Clues to prehistoric times, found in blind cavefish | Prosanta Chakrabarty

翻译人员: Wei Wu 校对人员: Conway Ye

Ichthyology,

鱼类学(Ichthyology)

the study of fishes.

是研究鱼类的学科。

It looks like a big, boring word,

这个词看着很无聊,

but it's actually quite exciting,

其实不然,

because ichthyology is the only "ology"

这个词是唯一个学科名里

with "YOLO" in it.

带有"YOLO"短语的。

(Laughter)

(笑声)

Now, to the cool kids in the audience,

对于台下很时髦的年轻人来说,

you already know, YOLO stands for "you only live once,"

你们已经知道"YOLO"这个缩写 代表着"你的人生只有一次",

and because I only have one life,

因为人生不能重来,

I'm going to spend it doing what I always dreamt of doing:

我希望去做我真正梦想的事情:

seeing the hidden wonders of the world and discovering new species.

去探索世界的未知, 去发现新的物种。

And that's what I get to do.

我说到做到了。

Now, in recent years, I really focused on caves for finding new species.

最近这几年我的研究重点放在了 洞穴鱼类新物种的发现上。

And it turns out, there's lots of new cavefish species out there.

我们发现洞穴里有很多的新物种。

You just have to know where to look,

你只需要知道去哪里找就行了,

and to maybe be a little thin.

可能还要身材苗条一点。

(Laughter)

(笑声)

Now, cavefishes can tell me a lot about biology and geology.

研究洞穴鱼类能够获得许多 生物学和地理学的发现。

They can tell me how the landmasses around them have changed and moved

它们虽然只是蜷缩在小小洞穴里, 却能够告诉我们世界的大格局,

by being stuck in these little holes,

告诉我们大陆如何漂移和变化,

and they can tell me about the evolution of sight, by being blind.

它们没有眼睛, 却让我们看到 眼睛的进化过程。

Now, fish have eyes that are essentially the same as ours.

一般而言鱼类都有眼睛, 跟我们一样。

All vertebrates do, and each time a fish species starts to adapt

所有的脊椎动物本来都有眼睛, 但是当生存环境变了,

to this dark, cold, cave environment,

如果一种鱼要适应阴冷的洞穴环境,

over many, many generations, they lose their eyes and their eyesight

经过一代又一代的演化, 这些鱼的视力逐渐退化,

until the end up like an eyeless cavefish like this one here.

现在的洞穴鱼类已经没有眼睛了。

Now, each cavefish species has evolved in a slightly different way,

每种洞穴鱼类的进化路线略有不同,

and each one has a unique geological and biological story to tell us,

每种鱼类都可以向我们讲述一段特别的地质和生物的故事,

and that's why it's so exciting when we find a new species.

这是我们在发现新物种的时候 激动不已的原因。

So this is a new species we described, from southern Indiana.

这是我们从印第安纳南部发现的新物种。

We named it Amblyopsis hoosieri, the Hoosier cavefish.

我们叫它" Amblyopsis hoosieri", 就是印第安纳洞穴鱼的意思。

(Laughter)

(笑声)

Its closest relatives are cavefishes in Kentucky,

它的近亲是肯塔基州的一种洞穴鱼,

in the Mammoth Cave system.

生活在猛犸洞穴系统中。

And they start to diverge when the Ohio River split them

他们因俄亥俄河的出现被分隔开,

a few million years ago.

已经分开了有几百年了.

And in that time they developed these subtle differences

从那时起它们的进化路线就不同了

in the genetic architecture behind their blindness.

各自在基因结构上演化, 视力各自退化了.

There's this gene called rhodopsin that's super-critical for sight.

有一种名叫"视紫红质"的基因, 对视力的形成起到关键作用,

We have it, and these species have it too,

人类和这些鱼类都有同样的基因,

except one species has lost all function in that gene,

但是有种洞穴鱼在进化中 完全丢掉了这个基因,

and the other one maintains it.

而其它的洞穴鱼类还保留着.

So this sets up this beautiful natural experiment

大自然为我们做了完美的实验

where we can look at the genes behind our vision,

让我们能够从基因角度 学习我们视觉的原理,

and at the very roots of how we can see.

