journey to the microcosmos
《微观旅途》
It is impossible to know just
我们无法知道
how many microbial species there are in the world.
世界上到底有多少种微生物
One recent estimate put the number somewhere around 1 trillion species,
最近一次估算表明 微生物种类大概在1兆左右
and the vast majority of those organisms still have yet to be discovered.
而绝大多数微生物仍未被发现
But even with our relatively limited knowledge of the microcosmos,
但即便我们对微生物世界的认知还相对有限
being able to identify microbes when we can is important,
尽我们所能来识别微生物仍很重要
from helping doctors diagnose their patients
因为这能帮助医生确诊疾病
to guiding scientists through their observations.
指导科学家的观察
And sometimes the goals are a little less urgent,
有时我们不急于识别新的微生物
but still meaningful.
但不代表这没有意义
Like for James, our Master of Microscopes
比如James 我们的显微镜大师
who collects these organisms and tends to them,
他收集微生物 对它们悉心照料
and for the rest of us on the journey to the microcosmos team
对《微观旅途》节目的其余队员来说
who want to share what we’ve learned.
我们希望可以分享自己学到的
We love showing off these organisms,
我们喜欢“炫耀”这些微生物
and the more specific we can get when we identify them,
当鉴别微生物时 获取的信息越具体
the more we can tell you about their lives.
我们就越能和你分享更多 它们的生活习性
But even if we humans have only discovered a small fraction of all the microbes,
但即使人类只探索了微生物世界的一角
there’s still a lot that we have found and named,
我们还是发现 并命名了很大一部分微生物
so figuring out what exactly is in our samples can be difficult.
有时 样本中的微生物种类会很难识别
It’s like playing the board game Guess Who,
这就像在玩“猜猜我是谁”的游戏
but first you have to solve a maze to find the right board.
但首先你得解决“选哪块正确样本”的谜题
And even when you do find it,
即使你找对了样本
you realize you are playing with the largest Guess Who board ever,
你也会发现 你玩的是史上最强版“猜猜我是谁”
and still, you can’t be sure it even holds the answer.
并且 你也不能确定 样本中是否包含正确答案
As we’ll talk about later,
咱们待会儿会聊到
scientists have devised a number of molecular methods
科学家们发明了许多种“分子法”
that make this task less daunting.
让这个猜谜游戏稍显轻松
But we do things the old-fashioned way:
但我们还是沿用老办法：
we just look at the organisms.
我们直接观察这些生物体
We collect our samples from nature,
我们从自然界获取样本
peering in to an assembly of microscopic animals and single-celled creatures,
观察一系列的微生物及单细胞生物
looking for clues in their morphology
从它们的形态寻找线索
that will hopefully reveal what they are.
希望能据此揭开它们神秘的面纱
So come along with us.
随我们一起
Let’s take you through some of the questions
我们先来提出问题
that help guide us through this process.
为接下来的观察指引方向
The best place to start is to ask yourself,
第一个问题就是问你自己
in the broadest sense, what you are looking at.
从广义上讲 你看到的东西是什么
Is it multicellular?
它是多细胞生物吗
Is it a unicellular eukaryote?
还是单细胞真核生物呢
A prokaryote?
还是原核生物呢
We’ll start with the multicellular organisms,
我们会从多细胞生物说起
in part because they’re generally a little easier to identify.
部分原因是 多细胞生物比较容易鉴别
There are fewer of them in total,
因为它们的种类较少
and their bodies just have more going on,
身体内部有更多信息
and that means that there’s more clues for us to find.
意味着这能给我们提供更多线索
Let’s take the tardigrade, as an example,
以草履虫为例
but pretend that you don’t know what tardigrades look like.
但先装作你不知道草履虫的样子
You went down to your favorite pond,
去你最喜欢的池塘走一趟
gathered some water,
收集一些水样本
and now you are looking at what you collected through the microscope
现在 通过显微镜观察你收集的水样本
On the other side is this delightful, bumbling bit of life.
在显微镜下 这个有趣的小生物笨手笨脚地蠕动着
You see some stubby legs waving around,
你能观察到它又短又粗的腿正蠕动着
a pair of eyes,
一对眼睛
and maybe some strange things moving around inside its body.
体内还有一些奇怪的东西在移动
All those details are helpful.
所有的细节都能提供帮助
Legs are a great clue, as our eyes.
和人的眼睛一样 它们的“脚”也有很多线索
And inside, the moving things you’re watching
看它体内正在移动的东西
seem a bit like organs.
