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Narrator:Listen to part of a lecture in a biology class.
獨白:聽一段生物學的課堂演講
Professor:OK. We've been talking till now about the two basic needs of a biological community-an energy source to produce organic materials, you know ah, food for the organism, and the waste recycling or breakdown of materials back into inorganic molecules, and about how all this requires photosynthesis when green plants or microbes convert sunlight into energy and also requires microorganisms, bacteria, to secrete chemicals that break down or recycle the organic material to complete the cycle.
教授:好了。我們一直在講生物群體的兩種基本需求-能源資源產出有機物質，你們知道的，有機物的食物，以及廢物回收或者物質破壞回歸無機分子，以及當綠色植物或者微生物將陽光轉化為能源時，所有這些都需要光合作用，還需要微生物、細菌來分泌化學物質來分解或者再循環這些有機物質，來完成循環。
So, now we are done with this chapter of the textbook, we can just review for the weekly quiz and move on to the next chapter, right?
那么，現在我們完成了教科書上這章的內容了，是吧？
Well, not so fast.
嗯，還沒有這么快。
First, I'd like to talk about some discoveries that have challenged one of these fundamental assumptions about what you need in order to have a biological community.
首先我來講一些發現，這些發現就挑戰了夠成生物群的基本需要的基本假定。
And, well, there actually were quite a few surprises.
而且，事情上有很多讓人感到驚奇的地方。
It all began in 1977with the exploration of hydrothermal vents on the ocean floor.
一切始于 1977 年的一次海底上深海熱泉的探索。
Hydrothermal vents are cracks in the Earth's surface that occur, well, the ones we are talking about here are found deep at the bottom of the ocean.
深海熱泉是地球表面存在的裂縫，我們說的這個就是在海底的裂縫。
And these vents on the ocean floor, they release this incredibly hot water, 3-4 times the temperature that you boil water at because this water has been heated deep within the Earth.
這些海底的出口，排除及其熱的水，溫度比開水還要高 3 到 4 倍，因為這些水是從地球內部加熱的。
Well about 30 years ago, researchers sent a deep-sea vessel to explore the ocean's depth, about 3kilometers down, way deep to ocean floor, No one had ever explored that far down before.
大概 30年前，研究人員派出了一個深海船來探察海洋深度，到海洋底部大約是 3 千公里深，之前從里沒有人到如此的深度來探索過。
Nobody expected there to be any life down there because of the conditions.
由于下面的這種環境，沒有人想過下面會有生命。
First of all, sunlight doesn't reach that far down so it's totally dark.
首先，陽光不能到達那么遠，因此下面是漆黑一片。
There couldn't be any plant or animal life since there's no sunlight, no source of energy to make food.
也不可能有任何動植物，因為那里沒有陽光，沒有能源來提供食物。
If there was any life at all, it'd just be some bacteria breaking down any dead materials that might have fallen to the bottom of the ocean. And?
如果有生命的話，也就是一些分解任何死去物質的細菌可能跌落直海洋底層。還有呢？
Student:And what about the water pressure?
學生:還有水壓。
Didn't we talk before about how the deeper down into the ocean you go, the greater the pressure?
我們之前不是講過，越往海洋深度去，壓強就越大嗎？
Professor:Excellent point!
教授:說到點子上了。
And not only the extreme pressure, but also the extreme temperature of the water around these vents.
而且不僅是極大的壓強，還有這些出口附近水的溫度。
If the lack of sunlight didn't rule out the existence of a biological community down there then these factors certainly would, or so they thought.
如果陽光的缺失沒有使這里的生物群體消失的話，那么這些因素也會的，人們起初這么想。
Student:So you are telling us they did find organisms that could live under those conditions?
學生:那么你是在說他們在那種環境下找到有機物了？
Professor:They did indeed, something like 300 different species.
教授:確實。找到了大概 300 個物種。
Student:But... but how could that be? I mean without sunlight, no energy, no no …
學生:但是那怎么可能呢？我的意思是說沒有陽光，沒有能源，沒有…
Professor:What they discovered was that microorganisms, bacteria, had taken over both functions of the biological community-the recycling of waste materials and the production of energy.
教授:他們找到的是有兩種生物群體功能的微生物、細菌-廢物循環及能源再生。
They were the energy source.
他們就是能源。
You see, it turns out that certain microorganisms are chemosynthetic -they don't need sunlight because they take their energy from chemical reactions.
你們看，原來有些微生物是化學合成的，他們不需要陽光，因為他們從化學作用中吸取能源。
So, as I said, unlike green plants which are photosynthetic and their energy from sunlight, these bacteria that they found at the ocean floor, these are chemosynthetic, which means that they get their energy from chemical reactions.
因此，正如我所說，和進行光合作用并從陽光中吸取能源的綠色植物不一樣，這些人們在海底發現的細菌是化學合成的，意味著他們通過化學作用來獲得能源。
How does this work?
那是怎么回事呢？
As we said, these hydrothermal vents are releasing into the ocean depth this intensely hot water and here is the thing, this hot water contains a chemical called hydrogen sulfide, and also a gas, carbon dioxide.
正如我們說的，海底熱泉往海中中釋放及其熱的水，是這么回事，這種熱水包含化學物質硫化氫和一種氣體，就是二氧化碳。
Now these bacteria actually combine the hydrogen sulfide with the carbon dioxide and this chemical reaction is what produces organic material which is the food for larger organisms.
這些細菌實際上就是硫化氫和二氧化碳的結合體，這種化學反應就產出了有機物質，也就是更大的有機體的食物。
The researchers had n ever seen anything like it before.
研究人員之前從來沒有看過這種現象。
Student:Wow! So just add a chemical to a gas, and bingo, you've got a foodsupply?
學生:哇哦。那么說往氣體里放點化學位置，然后就變成了食物供應？
Professor:Not just that!
教授:不僅是如此。
What was even more surprising were all the large organisms that lived down there.
更讓人吃驚的是居住在那里的大有機物。
The most distinctive of these was something called the tube worm.
最有特點的一個叫做管蟲。
Here, let me show you a picture.
來，我給你們看一張照片。
The tube of the tube worm is really, really long.
這管蟲特別長。
They can be up to one and half meters long, and these tubes are attached to the ocean floor, pretty weird looking, huh?
可能達到一米半那么長。而這些管子是連在海底呢，長的很奇怪是吧？
And another thing, the tube worm has no. mouth, or digestive organs.
還有一個問題。管蟲沒有嘴，沒有消化器官。
So you are asking how does it eat.
你們會問，那它怎么吃東西啊？
Well, they have these special organs that collect the hydrogen sulfide and carbon dioxide and then transfer it to another organ, where billions of bacteria live.
嗯，他們有一些特殊的器官能收集硫化氫和二氧化碳并能將其轉化到另一個器官，那里有億萬個細菌。
These bacteria that live inside the tube worms, the tube worms provide them with hydrogen sulfide and carbon dioxide.
這些細菌生活在管蟲里面， 管蟲為他們提供硫化氫和二氧化碳。
And the bacteria, well the bacteria kind of feed the tube worms through chemosynthesis, remember that chemical reaction I described earlier.
而細菌呢，有點像通過化學合成的方式來為管蟲提供食物，記得之前講過的化學作用吧。
