 144 00:11:30,687 --> 00:11:35,044 If a few adventurous hunters did come through the corridor in the ice, 145 00:11:35,127 --> 00:11:37,277 we can be sure of one thing - 146 00:11:38,047 --> 00:11:40,163 it wouldn't have been easy. 147 00:11:41,287 --> 00:11:44,165 Even today, it feels as though the Ice Age 148 00:11:44,247 --> 00:11:46,807 still has a grip on these mountains. 149 00:11:47,847 --> 00:11:49,963 Trucker Bert Van de Wetering 150 00:11:50,047 --> 00:11:54,165 knows how treacherous this northern landscape can suddenly become. 151 00:11:57,327 --> 00:11:59,716 ROBERTS: So it's the middle of summer and you've still got snow. 152 00:11:59,807 --> 00:12:04,005 That's correct. The area that we're gonna get into here in a little bit 153 00:12:04,087 --> 00:12:07,045 has all these chutes coming down, so there are slides, 154 00:12:07,127 --> 00:12:11,245 and the highway is closed a lot of the time because of these avalanches. 155 00:12:11,327 --> 00:12:15,479 I presume it gets quite icy and slippery in the depths of winter. 156 00:12:15,567 --> 00:12:18,081 BERT: It can get very crazy here. 157 00:12:18,167 --> 00:12:21,318 You can get freezing rain, you can get real cold temperatures. 158 00:12:21,407 --> 00:12:23,284 Sometimes we see a lot of snow. 159 00:12:23,367 --> 00:12:25,961 Yeah. How cold does it get? 160 00:12:26,047 --> 00:12:30,120 We get minus 20. I think it's been colder in the past, 161 00:12:30,207 --> 00:12:31,560 but we're still getting minus 20. 162 00:12:31,647 --> 00:12:32,636 That's cold enough. 163 00:12:32,727 --> 00:12:34,080 Oh, yeah. 164 00:12:36,807 --> 00:12:42,882 But that's nothing compared with the ice-free corridor 1 3,500 years ago. 165 00:12:47,007 --> 00:12:49,521 Any families coming through that corridor 166 00:12:49,607 --> 00:12:52,440 would surely have faced a hellish journey, 167 00:12:54,167 --> 00:12:56,362 huddled against the howling wind 168 00:12:56,447 --> 00:13:00,440 in a land of torrential rivers and floating ice. 169 00:13:10,367 --> 00:13:12,676 So did anyone try? 170 00:13:12,767 --> 00:13:15,406 And if so, did they make it? 171 00:13:17,967 --> 00:13:22,563 The answers to all these questions lie in that direction. 172 00:13:28,087 --> 00:13:30,601 Because right across North America 173 00:13:30,687 --> 00:13:35,522 archaeologists have been finding thousands of objects like this. 174 00:13:38,367 --> 00:13:41,086 They're called Clovis points. 175 00:13:47,767 --> 00:13:51,077 And they date from just a few hundred years 176 00:13:51,167 --> 00:13:53,840 after the corridor in the ice appeared. 177 00:13:57,247 --> 00:13:59,807 So this could have been the way in. 178 00:14:03,527 --> 00:14:05,677 But what kind of a world 179 00:14:05,767 --> 00:14:09,601 would these pioneers find on the other side of the ice? 180 00:14:21,127 --> 00:14:24,324 The tools themselves are important clues. 181 00:14:24,407 --> 00:14:28,195 And to find out how, I'm meeting archaeologist Andy Hemmings. 182 00:14:28,967 --> 00:14:33,324 So these are these really classic stone Clovis spear points. 183 00:14:33,407 --> 00:14:36,046 Yeah. It's important to understand about Clovis, though, 184 00:14:36,127 --> 00:14:37,560 that they aren't just stone points, 185 00:14:37,647 --> 00:14:41,959 they also made some very lethal and effective bone and ivory points as well. 186 00:14:42,047 --> 00:14:46,563 These are state-of-the-art, lethal killing machines from 1 3,000 years ago. 187 00:14:46,647 --> 00:14:49,639 And what sort of animals do you think they would have hunted with them? 188 00:14:49,727 --> 00:14:52,525 The most common that we've found them directly associated with 189 00:14:52,607 --> 00:14:56,520 are mammoths, bison and mastodon, in that order. 190 00:14:57,007 --> 00:14:59,237 But at clovis sites across the New World, 191 00:14:59,327 --> 00:15:03,115 we've found more than 1 25 species of plants and animals. 192 00:15:03,207 --> 00:15:04,640 So they're general hunters, 193 00:15:04,727 --> 00:15:07,685 but you really think they were hunting mammoth? 194 00:15:07,767 --> 00:15:09,086 Oh, absolutely. 195 00:15:09,167 --> 00:15:12,045 The best example probably is a site in southeast Arizona, 196 00:15:12,127 --> 00:15:15,324 where eight Clovis points were found with one mammoth body. 197 00:15:15,407 --> 00:15:17,477 Five of them were found behind the back of the head 198 00:15:17,567 --> 00:15:18,920 and in front of the shoulder blades, 199 00:15:19,007 --> 00:15:22,682 any one of which probably would have been about a lethal wound. 200 00:15:22,767 --> 00:15:25,725 Andy shows me how he thinks they did it. 201 00:15:30,567 --> 00:15:33,639 Andy, that doesn't look much like a mammoth to me. 202 00:15:33,727 --> 00:15:36,685 There's no animal in the Pleistocene that had a hide that tough. 203 00:15:36,767 --> 00:15:40,237 And if we can poke a hole in that... If you can poke a hole in that, 204 00:15:40,327 --> 00:15:42,761 we could've eaten anything. Just like the Clovis people did. 205 00:15:42,847 --> 00:15:44,678 Right. So I've got my spear thrower. 206 00:15:44,767 --> 00:15:47,076 ANDY: Let's see what you can do. 207 00:15:49,607 --> 00:15:51,404 A glancing blow, you've slowed him. 208 00:15:51,487 --> 00:15:53,478 -Got his feet. -Try again. 209 00:15:57,447 --> 00:15:58,880 Scratched it. 210 00:15:59,447 --> 00:16:01,119 Do you wanna show me how it's done, Andy? 211 00:16:01,207 --> 00:16:02,686 I'll give it a try. 212 00:16:04,447 --> 00:16:06,165 ROBERTS: Oh, my God! 213 00:16:08,647 --> 00:16:11,684 Well, that's made a hell of a dent in this metal door. 214 00:16:11,767 --> 00:16:15,043 I hit it pretty cleanly, and you can see I just destroyed the end of my spear. 215 00:16:15,127 --> 00:16:17,322 It would have stuck in the hide of a mammoth or a mastodon. 216 00:16:17,407 --> 00:16:18,476 Yeah. 217 00:16:20,967 --> 00:16:24,277 The mammoth and mastodon, two of the mighty animals 218 00:16:24,367 --> 00:16:26,927 roaming this vast landscape. 219 00:16:31,487 --> 00:16:36,686 But little match for people with a weapon as deadly as the Clovis point. 220 00:16:41,607 --> 00:16:44,997 Some think that these pioneers of the new frontier 221 00:16:45,087 --> 00:16:47,555 plunged into an orgy of slaughter, 222 00:16:47,647 --> 00:16:51,003 wiping out Ice Age animals like the mammoth. 223 00:16:53,647 --> 00:16:56,115 The evidence is questionable. 