And I'm only half-kidding, because they basically are rocks made of millions of tiny mineralized crystals.

我只是半開玩笑，因為它們基本上就是由數百萬微小礦化晶體組成的岩石。

But things get tricky when that mineral degrades.

但是，當這種礦物質降解時，事情就變得棘手了。

Because unlike bones or skin, your teeth can't heal themselves.

因為與骨骼或皮膚不同，牙齒無法自我癒合。

So when we get a cavity or a hole in our tooth, we need help fixing it.

所以，當我們的牙齒出現蛀牙或牙洞時，我們需要幫助來修復它。

So you might be thinking that before modern dentistry became a thing, people must have had even worse teeth, rotting out of their heads left and right.

所以，你可能會想，在現代牙科技術出現之前，人們的牙齒一定更糟糕，左右腐爛。

And yeah, while there are some gnarly examples of ancient humans with cavities, they weren't like, eating candy by the handful and washing it down with energy drinks.

是的，雖然有一些古人類患有齲齒的可怕例子，但他們並不像現在這樣，大把大把地吃糖，然後用能量飲料沖掉。

At the same time, the story isn't as simple as humans get a lot of cavities now that we eat processed foods, either.

與此同時，事情也並不像人類現在吃加工食品會得很多蛀牙那麼簡單。

So let's take a peek back in time and figure out why humans have the worst teeth in the animal kingdom.

所以，讓我們回顧一下過去，弄清楚為什麼人類的牙齒是動物王國中最糟糕的。

[♪ INTRO ♪)]

[♪ INTRO ♪)]

The most common tooth problem in our species is cavities, also known as caries.

我們人類最常見的牙齒問題是齲齒，也稱為蛀牙。

Over 90% of us will get at least one at some point in our adult lives.

在我們的成年生活中，90% 以上的人至少都會有一次這樣的經歷。

And the cause of this pesky tooth decay is the presence of certain bacteria in our mouth.

而造成這種討厭的蛀牙的原因就是我們口腔中存在的某些細菌。

Or, more precisely, in the dental plaque that builds up on the surface of our teeth.

更確切地說，是堆積在我們牙齒表面的牙菌斑。

The bacterium Streptococcus mutans is the main culprit, breaking down sugars in the food we eat and creating acidic byproducts in the process.

變異鏈球菌是罪魁禍首，它能分解食物中的糖分，並在此過程中產生酸性副產品。

And it's those acids that erode or weaken our enamel, making it susceptible to cavities.

正是這些酸性物質侵蝕或削弱了我們的牙釉質，使其容易產生齲齒。

There are other factors that play into it, too, like how much saliva you produce, whether you practice good dental hygiene, or even your genetic makeup.

還有其他一些因素，比如唾液分泌量、是否保持良好的牙齒衛生習慣，甚至是基因構成。

But the biggest factor we have to come back to is sugar.

但是，我們必須回到糖這個最大的因素上來。

Now, sugar can mean a lot of things, and not just candy.

現在，糖意味著很多東西，不僅僅是糖果。

And it's not just classic table sugar that leads to cavities, but also starches found in foods like bread, rice, and pasta.

導致齲齒的不僅僅是傳統的食糖，還有面包、米飯和麵食等食物中的澱粉。

Our love of sugary and starchy things goes way back to before farming, and even before our species existed.

我們對含糖和澱粉類食物的喜愛可以追溯到農耕時代，甚至在我們人類出現之前。

Humans are primates, and our extinct ancestors and living relatives are mostly fruit-eaters.

人類是靈長類動物，我們已經滅絕的祖先和現存的親屬大多以水果為食。

Since fruit is basically sugar plus fiber, it's not surprising that fossil primates from as long as 54 million years ago had cavities in their teeth, as do some fruit-loving monkeys and apes alive today.

由於水果基本上就是糖加纖維，所以早在 5400 萬年前的靈長類化石牙齒上就有蛀牙，這並不奇怪，今天一些喜歡吃水果的猿猴也是如此。

Primates can definitely have a sweet tooth.

靈長類動物肯定喜歡甜食。

There are chimps who eat huge amounts of fruit, and like to chew and suck on wads of fig gunk for hours on end.

有些黑猩猩吃大量的水果，喜歡咀嚼和吸吮無花果的果肉，一吸就是幾個小時。

And yet, chimps only have something like a 45% max cavity rate across individuals, which is half of the 90-plus percent in present-day humans.

