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  • So, this is a story

    翻訳: Kazunori Akashi 校正: Casey Nakazawa Williams

  • about how we know what we know.

    これは 私たちがどうやって

  • It's a story about this woman,


  • Natalia Rybczynski.

    話の主役は この女性

  • She's a paleobiologist,


  • which means she specializes in digging up really old dead stuff.


  • (Audio) Natalia Rybczynski: Yeah, I had someone call me "Dr. Dead Things."


  • Latif Nasser: And I think she's particularly interesting

    (声)ナタリア・リプチンスキー: 人には「死骸博士」って呼ばせてたわ

  • because of where she digs that stuff up,

    ラティフ・ナサー: 特に面白いと思ったのは

  • way above the Arctic Circle in the remote Canadian tundra.


  • Now, one summer day in 2006,

    北極圏のはるか北 人里離れた カナダのツンドラ地帯だからです

  • she was at a dig site called the Fyles Leaf Bed,


  • which is less than 10 degrees latitude away from the magnetic north pole.

    彼女はファイルズリーフベッドという 発掘現場にいました

  • (Audio) NR: Really, it's not going to sound very exciting,


  • because it was a day of walking with your backpack and your GPS

    (声)ナタリア: 退屈だと思うかもしれません

  • and notebook and just picking up anything that might be a fossil.

    リュックを背負って GPSとノートを抱え

  • LN: And at some point, she noticed something.

    化石らしきものを拾いながら 1日中歩き回るだけですから

  • (Audio) NR: Rusty, kind of rust-colored,

    ラティフ:ある時 彼女は 何かに気づきました

  • about the size of the palm of my hand.

    (声)ナタリア:古い 赤褐色をした

  • It was just lying on the surface.


  • LN: And at first she thought it was just a splinter of wood,


  • because that's the sort of thing people had found

    ラティフ:最初は ただの木片だと思いました

  • at the Fyles Leaf Bed before -- prehistoric plant parts.

    というのも ファイルズリーフベッドでは

  • But that night, back at camp ...

    太古の植物の破片が よく見つかったからです

  • (Audio) NR: ... I get out the hand lens,

    ところが その夜キャンプに帰り ―

  • I'm looking a little bit more closely and realizing


  • it doesn't quite look like this has tree rings.

    もう少し よく見てみると

  • Maybe it's a preservation thing,


  • but it looks really like ...


  • bone.

    それは見れば見るほど —

  • LN: Huh. So over the next four years,


  • she went to that spot over and over,

    ラティフ:彼女は それから4年以上

  • and eventually collected 30 fragments of that exact same bone,

    何度も この地点を訪れ

  • most of them really tiny.

    最終的に 30個の 同じ骨の破片を集めました

  • (Audio) NR: It's not a whole lot. It fits in a small Ziploc bag.

    ほとんどが とても小さなものです

  • LN: And she tried to piece them together like a jigsaw puzzle.

    (声)ナタリア:数は多くありません 小さなビニール袋に収まるくらいです

  • But it was challenging.

    ラティフ:パズルのように 破片を組み合わせようとしましたが

  • (Audio) NR: It's broken up into so many little tiny pieces,


  • I'm trying to use sand and putty, and it's not looking good.

    (声)ナタリア:割れて 粉々になっていたので

  • So finally, we used a 3D surface scanner.

    砂とパテを使おうとしましたが うまくいきません

  • LN: Ooh! NR: Yeah, right?

    だから結局 3Dスキャナーを使いました

  • (Laughter)

    ラティフ:すごいな! ナタリア:でしょ?

  • LN: It turns out it was way easier to do it virtually.


  • (Audio) NR: It's kind of magical when it all fits together.

    ラティフ:画面上で作業した方が ずっと簡単です

  • LN: How certain were you that you had it right,

    (声)ナタリア:全部 組み合わさった時は ちょっと感動しました

  • that you had put it together in the right way?


  • Was there a potential that you'd put it together a different way

    自信は どのくらいありました?

  • and have, like, a parakeet or something?

    別の組み立て方をしたら 違うものになる可能性は?

  • (Laughter)


  • (Audio) NR: (Laughs) Um, no. No, we got this.


  • LN: What she had, she discovered, was a tibia, a leg bone,

    (声)ナタリア:いいえ 間違いありません

  • and specifically, one that belonged to a cloven-hoofed mammal,

    ラティフ:彼女が発見したのは けい骨 つまり脚の骨で

  • so something like a cow or a sheep.