224 00:16:56,207 --> 00:16:59,836 But that image of the mighty hunter has stuck. 225 00:17:10,407 --> 00:17:11,396 (BARKING) 226 00:17:14,167 --> 00:17:18,160 So it looks as if small groups of men, women and children 227 00:17:18,247 --> 00:17:23,958 made that first push into America about 1 3,500 years ago. 228 00:17:24,967 --> 00:17:29,757 Using their sophisticated tools, they made the most of their new home 229 00:17:29,847 --> 00:17:34,443 and spread right across the continent from coast to coast. 230 00:17:37,847 --> 00:17:40,805 Until recently, this was the version of American prehistory 231 00:17:40,887 --> 00:17:42,923 that most experts agreed on. 232 00:17:43,007 --> 00:17:45,396 But a new discovery here in Texas 233 00:17:45,487 --> 00:17:48,684 is threatening to rewrite the entire story. 234 00:18:00,447 --> 00:18:04,520 Archaeologist Mike Collins is a very patient man. 235 00:18:10,967 --> 00:18:16,758 For 1 5 years, he's been digging away in this small field near Austin. 236 00:18:18,327 --> 00:18:22,115 And he's found something that no one eXpected. 237 00:18:23,287 --> 00:18:26,006 So, Mike, what sort of dates have you got coming out of here? 238 00:18:26,087 --> 00:18:30,399 We have the entire prehistory of central Texas represented at this site. 239 00:18:30,487 --> 00:18:35,003 The kinds of artefacts we find and the few absolute dates that we have 240 00:18:35,087 --> 00:18:38,284 tell us that people were here from 500 years ago, 241 00:18:38,367 --> 00:18:41,677 back 1 3,500 years ago. 242 00:18:42,367 --> 00:18:45,962 Even more importantly, we have stuff below that. 243 00:18:46,047 --> 00:18:47,526 Below Clovis, so older than Clovis? 244 00:18:47,607 --> 00:18:49,598 Older than Clovis. Pre-Clovis. 245 00:18:49,687 --> 00:18:51,200 -Right. -Right here at this site. 246 00:18:53,047 --> 00:18:54,799 But for years archaeologists have thought 247 00:18:54,887 --> 00:18:57,481 that Clovis was the first culture in the Americas. 248 00:18:57,567 --> 00:18:59,285 Yeah, most archaeologists have thought that, 249 00:18:59,367 --> 00:19:01,562 but there's a few of us that have known better. 250 00:19:01,647 --> 00:19:05,083 And over on the other side of the site, you can see the Clovis level 251 00:19:05,167 --> 00:19:06,964 and you can see artefacts below it. 252 00:19:07,047 --> 00:19:08,526 -You want to see that? -I'd love to see it. 253 00:19:08,607 --> 00:19:10,199 Let's go see it. 254 00:19:19,207 --> 00:19:21,323 Mike, this is an incredibly deep test pit. 255 00:19:21,407 --> 00:19:22,886 Yes, it's a deep test pit 256 00:19:22,967 --> 00:19:25,686 and we're really interested in this part of it, right here. 257 00:19:25,767 --> 00:19:28,440 Because right through here we get Clovis artefacts, 258 00:19:28,527 --> 00:19:31,678 but as we dug down we continued to get artefacts below that 259 00:19:31,767 --> 00:19:35,601 for about 20 or 25 centimetres more. 260 00:19:35,687 --> 00:19:38,599 A nice flake here, for example, with a platform 261 00:19:38,687 --> 00:19:41,360 and good flake scars on it. 262 00:19:41,967 --> 00:19:45,801 We have one date from down here of 1 4,400 years. 263 00:19:45,887 --> 00:19:47,320 1 4,400? 264 00:19:47,407 --> 00:19:48,522 Yeah. 265 00:19:48,607 --> 00:19:50,165 So that's pre-Clovis. 266 00:19:50,247 --> 00:19:52,158 By a thousand years. 267 00:19:52,247 --> 00:19:55,796 I mean, that's amazing, because that makes us rethink 268 00:19:55,887 --> 00:19:58,481 all of our theories about early Americans. 269 00:19:58,567 --> 00:20:01,286 Yes, we have to rethink our paradigm. 270 00:20:01,367 --> 00:20:05,485 We have to come up with a new accounting of the peopling of the Americas. 271 00:20:05,567 --> 00:20:09,401 Mike, how sure are you about the date of these artefacts? 272 00:20:09,487 --> 00:20:10,920 It's just one date, 273 00:20:11,007 --> 00:20:13,840 so you need to corroborate it with further evidence. 274 00:20:13,927 --> 00:20:16,043 And that's what we're working on. 275 00:20:29,447 --> 00:20:32,405 Now, we can only draw tentative conclusions 276 00:20:32,487 --> 00:20:34,955 from the evidence emerging here, 277 00:20:35,047 --> 00:20:39,563 but our grand theory about how humans first got into North America 278 00:20:39,647 --> 00:20:42,445 is starting to look decidedly dodgy. 279 00:20:42,527 --> 00:20:44,518 Because if there really were 280 00:20:44,607 --> 00:20:47,883 people living here at Gault as early as Mike says there were, 281 00:20:47,967 --> 00:20:51,846 then there must have been another route into the Americas, 282 00:20:51,927 --> 00:20:55,124 because the ice-free corridor wasn't open yet. 283 00:20:55,207 --> 00:20:57,243 But what I need is more proof. 284 00:20:57,327 --> 00:21:01,206 And if the claims coming out of South America are to believed, 285 00:21:01,287 --> 00:21:05,565 then they may have even earlier and more compelling evidence 286 00:21:05,647 --> 00:21:07,842 than I've seen here in Texas. 287 00:21:11,167 --> 00:21:14,955 It's time to leave North America for the South. 288 00:21:15,047 --> 00:21:20,041 Ahead of me is a three-day journey, but one I hope will be worth it. 289 00:21:20,127 --> 00:21:23,915 Because what I'm off to see could change everything. 290 00:21:25,087 --> 00:21:28,682 My destination is Santarem in Brazil. 291 00:21:29,287 --> 00:21:34,600 And it's got a rather eXcellent prehistoric transport link - the Amazon. 292 00:21:55,247 --> 00:21:57,715 I'm about to embark on a seven-hour river journey 293 00:21:57,807 --> 00:22:01,880 to reach a very special place, the home of some of the earliest South Americans. 294 00:22:01,967 --> 00:22:06,279 And unless I want to be standing the whole way, I'd better get a move-on. 295 00:22:15,007 --> 00:22:16,918 I think this is going to be quite comfortable. 296 00:22:20,967 --> 00:22:25,722 Looking around at my fellow passengers, I have a sense of deja vu. 297 00:22:27,327 --> 00:22:31,161 I'm sure I can see those same East Asian features 298 00:22:31,247 --> 00:22:33,044 that I saw in the north. 299 00:22:35,087 --> 00:22:38,318 Could it be that these are still echoes 300 00:22:38,407 --> 00:22:42,161 of an ancient Siberian ancestry? 301 00:23:02,087 --> 00:23:06,205 Impromptu fireworks finally announce our arrival 302 00:23:06,287 --> 00:23:08,721 at the tiny port of Monte Alegre. 303 00:23:09,527 --> 00:23:12,997 Well, we're just coming into port, so my journey's almost over for today. 