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  • I'd like to introduce you to a tiny microorganism

    譯者: Lilian Chiu 審譯者: Yanyan Hong

  • that you've probably never heard of:

    我要向各位介紹 一種極小的微生物,

  • its name is Prochlorococcus,

    各位可能從來沒有聽過:

  • and it's really an amazing little being.

    它叫做原綠球藻,

  • For one thing, its ancestors

    它是種非常不可思議的小生命。

  • changed the earth in ways that made it possible for us to evolve,

    一則,它的祖先

  • and hidden in its genetic code

    改變了地球, 讓我們在地球上的演化成為可能,

  • is a blueprint

    而隱藏在它的基因碼之中的,

  • that may inspire ways to reduce our dependency on fossil fuel.

    是一張藍圖,

  • But the most amazing thing

    或許可以啟發一些讓我們 減少對化石燃料依賴的方式。

  • is that there are three billion billion billion

    但最不可思議的是,

  • of these tiny cells on the planet,

    在地球上有三千億億億個

  • and we didn't know they existed until 35 years ago.

    這種微小細胞,

  • So to tell you their story,

    且一直到三十五年前 我們才知道它們的存在。

  • I need to first take you way back,

    要說它們的故事之前,

  • four billion years ago, when the earth might have looked something like this.

    我得要先帶各位回頭,

  • There was no life on the planet,

    回到四十億年前,

  • there was no oxygen in the atmosphere.

    當時地球可能看起來還像是這樣子。

  • So what happened to change that planet into the one we enjoy today,

    地球上沒有生命,

  • teeming with life,

    大氣中沒有氧氣。

  • teeming with plants and animals?

    發生了什麼事,讓地球改變成 我們現今能享受的模樣,

  • Well, in a word, photosynthesis.

    充滿生命,

  • About two and a half billion years ago,

    充滿植物和動物?

  • some of these ancient ancestors of Prochlorococcus evolved

    用個詞來說,就是「光合作用」。

  • so that they could use solar energy

    大約二十五億年前,

  • and absorb it

    原綠球藻的某些古老祖先演化了,

  • and split water into its component parts of oxygen and hydrogen.

    它們開始能使用太陽能,

  • And they used the chemical energy produced

    吸收它,

  • to draw CO2, carbon dioxide, out of the atmosphere

    並將水分解成氧和氫。

  • and use it to build sugars and proteins and amino acids,

    它們用這過程所產生的化學能

  • all the things that life is made of.

    來把二氧化碳從大氣中汲取出來,

  • And as they evolved and grew more and more

    用它做成糖、蛋白質,和氨基酸,

  • over millions and millions of years,

    這些都是生命的組成成份。

  • that oxygen accumulated in the atmosphere.

    隨著它們演化及不斷地成長,

  • Until about 500 million years ago,

    經過了數百萬年,

  • there was enough in the atmosphere that larger organisms could evolve.

    大氣中累積了氧氣。

  • There was an explosion of life-forms,

    直到大約五億年前,

  • and, ultimately, we appeared on the scene.

    大氣中有足夠的氧氣, 讓比較大的有機體能夠演化。

  • While that was going on,

    各種生命形式劇增,

  • some of those ancient photosynthesizers died

    最終,我們人類也出現了。

  • and were compressed and buried,

    在那個過程中,

  • and became fossil fuel

    有些古老的光合作用生物死亡了,

  • with sunlight buried in their carbon bonds.

    它們被壓縮及掩埋,

  • They're basically buried sunlight in the form of coal and oil.

    變成了化石燃料,

  • Today's photosynthesizers,

    在它們的碳鍵當中埋藏了太陽光。

  • their engines are descended from those ancient microbes,

    基本上,可以說它們就是太陽光, 以煤和石油的形式被掩埋。

  • and they feed basically all of life on earth.

    現今行光合作用的生物,

  • Your heart is beating using the solar energy

    它們的引擎就是由那些 古老的微生物所傳下來的,

  • that some plant processed for you,

    基本上,它們養活了 地球上所有的生命。

  • and the stuff your body is made out of

    你的心臟跳動,用的是由某些植物

  • is made out of CO2

    為你處理過的太陽能,

  • that some plant processed for you.

    你的身體組成成份

  • Basically, we're all made out of sunlight and carbon dioxide.