  • But it couldn't have been either of those.


  • It was just too big.

    ただ この骨は牛や羊のはずは ありませんでした

  • (Audio) NR: The size of this thing, it was huge. It's a really big animal.


  • LN: So what animal could it be?

    (声)ナタリア:特大サイズでした すごく大きな動物です

  • Having hit a wall, she showed one of the fragments


  • to some colleagues of hers in Colorado,

    行き詰った彼女は 骨片の1つを

  • and they had an idea.


  • (Audio) NR: We took a saw, and we nicked just the edge of it,


  • and there was this really interesting smell that comes from it.

    (声)ナタリア:私たちが のこぎりで 骨の端に切り目を入れると

  • LN: It smelled kind of like singed flesh.


  • It was a smell that Natalia recognized


  • from cutting up skulls in her gross anatomy lab:

    不気味な解剖室で ナタリアが

  • collagen.

    頭蓋骨を切断した時に 嗅いだのと同じ匂いでした

  • Collagen is what gives structure to our bones.


  • And usually, after so many years,

    コラーゲンは骨の構造を保つ 役割を果たします

  • it breaks down.

    年月が経つと 普通は

  • But in this case, the Arctic had acted like a natural freezer and preserved it.


  • Then a year or two later, Natalia was at a conference in Bristol,

    この場合 北極圏の気候が 天然の冷蔵庫となって保存したのです

  • and she saw that a colleague of hers named Mike Buckley

    それから1〜2年経って ナタリアがブリストルで学会に参加した時

  • was demoing this new process that he called "collagen fingerprinting."


  • It turns out that different species have slightly different structures

    「コラーゲン鑑定」という新しい処理法の デモをしていました

  • of collagen,

    動物はそれぞれ コラーゲンの構造が少しずつ

  • so if you get a collagen profile of an unknown bone,


  • you can compare it to those of known species,


  • and, who knows, maybe you get a match.

    既に分かっている動物のものと 比較でき

  • So she shipped him one of the fragments,

    ひょっとしたら 特定できるかもしれません

  • FedEx.

    だから 骨片を1つ送ったのです

  • (Audio) NR: Yeah, you want to track it. It's kind of important.


  • (Laughter)

    (声)ナタリア:大切なものだから 追跡したかったんです

  • LN: And he processed it,


  • and compared it to 37 known and modern-day mammal species.


  • And he found a match.


  • It turns out that the 3.5 million-year-old bone


  • that Natalia had dug out of the High Arctic

    ナタリアが高緯度の北極圏で 発掘した

  • belonged to ...


  • a camel.


  • (Laughter)


  • (Audio) NR: And I'm thinking, what? That's amazing -- if it's true.


  • LN: So they tested a bunch of the fragments,

    (声)ナタリア:「え?」って思いました 本当なら すごいことです

  • and they got the same result for each one.

    ラティフ:多くの骨片を 検査しましたが

  • However, based on the size of the bone that they found,


  • it meant that this camel was 30 percent larger than modern-day camels.

    ただし 発見した骨の サイズから考えると

  • So this camel would have been about nine feet tall,

    このラクダは 現在のものより 3割も大きかったのです

  • weighed around a ton.

    背の高さは およそ2.7m —

  • (Audience reacts)


  • Yeah.


  • Natalia had found a Giant Arctic camel.


  • (Laughter)

    ナタリアが発見したのは 「巨大 北極ラクダ」だったんです

  • Now, when you hear the word "camel,"


  • what may come to mind is one of these,


  • the Bactrian camel of East and Central Asia.


  • But chances are the postcard image you have in your brain

    東・中央アジアに生息する フタコブラクダか

  • is one of these, the dromedary,

    頭の中の 絵はがきのイメージは きっと

  • quintessential desert creature --


  • hangs out in sandy, hot places like the Middle East and the Sahara,

    砂漠の生き物といえば これです

  • has a big old hump on its back

    中東やサハラ砂漠といった 高温の砂漠に暮らし

  • for storing water for those long desert treks,


  • has big, broad feet to help it tromp over sand dunes.


  • So how on earth would one of these guys end up in the High Arctic?

