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  • Millions of years ago, wisdom teeth were dead useful.

    幾百萬年前,智齒是死有用的。

  • Those hefty molars helped us grind up fibrous veggies.

    那些碩大的臼齒幫我們磨碎了纖維素。

  • Then, around 1 million to 2 million years ago,

    那麼,大約在100萬至200萬年前。

  • we invented cooking,

    我們發明了烹飪。

  • which softened food so we didn't need to chew as much.

    它使食物變軟,所以我們不需要咀嚼那麼多。

  • That put wisdom teeth out of a job.

    這讓智齒失去了工作。

  • Around 10,000 years ago,

    大約在一萬年前。

  • we began to farm and cook our food even more.

    我們開始耕種,並更多地烹飪我們的食物。

  • With less work to do, our powerful jaws shrank,

    隨著工作的減少,我們有力的下巴也縮了起來。

  • making it harder for those extra teeth

    讓那些多餘的牙齒更難長出來

  • to fit in our mouths.

    以適應我們的嘴。

  • And today, we suffer the consequences.

    而今天,我們卻要承受這樣的後果。

  • Gum infection, tooth decay, even tumors.

    牙齦感染,蛀牙,甚至腫瘤。

  • But, unfortunately, annoying extra molars

    但是,不幸的是,惱人的多出的臼齒。

  • aren't the only way evolution screwed us over.

    並不是只有進化論才把我們搞垮的。

  • All primates, including humans, have something in common:

    所有的靈長類動物,包括人類,都有一些共同點。

  • We have incredibly bony feet.

    我們有一雙骨感十足的腳。

  • Each one contains 26 bones.

    每個人都有26根骨頭。

  • Together, that's almost a quarter

    加在一起,差不多有四分之一

  • of all the bones in our body.

    在我們身體的所有骨骼中。

  • Now, this foot design makes perfect sense

    現在,這個腳的設計很有意義

  • to our ancient primate ancestors,

    我們的遠古靈長類動物的祖先。

  • because all those tiny moving parts

    因為所有這些微小的運動部件

  • made their feet flexible enough to cling to branches.

    使它們的腳靈活得可以緊緊抓住樹枝。

  • But here's the problem:

    但問題就在這裡。

  • Once our ancestors left the trees

    一旦我們的祖先離開樹

  • and started walking upright,

    並開始直立行走。

  • we needed a more rigid, stable foot to balance

    我們需要一個更堅硬,更穩定的腳來平衡

  • and propel ourselves from one step to the next.

    並推動我們自己從一個臺階走向另一個臺階。

  • We didn't lose a single bone.

    我們沒有失去一根骨頭。

  • The result? Our feet are too flexible,

    結果呢?我們的腳太靈活了。

  • and they can easily twist the wrong way,

    而且他們很容易扭錯方向。

  • which leads to all sorts of foot-related ailments,

    導致各種與腳有關的疾病。

  • like sprains, stress fractures, and tendonitis.

    如扭傷、應力性骨折和肌腱炎。

  • If that's not bad enough,

    如果這還不夠糟的話

  • walking upright also messed up our spine.

    直立行走也把我們的脊柱弄得亂七八糟。

  • In animals that walk on all fours,

    在四肢行走的動物中。

  • the spine arches like a bridge,

    脊樑拱起如橋。

  • which helps support the weight

    這有助於支持重量

  • of their internal organs dangling beneath.

    他們的內臟在下面垂著。

  • Then, 6 million years ago,

    那麼,600萬年前。

  • our ancestors first stood up

    吾祖先立

  • and forced that smooth arch into an S shape.

    並將那光滑的拱形逼成S形。

  • The top is curved outward to support the weight of our head,

    頂部向外彎曲,以支撐我們頭部的重量。

  • and the bottom is curved inward

    而底部向內彎曲

  • to keep our torso in line with our feet,

    以使我們的軀幹與腳步保持一致。

  • so we can balance.

    所以我們可以平衡。

  • Unfortunately, this design isn't very sound.

    可惜的是,這種設計並不是很完善。

  • That bend in our lower back

    腰部的彎曲

  • puts a tremendous amount of pressure on our backbone.

    給我們的骨幹帶來了巨大的壓力。

  • So it's no wonder that 60% to 70% of people worldwide

    所以,難怪全球有六七成的人... ...

  • experience lower-back pain sometime in their life.

    在他們的一生中的某個時候會經歷下背部疼痛。

  • Speaking of pain, let's talk about

    說到疼痛,我們來談談

  • getting hit in the testicles.

    被擊中的睪丸。

  • Unlike most of your organs,

    不像你的大部分器官。

  • they hang outside your body,

    他們掛在你的身體外面。

  • so they aren't protected by muscles, fat, and bone,

    所以他們沒有被肌肉、脂肪和骨骼保護。

  • which makes them a prime target for incoming soccer balls.

