over the past six million years.

私は18分の持ち時間で

All right.

過去6百万年間に起きたことを お話しします

We all have come from a long way,

では始めます

here in Africa, and converged in this region of Africa,

私達は長い距離を旅して

which is a place where 90 percent of our evolutionary process took place.

アフリカの この場所にやってきました

And I say that not because I am African,

人類の進化の90%はアフリカで起きました

but it's in Africa that you find the earliest evidence

私がアフリカ人だから言うのではなく

for human ancestors, upright walking traces,

理由はアフリカで直立歩行する

even the first technologies in the form of stone tools.

人類の祖先の最初の形跡と

So we all are Africans, and welcome home.

石器が発見されたからです

All right.

私達全員アフリカ人なのです 皆さんの故郷にようこそ

I'm a paleoanthropologist, and my job is to define

さて

man's place in nature and explore what makes us human.

私は古生物学者で自然界の中のヒトの役割および

And today, I will use Selam, the earliest child ever discovered,

我々をヒトと成すのは何か研究しています

to tell you a story of all of us.

今日は発見した最古の子供 セラムを紹介しながら

Selam is our most complete skeleton of a three-year-old girl

私達の物語をお話しします

who lived and died 3.3 million years ago.

セラムはもっとも完全な骨格が残っている

She belongs to the species known as Australopithecus afarensis.

3.3百万年前に生きた 3歳の女の子です

You don't need to remember that.

アウストラロピテクス・アファレンシスという種に属します

That's the Lucy species, and was found by my research team

覚える必要はないですよ

in December of 2000 in an area called Dikika.

ルーシー種とも呼ばれ 私の研究チームが発見しました

It's in the northeastern part of Ethiopia.

2000年12月のこと ディキカという所でした

And Selam means peace in many Ethiopian languages.

エチオピア北東部に位置します

We use that name to celebrate peace in the region and in the planet.

セラムとはエチオピアの多くの言語で平和を意味します

And the fact that it was the cover story of all these famous magazines

この名前は地域と世界の平和を祈願して付けました

gives you already an idea of her significance, I think.

多くの有名な雑誌の表紙を飾ったことで

After I was invited by TED, I did some digging,

彼女の意義がお分かりになると思います

because that's what we do, to know about my host.

TED の招待を受けてから少しTEDの調査をしました

You don't just jump into an invitation.

招待してくれた人に敬意を払うためです

And I learned that the first technology appeared

黙って招待は受けません

in the form of stone tools, 2.6 million years ago.

分かったのは最初の石器作りが

First entertainment comes evidence from flutes that are 35,000 years old.

始まったのは 2.6百万年前ということです

And evidence for first design comes 75,000 years old -- beads.

最初の娯楽道具はフルートで 3.5万年前に作られました

And you can do the same with your genes and track them back in time.

最初の装飾品はビーズで 7.5万年前に作られました

And DNA analysis of living humans and chimpanzees

皆さんの遺伝子についても 同様に時間を遡ってみましょう

teaches us today that we diverged sometime around seven million years ago

現在のヒトとチンパンジーを分析すると

and that these two species share over 98 percent of the same genetic material.

約7百万年前に分岐したことが分かります

I think knowing this is a very useful context

２つの種は同じ遺伝物質を98%以上共有しています

within which we can think of our ancestry.

我々の祖先を考える上で

However, DNA analysis informs us only about

たいへん有益な情報です

the beginning and the end, telling us nothing

しかしながら この分析だけでは

about what happened in the middle.

始めと終わりしか分からず中間で起こったことは

So, for us, paleoanthropologists, our job is to find the hard evidence,

何も分かりません

the fossil evidence, to fill in this gap

そこで我々古生物学者は 化石等の確固な証拠を探して

and see the different stages of development.

ギャップを埋めようとするのです

Because it's only when you do that, that you can talk about --

そして発展の段階を辿ろうとします

(Laughter) --

これでようやく お話できる

it's only when you do that, [that] you can talk about

(笑)

how we looked like and how we behaved at different times,

これでようやく別々の時間に

and how those likes and looks and behaviors changed through time.

我々の祖先の容姿と行動について

That then gives you an access

また時間を経てそれらがどう変化したか 語ることができるのです

to explore the biological mechanisms

そうすることで

and forces that are responsible for this gradual change

今日の私達を作りだした

that made us what we are today.

緩やかな進化を司る 生物学的な仕組みや

But finding the hard evidence is a very complicated endeavor.

力について探究できるのです

It's a systematic and scientific approach,

確固たる証拠を探すのはとても複雑な作業です

which takes you to places that are remote, hot, hostile and often with no access.