    大きな幅広い足で 砂丘を踏みしめて進みます

  • Well, scientists have known for a long time, turns out,

    一体なぜ そんな動物がカナダ北部の 北極圏に到達したのでしょう?

  • even before Natalia's discovery,

    実は 科学者が以前から 知っていたことがあります

  • that camels are actually originally American.


  • (Music: The Star-Spangled Banner)

    実は ラクダの原産地は アメリカなんです

  • (Laughter)


  • They started here.


  • For nearly 40 of the 45 million years that camels have been around,


  • you could only find them in North America,

    ラクダが出現してから 約4,500万年経ちますが

  • around 20 different species, maybe more.

    そのうち ほぼ4,000万年の間 北米だけに分布し

  • (Audio) LN: If I put them all in a lineup, would they look different?

    種類は およそ20種類 多分それ以上いました

  • NR: Yeah, you're going to have different body sizes.

    (声)ラティフ:全部 並べたら 違いは分かったでしょうか?

  • You'll have some with really long necks,

    ナタリア:ええ 体の大きさはまちまちで

  • so they're actually functionally like giraffes.


  • LN: Some had snouts, like crocodiles.


  • (Audio) NR: The really primitive, early ones would have been really small,

    ラティフ:ワニのような 顔をしたものもいました

  • almost like rabbits.

    (声)ナタリア:初期の 原始的なラクダは とても小さくて

  • LN: What? Rabbit-sized camels?


  • (Audio) NR: The earliest ones.

    ラティフ:ええっ? ウサギサイズのラクダですか?

  • So those ones you probably would not recognize.


  • LN: Oh my God, I want a pet rabbit-camel.


  • (Audio) NR: I know, wouldn't that be great?


  • (Laughter)

    (声)ナタリア:ええ きっと最高ね

  • LN: And then about three to seven million years ago,


  • one branch of camels went down to South America,

    ラティフ:その後 3〜700万年前に

  • where they became llamas and alpacas,


  • and another branch crossed over the Bering Land Bridge


  • into Asia and Africa.


  • And then around the end of the last ice age,


  • North American camels went extinct.


  • So, scientists knew all of that already,


  • but it still doesn't fully explain how Natalia found one so far north.

    ここまでは すでに判明していることです

  • Like, this is, temperature-wise, the polar opposite of the Sahara.

    とは言え あれほど北で発見されたことが 完全に説明できるわけではありません

  • Now to be fair,

    例えば気温の面で サハラ砂漠とは正反対ですから

  • three and a half million years ago,


  • it was on average 22 degrees Celsius warmer than it is now.


  • So it would have been boreal forest,

    現代より平均22度 高かったんです

  • so more like the Yukon or Siberia today.


  • But still, like, they would have six-month-long winters

    今のユーコン川流域やシベリアに 似ていたかもしれません

  • where the ponds would freeze over.

    ただ それでも 冬は6か月間も続き

  • You'd have blizzards.


  • You'd have 24 hours a day of straight darkness.


  • Like, how ... How?

    夜の暗闇が 24時間続く時期もあったでしょう

  • How is it that one of these Saharan superstars


  • could ever have survived those arctic conditions?

    このサハラ砂漠の スーパースターは どうやって

  • (Laughter)

    北極圏の気候を 生き延びることができたのでしょう?

  • Natalia and her colleagues think they have an answer.


  • And it's kind of brilliant.

    ナタリアと仲間の学者たちは 答えを見つけたと考えています

  • What if the very features that we imagine make the camel so well-suited


  • to places like the Sahara,

    サハラ砂漠のような場所に 適応するためだと 私たちが考えてきた

  • actually evolved to help it get through the winter?


  • What if those broad feet were meant to tromp not over sand,

    実は 冬を乗り切るために 進化したものだとしたら?

  • but over snow, like a pair of snowshoes?

    幅の広い足は 砂の上を歩くためではなく

  • What if that hump -- which, huge news to me,

    かんじきのように 雪上を歩くためのものだとしたら?

  • does not contain water, it contains fat --

    背中のこぶには — 私は知らなくて 驚いたんですが

  • (Laughter)

    水ではなく 脂肪が詰まっています

  • was there to help the camel get through that six-month-long winter,


  • when food was scarce?

    そのこぶが 食料の少ない 半年に渡る冬を乗り切るのに

  • And then, only later, long after it crossed over the land