304 00:23:13,087 --> 00:23:15,681 But I've still got quite a long way to go tomorrow. 305 00:23:19,607 --> 00:23:21,120 -Nelsi. -Oi! 306 00:23:21,207 --> 00:23:23,004 Hello. Oi! 307 00:23:24,327 --> 00:23:27,285 The neXt morning, I'm picked up by Nelsi Sadeck, 308 00:23:27,367 --> 00:23:31,963 a man with a wealth of knowledge about the special site he's going to show me. 309 00:23:33,927 --> 00:23:38,079 It's a long drive, and I've been warned it could get a bit rough. 310 00:23:48,607 --> 00:23:50,006 (LAUGHING) 311 00:23:50,767 --> 00:23:54,362 As well as being incredibly bumpy, you've got to watch out for your head. 312 00:23:55,127 --> 00:23:56,446 (LAUGHING) 313 00:23:57,007 --> 00:23:58,042 Ow! 314 00:24:03,247 --> 00:24:05,283 We're just going to clear some foliage out of the way 315 00:24:05,367 --> 00:24:07,483 before we can go any further. 316 00:24:07,567 --> 00:24:10,877 I can see why it isn't a major tourist attraction. 317 00:24:11,287 --> 00:24:12,606 MAN: Okay! 318 00:24:21,767 --> 00:24:23,325 Ooh, it's hot now. 319 00:24:35,567 --> 00:24:37,285 (BATS SQUEAKING) 320 00:24:38,007 --> 00:24:40,840 We really have to proceed with caution here, 321 00:24:40,927 --> 00:24:42,599 because there are bats, I can hear them. 322 00:24:42,687 --> 00:24:46,680 So a risk of rabies, and there are poisonous wasps as well 323 00:24:46,767 --> 00:24:48,325 that have made their nests all over this cave. 324 00:24:48,407 --> 00:24:50,875 So we don't want to disturb them. 325 00:24:55,407 --> 00:24:57,238 Oh, look, look. Bats. 326 00:25:00,047 --> 00:25:01,685 NELSI: Many bats. 327 00:25:02,007 --> 00:25:03,042 (NELSI SPEAKING PORTUGUESE) 328 00:25:03,127 --> 00:25:04,242 vampire bats? 329 00:25:04,327 --> 00:25:05,885 -Honestly? -Yes. 330 00:25:07,607 --> 00:25:10,121 Right. Even more cautious, then. 331 00:25:13,407 --> 00:25:15,682 When these caves were eXcavated, 332 00:25:15,767 --> 00:25:19,442 it became clear that they had been home to ancient people. 333 00:25:20,087 --> 00:25:25,639 Archaeologists found animal bones, shells and some eXquisite stone tools. 334 00:25:29,167 --> 00:25:32,079 Well, this is a replica of some of the points 335 00:25:32,167 --> 00:25:34,078 that have been found in these caves. 336 00:25:34,167 --> 00:25:38,445 And it's very beautiful. Perhaps an arrowhead or a harpoon point. 337 00:25:39,127 --> 00:25:41,766 very finely worked, and you can see the stem here, 338 00:25:41,847 --> 00:25:44,520 where it's designed to be attached to a shaft. 339 00:25:44,607 --> 00:25:48,361 And it's also very different from those characteristic points 340 00:25:48,447 --> 00:25:50,756 that we saw in North America. 341 00:25:50,847 --> 00:25:53,839 And, in fact, all of the stone tools are different down here. 342 00:25:53,927 --> 00:25:58,239 They tell us that people are surviving in a very different environment. 343 00:25:58,327 --> 00:26:01,444 There's a whole other way of life going on here. 344 00:26:03,007 --> 00:26:07,717 A rainforest culture with new foods and threats, 345 00:26:07,807 --> 00:26:10,958 a world away from the open plains of the north. 346 00:26:11,887 --> 00:26:16,836 It's a wonderful eXample of our ability to adjust to new environments. 347 00:26:16,927 --> 00:26:19,646 So this is the main part of the cave. 348 00:26:27,407 --> 00:26:30,638 Locals call this the Cave of the Painted Rock. 349 00:26:39,767 --> 00:26:44,682 No one knows the meaning of these strange symbols, painted in red ochre. 350 00:26:51,047 --> 00:26:53,277 But during the eXcavations, 351 00:26:53,367 --> 00:26:56,677 the cave started to yield other treasures. 352 00:26:58,247 --> 00:27:02,798 So, Nelsi, it was in this cave that you were excavating in the early 1 990s? 353 00:27:02,887 --> 00:27:05,606 (SPEAKING PORTUGUESE) 354 00:27:05,687 --> 00:27:09,999 MAN: Yes, from the ground down, we eXcavated 2.2 metres. 355 00:27:10,087 --> 00:27:12,920 And in each layer, many things were found. 356 00:27:13,007 --> 00:27:17,523 Many bones from birds, from fishes. Not to mention plant remains. 357 00:27:19,567 --> 00:27:22,877 ROBERTS: And those plant remains helped give archaeologists 358 00:27:22,967 --> 00:27:27,006 their most important piece of information, a date. 359 00:27:27,927 --> 00:27:29,963 (SPEAKING PORTUGUESE) 360 00:27:30,047 --> 00:27:35,565 MAN: The evidence in the deepest layers dates to around 1 3,000 years ago. 361 00:27:35,647 --> 00:27:39,879 These are the oldest dates we have for humans living here. 362 00:27:39,967 --> 00:27:43,243 1 3,000 years. That's an incredibly early date for South America. 363 00:27:43,327 --> 00:27:44,442 (AGREES IN PORTUGUESE) 364 00:27:44,527 --> 00:27:47,166 MAN: Yes, these dates are very ancient. 365 00:27:47,247 --> 00:27:51,081 And you must have been incredibly excited when you found out that date. 366 00:27:51,167 --> 00:27:52,680 Yes, yes, yes. 367 00:28:01,567 --> 00:28:06,243 Now, this date of around 1 3,000 years ago is actually problematic. 368 00:28:06,327 --> 00:28:10,286 It challenges the traditional story of how the Americas were colonised. 369 00:28:10,367 --> 00:28:13,359 Because it means that people were here in Pedra Pintada 370 00:28:13,447 --> 00:28:17,599 at the same time as those hunters in North America. 371 00:28:17,687 --> 00:28:21,680 The date is so early that I find it really difficult to believe 372 00:28:21,767 --> 00:28:25,396 that their ancestors came through that ice-free corridor. 373 00:28:25,727 --> 00:28:28,799 Because if they did, that means they would have had 374 00:28:28,887 --> 00:28:33,324 just a few hundred years to work their way 375 00:28:33,407 --> 00:28:37,559 all the way down through North America, Central America 376 00:28:38,407 --> 00:28:39,920 and down here to the Amazon basin, 377 00:28:40,007 --> 00:28:43,477 adapting to all the diverse environments as they went. 378 00:28:44,087 --> 00:28:45,839 I don't believe it. 379 00:28:48,687 --> 00:28:51,326 It now looks even more unlikely 380 00:28:51,407 --> 00:28:55,639 that the ice-free corridor was the first route into the Americas. 381 00:28:58,047 --> 00:29:02,086 The dates from the Cave of the Painted Rock just don't fit. 382 00:29:04,367 --> 00:29:08,121 But there's another even more incredible discovery 383 00:29:08,207 --> 00:29:12,405 from South America that should settle this argument for good. 384 00:29:15,487 --> 00:29:20,561 The archaeological trail leads 5,000 kilometres south 385 00:29:20,647 --> 00:29:25,801 to a part of Chile, called Los Lagos, the lake district, 386 00:29:25,887 --> 00:29:29,766 famous for its stunning, volcanic landscape. 