or a clapping

或拍手？

I'm interested in how many

我很好奇

are three to 12 years old.

這裡有多少 3 到 12 歲的小朋友

(Laughter)

(笑聲)

None, huh?

竟然沒有？

All right.

好吧！

I'm going to talk about dinosaurs.

我今天要和各位談恐龍

Do you remember dinosaurs when you were that age?

這裡有人小時候很愛恐龍的嗎？

(Applause)

(掌聲)

Dinosaurs are kind of funny, you know.

你知道，恐龍蠻有趣的

(Laughter)

(笑聲)

We're going to kind of go in a different direction right now.

我們現在要進到一個不同的領域

I hope you all realize that.

希望你們有發現這點

So I'll just give you my message up front:

我就直接說出我的演講主題了：

Try not to go extinct.

試著不要滅絕

(Laughter)

(笑聲)

That's it.

就是這樣

(Laughter)

(笑聲)

People ask me a lot --

人們經常問我

in fact, one of the most asked questions I get

事實上，我最常被問到的一個問題是

is, why do children like dinosaurs so much?

為什麼小朋友這麼喜歡恐龍？

What's the fascination?

恐龍有什麼魅力？

And I usually just say,

我通常會回答

"Well dinosaurs were big,

「這個嘛 ... 恐龍都很巨大

different and gone."

特別，而且都消失了。」

They're all gone.

牠們全都消失了

Well that's not true,

其實這些並不全是事實

but we'll get to the goose in a minute.

不過我們就快說到重點了

So that's sort of the theme:

所以，主題是這樣的：

big, different and gone.

巨大、特別而且消失了

The title of my talk:

我的演講主題：

Shape-shifting Dinosaurs:

千變萬化的恐龍：

The Cause of a Premature Extinction.

未成熟恐龍滅絕的原因

Now I assume that we remember dinosaurs.

我假設大家都記得恐龍的樣子

And there's lots of different shapes.

有各種不同外型的　

Lots of different kinds.

各種不同種類的

A long time ago,

很久以前

back in the early 1900s,

這可以追溯到 1900 年代早期

museums were out looking for dinosaurs.

那時許多博物館都在尋找恐龍化石

They went out and gathered them up.

他們將這些化石收集起來

And this is an interesting story.

這是一個很有趣的故事

Every museum wanted a little bigger or better one

每座博物館都想要一個比別人

than anybody else had.

更大、更好的恐龍化石

So if the museum in Toronto went out

所以，如果多倫多的博物館考古

and collected a Tyrannosaur, a big one,

發現了一隻巨大暴龍的化石

then the museum in Ottawa wanted a bigger one

那渥太華的博物館就想要一個更大的

and a better one.

更好的

And that happened for all museums.

所有的博物館都是這樣

So everyone was out looking

所有人都在尋找

for all these bigger and better dinosaurs.

更大、更好的恐龍化石

And this was in the early 1900s.

這是 1900 年代早期的情況

By about 1970,

大約 1970 年代以前

some scientists were sitting around

許多科學家坐下來討論

and they thought, "What in the world?

他們想，「這到底是為什麼？

Look at these dinosaurs.

看看這些恐龍化石

They're all big.

牠們都如此巨大

Where are all the little ones?"

那小隻的恐龍在哪裡？」

And they thought about it

他們探討了這個問題

and they even wrote papers about it:

甚至針對這個主題寫了論文：

"Where are the little dinosaurs?"

「小恐龍去哪了？」

(Laughter)

(笑聲)

Well, go to a museum, you'll see,

到博物館，你就會發現

see how many baby dinosaurs there are.

那裡有多少恐龍寶寶

People assumed -- and this was actually a problem --

那時人們假設，這其實是一個問題

people assumed

人們假設

that if they had little dinosaurs,

如果他們有小恐龍的化石

if they had juvenile dinosaurs,

如果他們有幼年恐龍的化石

they'd be easy to identify.

這些化石會很容易辨識

You'd have a big dinosaur

這樣一來 你會有大的恐龍化石

and a littler dinosaur.

和小一點的恐龍化石

But all they had were big dinosaurs.

