Over a century ago,

一個多世紀前。

the United States Fish Commission

美國漁業委員會

dug a well plunging 188 feet into the earth

掘井

right at the heart of the city.

就在城市的中心。

And when they did, water rushed to the surface

當他們這樣做的時候，水湧到了水面。

at thousands of gallons a minute,

以每分鐘數千加侖的速度。

flushing out dozens of undiscovered creatures

湧現出數十種未被發現的生物。

from the depths below.

從下面的深處。

These animals had never seen the surface.

這些動物從未見過水麵。

Nor would they,

他們也不會。

because all of them were blind.

因為他們都是瞎子。

Perhaps the strangest-looking animal in this catch

也許是這次抓到的動物中最奇怪的一個了

was a species dubbed Eurycea rathbuni,

是一個被稱為Eurycea rathbuni的物種。

now known as the Texas blind salamander.

現在被稱為德州盲螈。

Upon discovery, herpetologist Leonhard Stejneger

發現後，動物學家Leonhard Stejneger

described them as such:

對他們的描述是這樣的。

Narrator: These unusual conditions are contained

旁白：這些不尋常的情況都包含在

to a specific 26-mile stretch of caves

到特定的26英里長的洞穴中

in the Edwards Aquifer,

愛德華茲含水層中。

an extensive underground layer of rocks.

一個廣泛的地下岩石層。

It's the only place in the world

這裡是世界上唯一的地方

this species of salamander has ever been recorded.

這個物種的蠑螈曾經被記錄。

So, how did these caves create the "profound differences"

那麼，這些洞穴是如何產生 "深刻的差異"

in these salamanders' appearance?

在這些蠑螈的外表?

In other words, how did they end up looking so weird?

換句話說，他們的長相怎麼會如此怪異？

To answer this question,

為了回答這個問題：

we have to go back in time.

我們必須回到過去

Way back.

很久以前的事了

Tom Devitt: Take the dates with a grain of salt,

湯姆-德維特：對棗子持懷疑態度。

but we think that this group split off

但我們認為，這組分裂出來的

from its most recent common ancestor probably around

從其最近的共同祖先可能大約為

somewhere between 10 and 15 million years ago.

在1000萬到1500萬年前的某個地方。

Narrator: And geologists estimate that the aquifer

旁白：地質學家估計，含水層

had been hundreds of millions of years in the making.

已經有數億年的歷史了。

During the Jurassic period, some 200 million years ago,

在侏羅紀時期，大約2億年前。

the area was occasionally covered in shallow oceans,

該地區偶爾會被淺海覆蓋。

but when the area was dry and exposed to air,

但當該地區乾燥並暴露在空氣中時。

the rocks were eroded by weather to make porous caverns.

岩石被天氣侵蝕，形成多孔洞。

Eventually, a shallow basin of water and sediment

最終，一個由水和泥沙組成的淺水盆地。

covered the land.

覆蓋了這片土地。

Then that basin dried up.

然後那盆水就幹了。

But rainfall continued to eat away at the earth

但降雨仍在不斷侵蝕著大地

to create the deep fissures and caverns inside the aquifer.

以在含水層內形成深層裂縫和溶洞。

Scientists like Devitt think

德維特等科學家認為

that as the climate became more arid,

隨著氣候變得更加乾旱，

some salamanders crawled beneath the surface,

一些蠑螈在地表下爬行。

seeking refuge in the cool and stable environment

避風塘

of the Edwards Aquifer.

愛德華茲含水層的。

And over the course of millions of years,

而在數百萬年的時間裡。

these salamanders adapted to the aquatic subterranean caves

適應水生地下洞穴的蠑螈

by evolving certain features,

通過演化某些特徵。

like blood-red gills outside of their body,

如同它們身體外面的血紅色的鰓。

while losing others, like their eyes.

而失去了其他的，比如他們的眼睛。

Living in complete darkness

生活在完全的黑暗中

alongside prey that was also blind,

與同樣是盲人的獵物並肩作戰。

the salamanders simply didn't need to see,

蠑螈根本不需要看。

and energy used for sight would only be wasted.

而用於視覺的能量只會被浪費掉。

Today, only two small black dots just under the skin

今天，只有兩個小黑點在皮膚下。

remain as evidence of eyes past.

留作眼睛過去的證據。

Those dots likely only detect if it's light or dark out.

那些點很可能只檢測到外面是亮還是暗。

This use-it-or-lose-it type of evolution

這種不成功便成仁的演化方式。

also applies to their silvery white skin.

也適用於他們銀白色的皮膚。

Skin pigmentation usually protects animals

皮膚色素通常可以保護動物

from the sun's UV light

紫外光

and serves as camouflage from predators,

並起到偽裝作用，不被捕食者發現。

but both of those are nonissues for the blind salamanders,

但對於盲螈來說，這兩點都不是問題。

who don't have to worry about the sun or predators.

誰也不用擔心太陽或捕食者。

These small, spindly salamanders

這些小而瘦的蠑螈

are at the top of the food chain in this ecosystem,

處於這個生態系統中食物鏈的頂端。

feeding on various crustaceans, like shrimp.

