Maybe you built a mashed potato volcano or concocted a potion.

也許你建造了一座土豆泥火山，或者調製了一種藥水。

Yeah, that one didn't taste very good or give me special powers.

是啊，那個味道不怎麼樣，也沒有給我帶來特殊能力。

I want my money back.

我要拿回我的錢。

But the thing is, we humans have been playing with our food for thousands of years and with some pretty amazing results, from seedless watermelons to bean plants that can survive frigid winters to regular old broccoli.

但問題是，幾千年來，我們人類一直在玩弄我們的食物，從無籽西瓜到能在寒冬中存活的豆類植物，再到普通的西蘭花，都取得了令人驚歎的成果。

So much of what we find in the produce section we've altered in one way or another.

我們在農產品區找到的很多東西都經過了這樣或那樣的改動。

For as long as humans have grown food, we've tinkered with it, trying to make our crops more nutritious, delicious, and resistant to harmful things like disease and drought.

自從人類種植糧食以來，我們就一直在對糧食進行修補，試圖讓農作物變得更有營養、更美味、更能抵禦疾病和乾旱等有害物質。

And more recently, we figured out how to speed up the process by directly editing plant genes, those tiny units of DNA.

最近，我們發現瞭如何通過直接編輯植物基因（DNA 的微小單元）來加快這一過程。

Hi, I'm Alexis, and this is Crash Course Botany.

大家好，我是亞歷克西斯，這裡是植物學速成班。

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Our understanding of plant genetics, or how traits get passed down from generation to generation in plants, has developed over thousands of years, from ancient farmers manually pollinating crops to everyone's favorite 19th century pea plant matchmaker and beyond.

我們對植物遺傳學，即植物的性狀如何代代相傳的認識，已經經歷了數千年的發展，從古代農民為農作物人工授粉，到 19 世紀每個人都喜愛的豌豆植物媒人，等等。

We now know that organisms pass down traits that make them more likely to survive and reproduce in their environment.

我們現在知道，生物遺傳的特性使它們更有可能在環境中生存和繁衍。

Over time, populations evolve as traits that help them survive are typically selected, and traits that make it harder to survive are usually weeded out.

隨著時間的推移，種群會不斷進化，因為有助於其生存的特徵通常會被選擇，而使其更難生存的特徵通常會被淘汰。

That's natural selection at work, one of the main drivers of evolution.

這就是自然選擇的作用，是進化的主要驅動力之一。

But long before we knew what evolution was, humans figured out that if we selected plants or animals with the traits we liked and got them to reproduce, their offspring would likely have those same traits.

但是，早在我們知道進化是什麼之前，人類就發現，如果我們選擇具有我們喜歡的特徵的植物或動物，並讓它們繁殖，它們的後代就很可能具有相同的特徵。

Scientists later dubbed this artificial selection because people were actively choosing what traits to pass down.

科學家們後來把這稱為人工選擇，因為人們在主動選擇要傳承的特徵。

And artificial selection through breeding, or controlling which plants reproduce with which, can lead to dramatic results in just a few generations, compared to natural selections millions of years.

通過育種進行人工選擇，或控制哪種植物與哪種植物進行繁殖，只需幾代人就能取得顯著效果，而自然選擇則需要數百萬年。

For example, around 4,000 years ago, farmers in the Mediterranean took a leafy weed and bred it with varieties they acquired through trade, encouraging an array of desirable traits.

例如，大約 4000 年前，地中海地區的農民將一種多葉雜草與他們通過貿易獲得的品種進行雜交，從而培育出一系列理想的性狀。

Eventually, that weed diverged into kale, kohlrabi, cauliflower, collard greens, cabbage, brussels sprouts, Romanesco, and broccoli.

最後，這些雜草變成了羽衣甘藍、苤藍、花椰菜、油麥菜、捲心菜、球芽甘藍、羅馬菜和西蘭花。

Yup, those are all different varieties of the same species.

是的，這些都是同一物種的不同品種。

It's artificial selection so extreme that they're known as the dog breeds of the plant world.

這種人工選擇如此極端，以至於它們被稱為植物界的狗種。

And today, as climate change affects crops globally, scientists are investigating new, and harnessing old, ways to breed plants that could help stabilize and even increase our food supply.