有点像器官
If you weren’t sure that you were looking at a multicellular organism before,
如果你之前 不确定自己看到的是多细胞生物
you probably are now.
现在应该确定了
And beyond what you see,
除去你对它的观察
there’s also what you know.
还有你知道的信息
You know that you got this little guy from a pond,
你从池塘里找到这个小家伙
meaning a freshwater environment.
意味着它生活在淡水环境中
That means you can rule out organisms that only live in marine environments.
也就意味着你能排除所有海洋生物
So what now?
下一步呢
You might be able to get help from a freshwater biology book,
你也许能从淡水生态学的书籍得到帮助
but if you’re a hobbyist,
但如果你是个业余爱好者
those books might not be worth the cost.
那么没必要花大价钱买这些书
Luckily, as old-fashioned as our methodology is,
幸运的是 尽管观察形态的办法比较过时
we have a resource that the microbe hunters of yore did not:
但我们也具备从前“微生物猎人”没有的资源：
the good ol’ internet,
那就是强大的互联网
a source not just of cat pictures and arguments,
其中不仅有猫咪图片 网友掐架
but also of the many microorganisms
还有很多“微生物”的信息
that scientists and science enthusiasts like yourself
它们由科学家 以及和你一样的科学爱好者
have studied and documented.
研究并整理
Sometimes, all you need to do is just a simple search for something like
有时你只需要简单搜索
“freshwater microscopic animal”
如“淡水微生物”
and look through images
然后浏览图片
until you find something that matches what you’re looking at.
直到找到和你观察生物相匹配的图片
Now, of course,
当然了
“freshwater microscopic animal” can bring up a whole range of species,
“淡水微生物”包含了一系列生物
like rotifers, hydras and Gastrotrich.
比如轮虫 水螅和腹毛动物
But each of those animals is very different from the others,
但这些生物互不相同
which can help narrow down
这也有助于缩小范围
what your unidentified microbial organism is and is not.
来判断你正观察的未知微生物种类
If you find this process overwhelming at first,
要是在最开始 你觉得这一过程过于艰巨
because you are trying to narrow down the vastness
因为你得试着 从众多微生物中
of the microcosmos into just one species.
缩小到某一种生物
That’s okay!
那也没关系
Every time you do this, you will get better at it.
每实践一次 你都会变得更熟练
It takes years of practice and experience
这需要长年累月的练习和经验
to figure out how to use all of the information available to you
才能学会充分利用已知信息
and pick out the most useful details.
筛选出最有用的那些细节
And like a baby tardigrade waving its legs for the first time,
和刚刚学会”走路”的幼期水熊虫一样
we all have to start somewhere.
我们都要从开始学起
With single-celled eukaryotes,
对于单细胞真核生物
the process starts to get more difficult.
观察过程就要难一些了
You won’t see the complex structures and systems
你看不到复杂的结构和系统
that distinguish multicellular organisms,
将其与多细胞生物区分开来
but you will see organelles that can help clarify what you’re looking at.
但它体内的细胞器能帮你认识其身份
For example, one major clue can be picking out
比如 这个主要的线索可用来区分微生物：
which organisms have those beating hairs called cilia
有的微生物表面长着纤毛
versus which ones have more whip-like hair called flagella.
有的微生物表面长着鞭毛
And if you see the green color of chloroplasts,
你要是看到叶绿体
you know that you need to find an organism capable of photosynthesis.
你便明白这种生物能进行光合作用
For example, what if you see the tell-tale trumpet morphology in your collection?
比如 要是你在样本中看到标志性的喇叭形状
“Aha,” you might say, “that is a Stentor!”
你可能会说：“啊哈 这是一只喇叭虫！”
And you would be correct,
你说对了
but which Stentor?
但它是哪一种喇叭虫呢
While Stentors have varying numbers of micronuclei,
不同喇叭虫体内含有不同数量的微核
these are hard to see without staining.
不经过染色的话 很难看见微核的存在
The macronucleus, however, is visible and can be helpful.
然而 大核是可见的 且能提供有用信息
For Stentor coeruleus,
对于蓝态多态喇叭虫
the macronucleus resembles beads strung together across the cell
大核就像散落在细胞内的一连串珠子
which is called a moniliform nucleus.
称作“念珠核”
Stentor polymorphous also has a moniliform nucleus,
多态喇叭虫也有一个念珠核
but it’s easier to distinguish from the Stentor coeruleus.