387 00:29:36,207 --> 00:29:38,516 It's the middle of the Chilean winter, 388 00:29:38,607 --> 00:29:41,838 and after the heat and humidity of Brazil, 389 00:29:41,927 --> 00:29:44,725 the conditions feel very different here. 390 00:29:48,567 --> 00:29:50,683 I'm headed to a place called Monte verde, 391 00:29:50,767 --> 00:29:54,601 a tiny hamlet of no real significance at all, 392 00:29:54,687 --> 00:29:56,643 were it not for the fact it's the site 393 00:29:56,727 --> 00:29:59,719 of perhaps the most important archaeological discovery 394 00:29:59,807 --> 00:30:01,763 in the whole of the Americas. 395 00:30:05,647 --> 00:30:10,357 The finds from Monte Verde are nothing short of miraculous. 396 00:30:20,527 --> 00:30:22,199 It's quite strange, there's no evidence at all 397 00:30:22,287 --> 00:30:25,199 of it ever having been an archaeological site. 398 00:30:25,287 --> 00:30:27,243 There are sheep grazing. 399 00:30:27,327 --> 00:30:29,602 There's nothing obvious at all. 400 00:30:30,367 --> 00:30:34,963 But a few years back, local villagers came across something strange 401 00:30:35,047 --> 00:30:37,322 sticking out of the river bank. 402 00:30:38,367 --> 00:30:41,086 Bones from a mastodon, 403 00:30:41,167 --> 00:30:44,159 a prehistoric relative of the modern elephant. 404 00:30:45,767 --> 00:30:47,837 It was a bank just like this that 405 00:30:47,927 --> 00:30:50,316 the animal bones were originally found in 406 00:30:50,407 --> 00:30:55,527 that alerted people to the fact that this was an archaeological site. 407 00:30:57,287 --> 00:30:59,039 As eXperts dug down, 408 00:30:59,127 --> 00:31:03,120 they discovered much more than just ancient animal bones. 409 00:31:07,967 --> 00:31:09,639 Layer by layer, 410 00:31:09,727 --> 00:31:13,606 the remains of an entire human settlement emerged. 411 00:31:15,047 --> 00:31:19,518 Home to a community of perhaps 20 or 30 people, 412 00:31:19,607 --> 00:31:24,158 with shelters, work areas and rubbish tips. 413 00:31:24,247 --> 00:31:27,956 A unique relic of our prehistoric past. 414 00:31:31,847 --> 00:31:36,602 The main structure on this site was a very long hut, 20 metres long. 415 00:31:36,687 --> 00:31:39,440 I'm gonna have a go at measuring it out, 416 00:31:39,527 --> 00:31:41,119 but I think I might come into some difficulties, 417 00:31:41,207 --> 00:31:43,801 because of where the stream is today. 418 00:31:45,247 --> 00:31:49,923 Because this log is actually around about 7 metres long. 419 00:31:50,607 --> 00:31:51,642 (CHUCKLES) 420 00:31:51,727 --> 00:31:54,036 Ten metres is gonna take me up to there. 421 00:31:54,127 --> 00:31:55,560 I don't want to go any further, 422 00:31:55,647 --> 00:31:57,797 'cause I don't want to end up in that very cold stream. 423 00:31:57,887 --> 00:32:01,641 But you can imagine how far this hut extended. 424 00:32:02,767 --> 00:32:06,282 And amazingly, we know how this hut was built, 425 00:32:06,367 --> 00:32:10,724 because the remains of the wooden stakes and the animal hides that covered it 426 00:32:10,807 --> 00:32:13,719 were preserved in the waterlogged ground. 427 00:32:14,887 --> 00:32:18,721 And inside this long hut the archaeologists found hearths, 428 00:32:18,807 --> 00:32:21,879 and in them the remains of nuts and berries and seeds 429 00:32:21,967 --> 00:32:23,241 that people had been eating. 430 00:32:23,327 --> 00:32:25,443 The hearths were lined with clay. 431 00:32:25,527 --> 00:32:29,725 And in part of this clay that presumably was wet at some point, 432 00:32:29,807 --> 00:32:32,116 there was somebody's footprint. 433 00:32:39,887 --> 00:32:44,324 About 30 metres away was this strange outline 434 00:32:44,407 --> 00:32:47,763 of what was, perhaps, another much smaller hut. 435 00:32:49,327 --> 00:32:52,524 Outside it there were butchered mastodon bones, 436 00:32:52,607 --> 00:32:55,963 but inside it there were some very intriguing finds indeed. 437 00:32:56,047 --> 00:32:58,766 Some plant remains, a few of them seaweeds 438 00:32:58,847 --> 00:33:03,125 that are still used by the Mapuche Indians today as medicines. 439 00:33:04,767 --> 00:33:09,716 Incredibly, the team even discovered the remains of potato skins. 440 00:33:10,407 --> 00:33:13,524 It's the first evidence anywhere in the world 441 00:33:13,607 --> 00:33:16,917 of humans using, eating potatoes. 442 00:33:17,007 --> 00:33:21,842 It's amazing to have this degree of preservation on an archaeological site. 443 00:33:21,927 --> 00:33:24,282 This really is a treasure trove. 444 00:33:30,447 --> 00:33:35,316 Monte Verde gives us an incredibly rare and wonderful window 445 00:33:35,447 --> 00:33:38,041 into our ancestors' daily lives. 446 00:33:39,047 --> 00:33:40,526 But for all that, 447 00:33:40,607 --> 00:33:44,998 what's most astonishing about Monte Verde is its age. 448 00:33:52,167 --> 00:33:57,116 The 50,000-odd artefacts from the site are now stored here 449 00:33:57,167 --> 00:33:59,681 at the University of Southern Chile. 450 00:34:05,447 --> 00:34:09,281 The archaeological finds from Monte verde really are extraordinary. 451 00:34:09,367 --> 00:34:13,246 This piece of wood here has obviously been worked by human hand. 452 00:34:13,327 --> 00:34:16,205 It's been drilled or gouged into here. 453 00:34:16,607 --> 00:34:19,041 Perhaps used to make fire. 454 00:34:19,127 --> 00:34:21,436 This piece of wood has been sharpened into a point. 455 00:34:21,527 --> 00:34:25,076 It was found stuck in the ground, as though it was a tent peg. 456 00:34:25,167 --> 00:34:27,203 And this is really wonderful. 457 00:34:27,287 --> 00:34:30,723 This is a piece of mastodon hide. 458 00:34:31,367 --> 00:34:32,686 Just look at that. 459 00:34:37,967 --> 00:34:42,085 Using radiocarbon dating on charred wood from the site, 460 00:34:42,167 --> 00:34:45,318 scientists could pinpoint its age. 461 00:34:48,127 --> 00:34:49,765 And what those dates tell us 462 00:34:49,847 --> 00:34:52,884 is that there were people down here in southern Chile 463 00:34:52,967 --> 00:34:55,800 1 4,500 years ago. 464 00:34:55,887 --> 00:34:59,675 That's even earlier than the evidence I looked at in Brazil. 