能够知道视觉感知的最根本原因.

But the genes in these cavefishes

而且这些洞穴鱼类的基因

can also tell us about deep geological time,

能够向我们讲述 地理环境的变化,

maybe no more so than in this species here.

可能没有谁比它们更能展示这种变化了.

This is a new species we described from Madagascar

这是我们在马达加斯加 发现的新物种

that we named Typhleotris mararybe.

取名为"Typhleotris mararybe".

That means "big sickness" in Malagasy,

在马达加斯加语中是"大病"的意思,

for how sick we got trying to collect this species.

你们不知道为了找这个物种 我们吃了多少苦头.

Now, believe it or not,

不管你信不信,

swimming around sinkholes full of dead things

在污水坑里游泳, 周围都是动物尸体

and cave full of bat poop

在满是蝙蝠粪便的洞穴里翻找

isn't the smartest thing you could be doing with your life,

肯定不是你生命中 做的最明智的选择,

but YOLO.

但是, YOLO!

(Laughter)

(笑声)

Now, I love this species despite the fact that it tried to kill us,

尽管这个鱼差点要杀死我, 我还是很爱它,

and that's because this species in Madagascar,

因为这种生活在马达加斯加的鱼,

its closest relatives are 6,000 kilometers away,

最近的近亲远在6000公里之外,

cavefishes in Australia.

是一种生活在澳大利亚的鱼类.

Now, there's no way a three-inch-long freshwater cavefish

我们很清楚这种巴掌大的淡水鱼

can swim across the Indian Ocean,

是无法在印度洋里游过来的,

so what we found when we compared the DNA of these species

所以我们通过对比这两个物种的DNA,

is that they've been separated for more than 100 million years,

知道他们在一亿年前就已经分隔开了,

or about the time that the southern continents were last together.

这大概就是大陆开始漂移的时候.

So in fact, these species didn't move at all.

事实上这些洞穴鱼根本没挪过窝.

It's the continents that moved them.

是大陆板块在移动.

And so they give us, through their DNA,

这些洞穴鱼类通过它们的DNA,

this precise model and measure

为我们提供了精确的模型,

of how to date and time these ancient geological events.

让我们知道远古时代 地理变化的具体时间.

Now, this species here is so new

这个鱼类刚刚发现

I'm not even allowed to tell you its name yet,

还没有取好名字,

but I can tell you it's a new species from Mexico,

这个鱼类是在墨西哥发现的,

and it's probably already extinct.

已经频临绝种.

It's probably extinct because the only known cave system it's from

这种鱼类之所以绝种是因为 它们生存的唯一的洞穴环境

was destroyed when a dam was built nearby.

因为附近修建的一座大坝而被破坏了.

Unfortunately for cavefishes,

对洞穴鱼类而言, 很不幸地,

their groundwater habitat

它们栖息的地下水

is also our main source of drinking water.

正好被人类作为饮用水源.

Now, we actually don't know this species' closest relative, yet.

我们目前还不知道这中鱼的近亲.

It doesn't appear to be anything else in Mexico,

它跟墨西哥任何物种都不像,

so maybe it's something in Cuba,

可能来自古巴,

or Florida, or India.

或者佛罗里达, 或者印度.

But whatever it is, it might tell us something new about the geology

不管来自哪里, 它都很有可能 告诉我们加勒比海的变迁,

of the Caribbean, or the biology of how to better diagnose

也可能让我们对于视觉的 生物学原理有进一步认识

certain types of blindness.

帮助我们治疗人类的眼疾.

But I hope we discover this species before it goes extinct too.

我希望能够在物种灭绝前发现它们.

And I'm going to spend my one life

我愿意用我一生努力

as an ichthyologist trying to discover and save

作为一名鱼类学家, 去发现和保护

these humble little blind cavefishes

这些不起眼的、没有眼睛的 洞穴鱼类

that can tell us so much about the geology of the planet

它们能够告诉我们太多 这个星球的地理变化

and the biology of how we see.

解释为何我们能看见 这五彩的世界.

Thank you.

谢谢.

(Applause)

(掌声)