但博物館只有大的恐龍化石

And it comes down to a couple of things.

這有幾個原因

First off, scientists have egos,

首先，科學家有自尊心

and scientists like to name dinosaurs.

他們很喜歡為恐龍命名

They like to name anything.

他們喜歡為所有東西命名

Everybody likes to have their own animal that they named.

每個人都想要一個自己命名的動物

(Laughter)

(笑聲)

And so every time they found something that looked a little different,

所以每次當他們找到 長的稍微不同的東西

they named it something different.

他們就替它取一個新名字

And what happened, of course,

想當然，事情就這樣發生了

is we ended up with a whole bunch of different dinosaurs.

最後出現了各種不同名字的恐龍

In 1975,

1975 年

a light went on in somebody's head.

有個人忽然靈光乍現

Dr. Peter Dodson

Peter Dodson 博士

at the University of Pennsylvania

賓夕法尼亞大學的教授

actually realized

發現

that dinosaurs grew

恐龍成長的方式

kind of like birds do,

與鳥類有些相似

which is different

而不同於

than the way reptiles grow.

爬蟲類成長的方式

And in fact,

事實上

he used the cassowary as an example.

他以食火雞為例子

And it's kind of cool -- if you look at the cassowary,

這還蠻酷的，如果你觀察食火雞

or any of the birds that have crests on their heads,

或任何頭上有冠的鳥

they actually grow

牠們成長到

to about 80 percent adult size

大約是成熟食火雞的 80 % 大小時

before the crest starts to grow.

鳥冠才會開始生長

Now think about that.

試想一下

They're basically retaining their juvenile characteristics

基本上，牠們一直保留幼年的特徵

very late in what we call ontogeny.

到個體發生的非常晚期

So allometric cranial ontogeny

所以異速的頭蓋骨個體發生

is relative skull growth.

指的就是頭蓋骨的異速生長

So you can see

因此你會發現

that if you actually found one

如果你看到一隻鳥

that was 80 percent grown

成長到成熟型態的 80 % 時

and you didn't know that it was going to grow up to a cassowary,

你並不會知道牠會長成一隻食火雞

you would think they were two different animals.

你會以為牠們是兩種動物

So this was a problem,

這就是問題所在

and Peter Dodson pointed this out

Peter Dodson 點出了這件事

using some duck-billed dinosaurs

他舉了一些鴨嘴龍科的恐龍為例子

then called Hypacrosaurus.

那時牠們被稱為亞冠龍屬

And he showed

Dodson 指出

that if you were to take a baby and an adult

如果你用一隻恐龍寶寶和成熟的恐龍

and make an average of what it should look like,

算出一個平均值 看看牠們綜合起來長怎樣

if it grew in sort of a linear fashion,

牠會照著一個線性方式成長

it would have a crest

牠會長出

about half the size of the adult.

大約是成熟恐龍一半大小的冠

But the actual sub-adult

但實際上，接近成年

at 65 percent

成熟度 65 % 的恐龍

had no crest at all.

頭上卻沒有冠

So this was interesting.

這十分有趣

So this is where

這使得

people went astray again.

人們再次被誤導

I mean, if they'd have just taken that,

如果他們單單接受

taken Peter Dodson's work, and gone on with that,

Peter Dodson 的研究成果，以此為基礎發展的話

then we would have a lot less dinosaurs

我們便會少了很多種恐龍

than we have.

不像現在的種類這麼豐富

But scientists have egos;

但科學家有自尊心

they like to name things.

他們喜歡為東西命名

And so they went on naming dinosaurs

於是他們繼續為恐龍命名

because they were different.

因為他們認為 這些恐龍是不同種類的

Now we have a way of actually testing

我們現在有種技術 能實際測試

to see whether a dinosaur, or any animal,

看看一隻恐龍，或是任何動物

is a young one or an older one.

是年輕或是較年長的

And that's by actually cutting into their bones.

透過直接切入牠們的骨頭

But cutting into the bones of a dinosaur

不過，要切入恐龍的骨頭

is hard to do, as you can imagine,

是困難的，你可以想像

because in museums

在博物館

bones are precious.