如今，隨著氣候變化對全球作物的影響，科學家們正在研究新的和利用舊的方法來培育植物，以幫助穩定甚至增加我們的糧食供應。

Like in Mexico, indigenous farmers have been breeding spineless cacti for centuries as a drought-tolerant crop to feed livestock.

就像在墨西哥，幾百年來，當地農民一直在培育無刺仙人掌，作為飼養牲畜的耐旱作物。

But now, these cacti are also being grown by farmers in Eastern Africa and the Middle East, where climate change-induced drought has hit hard.

但現在，東非和中東地區的農民也開始種植這些仙人掌，氣候變化引發的乾旱給這些地區造成了嚴重影響。

And similar strategies are being used all over the world to breed more resilient staples of the human diet, too.

世界各地也在採用類似的策略來培育生命力更頑強的人類主食。

Beneficial traits like drought tolerance are caused by specific genes encoded in a plant's DNA, which is basically its molecular instruction manual on how to be a plant.

耐旱性等有益性狀是由植物 DNA 中編碼的特定基因造成的，而 DNA 基本上就是植物的分子說明書。

But when you breed plants, you're mixing all their genes together.

但當你培育植物時，你會把它們的所有基因混合在一起。

So it can take a really long time to get the combination you're looking for.

是以，你可能需要很長時間才能得到你想要的組合。

We don't all have years to spend in a monastery garden playing with pea plants.

我們不可能常年在修道院的花園裡擺弄豌豆植物。

So to complement plant breeding, scientists have developed new biotechnology tools, which are exactly what they sound like, technological inventions using living things.

是以，為了補充植物育種的不足，科學家們開發了新的生物技術工具，也就是利用生物進行技術發明。

Like, thanks to DNA sequencing technology, we're able to identify the specific genes that cause certain traits and target our efforts more precisely.

比如，得益於 DNA 測序技術，我們能夠確定導致某些性狀的特定基因，從而更精確地確定我們的工作目標。

And a major tool in the biotech toolbox is genetic modification.

而生物技術工具箱中的一個主要工具就是基因改造。

A genetically modified organism, or GMO, is any living thing that's had its DNA changed in some way.

轉基因生物（GMO）是指其 DNA 發生某種改變的任何生物。

Chances are you've heard of GMOs before, maybe on the news or on the non-GMO packaging of different foods like popcorn, yogurt, and grape nuts.

您可能聽說過轉基因生物，也許是在新聞中，也許是在爆米花、酸奶和葡萄堅果等不同食品的非轉基因包裝上。

Am I the only one who likes grape nuts?

難道只有我喜歡葡萄果仁嗎？

And just like any new technology, people have lots of questions.

就像任何新技術一樣，人們也會有很多疑問。

We all want to know if what's going into our bodies is healthy and safe.

我們都想知道進入體內的東西是否健康安全。

And the idea of tweaking our food's DNA in a lab can make some people feel uneasy.

在實驗室中調整食物 DNA 的想法會讓一些人感到不安。

Like, if we eat GMOs, will we suddenly inflate into huge green superheroes and want to Hulk smash everything in our path?

比如說，如果我們吃了轉基因生物，我們會不會突然膨脹成巨大的綠色超級英雄，想要用綠巨人砸碎擋在我們面前的一切？

The short answer is no.

簡短的回答是否定的。

While biologists do make GMOs in a lab, the way they do it is actually sort of natural.

雖然生物學家確實是在實驗室裡製造轉基因生物，但他們的製造方式其實是一種自然的方式。

They use organisms that have naturally evolved a way to genetically modify plants.

他們利用自然進化的生物來改變植物的基因。

Like agrobacterium, agro for short, is a type of bacteria that can make GMOs.

就像農桿菌，簡稱 agro，是一種可以製造轉基因生物的細菌。

When agro infects a plant, it inserts its own genes into the plant's DNA.

當農業生物感染植物時，它會將自己的基因植入植物的 DNA 中。

Those genes basically instruct the plant to produce a big house and lots of food for the agro.

這些基因基本上是指示植物為農業生產一座大房子和大量食物。

But scientists figured out they could remove the agro's genetic instruction and replace it with a different genetic instruction, one that makes a plant resistant to disease or produce more nutrients.