465 00:35:00,447 --> 00:35:04,201 So early as to completely rule out the idea 466 00:35:04,287 --> 00:35:08,041 that the first Americans came through the ice-free corridor 467 00:35:08,127 --> 00:35:10,038 once and for all. 468 00:35:10,807 --> 00:35:13,162 People must have got to the Americas 469 00:35:13,247 --> 00:35:15,681 long before the corridor appeared. 470 00:35:17,087 --> 00:35:18,998 But how did people get here, 471 00:35:19,087 --> 00:35:23,399 when the way down through North America was blocked by solid ice? 472 00:35:31,287 --> 00:35:34,677 Well, maybe I've just been missing the obvious 473 00:35:37,847 --> 00:35:41,760 and there was another way we could have reached this continent. 474 00:35:48,807 --> 00:35:51,924 Up until now, I've assumed that people got into the Americas 475 00:35:52,007 --> 00:35:54,316 from the north, from Beringia. 476 00:35:54,407 --> 00:35:55,840 But what if they didn't? 477 00:35:55,927 --> 00:36:00,045 What if they came straight from Asia from across the ocean? 478 00:36:00,127 --> 00:36:02,800 Then the ice sheets wouldn't have even been an issue. 479 00:36:02,927 --> 00:36:05,646 Is it really such a crazy idea? 480 00:36:14,487 --> 00:36:18,036 If the forefathers of those early South Americans 481 00:36:18,127 --> 00:36:21,722 couldn't have arrived through the ice-free corridor, 482 00:36:21,807 --> 00:36:25,117 then maybe they did come across the Pacific. 483 00:36:29,367 --> 00:36:32,120 And if they did, that might eXplain 484 00:36:32,207 --> 00:36:35,404 one of the great mysteries of our human journey. 485 00:36:38,647 --> 00:36:41,684 I'm back in Brazil, this time in Rio de Janeiro, 486 00:36:41,767 --> 00:36:44,964 where I'm going to see some very ancient human remains 487 00:36:45,047 --> 00:36:48,084 that I'm hoping will shed some light on this idea 488 00:36:48,167 --> 00:36:51,239 of our migration across the Pacific. 489 00:37:00,127 --> 00:37:02,118 So precious are these remains 490 00:37:02,207 --> 00:37:05,802 that they've been kept for 30 years under lock and key 491 00:37:05,887 --> 00:37:08,037 at Brazil's National Museum. 492 00:37:08,607 --> 00:37:11,997 This beautiful skull has been nicknamed Luzia. 493 00:37:12,087 --> 00:37:15,841 It belonged to a woman who was in her early 20s when she died. 494 00:37:15,927 --> 00:37:19,636 And it dates to around 1 3,000 years ago. 495 00:37:20,287 --> 00:37:23,324 But it's not just the date that I'm interested in. 496 00:37:23,647 --> 00:37:25,638 It's what she looks like. 497 00:37:31,007 --> 00:37:33,202 Anthropologist Walter Neves 498 00:37:33,287 --> 00:37:36,597 believes that he's uncovered a secret about Luzia. 499 00:37:38,127 --> 00:37:40,482 Well, this is Luzia's skull. 500 00:37:40,567 --> 00:37:45,960 And the bad news are that she doesn't look like she should look like. 501 00:37:46,567 --> 00:37:48,319 So what would you expect her to look like? 502 00:37:48,407 --> 00:37:49,965 Well, as you know, 503 00:37:50,047 --> 00:37:53,244 Native Americans came from East Asia. 504 00:37:53,327 --> 00:37:58,447 And I will show you a typical skull from East Asia. 505 00:37:58,567 --> 00:38:00,842 And as you can see, 506 00:38:00,927 --> 00:38:03,487 they have very different faces. 507 00:38:03,607 --> 00:38:05,643 One of the greatest differences, 508 00:38:05,727 --> 00:38:07,718 in terms of facial morphology, 509 00:38:07,807 --> 00:38:09,798 happens in the cheekbones. 510 00:38:09,887 --> 00:38:12,082 You see that Asians, 511 00:38:12,167 --> 00:38:14,886 they have very wide cheekbones. 512 00:38:14,967 --> 00:38:16,002 -ROBERTS: Yes. -Okay? 513 00:38:16,087 --> 00:38:18,282 Kind of laterally projecting. 514 00:38:18,367 --> 00:38:20,722 -Yes, it gives this very wide face. -That's right. 515 00:38:20,807 --> 00:38:23,241 -Doesn't it, across the cheekbones? -That's right. Yeah, yeah. 516 00:38:23,367 --> 00:38:27,963 If you go to Luzia, you find kind of narrow cheekbones. 517 00:38:31,487 --> 00:38:34,843 Okay, if Luzia and her population 518 00:38:34,927 --> 00:38:39,000 don't look like East Asians and they don't look like modern Native Americans, 519 00:38:39,087 --> 00:38:40,645 who do they look like? 520 00:38:40,727 --> 00:38:43,400 We discovered that, amazingly, 521 00:38:43,727 --> 00:38:49,006 she looks much more like Australasians, 522 00:38:49,367 --> 00:38:53,280 than with East Asians or Native Americans, if you want. 523 00:38:54,527 --> 00:38:57,997 ROBERTS: Australasian? It sounds bizarre. 524 00:38:59,087 --> 00:39:00,964 But Walter found that Luzia 525 00:39:01,047 --> 00:39:05,438 had more similarities with Australasian skulls than any others. 526 00:39:07,447 --> 00:39:10,245 And when Luzia's features are reconstructed, 527 00:39:10,327 --> 00:39:12,079 it's even more obvious 528 00:39:12,167 --> 00:39:16,877 that she looks nothing like modern Siberians or Native Americans. 529 00:39:20,327 --> 00:39:24,400 It suggests a superhuman feat of seafaring. 530 00:39:27,167 --> 00:39:31,957 So if these early Americans look more like Australians or Melanesians, 531 00:39:32,047 --> 00:39:35,005 does that mean that they arrived here across the Pacific? 532 00:39:35,087 --> 00:39:38,557 No, no, no, because if you take into account 533 00:39:38,927 --> 00:39:44,160 the technology available like 1 2-1 3,000 years ago, 534 00:39:44,247 --> 00:39:45,885 that would be impossible. 535 00:39:45,967 --> 00:39:46,956 Okay. 536 00:39:47,047 --> 00:39:49,880 But then how do you explain the fact that 537 00:39:49,967 --> 00:39:54,518 modern living Native Americans don't look like Luzia, 538 00:39:55,087 --> 00:39:56,839 they do look like East Asians? 539 00:39:56,927 --> 00:39:58,883 It's very easy to explain. 540 00:39:58,967 --> 00:40:01,800 Because if you go back to Asia, 541 00:40:01,887 --> 00:40:04,560 around 1 4,000 years ago, 542 00:40:05,727 --> 00:40:08,002 the people that lives today in Asia, 543 00:40:08,087 --> 00:40:11,363 with their typical morphology, they were not there. 544 00:40:11,447 --> 00:40:13,403 Right, so you're saying that 545 00:40:13,487 --> 00:40:16,001 Luzia's people came into the Americas 546 00:40:16,087 --> 00:40:18,157 before the appearance of East Asian features. 547 00:40:18,247 --> 00:40:19,885 Definitely, definitely. 548 00:40:19,967 --> 00:40:23,277 But they used the same route 549 00:40:23,367 --> 00:40:28,316 as the Mongoloids did some couple of thousand years later. 550 00:40:28,407 --> 00:40:30,318 So this is absolutely 551 00:40:30,407 --> 00:40:33,843 not evidence for any sort of trans-Pacific crossing. 