I'm here to spread the word about the magnificence of spiders and how much we can learn from them. Spiders are truly global citizens. You can find spiders in nearly every terrestrial habitat. This red dot marks the Great Basin of North America, and I'm involved with an alpine biodiversity project there with some collaborators. Here's one of our field sites, and just to give you a sense of perspective, this little blue smudge here, that's one of my collaborators. This is a rugged and barren landscape, yet there are quite a few spiders here. Turning rocks over revealed this crab spider grappling with a beetle.
我為了宣傳蜘蛛的偉大 及眾多可向其學習之處 而來到這邊。 蜘蛛是世界公民, 你幾乎可以在世界各地 皆發現到蜘蛛的蹤跡。 這些紅點 是北美大盆地, 我與一些人在那邊合作 研究高山生物多樣性。 這是一個我們做田野調查的地方, 讓你們瞭解一下, 這些藍色的點點, 那是我合作的其中一個對象。 這是一個崎嶇的荒蕪地, 但那裡也有許多蜘蛛。 把石頭翻開就會發現下面有很多蟹蛛 抓著甲蟲。
Spiders are not just everywhere, but they're extremely diverse. There are over 40,000 described species of spiders. To put that number into perspective, here's a graph comparing the 40,000 species of spiders to the 400 species of primates. There are two orders of magnitude more spiders than primates. Spiders are also extremely old. On the bottom here, this is the geologic timescale, and the numbers on it indicate millions of years from the present, so the zero here, that would be today. So what this figure shows is that spiders date back to almost 380 million years. To put that into perspective, this red vertical bar here marks the divergence time of humans from chimpanzees, a mere seven million years ago.
蜘蛛不只是到處都是, 它們也極其多樣化。 已知的蜘蛛種類有 四萬多種。 為了讓你們對此數字有更深刻的體認, 這個圖將四萬種蜘蛛 和四百種靈長類 放在一起做比較。 蜘蛛比靈長類 多了百倍。 蜘蛛也是很古老的。 在這邊底下, 這是地質時間表, 這些數字代表百萬年前, 所以這邊這個零 就是現在。 這個圖表告訴我們 蜘蛛在三億八千多萬年前就存在了。 巨觀來看,這個紅線 劃出人和黑猩猩 開始分歧的時間點, 僅僅發生在七百萬年前。
All spiders make silk at some point in their life. Most spiders use copious amounts of silk, and silk is essential to their survival and reproduction. Even fossil spiders can make silk, as we can see from this impression of a spinneret on this fossil spider. So this means that both spiders and spider silk have been around for 380 million years. It doesn't take long from working with spiders to start noticing how essential silk is to just about every aspect of their life. Spiders use silk for many purposes, including the trailing safety dragline, wrapping eggs for reproduction, protective retreats and catching prey.
所有蜘蛛在它一生中 的某些時刻都會製造蜘蛛絲。 大部份蜘蛛會用大量的蜘蛛絲, 且蜘蛛絲對牠們的生存 和繁殖非常重要。 就連遠古時期的蜘蛛也可以製造絲, 我們可以從這個化石印記上 看到這石化蜘蛛的噴絲頭。 所以這表示 蜘蛛和蜘蛛絲都已存在 三億八千多萬年了。 其實不需要研究蜘蛛很久 就可以發現蜘蛛絲對蜘蛛有多重要 幾乎與蜘蛛生存的每一個層面都息息相關。 蜘蛛用蜘蛛絲做很多事, 像是用以作攀登的安全索、 包覆卵以利繁殖、 協助逃跑、 和捕捉獵物。
There are many kinds of spider silk. For example, this garden spider can make seven different kinds of silks. When you look at this orb web, you're actually seeing many types of silk fibers. The frame and radii of this web is made up of one type of silk, while the capture spiral is a composite of two different silks: the filament and the sticky droplet. How does an individual spider make so many kinds of silk? To answer that, you have to look a lot closer at the spinneret region of a spider. So silk comes out of the spinnerets, and for those of us spider silk biologists, this is what we call the "business end" of the spider. (Laughter) We spend long days ... Hey! Don't laugh. That's my life. (Laughter) We spend long days and nights staring at this part of the spider. And this is what we see. You can see multiple fibers coming out of the spinnerets, because each spinneret has many spigots on it. Each of these silk fibers exits from the spigot, and if you were to trace the fiber back into the spider, what you would find is that each spigot connects to its own individual silk gland. A silk gland kind of looks like a sac with a lot of silk proteins stuck inside. So if you ever have the opportunity to dissect an orb-web-weaving spider, and I hope you do, what you would find is a bounty of beautiful, translucent silk glands.