整然とした科学的手法をとりますが

Just to give you an example, when I went to Dikika,

行く先は たどり着くのも困難な高温で 厳しい環境の僻地なのです

where Selam was found, in '99 -- and it's about 500 kilometers

例をあげると

from Addis Ababa, the capital of Ethiopia.

99年にセラムを発見したディキカは

It took us only seven hours to do the first 470 kilometers of the 500,

エチオピア首都アジスアベバから 約500キロの所です

but took four, solid hours to do the last only 30 kilometers.

はじめの470キロを旅するのに 要したのはわずか7時間でしたが

With the help of the locals and using just shovels and picks, I made my way.

残りの30キロは4時間もかかりました

I was the first person to actually drive a car to the spot.

現地の人の助けや シャベルとツルハシを使って進みました

When you get there, this is what you see,

現地に最初に到達したのは私が運転した車でした

and it's the vastness of the place which makes you feel helpless and vulnerable.

着いた景色がこれです

And once you make it there, the big question is where to start.

何もない場所なので とても不安になります

(Laughter)

そして着くと同時に どこから始めるんだ という疑問が湧きます

And you find nothing for years and years.

(笑)

When I go to places like this, which are paleontological sites,

そして何年かけても何も見つかりません

it's like going to a game park, an extinct game park.

このような古生物学的地点に行くと

But what you find are not the human remains,

そこは まるで自然動物保護区です― それも絶滅した

such as Selam and Lucy, on a day-to-day basis.

セラムやルーシーのような人類の形跡を

You find elephants, rhinos, monkeys, pigs, etc.

いつも発見できるとは限りません

But you could ask, how could these large mammals

見つかるのはゾウ サイ サル ブタ等です

live in this desert environment?

なぜこんな砂漠にそんな大きな

Of course, they cannot, but I'm telling you already

哺乳類が棲めたのか と思うでしょう?

that the environment and the carrying capacity

もちろん無理です

of this region was drastically different from what we have today.

つまり今日と当時の環境や生物の

A very important environmental lesson could be learned from this.

収容能力は大きく異なっていたのです

Anyway, once we made it there, then it's a game park, as I said, an extinct game park.

この事実から重要な環境の教訓を得ることができます

And our ancestors lived in that game park,

いずれにせよ ここは自然動物保護区 絶滅保護区です

but were just the minorities. They were not as successful

我々の祖先もそこに暮らしていたのですが

and as widespread as the Homo sapiens that we are.

少数派でした

To tell you just an example, an anecdote about their rarity,

我々ホモサピエンスほど うまく適用して 広く存在してはいませんでした

I was going to this place every year and would do fieldwork here,

いかに稀小な生き物だったかを示す逸話です

and the assistants, of course, helped me do the surveys.

私は毎年この場所に出かけて発掘調査をしました

They would find a bone and tell me, "Here is what you're looking for."

もちろん調査を手伝う助手がいます

I would say, "No, that's an elephant."

彼らは骨を見つけては私に言います “探していたのはこれじゃない?”

Again, another one, "That's a monkey." "That's a pig," etc.

私は “いや それはゾウだ”

So one of my assistants, who never went to school, said to me, "Listen, Zeray.

別の骨には “それはサルだ” “それはブタだ” 等々

You either don't know what you're looking for,

学校に行ったことがない助手たちは言うのです

or you're looking in the wrong place," he said.

“もしかして探しているのが何か知らないか

(Laughter)

探す場所を間違えてるんじゃないの”

And I said, "Why?" "Because there were elephants and lions,

(笑)

and the people were scared and went somewhere else.

“どうして” と言うと “だってゾウやライオンがいるから

Let's go somewhere else."

人は怖くてどっかに逃げたんだよ

Well, he was very tired, and it's really tiring.

違う場所いこうよ”

It was then, after such hard work and many frustrating years that we found Selam,

とても疲れていました 本当に疲れます

and you see the face here covered by sandstone.

そのような苦労と困難を乗り越えて ようやくセラムを発見しました

And here is actually the spinal column

砂岩に囲まれた顔です

and the whole torso encased in a sandstone block,

これは背骨です

because she was buried by a river.

上半身が砂岩の塊に埋もれています

What you have here seems to be nothing,

川の側に埋められたのです

but contains an incredible amount of scientific information

見た目は大したことありませんが

that helps us explore what makes us human.

我々をヒトと成すのは何かを解き明かす

This is the earliest and most complete juvenile human ancestor

驚くべきほどの科学的情報がここにあります

ever found in the history of paleoanthropology,

古生物学の歴史上 発見された 最も古く 最も保存状態のよい

an amazing piece of our long, long history.