552 00:40:34,567 --> 00:40:36,603 Definitely not a crossing. 553 00:40:38,487 --> 00:40:41,047 ROBERTS: Walter is adamant that Stone Age people 554 00:40:41,127 --> 00:40:44,039 could not have made it across the Pacific. 555 00:40:45,647 --> 00:40:49,117 He believes Luzia's ancestors did come from Asia, 556 00:40:49,207 --> 00:40:54,361 but before those classic East Asian features became common. 557 00:40:56,367 --> 00:40:59,518 However, Walter hasn't solved the mystery 558 00:40:59,607 --> 00:41:04,920 of how Luzia's ancestors found a way past all that ice. 559 00:41:10,927 --> 00:41:12,883 Well, it looks like I've reached a dead end again. 560 00:41:12,967 --> 00:41:18,439 There doesn't seem to be any evidence for a migration across the Pacific. 561 00:41:18,527 --> 00:41:22,918 So that means the only way into South America was from the north, 562 00:41:23,007 --> 00:41:27,364 across the ice sheets, but that just doesn't make sense. 563 00:41:28,807 --> 00:41:32,561 Unless, rather than coming across the ice, 564 00:41:32,647 --> 00:41:36,765 the first Americans found a way to get around it. 565 00:41:38,167 --> 00:41:41,716 Perhaps the sea might hold the answer after all. 566 00:41:41,847 --> 00:41:44,315 If they didn't cross the open ocean, 567 00:41:44,407 --> 00:41:47,797 could they possibly have followed the coast? 568 00:41:49,407 --> 00:41:51,443 It still seems unlikely. 569 00:41:53,687 --> 00:41:56,247 It's time to retrace my steps, 570 00:41:56,327 --> 00:41:59,876 and head back up north to the west coast of Canada. 571 00:42:06,527 --> 00:42:09,803 There should be evidence along these shores. 572 00:42:11,687 --> 00:42:13,518 But there's a problem. 573 00:42:14,327 --> 00:42:16,204 How do you search for something 574 00:42:16,287 --> 00:42:19,677 that's hidden beneath a hundred metres of water? 575 00:42:20,567 --> 00:42:22,478 Well, at the peak of the last Ice Age 576 00:42:22,567 --> 00:42:25,604 the water level would have been so much lower than it is today 577 00:42:25,687 --> 00:42:29,566 that many of these fjords would have been steep-sided valleys. 578 00:42:32,527 --> 00:42:36,839 Today, those same valleys, where our ancestors may have lived, 579 00:42:37,007 --> 00:42:38,804 are full of water. 580 00:42:40,167 --> 00:42:42,681 So as much as this could be the perfect place 581 00:42:42,767 --> 00:42:45,076 to look for signs of a coastal route... 582 00:42:45,167 --> 00:42:50,764 The frustrating thing is that so much of the evidence is probably down there. 583 00:42:55,127 --> 00:42:57,846 ...this is the point at which direct evidence 584 00:42:57,927 --> 00:43:00,919 of humans in North America runs out. 585 00:43:02,767 --> 00:43:08,558 But can we discover whether such a coastal journey was at least possible? 586 00:43:20,807 --> 00:43:25,801 I'm in Vancouver to meet forensic botanist Rolf Mathewes. 587 00:43:28,727 --> 00:43:33,164 His skills are often called upon in high-profile murder cases. 588 00:43:33,687 --> 00:43:35,279 (SIRENS WAILING) 589 00:43:35,367 --> 00:43:37,244 FEMALE REPORTER: On Sunday, the partially-clothed body 590 00:43:37,327 --> 00:43:40,399 of the little girl was discovered floating in... 591 00:43:40,487 --> 00:43:44,196 ROBERTS: When the body of a young girl was recently discovered in a lake, 592 00:43:44,287 --> 00:43:47,563 Rolf's identification of plant remains in her hair 593 00:43:47,647 --> 00:43:49,717 helped convict the killer. 594 00:43:54,087 --> 00:43:56,237 But when he's not solving murders, 595 00:43:56,327 --> 00:44:00,400 Rolf has a passion for trying to solve riddles of the past. 596 00:44:04,687 --> 00:44:06,917 And the evidence he relies on 597 00:44:07,007 --> 00:44:11,000 is so minuscule as to be invisible to the naked eye. 598 00:44:12,487 --> 00:44:15,877 This is one pollen grain of a sedge. 599 00:44:15,967 --> 00:44:18,037 And they're fairly nondescript-looking things, 600 00:44:18,127 --> 00:44:20,357 but I can put it on the screen over here. 601 00:44:20,447 --> 00:44:24,725 It's only about thirty-thousandths of a millimetre in size. 602 00:44:24,807 --> 00:44:29,119 So this is a sedge pollen grain from a marine core? 603 00:44:29,207 --> 00:44:30,435 Well, it's not a marine core. 604 00:44:30,527 --> 00:44:34,122 It's a core taken under 30 metres of water in the Hecate Strait. 605 00:44:34,207 --> 00:44:37,563 When the sea level was much lower, this area was dry land 606 00:44:37,647 --> 00:44:39,956 with marshes and rivers and lakes on it. 607 00:44:40,047 --> 00:44:42,277 -But now it's submerged. -Now it's submerged. 608 00:44:42,367 --> 00:44:44,039 So have you got dates on this pollen, then? 609 00:44:44,127 --> 00:44:46,436 Have you been able to radiocarbon date them? 610 00:44:46,527 --> 00:44:48,722 We can't radiocarbon date individual pollen grains, 611 00:44:48,807 --> 00:44:50,684 but this core where this sample has come from, 612 00:44:50,767 --> 00:44:54,316 this sample is about 1 7,000 years old. 613 00:44:54,727 --> 00:44:56,843 So 1 7,000 years ago, then, 614 00:44:56,927 --> 00:44:59,202 in the Queen Charlotte Islands here off the west coast of Canada, 615 00:44:59,287 --> 00:45:02,882 the ice sheets are pulling back and we've got vegetation. 616 00:45:02,967 --> 00:45:05,003 Not as a single straight-line wall. 617 00:45:05,087 --> 00:45:07,647 It came back in very irregular lobes, 618 00:45:07,727 --> 00:45:09,319 and pulled back at various rates, 619 00:45:09,407 --> 00:45:12,683 depending on how thick the ice was, and so forth. 620 00:45:12,767 --> 00:45:14,883 Now, what I'm really interested in is 621 00:45:14,967 --> 00:45:17,959 the possibility of a coastal route 622 00:45:18,047 --> 00:45:20,641 into North America for the first colonisers. 623 00:45:20,727 --> 00:45:23,116 -Yes. -So is this, 624 00:45:23,487 --> 00:45:26,604 the pollen on those islands, an isolated incidence 625 00:45:26,687 --> 00:45:29,918 or do we actually find vegetation along the coast? 626 00:45:30,007 --> 00:45:33,317 By the time you get to about 1 6,000 years ago, 627 00:45:33,407 --> 00:45:36,524 there are a number of ice-free areas from the Gulf of Alaska 628 00:45:36,607 --> 00:45:39,883 all the way to down to southern British Columbia, 629 00:45:39,967 --> 00:45:42,686 which were also de-glaciating rapidly. 630 00:45:42,767 --> 00:45:44,246 So do you think 631 00:45:44,367 --> 00:45:48,485 humans could have been coming down this de-glaciated route? 