    是由某些植物

  • Fundamentally, we're just hot air.

    為你處理過的二氧化碳。

  • (Laughter)

    基本上,我們都是由 太陽光和二氧化碳所組成。

  • So as terrestrial beings,

    從根本上來看,我們只是熱空氣。

  • we're very familiar with the plants on land:

    (笑聲)

  • the trees, the grasses, the pastures, the crops.

    身為陸地生物,

  • But the oceans are filled with billions of tons of animals.

    我們對地面上的植物非常熟悉:

  • Do you ever wonder what's feeding them?

    樹木、草、牧草、作物。

  • Well there's an invisible pasture

    但海洋中還有數十億種 各式各樣的動物。

  • of microscopic photosynthesizers called phytoplankton

    你可曾納悶牠們靠什麼維生?

  • that fill the upper 200 meters of the ocean,

    有一種看不見的牧草,

  • and they feed the entire open ocean ecosystem.

    只能從顯微鏡看到的 光合作用生物,叫做浮游植物,

  • Some of the animals live among them and eat them,

    它們滿佈在海洋上層 兩百公尺的區域,

  • and others swim up to feed on them at night,

    整個開放的海洋生態系統的 食物都要靠它們。

  • while others sit in the deep and wait for them to die and settle down

    有些動物住在它們當中, 以它們為食,

  • and then they chow down on them.

    其他的動物晚上游上來吃它們,

  • So these tiny phytoplankton,

    還有深海中的動物, 等它們死亡後沉澱下來,

  • collectively, weigh less than one percent of all the plants on land,

    再來吃它們。

  • but annually they photosynthesize as much as all of the plants on land,

    所以,這些微小的浮游植物,

  • including the Amazon rainforest

    全部加在一起還不到 地面所有植物重量的 1%,

  • that we consider the lungs of the planet.

    但每年,它們行光合作用的產能 並不輸給地面上的植物,

  • Every year, they fix 50 billion tons of carbon

    包括被我們視為是地球肺部的

  • in the form of carbon dioxide into their bodies

    亞馬遜雨林在內。

  • that feeds the ocean ecosystem.

    每年,它們將五百億噸的碳,

  • How does this tiny amount of biomass

    以二氧化碳的形式 存放在它們的體內,

  • produce as much as all the plants on land?

    成為海洋生態系統的食物。

  • Well, they don't have trunks and stems

    這麼微量的生物量,產量是如何

  • and flowers and fruits and all that to maintain.

    能不輸給陸地上的所有植物?

  • All they have to do is grow and divide and grow and divide.

    嗯,它們沒有樹幹和莖,

  • They're really lean little photosynthesis machines.

    也沒有花和果實,不用去維持這些。

  • They really crank.

    它們只需要專心 成長和分裂,成長和分裂。

  • So there are thousands of different species of phytoplankton,

    它們其實算是很精實的 小型光合作用機器。

  • come in all different shapes and sizes,

    它們的動作真的很快。

  • all roughly less than the width of a human hair.

    所以,浮游植物的種類有數千種,

  • Here, I'm showing you some of the more beautiful ones,

    形狀、大小皆不同,

  • the textbook versions.

    幾乎都不到一根人類頭髮的寬度。

  • I call them the charismatic species of phytoplankton.

    我給各位看的, 是其中一些比較漂亮的,

  • And here is Prochlorococcus.

    教科書版本的。

  • I know,

    我稱它們為有魅力的浮游植物物種。

  • it just looks like a bunch of schmutz on a microscope slide.

    這是原綠球藻。

  • (Laughter)

    我知道,

  • But they're in there,

    在顯微鏡載片上, 它看起來就像一堆污垢。

  • and I'm going to reveal them to you in a minute.

    (笑聲)

  • But first I want to tell you how they were discovered.

    但它們就在那裡,

  • About 38 years ago,

    我很快就會向各位揭露它們。

  • we were playing around with a technology in my lab called flow cytometry

    但首先,我想要告訴各位, 它們是如何被發現的。

  • that was developed for biomedical research for studying cells like cancer cells,

    大約三十八年前,

  • but it turns out we were using it for this off-label purpose

    我們在我的實驗室中, 試玩一種技術叫做流式細胞術,

  • which was to study phytoplankton, and it was beautifully suited to do that.