    這使得他們成為傳入足球的主要目標。

  • So why are we, and many other mammals,

    那麼,為什麼我們,還有很多其他的哺乳動物。

  • stuck with such a risky arrangement?

    受困於這樣的風險安排?

  • Well, it turns out, sperm are healthiest

    原來,精子是最健康的。

  • when they're stored in a cool place.

    當它們被存放在陰涼的地方時。

  • So we hold them as far away from the body as possible

    所以我們拿著它們的時候要儘可能的遠離身體

  • to keep them a few extra degrees below body temperature.

    讓他們的體溫多低幾度。

  • And humans have it especially bad.

    而人類的情況特別嚴重。

  • Since we walk upright, gravity pulls

    由於我們是直立行走,重力會拉動

  • on our exposed testes,

    在我們裸露的睪丸上。

  • which can lead to a potentially excruciating condition

    這可能導致一個潛在的痛苦的狀況

  • called inguinal hernia.

    稱為腹股溝疝氣。

  • And while this might feel like the worst thing ever,

    雖然這可能會讓人感覺是最糟糕的事情,

  • other evolutionary quirks can be deadly.

    其他的進化怪癖可能是致命的。

  • Take the dangerous way our throat is structured.

    以我們的喉嚨結構的危險方式。

  • It contains two important tubes,

    它包含兩個重要的管。

  • the trachea, or windpipe, where air travels,

    氣管,即氣管,空氣流通的地方。

  • and the esophagus, where food travels.

    和食道,食物在那裡流動。

  • These pipes are nestled so close together,

    這些管子是如此緊密地依偎在一起。

  • it's just plain stupid.

    這只是普通的愚蠢。

  • Because when you swallow,

    因為當你吞下。

  • food can slip into your windpipe and block airflow,

    食物會滑入氣管,阻塞氣流。

  • causing you to choke or suffocate.

    導致你窒息或窒息。

  • Every year, about 5,000 Americans die

    每年約有5,000名美國人死亡

  • by choking on food.

    因噎廢食。

  • Meanwhile, other animals have a more sensible arrangement,

    同時,其他動物有更合理的安排。

  • where their windpipe and esophagus

    氣管和食管處

  • are far away from each other.

    是相距甚遠。

  • So, why don't we have that setup?

    那麼,為什麼我們沒有這種設置呢?

  • Well, by sticking the pipes together,

    好吧,通過把管子粘在一起。

  • we can open up extra space in our throats,

    我們可以打開額外的空間 在我們的喉嚨。

  • which acts like an echo chamber

    如同迴音室

  • to amplify sound to help us talk.

    來放大聲音,幫助我們說話。

  • But evolution doesn't always come with a silver lining.

    但進化並不總是一帆風順的。

  • In the 18th century, millions of sailors

    在18世紀,數以百萬計的水手

  • suffered from a horrible disease called scurvy.

    患上了一種可怕的疾病,叫壞血病。

  • Their gums would swell and bleed

    他們的牙齦會腫脹出血

  • as their skin disintegrated and their brains decayed.

    因為他們的皮膚在分解,大腦在腐爛。

  • The culprit?

    罪魁禍首?

  • Away from shore for months on end,

    連續幾個月遠離海岸。

  • the sailors had no access to fresh fruits and vegetables,

    水手們無法獲得新鮮水果和蔬菜。

  • key sources of vitamin C,

    維生素C的主要來源。

  • which plays a crucial role in how our body

    這對我們的身體起著至關重要的作用

  • repairs damaged tissue, bone, and nerves.

    修復受損的組織、骨骼和神經。

  • Now, humans, along with other apes,

    現在,人類與其他猿類。

  • guinea pigs, some bats, birds, and fish,

    豚鼠,一些蝙蝠,鳥類和魚類。

  • are the only animals that would ever have this problem,

    是唯一會出現這種問題的動物。

  • because everyone else can produce their own vitamin C,

    因為別人都可以自己生產維生素C。

  • no oranges needed.

    不需要橙子。

  • Meanwhile, humans have a gene mutation

    同時,人類有一個基因突變

  • that prevents us from doing the same.

    阻止我們做同樣的事情。

  • Which normally wouldn't be a problem

    這通常不會是一個問題

  • for our ancient, fruit-eating ancestors,

    為我們古老的、吃水果的祖先。

  • who didn't trap themselves on ships

    船大不壓死人

  • without fresh fruit for months.

    幾個月沒有新鮮水果。

  • Now, there doesn't seem to be any benefit to this mutation,

    現在看來,這種變異並沒有什麼好處。

  • which just goes to show,

    這正好說明。

  • evolution isn't always helpful.

    進化並不總是有用的。

  • In fact, it can make life a whole lot worse.

    事實上,它可以讓生活變得更糟糕。

Millions of years ago, wisdom teeth were dead useful.

幾百萬年前,智齒是死有用的。

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