632 00:45:48,647 --> 00:45:50,319 Well, I think absolutely. 633 00:45:50,407 --> 00:45:51,920 The possibilities are very strong. 634 00:45:52,007 --> 00:45:55,204 In fact, the only other route I can think of that they could have come 635 00:45:55,287 --> 00:45:57,517 is really down the coastal corridor, 636 00:45:57,607 --> 00:46:01,316 using these early de-glaciated areas as stopping places, 637 00:46:01,407 --> 00:46:02,601 as they worked their way south. 638 00:46:12,967 --> 00:46:16,323 ROBERTS: At last it feels like I'm getting somewhere. 639 00:46:19,967 --> 00:46:23,676 Before I met Rolf, I imagined the ice rising straight up out of the sea, 640 00:46:23,767 --> 00:46:27,396 and stretching from coast to coast, forming an impenetrable barrier. 641 00:46:27,567 --> 00:46:29,956 But what the pollen in his cores proves 642 00:46:30,047 --> 00:46:31,685 is that it would have been at least possible 643 00:46:31,767 --> 00:46:35,077 for humans to have got around the edge of the ice along the coast, 644 00:46:35,207 --> 00:46:39,359 long before the ice-free corridor opened further inland. 645 00:46:42,367 --> 00:46:44,642 But it wouldn't have been easy. 646 00:46:45,207 --> 00:46:49,359 Families inching along the coast would often have found the way blocked 647 00:46:49,447 --> 00:46:52,723 where the ice still reached right down to the sea. 648 00:46:54,807 --> 00:46:57,560 So if our ancestors did come this way, 649 00:46:57,727 --> 00:47:02,596 then at least part of their journey must have been made by boat. 650 00:47:03,647 --> 00:47:08,721 But is there anything to support this idea of ancient seafaring? 651 00:47:12,127 --> 00:47:14,083 1,500 kilometres away, 652 00:47:14,167 --> 00:47:16,283 on the coast of California, 653 00:47:16,367 --> 00:47:19,120 something remarkably rare has turned up. 654 00:47:20,167 --> 00:47:21,919 An ancient treasure, 655 00:47:22,007 --> 00:47:26,842 which for thousands of years has managed to escape the clutches of the sea. 656 00:47:28,527 --> 00:47:31,325 I'm on my way to a string of rocky islands 657 00:47:31,407 --> 00:47:33,967 just off the southern Californian coast. 658 00:47:34,047 --> 00:47:36,163 They're called the Channel Islands. 659 00:47:36,247 --> 00:47:39,842 And the one I'm interested in is Santa Rosa. 660 00:47:39,967 --> 00:47:41,798 Now, there's no daily ferry, 661 00:47:41,887 --> 00:47:44,401 and visitor numbers are strictly controlled. 662 00:47:44,487 --> 00:47:47,684 So instead, it's a short hop by air taxi. 663 00:47:53,647 --> 00:47:55,763 (PILOT CHATTERING ON RADIO) 664 00:47:58,927 --> 00:48:00,246 And we're off. 665 00:48:14,207 --> 00:48:17,199 We're just coming in to land on Santa Rosa. 666 00:48:17,287 --> 00:48:20,484 And I'm really lucky to actually be getting there, 667 00:48:20,567 --> 00:48:22,478 because speaking to Mike the pilot, 668 00:48:22,567 --> 00:48:25,001 on many days it's actually too foggy to land here. 669 00:48:27,407 --> 00:48:30,956 Today our problem isn't the fog, but the wind. 670 00:48:31,047 --> 00:48:33,845 PILOT: Watch your knees, bit bumpy there. 671 00:48:45,527 --> 00:48:47,802 -Beautifully done. -Thank you. 672 00:48:48,607 --> 00:48:52,043 That's one taXi driver who deserves a big tip. 673 00:49:11,007 --> 00:49:14,556 Morning reveals Santa Rosa's lonely beauty. 674 00:49:18,327 --> 00:49:20,124 (BIRDS CHIRPING) 675 00:49:27,447 --> 00:49:29,358 Thanks to their isolation, 676 00:49:29,447 --> 00:49:33,838 these islands are home to some 1 50 plant and animal species 677 00:49:34,127 --> 00:49:36,516 found nowhere else on the planet. 678 00:49:38,047 --> 00:49:42,802 And thousands of years ago, the wildlife was even more eXotic, 679 00:49:42,887 --> 00:49:48,678 with weird and wonderful creatures, like the giant mouse and pygmy mammoth. 680 00:49:51,007 --> 00:49:55,762 The evidence of Santa Rosa's unique past is everywhere. 681 00:49:58,287 --> 00:50:02,758 Look at that. If I'm not mistaken, that is a mammoth bone. 682 00:50:03,807 --> 00:50:06,526 That's a limb bone and then there are vertebrae, 683 00:50:06,607 --> 00:50:09,167 bones from the backbone, all the way through here. 684 00:50:09,247 --> 00:50:11,681 So these bones have been sealed in these sediments 685 00:50:11,767 --> 00:50:14,565 for tens of thousands of years, 686 00:50:14,647 --> 00:50:17,036 and are now just appearing again. 687 00:50:23,327 --> 00:50:28,196 In 1959, a local archaeologist came across what looked like 688 00:50:28,287 --> 00:50:30,562 more ancient animal bones. 689 00:50:32,487 --> 00:50:36,844 But what he'd found was something even more exciting. 690 00:50:37,327 --> 00:50:39,682 And these are the replicas. 691 00:50:40,087 --> 00:50:44,717 Sticking out of the hillside here, he found the fragmented remains 692 00:50:44,807 --> 00:50:49,039 of two human femurs, or thigh bones. 693 00:50:55,167 --> 00:50:59,285 Radiocarbon dating revealed that the bones belonged to a person 694 00:50:59,367 --> 00:51:02,837 who lived here almost 13,000 years ago. 695 00:51:07,007 --> 00:51:10,841 And the discovery of these bones is really surprising. 696 00:51:10,927 --> 00:51:12,155 Because back then, 697 00:51:12,247 --> 00:51:16,798 this island would still have been 1 0 kilometres away from the mainland. 698 00:51:18,687 --> 00:51:22,521 And that means the only way to have got here 699 00:51:22,687 --> 00:51:25,599 would have been by boat. 700 00:51:29,927 --> 00:51:33,636 So it doesn't seem so far-fetched to imagine 701 00:51:33,727 --> 00:51:36,764 that the very first people to reach America 702 00:51:36,847 --> 00:51:39,441 might also have had small boats, 703 00:51:42,327 --> 00:51:46,684 allowing them to travel from one headland to the neXt, 704 00:51:46,767 --> 00:51:49,156 in the hope that around the corner 705 00:51:49,247 --> 00:51:53,525 the ice would have melted enough to allow them to feel dry land again. 706 00:51:56,727 --> 00:52:01,960 But perhaps that's rather a lot to read into a couple of old leg bones. 707 00:52:03,687 --> 00:52:06,804 It's frustrating that the archaeological evidence 708 00:52:06,887 --> 00:52:10,004 for such a coastal route is so scarce. 709 00:52:10,087 --> 00:52:11,998 But there is something else 710 00:52:12,087 --> 00:52:15,523 that I'm hoping will help to settle this controversy 711 00:52:15,607 --> 00:52:19,156 about how the Americas were colonised once and for all. 712 00:52:21,567 --> 00:52:23,523 John Johnson is an eXpert 713 00:52:23,607 --> 00:52:26,644 on the prehistory of the American west coast. 