但科學家們發現，他們可以移除農作物的基因指令，並用不同的基因指令取而代之，這種指令可以使植物抗病或產生更多的養分。

Then the agro inserts those beneficial genes into the plant's DNA instead.

然後，農業公司將這些有益基因植入植物的 DNA 中。

After the agro has done its job, the scientists can remove it because the plant is now able to pass down its modified genes, along with all of its original genes, to its babies, same as any other plant.

在農用機械完成工作後，科學家就可以將其移除，因為植物現在可以將其改造過的基因和所有原始基因遺傳給它的孩子，這一點與其他植物相同。

Another natural genetic modification tool we use in the lab is called CRISPR, which we borrowed from a different species of bacteria.

我們在實驗室中使用的另一種天然基因改造工具叫做 CRISPR，它是從一種不同的細菌中借用的。

It's basically part of the bacteria's immune system.

它基本上是細菌免疫系統的一部分。

It remembers DNA sequences from attacking viruses and chops them up in specific places.

它能記住攻擊病毒的 DNA 序列，並在特定位置將其分解。

But we can tell it to chop up plant DNA instead or the DNA of other organisms, which allows us to use CRISPR as a super-precise gene editor.

但是，我們可以讓它去切割植物 DNA 或其他生物的 DNA，這樣我們就可以把 CRISPR 用作超級精確的基因編輯器。

Basically, it lets us change, add, or remove genes.

基本上，它可以讓我們更改、添加或刪除基因。

This may seem like newfangled technology, but it turns out we've been eating GMOs for a very long time, like thousands of years.

這似乎是一項新技術，但事實證明，我們食用轉基因生物已經有很長一段時間了，比如數千年。

Let's go to the Thought Bubble.

讓我們進入 "思想泡泡"。

Welcome to the International Potato Center, headquartered in Lima, Peru, whose vision is a healthy, inclusive, and resilient world through root and tuber systems.

歡迎訪問總部位於祕魯利馬的國際馬鈴薯中心，該中心的願景是通過根莖和塊莖系統建設一個健康、包容和有韌性的世界。

I need that on a T-shirt.

我要把這句話印在T恤上。

In 2015, scientists at the center were examining sweet potato DNA sequences when they stumbled upon some genes that were distinctly un-potato-like, genes from agrobacterium.

2015年，該中心的科學家在研究甘薯DNA序列時，偶然發現了一些明顯不像甘薯的基因，這些基因來自農桿菌。

At first, the team thought the agrogenes in the sweet potatoes might have been from a recent infection.

起初，研究小組認為紅薯中的農原體可能是最近感染的。

But when they tested the DNA of hundreds of sweet potato varieties from around the world, they found the agrogenes in all of them.

但是，當他們檢測世界各地數百個甘薯品種的 DNA 時，卻在所有品種中發現了農業基因。

This indicated it was actually the ancestor of all those potato varieties that got infected by the bacteria 8,000 years ago.

這表明，它實際上是 8000 年前受細菌感染的所有馬鈴薯品種的祖先。

And then that ancestor passed the agrogenes down to its offspring.

然後，這個祖先又把農業基因傳給了它的後代。

On top of that, they found the agrogenes were only present in domesticated sweet potato varieties, but not their closest wild relatives.

此外，他們還發現只有在馴化的甘薯品種中才存在農原體，而在其最接近的野生近緣種中卻不存在。

That suggests that the bacterial genes may have actually caused the potatoes to be more desirable to ancient farmers.

這表明，細菌基因實際上可能使古代農民更喜歡馬鈴薯。

These farmers probably intentionally selected the agro-infected potatoes for breeding because they all had a certain trait that made them extra tasty.

這些農民可能有意選擇受農業感染的馬鈴薯進行育種，因為它們都具有某種特質，使其特別美味。

The potato scientists are still working on identifying exactly what traits the agrogenes control in the sweet potato.

馬鈴薯科學家仍在努力確定農業基因到底控制了甘薯的哪些性狀。

But they think the original infection may have caused the roots to swell up and get extra potato-y and delicious.

但他們認為，最初的感染可能導致根部腫脹，使洋芋變得更加美味可口。

I, for one, cannot wait to see the fruits, uh, the roots, of their labor.

我迫不及待地想看到他們的勞動成果，呃，根。

Thanks, Thought Bubble.

謝謝，思想泡泡。

So it turns out that plants have been ahead of us in the GMO game for millennia.