以各種甲殼類動物為食，如蝦。

And even though they can go months without eating,

儘管他們可以幾個月不吃飯。

when a potential snack does swim by,

當一個潛在的小吃確實遊過。

several features help them capture their prey.

幾種功能幫助它們捕捉獵物。

One is a special adaptation

一是特別改編

similar to the lateral line found in fish,

類似於魚類的側線。

which detects vibrations in the water.

它可以檢測水中的振動。

The salamanders' sensory cells respond

蠑螈的感覺細胞的反應是

to changes in water movement and pressure,

對水的運動和壓力的變化。

letting them know what direction

讓他們知道

and how fast their meal is moving.

以及他們吃飯的速度有多快。

Another helpful feature is their large head,

另一個有用的特點是它們的頭大。

which fits 10% to 15% more teeth

可多裝10%至15%的牙齒

than surface salamanders.

比水面蠑螈。

More teeth means a deadlier bite,

更多的牙齒意味著更致命的咬合。

which is crucial if you come by prey

亡羊補牢

only a few times a year.

一年只有幾次。

Danté Fenolio: All of those things are characteristics

Danté Fenolio。所有這些東西都是特點

that help you survive

助你生存

in a very, very challenging environment,

在一個非常非常具有挑戰性的環境中。

so that's why they look the way that they do.

所以，這就是為什麼他們看起來的方式，他們做的。

Narrator: Fenolio is one of the lucky few

旁白：費諾里奧是少數幸運兒之一

who've seen these elusive salamanders up close.

誰已經看到了這些難以捉摸的蠑螈近距離。

Last year, his team at the San Antonio Zoo

去年，他的團隊在聖安東尼奧動物園。

bred Texas blind salamanders for the first time in a lab,

首次在實驗室中培育出德州盲螈。

and they've repeated their success four more times.

而他們又四次重複成功。

They're aiming to protect the species from extinction,

他們的目標是保護這個物種不被滅絕。

since the salamanders have been endangered since 1967.

因為自1967年以來，蠑螈已經瀕臨滅絕。

Two main things threaten the Texas salamander's survival.

有兩件主要的事情威脅著德州蠑螈的生存。

The first is contamination from wastewater runoff.

首先是廢水徑流的汙染。

This is a big issue,

這是個大問題。

because the Edwards Aquifer is a so-called karst aquifer,

因為愛德華茲含水層是所謂的喀斯特含水層。

which means it's made of soluble rock like limestone.

這意味著它是由石灰石等可溶性岩石製成的。

Any pollution on the surface

任何表面的汙染

can rapidly seep into and contaminate groundwater.

可迅速滲入並汙染地下水。

Wastewater typically holds tons of nutrients,

廢水中通常會有大量的營養物質。

which fuels the growth of algae.

助長了藻類的生長。

When the algae decompose,

當藻類分解後。

this process sucks oxygen from the water,

這個過程從水中吸取氧氣。

leaving less oxygen for our sensitive salamanders.

給我們敏感的蠑螈留下更少的氧氣。

The second threat is a loss of habitat.

第二個威脅是生境的喪失。

This happens when rainfall cannot adequately replenish

當降雨不能充分補充時，就會出現這種情況。

the water that people take,

人服用的水。

and this threat is real.

而這種威脅是真實存在的。

The aquifer serves several cities,

該含水層為幾個城市服務。

including San Antonio,

包括聖安東尼奧。

one of the fastest-growing cities in the nation

全國發展最快的城市之一。

and the largest city in the country

和全國最大的城市

that relies entirely on an aquifer for its water.

完全依靠含水層供水的。

So while being able to breed the salamanders

所以，雖然能夠培育出蠑螈們

is a good first step towards one day building up colonies,

是朝著有朝一日建立殖民地邁出的第一步。

the animal may be confined to labs

動物可能被限制在實驗室裡

if they have no home to return to.

如果他們無家可歸。

Devitt: You know, in areas where there's been

德維特：你知道，在一些地區，已經有了。

hundreds of feet of groundwater depletion,

數百英尺的地下水枯竭。

we've almost certainly already lost species to that,

我們幾乎可以肯定已經失去了物種，以。

but we just don't know about it,

但我們只是不知道它。

because we're still describing new species

因為我們還在描述新的物種

from the aquifer all the time.

從含水層一直到。

Narrator: Devitt's team is using new tools

旁白：Devitt的團隊正在使用新工具

to suss out blind salamander populations,

摸清盲蠑螈的數量。

such as a method that analyzes water samples

如分析水樣的方法

for traces of the animal's DNA.

尋找動物的DNA痕跡。

He and his collaborator

他和他的合作者

recently discovered four new related species

最近發現了四個新的相關物種

in the aquifer.

在含水層中。

For now, scientists say

科學家說，目前

that these salamanders can hang in there,

這些蠑螈可以堅持在那裡。

as long as the only home they've ever known stays constant,

只要他們唯一知道的家保持不變。

but that's an increasing challenge

但這是一個越來越大的挑戰

as more people move to the area.

隨著越來越多的人搬到該地區。