714 00:52:26,927 --> 00:52:29,043 But there are other genetic lineages among the Chumash 715 00:52:29,127 --> 00:52:31,880 that show them to be a very ancient group... 716 00:52:31,967 --> 00:52:35,084 ROBERTS: And for 15 years he's been collecting DNA 717 00:52:35,167 --> 00:52:37,476 from living Native Americans. 718 00:52:39,887 --> 00:52:43,323 John and his colleagues have pieced together what seems to be 719 00:52:43,407 --> 00:52:47,320 nothing less than an ancient genetic route map. 720 00:52:49,487 --> 00:52:52,843 A few years ago, a friend of mine called me up 721 00:52:53,087 --> 00:52:56,841 and told me that they had just identified DNA 722 00:52:56,927 --> 00:52:59,282 from an ancient jawbone 723 00:52:59,367 --> 00:53:02,165 found in southern Alaska, in a cave in southern Alaska. 724 00:53:02,847 --> 00:53:05,919 What's so fascinating is this is a rare type of DNA. 725 00:53:06,007 --> 00:53:09,238 It's only found among 2% of American Indians. 726 00:53:10,087 --> 00:53:13,204 ROBERTS: When John compared the DNA from the ancient jawbone 727 00:53:13,327 --> 00:53:16,364 with modern samples from across the two continents, 728 00:53:16,447 --> 00:53:18,278 he noticed a pattern. 729 00:53:18,447 --> 00:53:21,439 Okay, we have here in southern Alaska 730 00:53:21,527 --> 00:53:23,836 the original DNA from the jaw. 731 00:53:24,087 --> 00:53:27,841 Then we have the Chumash Indians that live in this part of California. 732 00:53:27,927 --> 00:53:31,636 We've also found this type in northwest Mexico. 733 00:53:31,727 --> 00:53:35,640 We've found it among the Caiap6 Indians in coastal Ecuador. 734 00:53:36,247 --> 00:53:40,479 We've also found it among the Mapuche Indians in southern Chile. 735 00:53:41,047 --> 00:53:44,722 Among the Yagan people of southern Patagonia. 736 00:53:45,047 --> 00:53:49,086 And here in prehistoric burials in Tierra del Fuego. 737 00:53:50,367 --> 00:53:53,359 All the way down the Pacific coast. 738 00:53:53,447 --> 00:53:56,245 Primarily Pacific coastal in distribution. 739 00:53:56,807 --> 00:53:58,957 So for you, does this really clinch it? 740 00:53:59,047 --> 00:54:02,437 Does this mean that there was a coastal dispersal? 741 00:54:03,047 --> 00:54:05,880 I think this is the best evidence to date. 742 00:54:05,967 --> 00:54:08,720 Indirect evidence of an ancient coastal migration, 743 00:54:08,807 --> 00:54:13,164 that this particular group gradually moved down the Pacific coast, 744 00:54:13,247 --> 00:54:15,522 taking advantage of coastal resources. 745 00:54:15,607 --> 00:54:20,044 And left behind descendants today who still live in all of these areas. 746 00:54:23,007 --> 00:54:26,522 ROBERTS: It feels as if the great mystery of this, 747 00:54:26,607 --> 00:54:29,963 our last human journey, is resolved. 748 00:54:32,127 --> 00:54:34,721 Looking at all these strands of evidence, then, 749 00:54:34,807 --> 00:54:38,402 it seems the most likely route taken by the first Americans 750 00:54:38,487 --> 00:54:41,160 was not down through the ice sheets, 751 00:54:41,247 --> 00:54:43,158 as many archaeologists used to think, 752 00:54:43,247 --> 00:54:49,277 but all the way down along the Pacific coast of the Americas. 753 00:54:51,247 --> 00:54:54,159 We can imagine those first pioneers 754 00:54:54,287 --> 00:54:59,281 paddling along the edge of the ice some 17,000 years ago. 755 00:54:59,367 --> 00:55:02,564 And their descendants moving down along the coast, 756 00:55:02,647 --> 00:55:05,639 reaching the southernmost tip of the Americas, 757 00:55:05,727 --> 00:55:08,400 within just a couple of thousand years. 758 00:55:11,327 --> 00:55:13,761 With a foothold in this New World, 759 00:55:13,847 --> 00:55:16,281 the first Americans flourished here, 760 00:55:16,367 --> 00:55:19,643 until eventually, some 15,000 years later, 761 00:55:19,727 --> 00:55:24,926 they were to come face to face with some distant members of their family tree. 762 00:55:29,927 --> 00:55:31,804 In 1492, 763 00:55:31,887 --> 00:55:37,484 a small group of European eXplorers arrived on the shores of the Americas, 764 00:55:37,567 --> 00:55:40,764 where they were met by bewildered locals. 765 00:55:46,927 --> 00:55:49,566 Even though both groups were branches 766 00:55:49,647 --> 00:55:54,437 of that original exodus from Africa some 70,000 years ago, 767 00:55:54,527 --> 00:55:58,156 the Europeans didn't see the inhabitants of America 768 00:55:58,247 --> 00:55:59,919 as long-lost cousins, 769 00:56:00,007 --> 00:56:05,206 but rather as wild, savage, even unhuman. 770 00:56:05,287 --> 00:56:08,484 And the Native Americans saw those strange visitors 771 00:56:08,567 --> 00:56:12,321 as deities possessed of supernatural powers. 772 00:56:12,687 --> 00:56:15,326 They just didn't recognise each other. 773 00:56:26,247 --> 00:56:31,765 Over the neXt 400 years or so, this physical and cultural divide 774 00:56:31,887 --> 00:56:35,436 would help fuel the slaughter of the native people. 775 00:56:38,647 --> 00:56:43,482 Even conservative estimates run into hundreds of thousands dead. 776 00:56:50,927 --> 00:56:54,715 A tragedy which seems so much more senseless 777 00:56:54,807 --> 00:56:59,039 in light of what we now know about our human story. 778 00:57:01,767 --> 00:57:07,319 Our origins in Africa, the journeys our ancestors made 779 00:57:07,407 --> 00:57:11,116 and the close genetic bond we all share. 780 00:57:14,127 --> 00:57:18,086 The differences between us all are really just superficial. 781 00:57:18,167 --> 00:57:24,163 We're all members of a young species that goes back less than 200,000 years, 782 00:57:24,287 --> 00:57:27,677 and we're all surprisingly closely related. 783 00:57:27,767 --> 00:57:29,166 This is the story 784 00:57:29,247 --> 00:57:32,000 that has emerged from the study of stones, 785 00:57:32,087 --> 00:57:34,396 bones and our genes. 786 00:57:34,487 --> 00:57:38,321 That wherever we've ended up all over the world, 787 00:57:38,407 --> 00:57:40,967 we are Africans under the skin. 788 00:57:41,607 --> 00:57:47,159 And uncovering that story, retracing the steps of our ancestors, 789 00:57:47,247 --> 00:57:51,718 has given me a profound sense of our common humanity, 790 00:57:51,807 --> 00:57:55,356 our shared past and our shared future.