然而，黑猩猩個體間的最大齲齒率僅為 45%，是當今人類 90% 以上齲齒率的一半。

So when did things really pop off for us, tooth decay-wise?

那麼，在蛀牙方面，我們的情況是什麼時候開始好轉的呢？

Well, the short answer is the Agricultural Revolution, around 10,000 BCE.

簡而言之，就是公元前 1 萬年左右的農業革命。

It happened at different times all across the globe, but in general, it caused massive dietary changes to the majority of people on Earth.

它發生在全球各地的不同時期，但總的來說，它給地球上的大多數人帶來了巨大的飲食變化。

Because before farming, people hunted and gathered foods that grew wild in their environment.

因為在農耕之前，人們狩獵和採集在其環境中野生生長的食物。

If we flash back to, say, 1.5 million years ago, early human relatives, like Paranthropus robustus, were eating different kinds of plants, but not a ton of sugary stuff.

如果我們把時間倒退回 150 萬年前，早期人類的近親，比如健壯的古人類，會吃不同種類的植物，但不會吃大量含糖的東西。

So it's not surprising that even though they had a few cavities, they had way fewer than the later, and more like us, Homo erectus from the same site.

所以，儘管他們有一些蛀洞，但數量遠遠少於後來的、更像我們的、來自同一遺址的直立人，也就不足為奇了。

Neanderthals had cavities too, but not many at all, despite the fact that they too carried the Streptococcus mutans bacterium.

尼安德特人也有齲齒，但數量並不多，儘管他們也攜帶變異鏈球菌。

We know that because some clever scientists chipped off the hardened dental plaque from some Neanderthal teeth and found DNA evidence of their microbiome inside.

我們之所以知道這一點，是因為一些聰明的科學家削掉了一些尼安德特人牙齒上的硬化牙菌斑，並在裡面發現了他們微生物群的 DNA 證據。

You know I wouldn't interrupt a SciShow video if it weren't for a really good reason, like showing our appreciation for the company that made it possible for us to make this video in the first place.

要知道，如果不是為了一個非常好的理由，我是不會打斷 SciShow 影片的，比如說，為了表達我們對公司的感激之情，是它讓我們有可能在第一時間製作這影片。

We've worked with Brilliant for years, and this year they've been our most consistent SciShow sponsor.

我們與 Brilliant 合作多年，今年他們是我們最穩定的 SciShow 贊助商。

But we don't take that for granted, and we are genuinely thrilled to continue working with people who feel the same way that we do about fun and accessible science.

但我們不會認為這是理所當然的，我們非常高興能夠繼續與那些和我們一樣對科學的趣味性和可及性有同樣感受的人們合作。

Brilliant is an online learning platform, and it offers thousands of lessons in a huge variety of topics throughout science, math, and computer science, and their range is impressive.

Brilliant 是一個在線學習平臺，提供成千上萬節課程，涵蓋科學、數學和計算機科學等各種主題，其範圍之廣令人印象深刻。

But it's how interactive their courses are that really sets them apart.

但是，他們課程的互動性才是真正的與眾不同之處。

The people at Brilliant go above and beyond to build in puzzles, quizzes, case studies, and hands-on learning opportunities.

Brilliant 的員工不遺餘力地為學員們提供謎題、測驗、案例研究和實踐學習的機會。

Even with all of that engagement, they prioritize accuracy, working with specialists from top universities to get the content right.

即便如此，他們仍將準確性放在首位，與頂尖大學的專家合作，確保內容的正確性。

And with courses covering data, programming, and large language models, it's good to have smart people behind the scenes.

課程涵蓋數據、編程和大型語言模型，有聰明的人在幕後工作是件好事。

So for pretty much all of the reasons that you like SciShow, you will probably like Brilliant, too.

所以，出於喜歡 SciShow 的所有原因，你可能也會喜歡 Brilliant。

And you can check them out at Brilliant.org slash SciShow, or at the link in the description down below.

您可以登錄 Brilliant.org slash SciShow 或下面說明中的連結查看。

That link also gives you 20% off an annual Premium Brilliant subscription, and you'll get your first 30 days for free.

通過該連結，您還可以享受每年訂閱 Premium Brilliant 八折優惠，而且前 30 天免費。

Now, back to the show.