蜘蛛絲有很多種, 舉例來說,這種花園蜘蛛 可以製造七種蜘蛛絲。 當你看著這個蜘蛛網的時候, 你事實上正在看著很多種絲纖維。 網的外框與輻射狀軸線 是由一種蜘蛛絲構成的, 而這用來捕捉獵物的螺旋狀絲線, 是由兩種不同的絲所組成的: 分別是絲狀物和這黏稠的液滴。 一隻蜘蛛是如何 製造這麼多種的蜘蛛絲呢? 要回答這個問題,你們必須更仔細地觀察 蜘蛛的噴絲頭區域。 蜘蛛從噴絲頭吐出絲, 而對我們這些研究蜘蛛絲的生物學家來說, 我們稱這個地方為蜘蛛「辦公」的地方。(笑聲) 我們花很多時間 嘿!不要笑!這是我的人生。 (笑聲) 我們日以繼夜地盯著 蜘蛛的這個部份。 而這是我們所看到的。 你們可以看到數條絲纖維 從噴絲頭出來, 因為每一個噴頭都有許多噴嘴。 每一條絲纖維從其中的一個噴嘴噴出, 而如果你順著纖維回溯到蜘蛛體內, 你會發現 每一個噴頭都連接著一個獨有的絲腺。 絲腺看起來像是一個 含有很多絲蛋白的囊袋。 所以如果你有機會解剖 圓網蜘蛛的話, 我希望你真的有這樣的機會, 你會看到很多 很漂亮的透明絲腺。
Inside each spider, there are hundreds of silk glands, sometimes thousands. These can be grouped into seven categories. They differ by size, shape, and sometimes even color. In an orb-web-weaving spider, you can find seven types of silk glands, and what I have depicted here in this picture, let's start at the one o'clock position, there's tubuliform silk glands, which are used to make the outer silk of an egg sac. There's the aggregate and flagelliform silk glands which combine to make the sticky capture spiral of an orb web. Pyriform silk glands make the attachment cement -- that's the silk that's used to adhere silk lines to a substrate. There's also aciniform silk, which is used to wrap prey. Minor ampullate silk is used in web construction. And the most studied silk line of them all: major ampullate silk. This is the silk that's used to make the frame and radii of an orb web, and also the safety trailing dragline.
每一隻蜘蛛有幾百 到幾千個絲腺。 這些腺體可以被分為七大類, 它們在大小、形狀、 有時甚至顏色上皆不同。 一隻圓網蜘蛛身上 可以找到七種不同的絲腺, 而我在這張圖片中所標示出來的, 從一點鐘方向開始, 這是管狀絲腺,是用來 製造蛋囊外面的絲。 這裡有聚結和條狀絲腺, 這兩種絲腺合起來可以製造 圓網中的黏性捕捉螺旋絲。 梨狀絲腺製造接著膠水, 就是用來將絲線和基質 黏接在一起的絲。 還有用來包覆獵物的 葡萄絲。 小型壺狀絲被用來製造蜘蛛網。 而最常被研究的蜘蛛絲 就是大型壺狀絲。 這是被用來製造圓型蜘蛛網 的外框和半徑的絲,也被用作 安全防護索使用。
But what, exactly, is spider silk? Spider silk is almost entirely protein. Nearly all of these proteins can be explained by a single gene family, so this means that the diversity of silk types we see today is encoded by one gene family, so presumably the original spider ancestor made one kind of silk, and over the last 380 million years, that one silk gene has duplicated and then diverged, specialized, over and over and over again, to get the large variety of flavors of spider silks that we have today. There are several features that all these silks have in common. They all have a common design, such as they're all very long -- they're sort of outlandishly long compared to other proteins. They're very repetitive, and they're very rich in the amino acids glycine and alanine. To give you an idea of what a spider silk protein looks like, this is a dragline silk protein, it's just a portion of it, from the black widow spider. This is the kind of sequence that I love looking at day and night. (Laughter)
但蜘蛛絲到底是什麼呢? 蜘蛛絲幾乎全由蛋白質所組成。 大部分的這些蛋白 可以經由一個基因家族來解釋, 也就是說我們看到的這麼多種蜘蛛絲 都是由一個基因家族所編碼出來的。 所以很有可能蜘蛛的祖宗 只製造一種絲, 而且在這三億八千萬年之中, 那個絲基因複製、 分歧、特化 一次又一次, 直到現在有這麼多種 不同的蜘蛛絲。 這麼多種不同的蜘蛛絲有數個共通點, 它們都有非常相似的設計, 像是它們都非常長, 也就是說它們比一般的蛋白質 長很多很多。 它們重複性很高,且它們含有大量的 甘胺酸和丙胺酸。 為了讓你們有個概念, 蜘蛛絲蛋白看起來大概像是這樣, 這是牽引絲蛋白, 這只是黑寡婦蜘蛛 的蜘蛛絲蛋白的一部份。 這是我最愛的一種序列, 我可以日以繼夜地看他。(笑聲)
