magnificence of spiders

我為了宣傳蜘蛛的偉大

and how much we can learn from them.

及眾多可向其學習之處

Spiders are truly global citizens.

而來到這邊。

You can find spiders in nearly

蜘蛛是世界公民，

every terrestrial habitat.

你幾乎可以在世界各地

This red dot marks

皆發現到蜘蛛的蹤跡。

the Great Basin of North America,

這些紅點

and I'm involved with an alpine biodiversity

是北美大盆地，

project there with some collaborators.

我與一些人在那邊合作

Here's one of our field sites,

研究高山生物多樣性。

and just to give you a sense of perspective,

這是一個我們做田野調查的地方，

this little blue smudge here,

讓你們瞭解一下，

that's one of my collaborators.

這些藍色的點點，

This is a rugged and barren landscape,

那是我合作的其中一個對象。

yet there are quite a few spiders here.

這是一個崎嶇的荒蕪地，

Turning rocks over revealed this crab spider

但那裡也有許多蜘蛛。

grappling with a beetle.

把石頭翻開就會發現下面有很多蟹蛛

Spiders are not just everywhere,

抓著甲蟲。

but they're extremely diverse.

蜘蛛不只是到處都是，

There are over 40,000 described species

它們也極其多樣化。

of spiders.

已知的蜘蛛種類有

To put that number into perspective,

四萬多種。

here's a graph comparing the 40,000

為了讓你們對此數字有更深刻的體認，

species of spiders

這個圖將四萬種蜘蛛

to the 400 species of primates.

和四百種靈長類

There are two orders of magnitude more

放在一起做比較。

spiders than primates.

蜘蛛比靈長類

Spiders are also extremely old.

多了百倍。

On the bottom here,

蜘蛛也是很古老的。

this is the geologic timescale,

在這邊底下，

and the numbers on it indicate millions

這是地質時間表，

of years from the present, so the zero here,

這些數字代表百萬年前，

that would be today.

所以這邊這個零

So what this figure shows is that spiders

就是現在。

date back to almost 380 million years.

這個圖表告訴我們

To put that into perspective, this red

蜘蛛在三億八千多萬年前就存在了。

vertical bar here marks the divergence time

巨觀來看，這個紅線

of humans from chimpanzees,

劃出人和黑猩猩

a mere seven million years ago.

開始分歧的時間點，

All spiders make silk

僅僅發生在七百萬年前。

at some point in their life.

所有蜘蛛在它一生中

Most spiders use copious amounts of silk,

的某些時刻都會製造蜘蛛絲。

and silk is essential to their survival

大部份蜘蛛會用大量的蜘蛛絲，

and reproduction.

且蜘蛛絲對牠們的生存

Even fossil spiders can make silk,

和繁殖非常重要。

as we can see from this impression of

就連遠古時期的蜘蛛也可以製造絲，

a spinneret on this fossil spider.

我們可以從這個化石印記上

So this means that both spiders

看到這石化蜘蛛的噴絲頭。

and spider silk have been around

所以這表示

for 380 million years.

蜘蛛和蜘蛛絲都已存在

It doesn't take long from working with spiders

三億八千多萬年了。

to start noticing how essential silk is

其實不需要研究蜘蛛很久

to just about every aspect of their life.

就可以發現蜘蛛絲對蜘蛛有多重要

Spiders use silk for many purposes, including

幾乎與蜘蛛生存的每一個層面都息息相關。

the trailing safety dragline,

蜘蛛用蜘蛛絲做很多事，

wrapping eggs for reproduction,

像是用以作攀登的安全索、

protective retreats

包覆卵以利繁殖、

and catching prey.

協助逃跑、

There are many kinds of spider silk.

和捕捉獵物。

For example, this garden spider can make

蜘蛛絲有很多種，

seven different kinds of silks.

舉例來說，這種花園蜘蛛

When you look at this orb web, you're actually

可以製造七種蜘蛛絲。

seeing many types of silk fibers.

當你看著這個蜘蛛網的時候，

The frame and radii of this web

你事實上正在看著很多種絲纖維。

is made up of one type of silk,

網的外框與輻射狀軸線

while the capture spiral is a composite

是由一種蜘蛛絲構成的，

of two different silks:

而這用來捕捉獵物的螺旋狀絲線，

the filament and the sticky droplet.