原來，幾千年來，植物在轉基因遊戲中一直走在我們前面。

We just didn't know it.

我們只是不知道而已。

And this reflects the scientific consensus that GMOs are safe to eat.

這反映了科學界對轉基因生物可安全食用的共識。

All plants contain DNA, regardless of their genetic modification status.

所有植物都含有 DNA，無論其基因改造狀況如何。

The only difference is that in a genetically modified plant, scientists have made a few changes to the plant's DNA.

唯一不同的是，在轉基因植物中，科學家對植物的 DNA 做了一些改變。

And scientists know exactly what those genetic changes are and what they do because they spend years confirming and analyzing their results through experimentation and peer review.

科學家們清楚地知道這些基因變化是什麼，它們有什麼作用，因為他們花費了數年時間，通過實驗和同行評議來確認和分析他們的結果。

And one thing GMOs definitely don't do is modify your genes if you eat them.

如果你吃了轉基因生物，它們絕對不會改變你的基因。

Plus, before GMOs ever reach the grocery store, they go through years of trials and tests to ensure their safety and efficacy.

此外，轉基因生物在進入雜貨店之前，要經過多年的試驗和測試，以確保其安全性和有效性。

And they're highly regulated by government entities across the globe.

它們受到全球各地政府實體的嚴格監管。

At this point, GMOs have been used widely for decades, so we have loads of data supporting they're safe for humans and livestock to eat.

在這一點上，轉基因生物已被廣泛使用了幾十年，是以我們有大量數據支持它們對人類和牲畜食用是安全的。

But as with any new technology, there are new challenges.

但與任何新技術一樣，新技術也會帶來新的挑戰。

There are tons of different things to consider when adopting a new strategy for something as ancient as farming.

對於像農業這樣古老的行業，在採用新策略時需要考慮大量不同的因素。

Take golden rice, a bio-fortified crop or a type of plant that's enhanced for better nutritional value.

以黃金大米為例，它是一種生物強化作物，或者說是一種營養價值更高的植物。

It has a gene from corn and a gene from a bacterium that allow it to produce tons of beta-carotene, which in turn produces vitamin A.

它有一個來自玉米的基因和一個來自細菌的基因，可以產生大量的β-胡蘿蔔素，進而產生維生素A。

Vitamin A deficiency is responsible for blindness and death in millions of children annually.

維生素 A 缺乏症每年導致數百萬兒童失明和死亡。

So this crop has the potential to alleviate a major cause of global malnutrition.

是以，這種作物有可能緩解全球營養不良的一個主要原因。

But it's one thing to invent a super-powered plant.

但發明一種超能力植物是一回事。

It's another to feed the world with it.

用它來養活世界則是另一回事。

And that takes much more than botanical research to make happen.

而這需要的不僅僅是植物學研究。

There's also politics, economics, culture, environmental effects, and a lot more.

還有政治、經濟、文化、環境影響等等。

For example, if a large corporation patents, therefore owns, a particular strain of genetically-modified seeds, that can have harmful financial effects on small farmers who have to pay for licenses to plant the seeds each year.

例如，如果一家大公司獲得了某種轉基因種子的專利權，從而擁有了這種種子，這可能會對小農戶造成有害的經濟影響，因為他們每年都要為種植這種種子支付許可費。

And it can give that company potentially dangerous control over the global food supply.

這可能會使該公司對全球食品供應進行危險的控制。

There's lots more of the social and political aspects of GMOs in Crash Course Geography.

地理速成班》中還有更多關於轉基因生物的社會和政治方面的內容。

Another concern is about pest-resistant GMOs, that they can stop working over time.

另一個擔憂是抗蟲害轉基因生物，它們會隨著時間的推移而停止工作。

New strains of insects start to emerge that can eat the crops without being poisoned.

新的昆蟲品系開始出現，它們可以吃農作物而不會中毒。

And that can lead to a whole lot of food being lost to pests that farmers thought couldn't harm their crops.

這可能會導致大量糧食因害蟲而損失，而農民們卻認為害蟲不會危害他們的莊稼。

There's also a chance that GMOs could begin cross-breeding and out-competing non-GMOs for access to resources.

轉基因生物也有可能開始雜交，並在獲取資源方面超越非轉基因生物。

And that could lead to less diversity in the species gene pool.