So what you're seeing here is the one letter abbreviation for amino acids, and I've colored in the glycines with green, and the alanines in red, and so you can see it's just a lot of G's and A's. You can also see that there's a lot of short sequence motifs that repeat over and over and over again, so for example there's a lot of what we call polyalanines, or iterated A's, AAAAA. There's GGQ. There's GGY. You can think of these short motifs that repeat over and over again as words, and these words occur in sentences. So for example this would be one sentence, and you would get this sort of green region and the red polyalanine, that repeats over and over and over again, and you can have that hundreds and hundreds and hundreds of times within an individual silk molecule.
所以你們現在看到的這些是 胺基酸的單字母縮寫, 我把甘胺酸標記成綠色, 然後把丙胺酸標記成紅色。 所以你可以看到有很多的 G 和 A。 你也可以看到有許多的短序列 一再地重複又重複, 舉例來說這邊有很多我們叫作 聚合丙胺酸的片段,也就是很多個 A。 這是 GGQ,這是 GGY。 你們可以把這些 不斷重複的短序列當成文字, 而這些文字在句子裡面出現。 舉例來說這是一個句子, 然後你有這些綠色的部份 和這些紅色的聚丙胺酸會一直 不斷地不斷地重複, 而且你可以在單一個絲分子中 找到好幾百次 的重複。
Silks made by the same spider can have dramatically different repeat sequences. At the top of the screen, you're seeing the repeat unit from the dragline silk of a garden argiope spider. It's short. And on the bottom, this is the repeat sequence for the egg case, or tubuliform silk protein, for the exact same spider. And you can see how dramatically different these silk proteins are -- so this is sort of the beauty of the diversification of the spider silk gene family. You can see that the repeat units differ in length. They also differ in sequence. So I've colored in the glycines again in green, alanine in red, and the serines, the letter S, in purple. And you can see that the top repeat unit can be explained almost entirely by green and red, and the bottom repeat unit has a substantial amount of purple. What silk biologists do is we try to relate these sequences, these amino acid sequences, to the mechanical properties of the silk fibers.
由同一隻蜘蛛所製造的絲可以有 非常不同的重複序列。 在螢幕上方,你可以看到 金蛛牽引絲的 重複單元, 它很短。在下面, 這是同一種蜘蛛 蛋殻的重複序列, 也就是管狀絲蛋白。你們可以看出 這兩種絲蛋白 有多麼不同 — 這就是 蜘蛛絲基因家族分歧 漂亮的地方。 你可以看到這些重複序列的 長短不同,它們的序列也不同。 所以這裡我再把甘胺酸標記成綠色、 丙胺酸為紅色、絲氨酸 縮寫為 S,標記成紫色。你可以看到 這些在上方的重複序列 幾乎全是綠色和紅色, 在這下面的重複序列 有很多紫色。 絲生物學家想將 這些胺基酸的序列 與絲纖維的機械性質 連結起來。
Now, it's really convenient that spiders use their silk completely outside their body. This makes testing spider silk really, really easy to do in the laboratory, because we're actually, you know, testing it in air that's exactly the environment that spiders are using their silk proteins. So this makes quantifying silk properties by methods such as tensile testing, which is basically, you know, tugging on one end of the fiber, very amenable. Here are stress-strain curves generated by tensile testing five fibers made by the same spider. So what you can see here is that the five fibers have different behaviors. Specifically, if you look on the vertical axis, that's stress. If you look at the maximum stress value for each of these fibers, you can see that there's a lot of variation, and in fact dragline, or major ampullate silk, is the strongest of these fibers. We think that's because the dragline silk, which is used to make the frame and radii for a web, needs to be very strong.