是由兩種不同的絲所組成的：

How does an individual spider

分別是絲狀物和這黏稠的液滴。

make so many kinds of silk?

一隻蜘蛛是如何

To answer that, you have to look a lot closer

製造這麼多種的蜘蛛絲呢？

at the spinneret region of a spider.

要回答這個問題，你們必須更仔細地觀察

So silk comes out of the spinnerets, and for

蜘蛛的噴絲頭區域。

those of us spider silk biologists, this is what

蜘蛛從噴絲頭吐出絲，

we call the "business end" of the spider. (Laughter)

而對我們這些研究蜘蛛絲的生物學家來說，

We spend long days ...

我們稱這個地方為蜘蛛「辦公」的地方。（笑聲）

Hey! Don't laugh. That's my life.

我們花很多時間

(Laughter)

嘿！不要笑！這是我的人生。

We spend long days and nights

（笑聲）

staring at this part of the spider.

我們日以繼夜地盯著

And this is what we see.

蜘蛛的這個部份。

You can see multiple fibers

而這是我們所看到的。

coming out of the spinnerets, because

你們可以看到數條絲纖維

each spinneret has many spigots on it.

從噴絲頭出來，

Each of these silk fibers exits from the spigot,

因為每一個噴頭都有許多噴嘴。

and if you were to trace the fiber back

每一條絲纖維從其中的一個噴嘴噴出，

into the spider, what you would find is that

而如果你順著纖維回溯到蜘蛛體內，

each spigot connects to its own individual

你會發現

silk gland. A silk gland kind of looks like a sac

每一個噴頭都連接著一個獨有的絲腺。

with a lot of silk proteins stuck inside.

絲腺看起來像是一個

So if you ever have the opportunity to dissect

含有很多絲蛋白的囊袋。

an orb-web-weaving spider,

所以如果你有機會解剖

and I hope you do,

圓網蜘蛛的話，

what you would find is a bounty

我希望你真的有這樣的機會，

of beautiful, translucent silk glands.

你會看到很多

Inside each spider, there are hundreds

很漂亮的透明絲腺。

of silk glands, sometimes thousands.

每一隻蜘蛛有幾百

These can be grouped into seven categories.

到幾千個絲腺。

They differ by size, shape,

這些腺體可以被分為七大類，

and sometimes even color.

它們在大小、形狀、

In an orb-web-weaving spider,

有時甚至顏色上皆不同。

you can find seven types of silk glands,

一隻圓網蜘蛛身上

and what I have depicted here in this picture,

可以找到七種不同的絲腺，

let's start at the one o'clock position,

而我在這張圖片中所標示出來的，

there's tubuliform silk glands, which are used

從一點鐘方向開始，

to make the outer silk of an egg sac.

這是管狀絲腺，是用來

There's the aggregate and flagelliform silk

製造蛋囊外面的絲。

glands which combine to make the sticky

這裡有聚結和條狀絲腺，

capture spiral of an orb web.

這兩種絲腺合起來可以製造

Pyriform silk glands make the attachment

圓網中的黏性捕捉螺旋絲。

cement -- that's the silk that's used to adhere

梨狀絲腺製造接著膠水，

silk lines to a substrate.

就是用來將絲線和基質

There's also aciniform silk,

黏接在一起的絲。

which is used to wrap prey.

還有用來包覆獵物的

Minor ampullate silk is used in web construction.

葡萄絲。

And the most studied silk line

小型壺狀絲被用來製造蜘蛛網。

of them all: major ampullate silk.

而最常被研究的蜘蛛絲

This is the silk that's used to make the frame

就是大型壺狀絲。

and radii of an orb web, and also

這是被用來製造圓型蜘蛛網

the safety trailing dragline.

的外框和半徑的絲，也被用作

But what, exactly, is spider silk?

安全防護索使用。

Spider silk is almost entirely protein.

