Name: 我們該不會全部都是親戚吧？ (Are We All Related?)
Uploaded: 2017-09-26T21:59:58.000Z
Duration: 6 min 26 s

And these are your ancestors, a huge pyramid stretching into the past and balancing right

而這些是你的祖先，一個巨型的金字塔連結著過去和

Four generations back, your direct ancestors total 30.

連結四個世代以後，和你直接相連的祖先一共有 30 位

If we continue down this line, doubling every step, just 40 generations ago we’d find

如果我們朝著這方向下去，每隔兩代，到了第40代以後我們會發現

a trillion ancestors, all living *at the same time*.

That's not only more people than have ever been alive, it's more stars than are in

這不僅超越世界上人類生存的數目，這比銀河系上的星星

Since our species came on the scene 200,000 years ago, there have been maybe 7 or 8 *thousand*

我們人類是二十萬年前出現，所以可能經歷了七千或八千

generations of humans leading up to… you.

那麼那些遺失的祖先去哪了呢？

We’re not talking banjo-playing, King-of-Spain, Cersei-Jaime inbreeding, but every family

我們並不是要談論彈琵琶、西班牙國王或者是瑟曦潔米的亂倫，但每個

家族樹無可避免由這種方式開枝散葉

Before Tinder, choices for mates were often limited to as far as you could walk.

在有Tinder (交友軟體) 之前，選擇伴侶僅限於你行動的距離

Even people like Charles Darwin and Albert Einstein married their first cousins.

連查爾斯達爾文和亞博愛因斯坦都和他們第一代的親戚結婚

Because so many people with shared ancestors have reproduced, our number of actual ancestors

因為許多人有著相同的祖先，所以祖先的真實數字

is much smaller than what simple math tells us.

If we replace that with fancy math, factoring in how people moved and lived and paired up…

如果我們用這個取代數學邏輯，著重在人們遷徙居住並配對…

life expectancy, trade, geography, Genghis Khan… we find something interesting: every

生活的預期，貿易，地理，成吉思汗…我們會發現有趣的事情：

human alive today shares a common ancestor in their family tree, and this person lived

活在當今現代的人們有著共同的祖先在家族樹上，而這位祖先

That’s right, next time you get in a fight with a stranger on the internet, just remember

這就對了，下次你在網路上和陌生人開始爭論時，要記得

that you share the same great great great great great (fast foward) great grandfather

你們有著共同的曾曾曾曾曾(快轉) 曾祖父

The math tells us they must have existed, but they didn’t leave fossils or artifacts.

數學告訴我們他們一定存在，但他們並沒有留下化石或手工藝品

Though, writing birthday cards for each of their 7.4 Billion great great great great

然而，寫生日卡片給他們 74 億位的曾曾曾曾

great (fast forward) great grandchildren would have been nice gesture.

曾（快轉）曾孫可能會是一個好的方法

But we all carry a record of our ancestors in our genes.

但在我們的基因裡面有著我們祖先的影子

Because DNA is copied over and over, every so often a mistake is written in.

而 DNA 是一直重覆複製，所以有些錯誤也會被一同移植過來

You know how when you make a copy of a copy, it’s doesn't come out as sharp?

你知道每當你再複製一次，東西會變得更加模糊?

Like that, but since most of our DNA can be changed without affecting how things work,

就是如此，由於我們大部分的 DNA 可以被改變而不影響事情的運作方式

many of these mutations slip through to the next generation.

許多這些突變也會移轉到下一代

These genetic changes accumulate at a steady rate through time, so scientists can read

這些基因的改變會隨著時間的過去累積成一固定比例，科學家可以

them like a molecular clock, and estimate how much time has passed.

從這些數值做分子鐘的解讀，並去推算經歷多少時間

And which changes individuals share tell us how closely or distantly related they are.

而這些個體的改變告訴我們的關係多近或相隔幾代

Humans *seem* really different, but on a DNA level we’re remarkably similar.

人類「看似」非常不同，但在 DNA 我們其實是相同的

Groups of chimps in Central Africa, living right next to each other, show more genetic

中非黑猩猩群，他們住在彼此隔壁，展現了許多基因

variation than we find in the entire human population.

的變化遠比我們在全人類所發現

This genetic similarity tells us that our species is new, in the big scheme of things,

在整個大體系中，基因上的相似告訴我們人類還是新的物種

and that at one point our population was small, maybe as few as 10,000 of us.