現在，回到節目上來。

If we look at our own species, Homo sapiens, we see variation in how many people were affected by tooth decay.

如果我們看看我們自己的物種--智人，就會發現有多少人受到蛀牙的影響。

And groups that ate more sugary foods were usually the ones with more cavities.

而吃含糖食物較多的群體通常齲齒較多。

Take a site in Morocco from around 14 to 15,000 years ago known as La Grotte des Pigeons.

以摩洛哥一處距今約 1.4 萬至 1.5 萬年前的遺址 La Grotte des Pigeons 為例。

In a 2014 study, researchers found that around half of the teeth and 94% of the people had cavities, similar to modern industrialized populations.

在 2014 年的一項研究中，研究人員發現約有一半的牙齒和 94% 的人患有齲齒，與現代工業化人口相似。

Compare that to most other hunter-gatherer societies, which at most have cavities in, like, 15% of their teeth.

與大多數其他狩獵-採集社會相比，他們最多隻有 15%的牙齒有齲齒。

But how could that happen without gummy worms and Coca-Cola?

但是，如果沒有軟糖和可口可樂，這一切又怎麼可能發生呢？

Well, evidence suggests that they ate a boatload of an especially sweet kind of acorn that gets soft and sticky when cooked, in addition to wild oats and legumes.

有證據表明，除了野生燕麥和豆類，他們還吃了大量特別甜的橡子，這種橡子煮熟後會變得又軟又粘。

But the fun for Streptococcus mutans and its cavity-making pals really got started when we figured out how to farm grains, like wheat and barley.

但是，當我們知道如何種植小麥和大麥等穀物時，變異鏈球菌和它的蛀牙夥伴們的樂趣才真正開始。

And it got even worse with heavy food processing, and eventually adding sugar to everything from bread to sauces to fruit juice.

隨著食品加工業的蓬勃發展，從麵包到醬汁再到果汁，糖的添加量越來越大。

We have plenty of evidence that shows once farming was invented, people across the world had the potential to develop roughly modern-day levels of cavities.

我們有大量證據表明，一旦發明了農耕，全世界的人都有可能患上與現代水準大致相當的齲齒。

But we can also see evolution in the cavity-causing bacterium itself that came along with our changes in food production.

不過，我們也可以從蛀牙致病菌本身的進化中看到，這種進化是隨著我們食品生產方式的改變而產生的。

While ancient human relatives have been plagued by Streptococcus mutans since at least the Neanderthal days, there was a bump in the bacterium's genetic diversity around 10,000 BCE.

雖然至少從尼安德特人時代起，古人類親屬就一直受到變異鏈球菌的困擾，但在公元前 1 萬年左右，這種細菌的遺傳多樣性出現了突變。

These changes coincided with the advent of farming, and more changes have happened in the last 750 years since we started actively cultivating sugar.

這些變化與農耕時代的到來不謀而合，而自從我們開始積極種植蔗糖以來的 750 年裡，又發生了更多的變化。

Just like any good pathogen, it adapts to get better and better at exploiting its environment and doing its evolutionary job.

就像任何優秀的病原體一樣，它也會不斷適應，以便更好地利用環境，完成進化任務。

Which is ruining our teeth.

這正在毀掉我們的牙齒。

In fact, we might have to start worrying about it again, because it's becoming resistant to antibiotics.

事實上，我們可能又要開始擔心它了，因為它對抗生素產生了抗藥性。

The story of us, our teeth, and Streptococcus mutans is long, twisty, and far from over.

我們、我們的牙齒和變異鏈球菌之間的故事漫長而曲折，遠未結束。

But even though most of us will have to deal with a cavity at some point in our lives, at least we will live long enough to get them these days.

不過，儘管我們中的大多數人在一生中總要面對蛀牙的問題，但至少現在我們活得夠長了。

Which I can't say was true for many of the ancient people we talked about in this video.

我不能說我們在影片中談到的許多古人都是如此。

Tooth problems just come along with the territory.

牙齒問題也是人之常情。

But it's a small price to pay to be able to eat handfuls of candy in my jammies.

不過，為了能在睡衣裡吃到大把的糖果，付出的代價還是很小的。

[♪ OUTRO ♪)]

[♪ OUTRO ♪)]