Are naked mole rats the strangest mammals? - Thomas Park

譯者: Lilian Chiu 審譯者: Helen Chang

What mammal has the social life of an insect,

哪一種哺乳動物 有昆蟲般的社交生活，

the cold-bloodedness of a reptile,

爬蟲類般的冷血，

and the metabolism of a plant?

且具有植物的新陳代謝？

Bald and buck-toothed, naked mole rats may not be pretty,

無毛且暴牙的裸鼴鼠 可能其貌不掦，

but they’re extraordinary.

但牠們是很不凡的。

With a lifespan of 30 years,

牠們的壽命有三十年，

their peculiar traits have evolved over millions of years

罕見的特性也演化了數百萬年，

to make them uniquely suited to survive harsh conditions,

讓牠們能以獨特的方式 在嚴酷的條件下生存，

especially long periods without oxygen.

特別是長時間無氧的條件下。

In the deserts of East Africa, naked mole rats feed on root vegetables.

在東非的沙漠裡， 裸鼴鼠吃的是根類蔬菜。

They dig for the roots with teeth that can move independently, like chopsticks.

牠們會用牙齒來挖根，那些牙齒 能夠獨立移動，就像筷子一樣。

But even with these special teeth,

但即使有這些特殊的牙齒，

a single naked mole rat doesn’t stand a chance of finding enough food;

單隻裸鼴鼠也不可能 靠自己找到食物；

the roots are large and nutritious, but scattered far and wide.

根雖然很大又很營養， 但散佈得很遠且很廣。

A large workforce has a much better chance,

一個大型的勞動力團隊 成功機會就高許多，

so naked mole rats live in colonies.

所以裸鼴鼠是聚居的動物。

Similar to ants, bees, and termites, they build giant nests.

和螞蟻、蜜蜂，及白蟻一樣， 牠們會建立巨大的巢穴。

Housing up to 300 mole rats,

這些聚居地可以居住 高達三百隻裸鼴鼠，

these colonies feature complex underground tunnel systems,

特色是有複雜的地底通道系統、

nest chambers,

巢狀房室，

and community bathrooms.

以及社區的浴室。

Also like insects, naked mole rats have a rigid social structure.

裸鼴鼠也和昆蟲一樣， 有堅固的社會結構。

The dominant female, the queen,

統治的母鼠，也就是女王鼠，

and two to three males that she chooses,

以及牠所選中的二到三隻公鼠，

are the only naked mole rats in the colony who have babies.

是整個聚居地中 唯一有孩子的裸鼴鼠。

All the other naked mole rats,

所有其他的裸鼴鼠，

male and female,

不論公母，

are either soldiers, who defend the colony from possible invaders,

若不是負責防守聚居地 對抗可能入侵者的兵鼠，

or workers.

就是工鼠。

Teams of workers are dispatched to hunt for roots,

工鼠團隊會被派遺去尋找根，

and their harvest feeds the whole colony.

牠們收穫到的食物 要供應整個聚居地食用。

Living in a colony helps naked mole rats find enough food,

住在聚居地中，讓裸鼴鼠 能夠找到足夠的食物，

but when so many animals live in the same underground space,

但當有太多動物 住在同一個地下空間中時，

oxygen quickly runs out.

氧氣很快就會耗盡。

Mammals need a lot of oxygen;

哺乳類動物需要大量的氧氣；

we use it to make the energy that fuels everything

我們用氧氣來產生能量， 那是一切的基礎，

from maintaining our body temperatures

從維持體溫，

to our heartbeats

到心臟跳動，

to voluntary movements.

到隨意動作都要氧氣。

Without oxygen, we quickly die.

若沒有氧氣，我們很快就會死亡。

In fact, no other mammal could survive the oxygen depletion

事實上，沒有其他 哺乳類動物能夠在裸鼴鼠

experienced in a naked mole rat colony.

聚居地的這種 氧氣損耗條件下生存。

Naked mole rats can thrive in low oxygen

裸鼴鼠能在低氧氣條件下生長，

in part because they’ve abandoned one of the body functions

有部分原因是因為 牠們已經拋棄了其中一項

that requires the most oxygen:

最需要氧氣的身體功能：

thermoregulation.

身體溫度調節。

Most mammals are warm-blooded,

大部分的哺乳是溫血動物，

meaning they have to keep their body temperature consistent.

意思就是牠們得要 保持一定的體溫。

Naked mole rats don’t get enough oxygen to do this.

裸鼴鼠沒有足夠氧氣來做這件事。

Instead, they’re the only mammals

所以，牠們是唯一

whose body temperature fluctuates with their environment,

體溫隨著環境波動的哺乳類動物，

making them cold-blooded, like reptiles.

這點讓牠們變成是冷血的， 和爬蟲類一樣。

They also have a special type of hemoglobin,

牠們也有種很特別的血紅素，

the molecule in the blood that transports oxygen.

即血中運送氧氣的分子。

Their hemoglobin is much stickier for oxygen than ours

和我們相比，牠們的血紅素 更容易黏著氧氣，

and can pick oxygen up even when it’s scarce.

即使氧氣很稀少時， 也能取得氧氣。

In response to a real oxygen emergency,

當真正遇到氧氣不足的 緊急狀況時，

naked mole rats enter a state of suspended animation.

裸鼴鼠會進入 一種不省人事的狀態。

They stop moving,

牠們不動，

slow their breathing,

減緩呼吸，

and dramatically lower their heart rate.

心跳大大下降。

This greatly reduces the amount of energy, and therefore oxygen, they need.

這樣就能大量減少牠們需要的能量， 需要的氧氣也就少了。

At the same time, they begin to metabolize fructose, like a plant.

同時，牠們會開始代謝果糖， 就像植物一樣。

Fructose is a sugar that can be used to make energy without burning oxygen.

果糖是一種醣類，可以製造能量 但不用燃燒氧氣。

Usually, mammals metabolize a different sugar called glucose

通常，哺乳類動物所代謝的 是另一種醣類，叫做葡萄糖，

that makes more energy than fructose,

能製造出的能量比果糖多，

but glucose only works when oxygen’s available.

但若沒有氧氣，葡萄糖就沒有用。

Human brain and heart cells have some cellular machinery to use fructose,

人類大腦和心臟細胞 有一些細胞會用果糖，

but not nearly as much as naked mole rats.

但用量遠不及裸鼴鼠。

Naked mole rats are, in fact, the only mammals known to have this ability.

事實上，裸鼴鼠是唯一 有這種能力的哺乳類動物。

While we can hope humans won’t ever need

雖然我們希望人類永遠不需要

to exclusively live in underground tunnels,

變成只能住在地下通道中，

there are many situations where we would benefit from needing less oxygen.

但在許多情況下， 若需氧量能減少是有好處的。

During heart attacks and other medical emergencies,

在心臟病發以及其他 醫療緊急狀況發生時，

people often die or sustain debilitating organ damage from oxygen deprivation.

人通常會因為缺氧而死亡 或是受到組織損傷。

Could we replicate the naked mole rat’s use of the fructose pathway

如果我們能夠複製 裸鼴鼠使用果糖的方式，

for human health?

用在人類健康上呢？

It took millions of years of evolution to bring the behavior of an insect,

經過了數百年的演化， 才讓昆蟲的行為、

the temperature regulation of a reptile,

爬蟲類的溫度調節，

and the energy production of a plant

以及植物的能量產生，

together in one little mammal,

通通出現在一隻小小的 哺乳類動物身上，

but maybe, with enough study,

但也許，若有足夠的研究，

we can replicate just a few of their wild adaptations.

我們也能複製少數幾項 牠們的野生適應力。