但蜘蛛絲到底是什麼呢？

Nearly all of these proteins can be explained

蜘蛛絲幾乎全由蛋白質所組成。

by a single gene family,

大部分的這些蛋白

so this means that the diversity of silk types

可以經由一個基因家族來解釋，

we see today is encoded by one gene family,

也就是說我們看到的這麼多種蜘蛛絲

so presumably the original spider ancestor

都是由一個基因家族所編碼出來的。

made one kind of silk,

所以很有可能蜘蛛的祖宗

and over the last 380 million years,

只製造一種絲，

that one silk gene has duplicated

而且在這三億八千萬年之中，

and then diverged, specialized,

那個絲基因複製、

over and over and over again, to get

分歧、特化

the large variety of flavors of spider silks

一次又一次，

that we have today.

直到現在有這麼多種

There are several features that all these silks

不同的蜘蛛絲。

have in common. They all have a common

這麼多種不同的蜘蛛絲有數個共通點，

design, such as they're all very long --

它們都有非常相似的設計，

they're sort of outlandishly long

像是它們都非常長，

compared to other proteins.

也就是說它們比一般的蛋白質

They're very repetitive, and they're very rich

長很多很多。

in the amino acids glycine and alanine.

它們重複性很高，且它們含有大量的

To give you an idea of what

甘胺酸和丙胺酸。

a spider silk protein looks like,

為了讓你們有個概念，

this is a dragline silk protein,

蜘蛛絲蛋白看起來大概像是這樣，

it's just a portion of it,

這是牽引絲蛋白，

from the black widow spider.

這只是黑寡婦蜘蛛

This is the kind of sequence that I love

的蜘蛛絲蛋白的一部份。

looking at day and night. (Laughter)

這是我最愛的一種序列，

So what you're seeing here is the one letter

我可以日以繼夜地看他。（笑聲）

abbreviation for amino acids, and I've colored

所以你們現在看到的這些是

in the glycines with green,

胺基酸的單字母縮寫，

and the alanines in red, and so

我把甘胺酸標記成綠色，

you can see it's just a lot of G's and A's.

然後把丙胺酸標記成紅色。

You can also see that there's a lot of short

所以你可以看到有很多的 G 和 A。

sequence motifs that repeat over and over

你也可以看到有許多的短序列

and over again, so for example there's a lot of

一再地重複又重複，

what we call polyalanines, or iterated A's,

舉例來說這邊有很多我們叫作

AAAAA. There's GGQ. There's GGY.

聚合丙胺酸的片段，也就是很多個 A。

You can think of these short motifs

這是 GGQ，這是 GGY。

that repeat over and over again as words,

你們可以把這些

and these words occur in sentences.

不斷重複的短序列當成文字，

So for example this would be one sentence,

而這些文字在句子裡面出現。

and you would get this sort of green region

舉例來說這是一個句子，

and the red polyalanine, that repeats

然後你有這些綠色的部份

over and over and over again,

和這些紅色的聚丙胺酸會一直

and you can have that hundreds and

不斷地不斷地重複，

hundreds and hundreds of times within

而且你可以在單一個絲分子中

an individual silk molecule.

找到好幾百次

Silks made by the same spider can have

的重複。

dramatically different repeat sequences.

由同一隻蜘蛛所製造的絲可以有

At the top of the screen, you're seeing

非常不同的重複序列。

the repeat unit from the dragline silk

在螢幕上方，你可以看到

of a garden argiope spider.

金蛛牽引絲的

It's short. And on the bottom,

重複單元，

this is the repeat sequence for the

它很短。在下面，

egg case, or tubuliform silk protein,

這是同一種蜘蛛

for the exact same spider. And you can see

蛋殻的重複序列，

how dramatically different

也就是管狀絲蛋白。你們可以看出

these silk proteins are -- so this is

這兩種絲蛋白

sort of the beauty of the diversification

有多麼不同 — 這就是

of the spider silk gene family.

蜘蛛絲基因家族分歧

You can see that the repeat units differ

漂亮的地方。

in length. They also differ in sequence.

你可以看到這些重複序列的

So I've colored in the glycines again

長短不同，它們的序列也不同。

in green, alanine in red, and the serines,

所以這裡我再把甘胺酸標記成綠色、

the letter S, in purple. And you can see

丙胺酸為紅色、絲氨酸

that the top repeat unit can be explained

縮寫為 S，標記成紫色。你可以看到

almost entirely by green and red,

這些在上方的重複序列

and the bottom repeat unit has

幾乎全是綠色和紅色，

a substantial amount of purple.