骨頭是很珍貴的

You go into a museum and they take really good care of them.

博物館將骨頭保存的非常良好

They put them in foam, little containers.

他們將骨頭放在有泡沫的小容器

They're very well taken care of.

它們被保護的非常好

They don't like it if you come in

他們不想看著你走進來

and want to saw them open and look inside.

然後試圖把它們切開 瞧瞧裡頭長什麼樣子

(Laughter)

(笑聲)

So they don't normally let you do that.

所以他們通常不會讓你這樣做

But I have a museum

不過我有座博物館

and I collect dinosaurs

而且我收集恐龍化石

and I can saw mine open.

所以我可以把它們切開

So that's what I do.

我就這麼做了

(Applause)

(掌聲)

So if you cut open a little dinosaur,

如果你切開一隻小恐龍的骨頭

it's very spongy inside like A.

它內部會呈現多孔狀，就像 A 這張圖

And if you cut into an older dinosaur,

而如果你切開一隻較年長恐龍的骨頭

it's very massive.

它會是非常實心的

You can tell it's mature bone.

你可以看出它是成熟的骨頭

So it's real easy to tell them apart.

所以要分辨兩者是很容易的

So what I want to do

因此，我想要

is show you these.

讓你們看這些

In North America in the Northern Plains of the United States

在北美洲，美國北部的平原

and the Southern Plains of Alberta and Saskatchewan,

以及亞伯達和薩克斯其萬南部的平原

there's this unit of rock called the Hell Creek Formation

有一種岩石地層單位 叫做地獄溪地層

that produces the last dinosaurs that lived on Earth.

地球上最後存在的恐龍 就從這裡出土

And there are 12 of them

其中有 12 種

that everyone recognizes --

是大家耳熟能詳的

I mean the 12 primary dinosaurs

這 12 種主要的恐龍

that went extinct.

這些都已經滅絕的恐龍

And so we will evaluate them.

我們要來檢視牠們

And that's sort of what I've been doing.

這就是我在做的事

So my students, my staff,

我的學生、同事

we've been cutting them open.

我們持續的將恐龍的骨頭切開

Now as you can imagine,

你可以想像

cutting open a leg bone is one thing,

切開恐龍的腿骨是一件事

but when you go to a museum

但當你走進博物館

and say, "You don't mind if I cut open

對他們說，「你不介意我把你們收藏的

your dinosaur's skull do you?"

恐龍頭蓋骨切開吧？」

they say, "Go away."

他們會說，「走開。」

(Laughter)

(笑聲)

So here are 12 dinosaurs.

這裡有 12 隻恐龍

And we want to look at these three first.

我們要先來看這 3 隻

So these are dinosaurs that are called Pachycephalosaurs.

這些叫做腫頭龍

And everybody knows

大家都知道

that these three animals are related.

這 3 隻恐龍是彼此相關的

And the assumption is

有假設認為

is that they're related

牠們之間有關聯

like cousins or whatever.

就像堂/表兄弟姊妹或其他類似的關係

But no one ever considered

但從來沒有人想過

that they might be more closely related.

牠們可能有更深一層的關係

In other words,

換句話說

people looked at them and they saw the differences.

人們看到的是牠們之間的差異

And you all know

你們都知道

that if you are going to determine

如果要確定

whether you're related to your brother or your sister,

你和某人是不是兄弟姐妹

you can't do it by looking at differences, right?

不能只看你們之間的差異，對吧？

You can only determine relatedness

要確定關聯性

by looking for similarities.

只能透過尋找相似處

So people were looking at these

所以人們看著這些恐龍

and they were talking about how different they are.

討論著牠們之間的差異有多大

Pachycephalosaurus has a big, thick dome on its head,

腫頭龍頭上有一個又大又厚的圓頂

and it's got some little bumps on the back of its head,

牠的後腦杓有許多小腫塊

and it's got a bunch of gnarly things on the end of its nose.

鼻子末端還有一堆粗糙凸起的部分

And then Stygimoloch, another dinosaur

而冥河龍，另一種恐龍

from the same age, lived at the same time,

來自同一個時代，生長在同一個時期

has spikes sticking out the back of its head.