這可能導致物種基因庫的多樣性減少。

Which is a big deal, because genetic diversity helps organisms adjust to different environmental conditions and become less vulnerable to disease.

這是一件大事，因為遺傳多樣性有助於生物適應不同的環境條件，減少疾病的侵襲。

On top of that, GMOs may out-compete neighboring plants, potentially causing other species to die out.

此外，轉基因生物可能會與鄰近植物競爭，從而導致其他物種滅絕。

Scientists and regulators are working on solutions to these possible issues, and new research is being done all the time.

科學家和監管機構正在研究解決這些可能出現的問題的辦法，新的研究也在不斷進行。

But there are lots of extraordinary things we can do with GMOs already.

但是，我們已經可以用轉基因生物做很多了不起的事情。

We can create transgenic plants, which have genes derived from a different species.

我們可以創造轉基因植物，它們的基因來自不同的物種。

Like, a group of researchers in Germany studied the Artemisia annua plant, which produces a little bit of a drug that combats malaria.

比如，德國的一組研究人員對黃花蒿植物進行了研究，這種植物能產生一點抗瘧疾的藥物。

They developed a way to insert its genes into tobacco plants, which are more plentiful and can produce much more of the drug.

他們開發出一種方法，將其基因植入菸草植物中，因為菸草植物數量更多，可以生產更多的藥物。

This could make the medicine way cheaper and more accessible.

這將使藥品更便宜，更容易獲得。

Then there are cisgenic modifications that insert a gene from the same or similar species.

此外，還有插入相同或相似物種基因的同源修飾。

For example, there's a disease called apple scab that's threatening orchards.

例如，有一種叫做蘋果瘡痂病的疾病正在威脅著果園。

Scientists have discovered a resistance gene in a not-so-tasty apple.

科學家在一種並不美味的蘋果中發現了抗性基因。

But they can insert the resistance gene into a tasty variety, creating a cisgenic apple that's protected from the disease.

但是，他們可以將抗病基因植入美味的品種中，創造出一種不受病害影響的順式蘋果。

Researchers can also create subgenic modifications, which don't involve the addition of new genes, but edit existing genes instead.

研究人員還可以創建亞基因修飾，這不涉及增加新基因，而是對現有基因進行編輯。

Like, scientists in China recently used CRISPR to make a subgenic modification in wheat.

比如，中國科學家最近就利用 CRISPR 對小麥進行了亞基因改造。

They turned off three genes that repressed the wheat's immune response to a nasty fungal infection.

他們關閉了三個基因，這些基因抑制了小麥對討厭的真菌感染的免疫反應。

And that change made the wheat better at fighting the infection.

這種變化使小麥的抗感染能力更強。

So while we humans have been breeding plants to suit our needs for millennia, genetic modification can allow us to make crops that are even more nutritious and resilient.

是以，千百年來，我們人類一直在培育植物來滿足我們的需求，而轉基因技術可以讓我們培育出營養更豐富、生命力更頑強的作物。

And hey, if we keep playing with our food, who knows what other amazing technologies we'll come up with.

而且，如果我們繼續玩弄我們的食物，誰知道我們還會發明出什麼了不起的技術呢？

Next time, we'll be learning about how plants relate to each other in their communities and how ecologists and plant lovers are saving plant species from extinction.

下一次，我們將瞭解植物在群落中的相互關係，以及生態學家和植物愛好者如何拯救瀕臨滅絕的植物物種。

Hey, before we go, let's branch out.

嘿，在我們走之前，讓我們分頭行動。

A new GMO pineapple that recently hit grocery store shelves has fruit that is what color?

最近在雜貨店上架的一種新型轉基因菠蘿的果實是什麼顏色的？

Get the bunny started in the comments right now.

現在就在評論中開始吧。

Thanks for watching this episode of Crash Course Botany, which was filmed with the Demir Ferezenwich Studio and made in partnership with PBS Digital Studios and Nature.

感謝您收看本期《植物學速成班》，本期節目由 Demir Ferezenwich 工作室與美國公共廣播公司數字工作室和《自然》雜誌合作拍攝。

If you wanna help keep Crash Course free for everyone forever, you can join our community on Patreon.

如果您想幫助《速成課程》永遠免費，可以加入我們的 Patreon 社區。