    它是為了生物醫學研究而發展的, 用來研究像癌症細胞這類的細胞,

  • And here's how it works:

    但結果,我們把它拿來 做說明標籤上沒寫的用途,

  • so you inject a sample in this tiny little capillary tube,

    也就是研究浮游植物, 且還非常適合這個用途。

  • and the cells go single file by a laser,

    做法如下:

  • and as they do, they scatter light according to their size

    我們將樣本注射到 極小的毛細管當中,

  • and they emit light according to whatever pigments they might have,

    細胞會成一路縱隊,通過雷射,

  • whether they're natural or whether you stain them.

    通過的時候,它們就會因為 大小不同而造成不同的散射光,

  • And the chlorophyl of phytoplankton,

    它們也會根據它們 具有的顏色來發光,

  • which is green,

    不論是它們天生的 或是你人工染上的顏色。

  • emits red light when you shine blue light on it.

    而浮游植物的葉綠素

  • And so we used this instrument for several years

    是綠色的,

  • to study our phytoplankton cultures,

    當你對它照射藍光時, 它會發出紅光。

  • species like those charismatic ones that I showed you,

    所以,多年來我們用這項工具

  • just studying their basic cell biology.

    來研究我們的浮游植物培養,

  • But all that time, we thought, well wouldn't it be really cool

    比如我剛剛給各位看的 那些迷人物種,

  • if we could take an instrument like this out on a ship

    只是研究它們的基本細胞生物學。

  • and just squirt seawater through it

    但那段時間,我們總在想 一個應該會很酷的點子,

  • and see what all those diversity of phytoplankton would look like.

    把類似這樣的工具放到一艘船上,

  • So I managed to get my hands

    注入海水,通過這工具,

  • on what we call a big rig in flow cytometry,

    來看看浮游植物的多樣性, 看起來會是什麼樣子的。

  • a large, powerful laser

    所以我想辦法弄到了

  • with a money-back guarantee from the company

    我們在流式細胞術中 所謂的「鑽探設備」,

  • that if it didn't work on a ship, they would take it back.

    一種大型、強力的雷射,

  • And so a young scientist that I was working with at the time,

    還有公司的退款保證,

  • Rob Olson, was able to take this thing apart,

    若在船上無法使用, 他們願意接受退貨。

  • put it on a ship, put it back together and take it off to sea.

    所以,當時和我合作的 一位年輕科學家

  • And it worked like a charm.

    叫做羅勃歐森, 他能把這東西拆開,

  • We didn't think it would, because we thought the ship's vibrations

    帶到一艘船上, 再組裝起來,帶它出海。

  • would get in the way of the focusing of the laser,

    結果是順利得獲得大成功。

  • but it really worked like a charm.

    我們沒預期會成功, 因為我們以為船的震動

  • And so we mapped the phytoplankton distributions across the ocean.

    會影響到雷射的聚焦,

  • For the first time, you could look at them one cell at a time in real time

    但真的就是個大成功。

  • and see what was going on -- that was very exciting.

    所以我們在圖上畫出了 海中浮游植物的分佈。

  • But one day, Rob noticed some faint signals

    這是頭一次,

  • coming out of the instrument

    能夠一次觀看一個細胞, 且影像是即時的,

  • that we dismissed as electronic noise

    能看出發生了什麼事—— 那是很讓人興奮的。

  • for probably a year

    但有一天,羅勃注意到 這個工具出現了

  • before we realized that it wasn't really behaving like noise.

    一些微弱的訊號,

  • It had some regular patterns to it.

    我們當作是電子噪音 所以沒有理會,

  • To make a long story short,

    有一年的時間都如此,

  • it was tiny, tiny little cells,

    後來我們才發現, 它的行為並不像是噪音。

  • less than one-one hundredth the width of a human hair

    它有一些規則的模式。

  • that contain chlorophyl.

    長話短說,

  • That was Prochlorococcus.

    它是很微小很微小的細胞,

  • So remember this slide that I showed you?

    還不到人類頭髮寬度的百分之一,

  • If you shine blue light on that same sample,

    且它含有葉綠素。

  • this is what you see:

    那就是原綠球藻。

  • two tiny little red light-emitting cells.

    還記得我剛剛給各位看的載片嗎?

  • Those are Prochlorococcus.