牠的後腦杓有一些尖刺

It's got a little, tiny dome,

頭上有一個小小的圓頂

and it's got a bunch of gnarly stuff on its nose.

鼻子上有一堆粗糙凸起的部分

And then there's this thing called Dracorex,

最後一種叫做帝王龍

Hogwart's Eye.

全名為 Dracorex hogwartsia，霍格華茲的守護者

Guess where that came from? Dragon.

猜猜看這個名字怎麼來的？龍

So here's a dinosaur

這種恐龍

that has spikes sticking out of its head, no dome

後腦杓有一些尖刺，頭上沒有圓頂

and gnarly stuff on its nose.

鼻子上有一堆粗糙凸起的部分

Nobody noticed the gnarly stuff sort of looked alike.

沒有人發現這些粗糙凸起的部分很類似

But they did look at these three

但是他們看著這 3 隻恐龍

and they said, "These are three different dinosaurs,

說，「這是 3 種不同的恐龍

and Dracorex is probably the most primitive of them.

帝王龍可能是裡面最原始的

And the other one is more primitive than the other.''

而剩下的兩者中 其中一種又比另一種更原始。」

It's unclear to me

我不明白

how they actually sorted these three of them out.

當時人們是如何將這 3 隻恐龍如此分類的

But if you line them up,

不過如果你將它們排成一列

if you just take those three skulls and just line them up,

如果你將牠們的頭蓋骨排成一列

they line up like this.

就像這樣，你會看到

Dracorex is the littlest one,

帝王龍的骨頭是最小的

Stygimoloch is the middle size one,

冥河龍的介於中間

Pachycephalosaurus is the largest one.

腫頭龍的是最大的

And one would think,

看到的人心裡應該想

that should give me a clue.

這好像給了我一點線索

(Laughter)

(笑聲)

But it didn't give them a clue.

很顯然，他們並沒有發現這個線索

Because, well we know why.

因為呢，我們知道原因

Scientists like to name things.

科學家喜歡為東西命名

So if we cut open Dracorex --

所以，如果我們將帝王龍的頭蓋骨切開

I cut open our Dracorex --

我把我們博物館帝王龍的頭蓋骨切開

and look, it was spongy inside,

你看，骨頭內部呈現多孔狀

really spongy inside.

結構非常鬆散

I mean, it is a juvenile

這是幼年的特徵

and it's growing really fast.

這個部位正在快速生長

So it is going to get bigger.

所以頭部這個區塊的體積會越來越大

If you cut open Stygimoloch,

如果你將冥河龍的頭蓋骨切開

it is doing the same thing.

呈現的是同樣的情況

The dome, that little dome,

頭上的圓頂，那個小小的圓頂

is growing really fast.

正在快速成長

It's inflating very fast.

它正在快速膨脹

What's interesting is the spike on the back of the Dracorex

很有趣的是，帝王龍後腦杓的尖刺

was growing very fast as well.

此時也正在快速生長

The spikes on the back of the Stygimoloch

但冥河龍後腦杓的尖刺

are actually resorbing,

是在往內縮

which means they're getting smaller

這代表這些尖刺開始變得越來越小

as that dome is getting bigger.

同時，頭上的圓頂卻越來越大

And if we look at Pachycephalosaurus,

如果我們觀察腫頭龍

Pachycephalosaurus has a solid dome

腫頭龍頭上有一個堅固的圓頂

and its little bumps on the back of its head

而在牠後腦杓的小腫塊

were also resorbing.

也在往內縮

So just with these three dinosaurs,

因此，以這 3 隻恐龍而言

you can easily -- as a scientist --

身為一個科學家，你可以輕易

we can easily hypothesize

我們可以輕易的假設

that it is just a growth series

這 3 隻恐龍呈現的是一系列成長的過程

of the same animal.

牠們其實是同一種恐龍

Which of course means

當然，這就代表

that Stygimoloch and Dracorex

冥河龍和帝王龍

are extinct.

絕種了

(Laughter)

(笑聲)

Okay.

好的

Which of course means

當然這代表