蜘蛛僅在體外使用它們的蜘蛛絲 對我們來說是非常便利的。 這讓在實驗室中研究蜘蛛絲 非常、非常容易, 因為我們實際上是在空氣中測試它, 而這也正是 蜘蛛使用牠們絲蛋白的環境。 所以這些特性 讓我們可以做拉伸測試, 也就是 在纖維兩側拉扯。 這是從同一隻蜘蛛的 五種蜘蛛絲的 拉伸測試所得到的受力圖。 你們可以看到 這五種絲各有不同的表現。 如果你看 y 軸,這是拉力。 如果你看每一種絲 可以承受的拉力, 你會看到有很大的變異。 牽引絲,也就是大型壺狀絲, 是最強壯的絲。 我們認為這是因為牽引絲 是用來製作蜘蛛網外框和半徑的材料, 它需要非常強壯。
On the other hand, if you were to look at strain -- this is how much a fiber can be extended -- if you look at the maximum value here, again, there's a lot of variation and the clear winner is flagelliform, or the capture spiral filament. In fact, this flagelliform fiber can actually stretch over twice its original length. So silk fibers vary in their strength and also their extensibility. In the case of the capture spiral, it needs to be so stretchy to absorb the impact of flying prey. If it wasn't able to stretch so much, then basically when an insect hit the web, it would just trampoline right off of it. So if the web was made entirely out of dragline silk, an insect is very likely to just bounce right off. But by having really, really stretchy capture spiral silk, the web is actually able to absorb the impact of that intercepted prey.
從另一個角度看,如果你觀察應力, 這是纖維可以延伸的程度, 如果你看在這邊這個最大值, 又一次地,也是有很大的變異, 很明顯的這次是條狀絲 或稱捕捉螺旋絲大勝。 事實上,條狀纖維 可以延伸到超過原來長度的兩倍。 也就是說絲纖維的強度 和延展性都不相同。 以捕捉螺旋絲來說, 它需要有很好的延展性 來吸收獵物落網的衝力。 如果它們沒有這麼好的延展性, 當有昆蟲落入蜘蛛網的時候, 昆蟲只會直接從蜘蛛網上彈下來。 所以如果整張網都是由牽引絲所組成, 那麼昆蟲只會直接 彈下來。但因為有這樣 延展性非常好的捕捉螺旋絲,整張網 可以吸收獵物的衝力 並捕捉獵物。
There's quite a bit of variation within the fibers that an individual spider can make. We call that the tool kit of a spider. That's what the spider has to interact with their environment. But how about variation among spider species, so looking at one type of silk and looking at different species of spiders? This is an area that's largely unexplored but here's a little bit of data I can show you. This is the comparison of the toughness of the dragline spilk spun by 21 species of spiders. Some of them are orb-weaving spiders and some of them are non-orb-weaving spiders. It's been hypothesized that orb-weaving spiders, like this argiope here, should have the toughest dragline silks because they must intercept flying prey. What you see here on this toughness graph is the higher the black dot is on the graph, the higher the toughness.
一隻蜘蛛可以製造的不同絲纖維間 有很多差異。 我們稱之為蜘蛛的工具箱。 那是蜘蛛用來與環境 互動的工具。 但是不同種類蜘蛛間的差異呢? 如果我們觀察一種絲, 然後比較不同種類蜘蛛間這種絲的異同? 這是一個尚未被深入研究的領域, 但我可以給你們看一些數據。 這是 21 種蜘蛛間 牽引絲韌度 的比較。 這裡有些是圓網蜘蛛 有些是非圓網蜘蛛。 一般推測這些圓網蜘蛛, 像是這隻金蛛, 應該有最強韌的牽引絲, 因為他們需要攔截飛行獵物。 在這張韌性表中 黑點越高 表示韌性越高。
The 21 species are indicated here by this phylogeny, this evolutionary tree, that shows their genetic relationships, and I've colored in yellow the orb-web-weaving spiders. If you look right here at the two red arrows, they point to the toughness values for the draglines of nephila clavipes and araneus diadematus. These are the two species of spiders for which the vast majority of time and money on synthetic spider silk research has been to replicate their dragline silk proteins. Yet, their draglines are not the toughest. In fact, the toughest dragline in this survey is this one right here in this white region, a non orb-web-weaving spider. This is the dragline spun by scytodes, the spitting spider. Scytodes doesn't use a web at all to catch prey. Instead, scytodes sort of lurks around and waits for prey to get close to it, and then immobilizes prey by spraying a silk-like venom onto that insect. Think of hunting with silly string. That's how scytodes forages. We don't really know why scytodes needs such a tough dragline, but it's unexpected results like this that make bio-prospecting so exciting and worthwhile. It frees us from the constraints of our imagination.