但相比于蓝态喇叭虫 多态喇叭虫里的念珠核更易辨别
because of the endosymbiotic algae that turn it green.
因为内共生藻类将其变成了绿色
Stentor igneus, by contrast, is smaller,
相比之下 火喇叭虫更小
and has pink pigments, and contains an oval macronucleus.
它体内含粉色色素 还有一个椭圆大核
Stentors are a relatively easier genus to pick apart
喇叭虫的属类相对容易区分
because there are only about 20 species of Stentors to decide between.
因为你只需要从仅仅20种喇叭虫里判断
Other genera can have hundreds of species,
其他的属类可能包含数百种
and the differences might be more subtle.
种类之间的区别可能更加细微
That’s why sometimes you’ll see our organisms
这就是我们有时只能给各种生物贴上
labeled by the most narrow description we feel comfortable giving,
最一般性的描述标签的原因
whether that’s identifying an organism solely by its genus,
仅仅通过属来判断它的种类
or even going more broad and just calling it a “ciliate.”
或是泛泛的将它归为”纤毛虫”
These are cases where we just don’t know enough… yet.
这只能说明 我们对这些生物的了解 暂时还不够充分
For those of you who remember our mystery, real time video,
收看过James观察神秘生物视频的观众们：
it took James a year to be sure of what organisms he was watching.
James花了一年时间才确定他观察生物的种类
And until he identified the mystery organism,
在他揭晓这神秘生物的身份之前
we didn’t know what was happening in that video.
我们对视频里的生物一无所知
And of course it’s even more challenging to identify bacteria.
当然了 识别细菌更具挑战
We can use morphology to parse out cyanobacteria and sulfur bacteria.
我们可从形态区分蓝细菌和硫细菌
But with most of the bacteria in our samples,
但在我们样本中的多数细菌
it’s just impossible to tell without genetic sequencing,
都只能用基因测序来辨别
a technique that is not in our toolkit at the moment.
但我们团队目前还不具备这一技术
And for us, that’s okay.
但那也没关系
But there are cases where it’s important to dig further,
但有时候 有些生物需要更深层次的探究
and scientists have developed many molecular techniques
科学家们开创了许多分子技术
to identify the microbes in their samples.
用以识别样本中包含的微生物
There are stains to emphasize certain identifying structures,
有些染色剂能使一些特定结构显现出来
and biochemical tests to reveal the presence of specific enzymes.
也能通过生物化学实验揭晓某种酶的存在
Also, of course, there’s gene sequencing
当然了 还有基因测序技术
and other more advanced chemical methods
以及其他更加先进的化学办法
to probe what species a sample contains.
用以检测样本中所含的微生物
For James, who does the work of identifying our microbes without these molecular tests,
James在不具备这些分子技术条件下鉴别微生物时
what he’s able to name comes from years of studying
他鉴别微生物的能力来自常年的研究
and memorizing the drawings and pictures
从各种各样的书籍中
he’s found in various books and keys,
记忆其中的图解和关键信息
as well as an ongoing habit of reading papers every day.
以及他每天阅读论文的习惯
It’s more a way of life, a habit borne out of science,
这就是一种生活方式 一种从科学衍生出的习惯
an art, a labor of love.
这是一门艺术 一份热爱
Thank you for coming on this journey with us
感谢您和我们一起
as we explore the unseen world that surrounds us.
踏上探索周围未知世界的旅程
And all of these people on the screen right now,
这些出现在屏幕上的所有人
these are our patrons on Patreon.
都是在众筹网站上赞助我们的网友
We only have one Patreon tier, it’s $8 a month.
我们只有一种赞助方案 每月8美元
And with it, you get your name featured in the end of our video here,
赞助后 您的名字将会展示在视频的最后
a weekly hi-resolution image of one of our micro friends,
每周都能获取微生物的高清图片
and an extended video featuring uncut footage
以及未剪辑的加长版视频
with no narration from me,
其中不含我的讲解
just Andrew Huang’s wonderful music.
只有Andrew Huang的美妙音乐
And if you want to join up and help us out,
如果你想要加入会员
you can do that at patreon.com/journeytomicro.
就在该网站上赞助我们吧
If you want to see more from our Master of Microscopes James,
如果想观看更多《显微镜大师：James》
check out Jam & Germs on Instagram.
您可以在Ins上搜索Jam & Germs
And if you want to see more from us
如果想要收看《微观旅途》更多节目
just go to youtube.com/microcosmos.
可以直接访问我们的油管频道