在這下面的重複序列

What silk biologists do is we try to relate

有很多紫色。

these sequences, these amino acid

絲生物學家想將

sequences, to the mechanical properties

這些胺基酸的序列

of the silk fibers.

與絲纖維的機械性質

Now, it's really convenient that spiders use their silk

連結起來。

completely outside their body.

蜘蛛僅在體外使用它們的蜘蛛絲

This makes testing spider silk really, really

對我們來說是非常便利的。

easy to do in the laboratory, because

這讓在實驗室中研究蜘蛛絲

we're actually, you know, testing it in air

非常、非常容易，

that's exactly the environment that

因為我們實際上是在空氣中測試它，

spiders are using their silk proteins.

而這也正是

So this makes quantifying silk properties by

蜘蛛使用牠們絲蛋白的環境。

methods such as tensile testing, which is

所以這些特性

basically, you know, tugging on one end

讓我們可以做拉伸測試，

of the fiber, very amenable.

也就是

Here are stress-strain curves

在纖維兩側拉扯。

generated by tensile testing

這是從同一隻蜘蛛的

five fibers made by the same spider.

五種蜘蛛絲的

So what you can see here is that

拉伸測試所得到的受力圖。

the five fibers have different behaviors.

你們可以看到

Specifically, if you look on the vertical axis,

這五種絲各有不同的表現。

that's stress. If you look at the maximum

如果你看 y 軸，這是拉力。

stress value for each of these fibers,

如果你看每一種絲

you can see that there's a lot of variation,

可以承受的拉力，

and in fact dragline, or major ampullate silk,

你會看到有很大的變異。

is the strongest of these fibers.

牽引絲，也就是大型壺狀絲，

We think that's because the dragline silk,

是最強壯的絲。

which is used to make the frame and radii

我們認為這是因為牽引絲

for a web, needs to be very strong.

是用來製作蜘蛛網外框和半徑的材料，

On the other hand, if you were to look at

它需要非常強壯。

strain -- this is how much a fiber can be

從另一個角度看，如果你觀察應力，

extended -- if you look at the maximum value

這是纖維可以延伸的程度，

here, again, there's a lot of variation

如果你看在這邊這個最大值，

and the clear winner is flagelliform,

又一次地，也是有很大的變異，

or the capture spiral filament.

很明顯的這次是條狀絲

In fact, this flagelliform fiber can

或稱捕捉螺旋絲大勝。

actually stretch over twice its original length.

事實上，條狀纖維

So silk fibers vary in their strength

可以延伸到超過原來長度的兩倍。

and also their extensibility.

也就是說絲纖維的強度

In the case of the capture spiral,

和延展性都不相同。

it needs to be so stretchy to absorb

以捕捉螺旋絲來說，

the impact of flying prey.

它需要有很好的延展性

If it wasn't able to stretch so much, then

來吸收獵物落網的衝力。

basically when an insect hit the web,

如果它們沒有這麼好的延展性，

it would just trampoline right off of it.

當有昆蟲落入蜘蛛網的時候，

So if the web was made entirely out of

昆蟲只會直接從蜘蛛網上彈下來。

dragline silk, an insect is very likely to just

所以如果整張網都是由牽引絲所組成，

bounce right off. But by having really, really

那麼昆蟲只會直接

stretchy capture spiral silk, the web is actually

彈下來。但因為有這樣

able to absorb the impact

延展性非常好的捕捉螺旋絲，整張網

of that intercepted prey.

可以吸收獵物的衝力

There's quite a bit of variation within

並捕捉獵物。

the fibers that an individual spider can make.

一隻蜘蛛可以製造的不同絲纖維間

We call that the tool kit of a spider.

有很多差異。

That's what the spider has

我們稱之為蜘蛛的工具箱。

to interact with their environment.

那是蜘蛛用來與環境

But how about variation among spider

互動的工具。

species, so looking at one type of silk

但是不同種類蜘蛛間的差異呢？

and looking at different species of spiders?

如果我們觀察一種絲，

This is an area that's largely unexplored

然後比較不同種類蜘蛛間這種絲的異同？

but here's a little bit of data I can show you.

這是一個尚未被深入研究的領域，

This is the comparison of the toughness

但我可以給你們看一些數據。

of the dragline spilk spun

這是 21 種蜘蛛間