這 21 種蜘蛛的關係在這裡 用演化樹來表示出 它們之間的基因關係, 圓網蜘蛛在這邊被我以黃色標記。 如果你看這邊這兩個紅色箭頭, 它們指向 金蛛 (nephila clavipes) 和 歐洲圓蛛 (araneus diadematus) 的牽引絲強度。 絕大多數的金錢和時間 都被投注在人工合成複製 這兩種蜘蛛的牽引絲蛋白 的研究上。 但牠們的牽引絲卻不是韌性最高的。 事實上,在這份調查中韌性最高的牽引絲 是這個在白色區域中的這隻, 是一種非圓網蜘蛛。 這是花皮蛛 (scytodes) 所製造的牽引絲。 花皮蛛完全不用網來捕捉獵物。 相反地,它們在獵物附近徘徊, 並等待獵物靠近, 然後將絲狀毒素吐在獵物身上 使獵物動彈不得。 就像是用繩索捕捉獵物一樣, 花皮蛛就是這樣捕獵的。 我們不是很瞭解為什麼 花皮蛛需要如此強韌的牽引絲, 但就是這樣出乎意料的結果 讓生物研究如此有趣並有意義。 這讓我們不會被 成見所囿。
Now I'm going to mark on the toughness values for nylon fiber, bombyx -- or domesticated silkworm silk -- wool, Kevlar, and carbon fibers. And what you can see is that nearly all the spider draglines surpass them. It's the combination of strength, extensibility and toughness that makes spider silk so special, and that has attracted the attention of biomimeticists, so people that turn to nature to try to find new solutions. And the strength, extensibility and toughness of spider silks combined with the fact that silks do not elicit an immune response, have attracted a lot of interest in the use of spider silks in biomedical applications, for example, as a component of artificial tendons, for serving as guides to regrow nerves, and for scaffolds for tissue growth.
現在我想要談談 尼龍纖維、 家蠶、羊毛、 克維拉和碳纖維的韌性。 你們可以看到的是 幾乎所有蜘蛛牽引絲的韌性都優於這些材質。 這樣的強度、延展性 與韌性的組合使得蜘蛛絲如此特別, 這也是為什麼很多仿生學家 想要研究蜘蛛絲,也就是人們 向大自然找尋解答。 蜘蛛絲這樣的強度、延展力和韌性 再加上不會 引發任何免疫反應, 讓蜘蛛絲可以有很多 生物醫學上的用途, 舉例來說:可以用來 製造人工韌帶、 引導神經再生、或是 做為組織生長的鷹架。
Spider silks also have a lot of potential for their anti-ballistic capabilities. Silks could be incorporated into body and equipment armor that would be more lightweight and flexible than any armor available today. In addition to these biomimetic applications of spider silks, personally, I find studying spider silks just fascinating in and of itself. I love when I'm in the laboratory, a new spider silk sequence comes in. That's just the best. (Laughter) It's like the spiders are sharing an ancient secret with me, and that's why I'm going to spend the rest of my life studying spider silk. The next time you see a spider web, please, pause and look a little closer. You'll be seeing one of the most high-performance materials known to man. To borrow from the writings of a spider named Charlotte, silk is terrific.
蜘蛛絲的防彈特性, 也非常有應用潛力。 蜘蛛絲可以被置入人體、 或裝備護具來製造 比任何既有材質更輕更軟 的安全防具。 除了蜘蛛絲的 仿生用途外, 我個人認為研究蜘蛛絲 非常有趣。 我最喜歡我在實驗室的時候, 一個新的蜘蛛絲序列進來。 真的超棒的(笑聲) 這有點像是蜘蛛在跟我分享 一個古早的祕密,這也是為什麼 我接下來的人生 都會繼續研究蜘蛛絲。 下次你看到一張蜘蛛網, 拜託停下來更仔細地看看。 你會看到我們人類所知 最高性能的材料之一。 借用一隻名叫 夏綠蒂的蜘蛛所說的話: 絲真是太棒了!
Thank you. (Applause)
謝謝。(掌聲)
(Applause)
(掌聲)