    如果你對同樣的樣本照射藍光,

  • They are the smallest and most abundant photosynthetic cell on the planet.

    你就會看到:

  • At first, we didn't know what they were,

    兩個發射紅光的小細胞。

  • so we called the "little greens."

    那些就是原綠球藻。

  • It was a very affectionate name for them.

    它們是地球上最小 且最大量的光合作用細胞。

  • Ultimately, we knew enough about them to give them the name Prochlorococcus,

    一開始,我們不知道它們是什麼,

  • which means "primitive green berry."

    所以我們叫它們「小綠」。

  • And it was about that time

    那是個非常親切的名字。

  • that I became so smitten by these little cells

    最終,我們對它們夠了解了, 取了 Prochlorococcus 這個名字,

  • that I redirected my entire lab to study them and nothing else,

    意思就是「原綠球藻」。

  • and my loyalty to them has really paid off.

    大約在那個時候,

  • They've given me a tremendous amount, including bringing me here.

    我完全愛上了這些小細胞,

  • (Applause)

    我改變整個實驗室的方向, 不做別的就專門研究它們,

  • So over the years, we and others, many others,

    我對它們的忠誠真的讓我得到報償。

  • have studied Prochlorococcus across the oceans

    它們給了我好多好多, 包括讓我來到這裡。

  • and found that they're very abundant over wide, wide ranges

    (掌聲)

  • in the open ocean ecosystem.

    這些年來,我和其他人, 許多其他人,

  • They're particularly abundant in what are called the open ocean gyres.

    在研究海洋中的原綠球藻,

  • These are sometimes referred to as the deserts of the oceans,

    發現在開放的海洋生態系統中,

  • but they're not deserts at all.

    它們的種類和數量都非常多。

  • Their deep blue water is teeming

    在開放海洋的渦流中 特別多原綠球藻。

  • with a hundred million Prochlorococcus cells per liter.

    這些渦流有時候 被稱為海洋的沙漠,

  • If you crowd them together like we do in our cultures,

    但它們完全不是沙漠。

  • you can see their beautiful green chlorophyl.

    它們的深藍海水中滿是原綠球藻,

  • One of those test tubes has a billion Prochlorococcus in it,

    每公升就有一億個原綠球藻。

  • and as I told you earlier,

    若像我們這樣把培養的 原綠球藻聚集在一起,

  • there are three billion billion billion of them on the planet.

    就可以看見它們 漂亮的綠色葉綠素。

  • That's three octillion,

    只要一根這種試管, 裡面就有十億個原綠球藻,

  • if you care to convert.

    我剛才有提過,

  • (Laughter)

    地球上有三千億億億個原綠球藻。

  • And collectively, they weigh more than the human population

    如果你想換算的話,

  • and they photosynthesize as much as all of the crops on land.

    那是三乘以千的九次方。 (註:3 x 10 的 27 次方)

  • They're incredibly important in the global ocean.

    (笑聲)

  • So over the years, as we were studying them

    它們的總重量比全人類加起來還重,

  • and found how abundant they were,

    它們行的光合作用, 和陸地上的作物一樣多。

  • we thought, hmm, this is really strange.

    在全球海洋中,它們非常重要。

  • How can a single species be so abundant across so many different habitats?

    這些年來,我們研究它們,

  • And as we isolated more into culture,

    發現它們的數量多驚人,

  • we learned that they are different ecotypes.

    我們心想,嗯,這好奇怪。

  • There are some that are adapted to the high-light intensities

    怎麼可能有單一物種在這麼多 不同的棲息地都有很大的數量?

  • in the surface water,

    我們隔離培養更多的原綠球藻,

  • and there are some that are adapted to the low light in the deep ocean.

    發現它們的生態型並不相同。

  • In fact, those cells that live in the bottom of the sunlit zone

    有些能適應在接近水表面的

  • are the most efficient photosynthesizers of any known cell.

    高光強度,

  • And then we learned that there are some strains

    有些則能適應深海中的低光度。

  • that grow optimally along the equator,

    事實上,住在太陽光區域 底部的那些細胞

  • where there are higher temperatures,

    是所有已知細胞中, 光合作用效率最高的。

  • and some that do better at the cooler temperatures

    我們接著發現,有些種類

  • as you go north and south.

    最適合沿著赤道生長,

  • So as we studied these more and more and kept finding more and more diversity,

    那裡的溫度比較高,

  • we thought, oh my God, how diverse are these things?

