Name: 為什麼狗有下垂的耳朵：一個動畫故事（Why Dogs Have Floppy Ears: An Animated Tale）
Uploaded: 2021-10-05T19:18:11.000Z
Duration: 3 min 35 s

wolves and coyotes have these big upright ears.

Charles Darwin himself actually thought a lot about this question.

實際上，查爾斯‧達爾文對這個問題有很多想法

150 years ago, he published a book that said, "Look—it's not just pet dogs!”

一百五十年前，他出版了一本書叫“看，他不只是一隻寵物狗”

Farmed goats have floppier ears than wild goats.

馴養的山羊比野生山羊的耳朵下垂

There are floppy-eared rabbits, cows and sheep.

Tame animals tend to have shorter snouts, and their fur tends to be paler

溫馴的動物往往鼻子較短，而且他們的皮毛通常顏色較淺

All these mysterious traits put together have been called "domestication syndrome."

這些神秘的特徵被稱為“馴化症候群”

The story starts thousands and thousands of years ago

Our ancestors wanted them to be tamer, so sometimes

我們的祖先希望他們變得更溫馴，所以有時候

they tried breeding the friendliest ones.

At some point, strange side effects started to show up

在某些時候，奇怪的副作用開始顯現

Thousands of years later, good old Darwin noticed the domestication syndrome pattern,

幾前年後，達爾文注意到馴化症候群的模式，

but all he'd learned about change in the animal kingdom

但他所了解關於動物王國的變化

couldn't explain this connection between behavior and appearance.

無法解釋行為和外表之間的關聯

Scientists who came after him couldn't figure it out either.

But for the past few years, scientists have been throwing around a fascinating hypothesis.

但是在過去的幾年裡，科學家們已經拋出一個有趣的假設

They think the answer to this whole puzzle lies in a special group of cells.

他們認為這個難題的答案在於一群特殊的細胞

They're called neural crest cells, and coincidentally,

他們被稱為神經脊細胞，巧合的是，

they were discovered by Wilhelm His the exact same year Darwin published his book.

他們在達爾文出版他的書的同一年被威爾黑姆‧希斯發現

Neural crest cells show up very early in the development of all vertebrate embryos.

神經脊細胞在所有脊椎動物胚胎的早期就顯現出來了

As the embryo grows into a goat or a pig or a wolf,

隨著胚胎成長成山羊、豬和狼，

these special cells travel to every corner of the body

這些特殊的細胞會傳到身體的每個角落

Now, here's the thing: Some of these cells end up right here above the kidneys.

現在重點來了，這些細胞中的一部分最終停在腎臟上方。

They become cells that secrete adrenaline

Wild animals are always fighting or fleeing to survive,

野生動物總是為了生存而戰鬥或逃跑

and that makes it hard for humans to get close.

But what if an animal was born with fewer of these neural crest cells,

但如果一隻動物出生時擁有比較少的神經脊細胞，

又或者這些細胞不能很好的運作呢?

那隻動物就會擁有比較少的腎上腺素

It would probably be less freaked out by humans—

and it would pass that behavior on to its offspring.

然後將這種行為傳遞給他的後代

The idea is that this is what's going on in domesticated animals.

這個想法是馴養動物正在發生的事

Their neural crest cells have been dialed back.

And this would explain all the appearance stuff, too

because neural crest derived cells do a lot more than just make adrenaline.

因為神經脊細胞不僅僅是增加腎上腺素

Some of the cells end up forming parts of the face.

其中一些細胞最終形成臉的一部份

Some of them become cells that control the color of skin and hair.

其中一些成為控制皮膚和頭發顏色的細胞

And some make their way into the ears—and help make cartilage.

其中一些進入耳朵幫助生長軟骨

It's likely this is how dogs first got floppy ears.

And then centuries of intentional human breeding helped accentuate or reverse that change.

好幾個世紀的人類刻意地幫助突出和扭轉這個變化

But the neural crest cell hypothesis doesn't quite explain every bit of domestication syndrome.

但神經細胞並不能很好的解釋馴化症候群的每一點

Like—what's going on with other tame species that do have upright ears?

像為什麼其他溫馴的品種也有直立的耳朵

This be might be the excuse scientists need to spend more time with their pets.

這可能是科學家需要花更多時間陪他們的寵物的借口

Please subscribe and check out some papers about the neural crest cell hypothesis

字幕列表影片播放

為什麼狗有下垂的耳朵：一個動畫故事（Why Dogs Have Floppy Ears: An Animated Tale）

stuff

weird

subscribe

figure