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  • Narrator: Lions have them, hippos have them,

    旁白:獅子有、河馬有,

  • and even you and I have them: canines.

    甚至你我都有:犬齒。

  • Those long, pointy front teeth,

    那些長長尖尖的牙齒,

  • they're actually the longest teeth in the human mouth.

    其實是人類口中最長的牙齒。

  • So what are these long, sharp teeth

    那麼這些長尖牙

  • doing among our short, stubby ones?

    在我們粗短的牙齒之中有何功能呢?

  • Well, contrary to popular belief,

    與多數人的認知相反,

  • it's not for tearing and ripping meat.

    並不是用來撕扯肉。

  • The real reason is actually much more romantic than that.

    真實的理由其實比那浪漫多了。

  • Human men today have 10% longer canines than women,

    現代人類男性犬齒比女性的長了 10%,

  • and this difference isn't unique to our species.

    而這個差異並非人類獨有。

  • Our close relatives, gorillas, have

    我們的近親,大猩猩,也有

  • it as well to an even larger extent.

    甚至差異更懸殊。

  • Males' canines are twice as long as females'.

    雄性的犬齒是雌性的兩倍長。

  • That's because in gorilla society,

    那是因為在大猩猩的社會裡,

  • males compete for exclusive mating rights to

    雄性競爭唯一與整群母猩猩

  • the entire female troop, and the male

    交配的權利

  • with the longest, most intimidating

    而擁有最長、最有威脅力的一副尖牙

  • set of fangs usually wins.

    的雄性通常會勝出。

  • Over time, gorillas have evolved increasingly longer canines,

    隨著時間,大猩猩演化出了更長的犬齒,

  • but when it comes to humans, our teeth

    至於人類,我們的牙齒

  • took a different evolutionary path.

    走上一條不同的演化道路。

  • Our canines have actually become shorter over time.

    事實上,我們的犬齒隨著時間變得更短了。

  • Just look at the canines on the first human,

    看看第一個人類,

  • Ardipithecus ramidus,

    地猿、

  • or Australopithecus anamensis versus modern humans.

    或是湖畔南方古猿,相較於現代人的犬齒。

  • In fact, our canines today are the shortest

    事實上,我們現在的犬齒是

  • they've ever been, and the difference

    歷代以來最短的,

  • between male and female canines

    且雌雄犬齒之間的差異

  • got less pronounced as well.

    也變得不那麼明顯。

  • That's because unlike modern gorillas

    那是因為不像現代的大猩猩

  • who take after our shared ancient ancestors,

    仿效了我們共同的祖先,

  • human men eventually stopped fighting

    人類男性在演化路上某處

  • with their teeth somewhere along the way.

    最終停止了用牙齒打架。

  • Now, scientists aren't entirely sure why this happened,

    現今,科學家並未完全明瞭箇中原因,

  • but one possibility is that our babies

    但有一個可能是我們的嬰兒

  • grew increasingly defenseless, so males

    愈來愈無防備,所以男性

  • had to spend more time on childcare

    必須花更多時間照顧小孩

  • and less time on winning a mate.

    較少時間在贏得交配權。

  • As a result, all that's left in our mouths today

    結果,現在留在我們口中的

  • is the memory of a more slobbery method

    是用更多口水的方式

  • of one-upping our peers.

    贏過我們同輩的紀念。

  • That's right, those canines you carry

    沒錯,你現在的那些

  • around today aren't particularly useful.

    犬齒並不特別有用。

  • For one thing, they're not long enough

    一方面,它們不像獅子

  • to grab and hold on to prey the way lions use them,

    夠長去掠奪並抓住獵物,

  • and they're not big enough to intimidate

    也不像河馬

  • predators' arrivals the way hippos use them.

    夠大足以威脅掠食者。

  • Instead, they help us bite into food. That's it.

    它們幫助我們咬食物,僅此而已。

  • Turns out, evolution isn't always useful,

    結果,演化並非總是有用,

  • but while the truth about our canines

    但即使關於我們犬齒的事實

  • might be disappointing, those teeth

    可能令人失望,那些牙齒

  • are still pretty amazing because

    仍然很了不起,因為

  • anthropologists use canine size and shape

    人類學家利用犬齒的大小和形狀

  • to help track when humanlike ancestors evolved.

    協助追蹤人類祖先的演化。

  • So in a way, our tiny canines make us who we are.

    所以在某種意義上,我們小小的犬齒造就了現在的我們。

Narrator: Lions have them, hippos have them,

旁白:獅子有、河馬有,

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B2 中高級 中文 美國腔 牙齒 猩猩 人類 雄性 演化 河馬

人類擁有那些鋒利前牙的真正原因。 (The Real Reason Humans Have Those Sharp Front Teeth)

  • 178 6
    April Lu 發佈於 2021 年 01 月 14 日
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