人類の祖先の子供です

There were these three people and me, and I am taking the pictures,

長い歴史の中でも特筆すべきことです

that's why I am not in.

発見した3人と私です 私は写真を撮っていたので

How would you feel if you were me? You have something extraordinary in your hand,

写っていません

but you are in the middle of nowhere?

皆さんだったらどう思うでしょう とても貴重な物を手にしているのに

The feeling I had was a deep and quiet happiness and excitement,

何もない場所にいるのですから

of course accompanied by a huge sense of responsibility,

私は深く静かな喜びと興奮に包まれました

of making sure everything is safe.

もちろん同時に重大な責任感をもって

Here is a close-up of the fossil, after five years of cleaning,

全てが無事であることに努めました

preparation and description, which was very long,

これが化石のクローズアップです 5年の歳月をかけて

as I had to expose the bones from the sandstone block

清掃 準備 分類した結果です

I just showed you in the previous slide.

先のスライドでお見せした砂岩から骨を

It took five years.

すべて取り出したのです

In a way, this was like the second birth for the child, after 3.3 million years,

5年かかりました

but the labor was very long.

いわば この子にとっては 3.3百万年を経た 二度目の出産ですが

And here is full scale -- it's a tiny bone.

陣痛はとても長かったわけです

And in the middle is the minister of Ethiopian tourism,

全体図です 小さな骨です

who came to visit the National Museum of Ethiopia while I was working there.

中央がエチオピア観光相です

And you see me worried and trying to protect my child,

エチオピア国立博物館で 私が作業中に訪問を受けました

because you don't leave anyone with this kind of child,

私が子供を守ろうとして心配顔をしています

even a minister.

相手が大臣でもこのような子供は

So then, once you've done that, the next stage is to know what it is.

放っておけません

(Laughter)

それが終わると次に これがいったい何なのか調べます

Once that was done, then it was possible to compare.

(笑)

We were able to tell that she belonged

それが終わると比較が可能になります

to the human family tree because the legs, the foot,

彼女が人類に属していたのは明らかでした

and some features clearly showed that she walked upright,

なぜならば脚部や足 その他の特徴が

and upright walking is a hallmark in humanity.

直立歩行していたことを示しました

But in addition, if you compare the skull

直立歩行は人類の印です

with a comparably aged chimpanzee and little George Bush here,

さらに頭蓋骨を同年齢のチンパンジーと

you see that you have vertical forehead.

小さなジョージ・ブッシュで比較すると

And you see that in humans, because of the development

ヒトの額は垂直です

of the pre-frontal cortex, it's called.

ヒトには前頭前皮質と呼ばれる発達した

You don't see that in chimpanzees,

脳があるためです

and you don't see this very projecting canine.

チンパンジーにはありません

So she belongs to our family tree, but within that, of course,

鋭く突き出した犬歯も見られません

you do detailed analysis, and we know now

つまり彼女は人類に属しています

that she belongs to the Lucy species,

範囲を絞ってさらに調査を続け

known as Australopithecus afarensis.

彼女がアウストラロピテクス・アファレンシスと

The next exciting question is, girl or boy?

呼ばれるルーシー種であることが分かりました

And how old was she when she died?

次の大いなる疑問は女の子か男の子か

You can determine the sex of the individual

そして死んだのは何歳の時かです

based on the size of the teeth.

性別は歯の大きさで識別できます

How?

性別は歯の大きさで識別できます

You know, in primates, there is this phenomenon

どうやって?

called sexual dimorphism, which simply means

類人猿には性的二形という特徴があります

males are larger than females and males have larger teeth

類人猿には性的二形という特徴があります

than the females.

簡単にいうとオスはメスより大きく オスはメスより大きな歯をもっています

But to do that, you need the permanent dentition,

簡単にいうとオスはメスより大きく オスはメスより大きな歯をもっています

which you don't see here, because what you have here

比較するには永久歯が必要です

are the baby teeth.

この個体には乳歯しかありません

But using the CT scanning technology,

この個体には乳歯しかありません

which is normally used for medical purposes,

しかし 普段医療目的のCTスキャン技術を使って

you can go deep into the mouth and come up with this beautiful image

しかし 普段医療目的のCTスキャン技術を使って

showing you both the baby teeth here

口の中を詳しく検査するとこのように

and the still-growing adult teeth here.

美しい乳歯と成長中の

So when you measure those teeth,

永久歯両方のイメージを得えられます