    向北和向南,則還有一些 更能生長在較冷溫度的種類。

  • And about that time, it became possible to sequence their genomes

    隨著我們對它們的研究越來越多, 且不斷發現更多樣的種類,

  • and really look under the hood and look at their genetic makeup.

    我們心想,天啊, 這些東西到底有多少變化?

  • And we've been able to sequence the genomes of cultures that we have,

    大約在那時,已經有可能 定序它們的基因組,

  • but also recently, using flow cytometry,

    真正去深入了解它們的基因組成。

  • we can isolate individual cells from the wild

    我們也能夠將我們的 培養物做基因定序,

  • and sequence their individual genomes,

    此外,近期,用流式細胞術,

  • and now we've sequenced hundreds of Prochlorococcus.

    我們可以分離來自野外的個別細胞,

  • And although each cell has roughly 2,000 genes --

    並針對它們個別的基因組做定序,

  • that's one tenth the size of the human genome --

    現在我們已經將數百個 原綠球藻做了定序。

  • as you sequence more and more,

    雖然每個細胞都有 大約兩千個基因——

  • you find that they only have a thousand of those in common

    那是人類基因組 大小的十分之一——

  • and the other thousand for each individual strain

    隨著越來越多定序完成,

  • is drawn from an enormous gene pool,

    會發現它們只有一千個共同基因,

  • and it reflects the particular environment that the cell might have thrived in,

    每一種種類的另外一千個

  • not just high or low light or high or low temperature,

    都是從一個巨大的 基因庫中取出來的,

  • but whether there are nutrients that limit them

    反應出該細胞能夠 繁盛生長的特定環境,

  • like nitrogen, phosphorus or iron.

    不只是光強度的高低或溫度的高低,

  • It reflects the habitat that they come from.

    還包括是否有營養物限制它們,

  • Think of it this way.

    比如氮、磷,或鐵。

  • If each cell is a smartphone

    這會反應出它們的來源棲息地。

  • and the apps are the genes,

    用這種方式來看。

  • when you get your smartphone, it comes with these built-in apps.

    如果每個細胞是一支智慧手機,

  • Those are the ones that you can't delete if you're an iPhone person.

    應用程式是基因,

  • You press on them and they don't jiggle and they don't have x's.

    當你拿到你的智慧手機時, 本身就有一些內建的應用程式。

  • Even if you don't want them, you can't get rid of them.

    若你用的是 iPhone, 那些應用程式是你無法刪除的。

  • (Laughter)

    長按它們的圖示,它們不會抖動, 也沒有「X」出現。

  • Those are like the core genes of Prochlorococcus.

    即使你不想要那些 應用程式,也擺脫不了。

  • They're the essence of the phone.

    (笑聲)

  • But you have a huge pool of apps to draw upon

    那些就像是原綠球藻的核心基因。

  • to make your phone custom-designed for your particular lifestyle and habitat.

    它們是手機的本質。

  • If you travel a lot, you'll have a lot of travel apps,

    但你有一個很大的 應用程式庫讓你可以取用,

  • if you're into financial things, you might have a lot of financial apps,

    讓你的手機客製化設計, 配合你自己的生活方式和習慣。

  • or if you're like me,

    如果你常旅行, 你就會有很多旅行應用程式,

  • you probably have a lot of weather apps,

    如果你的興趣在財務, 就會有很多財務應用程式,

  • hoping one of them will tell you what you want to hear.

    或者,如果你和我很像,

  • (Laughter)

    你可能會有很多天氣應用程式,

  • And I've learned the last couple days in Vancouver

    希望其中有一個會告訴你 你想要聽的結果。

  • that you don't need a weather app -- you just need an umbrella.

    (笑聲)

  • So --

    過去這幾天在溫哥華 我學到了一件事,

  • (Laughter)

    你不需要天氣應用程式—— 你只需要一把傘。

  • (Applause)

    所以——

  • So just as your smartphone tells us something about how you live your life,

    (笑聲)

  • your lifestyle,

    (掌聲)

  • reading the genome of a Prochlorococcus cell

    所以,看了你的智慧手機就能知道 一些關於你如何過生活的資訊,

  • tells us what the pressures are in its environment.

    了解你的生活方式,