跟李想死磕TED｜01-02 The tiny creature that secretly powers the planet

So as terrestrial beings, we're very familiar with the plants on land: the trees, the grasses, the pastures, the crops. But the oceans are filled with billions of tons of animals. Do you ever wonder what's feeding them? Well there's an invisible pasture of microscopic photosynthesizers called phytoplankton that fill the upper 200 meters of the ocean, and they feed the entire open ocean ecosystem. Some of the animals live among them and eat them, and others swim up to feed on them at night, while others sit in the deep and wait for them to die and settle down and then they chow down on them.


作为陆生生物，我们对陆地上的植物、树木、草地、牧场、田园非常熟悉。但是在海洋里有成百上千吨的动物。你们是否想过它们吃什么？有一个由只能在显微镜下才能看到的光合作用体组成的肉眼看不到的牧场，被称为浮游植物，它们充斥在海洋200米的上层水域中，它们养育着整个开放海域生态系统。有些动物生活在过它们周围并以它们为食物，另外一些动物在夜间游上来进食，而还有另外一些只是呆在深水底部，等待它们死亡后沉到水底并大口吞食它们。


03:35
So these tiny phytoplankton, collectively, weigh less than one percent of all the plants on land, but annually they photosynthesize as much as all of the plants on land, including the Amazon rainforest that we consider the lungs of the planet. Every year, they fix 50 billion tons of carbon in the form of carbon dioxide into their bodies that feeds the ocean ecosystem. How does this tiny amount of  produce as much as all the plants on land? Well, they don't have trunks and stems and flowers and fruits and all that to maintain. All they have to do is grow and divide and grow and divide. They're really lean little photosynthesis machines. They really crank.


所以，这些微小的浮游植物，总和起来，重量比陆地上所有植物的总和的1%还少，但是一年的光合作用比陆地上的所有植物总和多得多，这还包括了我们认为是地球之肺的亚马逊雨林。每年，它们把500亿吨的碳吸收到自己身体里为海洋生态提供食物，而这些碳原来是以二氧化碳的形式存在的。这样少量的产量是怎样怎么做到和陆生植物相当的？嗯，它们没有树干、没有茎、没有花和水果，这些都不需要维持。所有它们要做的只是生长、分裂、生长、分裂。它们真是高效而小型的光合作用机器，它们太奇怪了。


04:27
So there are thousands of different species of phytoplankton, come in all different shapes and sizes, all roughly less than the width of a human hair. Here, I'm showing you some of the more beautiful ones, the textbook versions. I call them the charismatic species of phytoplankton.


所以，有成千上万的不同种类的浮游植物，它们的形状和大小不同，但都比人类的头发丝的宽度小。我在这里展示给大家看的是最漂亮的一部分，都是是教科书级别的。我称呼他们是浮游植物中的神之类别。




04:48
And here is Prochlorococcus. I know, it just looks like a bunch of schmutz on a microscope slide.


这儿就是原绿球藻，我知道它在显微镜载玻片上看起来就这么一滩。


04:56
(Laughter)（笑声）


04:58
But they're in there, and I'm going to reveal them to you in a minute. But first I want to tell you how they were discovered.


但是，它们就在这里，而且也是我马上要向大家展示的，但是我先想想告诉大家它们是怎么被发现的。




05:08
About 38 years ago, we were playing around with a technology in my lab called flow cytometry that was developed for biomedical research for studying cells like cancer cells, but it turns out we were using it for this off-label purpose which was to study phytoplankton, and it was beautifully suited to do that. And here's how it works: so you inject a sample in this tiny little capillary tube, and the cells go single file by a laser, and as they do, they scatter light according to their size and they emit light according to whatever pigments they might have, whether they're natural or whether you stain them. And the chlorophyl of phytoplankton, which is green, emits red light when you shine blue light on it. And so we used this instrument for several years to study our phytoplankton cultures, species like those charismatic ones that I showed you, just studying their basic cell biology.
大概在38年前，在我的实验室里，我们正在摆弄一种技术称为流血细胞计数器，它本来是用在生物医学领域搜寻并研究细胞的，比如癌细胞，但是我们把它挪作他用，用来研究浮游植物，没想到它用来干这件事太适合了。接下来是具体做法：你要把这些样本注射到这跟毛细试管中，然后这些细胞在激光的作用下排成一列，然后，它们依据自身的大小把光吸收，并依据自身所存在的色素发射出光线，无论是染不染色都一样。当用蓝色的光找到浮游植物上后发出了红色的光（叶绿素本身是绿色的）。接下来，我们用这套仪器花了几年时间研究我们的浮游植物的样本，样本的种类是那些刚才展示给大家的“神之类别”，研究的是它们的基础细胞生物特性。