而在某個層面上人類的數目算小，大概只有一萬個我們

To put that in perspective, that’s only a third of your average Bruce Springsteen

從這個觀點來看，這只是平均布魯斯·斯普林斯汀演唱會人數的三分之一

Today, any two humans only differ by about 1 out of 1000 DNA base pairs.

今日，任何兩個人只有千分之一的機率有不同的 DNA

But our genome is so big, that’s still millions of single letter differences, or SNPs, for

但是我們基因組成是太大了，仍然是數以百萬計的單字母差異或，或 SNPs

We tend to see combinations of these changes, chunks of SNPs, associated with different

我們想要把這些改變組合在一起，大部份的 SNPs，是關係著不同的

Companies that test your DNA ancestry read thousands of these single letter changes in

檢測 DNA 的公司會運用基因組中數千種單位改變來找出你的祖先

your genome, to make a sort of signature of your unique genetic variation.

並根據結果訂出相關特徵，就是專屬你的基因變化

Then they compare your signature to thousands of reference individuals from various parts

之後他們用你的特徵來配對數千個來自世界上不同區塊的參考個體

of the world, and do a bunch of fancy math to see which parts of your genome most likely

並用高度技巧的數學來分析你的基因組

My genetic results: Pretty much look like this.

我的基因結果：大概長得像這樣

My ancNewsprestors, on both sides of my family, are from Northern Europe and Scandinavia,

我的祖先，由父母兩方開始，都來自北歐和斯坎維尼亞

which explains my last name, why I’m tall, why I don’t tan, and also why I carry more

這就可以說明我的姓，為何我長的比較高，皮膚比較白和

相較於其他三分之二的人，我擁有尼安德塔爾人的 DNA

疑惑我什麼擁有尼安德塔爾人的DNA？

You should watch our last video. I didn’t find any surprises, but many people learn

你應該要看上一部影片。我並沒有感到驚訝，但許多人認識

about ancestry they didn’t know they had.

這他們其實有這個血統而不自知

Where we come from isn’t always obvious on the outside, but DNA doesn’t lie.

我們並不會輕易的從外在了解到我們來自何方，而 DNA 結果是最真實的

Before, using math, we identified an ancestor, not too long ago, that’s related to all

以前我們可以運用數學，來分辨我們的祖先，在不久前，我們發現我們是有相關的

But that person’s genetic influence has been shuffled so much it’s invisible in

但那基因影響已經隨著時間逐漸改組，至今在我們的 DNA 裡已經看不到了

Is there someone whose genes have been passed on, unbroken, to today?

有沒有誰的基因是經過時間更迭傳到今天呢？

Some leftover fingerprint from the mother of everyone alive?

有任何殘留的指紋是從母親那邊遺留下來的呢？

It lives in mitochondria, the POWERHOUSE OF THE CELL! – so we’re doing that again?

它住在線粒體。「細胞的動力！」，所以我們再來操作一次

Ok–mitochondria used to be free-swimming.

好的，線粒體一直都自由自在的

Unlike your other 46 chromosomes, there’s no shuffling when it’s passed between generations.

不像其他的46個染色體，並沒有轉移到下個世代

What’s more, all your mitochondria came from your mother’s egg, not your father’s

況且，所有的線粒體都是來自於媽媽的卵子而不是爸爸的

They trace an unbroken line of ancestors stretching back through every female in your family tree.

他們可以延著這條線追溯到每位家族樹上的女性

By comparing the changes that have accumulated over the millennia, we find the most ancient

在累積數千年後，比對這些改變，我們發現最原始

human mitochondrial DNA comes from Africa, where our species originated.

人類的線粒體 DNA 是來自於非洲，這是所有物種的發源地

We can even trace it back to one woman, about 150,000 years ago.

我們也可以追溯到第一位女性，大約十五萬年前

Other Homo sapiens females lived alongside her, but only her lineage lives on today,

其他女性人種和她生活在一起，但只有他的血統遺留到至今

all other Homo sapiens lineages are extinct.

And every single one of us, descend from her.

In the truest sense, we really are family.

Even if we’re just hundredth cousins or something.

But our ancestry isn’t just branches stretching into the past, it’s also a tree that extends

我們的祖先並不是只有過去的發展，也會連結到我們的未來

Today we have more power to mold that future, down to the genetic level, than we’ve ever

現在我們比以前有更多的能力去影響未來，可以深至基因階段

So what might our species’ future look like?

那麼我們未來物種會長什麼樣子呢？

字幕列表影片播放

我們該不會全部都是親戚吧？ (Are We All Related?)

stretch

fancy

inevitably

ancestor