此时此地 在科学秀总部 我们为员工们准备了一小片食物区
Here at SciShow HQ we have a little food area for the employees –
有时有甜甜圈 有时有坚果 有时有芒果干
Sometimes there are donuts. Sometimes there are nuts. Sometimes dried mango.
但有一件东西 它从不停留 而且
But the one thing that never sticks around and is
能买的时候就消失了 它就是那美妙的、
gone as soon as we can buy it is the wonderful,
漂亮的 高贵的香蕉 对我们而言 不幸的是 它们不能永远出现在身边
beautiful, noble banana. Unfortunately for us, they may not be around forever.
[开场音乐]
[Intro Music]
首先 香蕉的优点在于其有益健康还富含营养和能量
First, the good: bananas are healthy, packed with nutrition and energy, they
它们拿在手上刚刚好 并且当它完全熟了时它会给你小的暗示
fit in your hand and give nice little cues when they’re perfectly ripe, and are
它们剥皮容易 吃起来省事 统计数据表明 令人惊奇的是
easy to peel and eat; shocking statistic, the banana
香蕉是沃尔玛里销量第一的物品 而不是薯条、可口可乐、《五十度灰》
is Wal-mart’s number one selling item. Not the potato chip, not Coca-Cola,
对于人类而言 香蕉是如此完美的食物
not Fifty Shades of Grey, bananas. They appear to be so perfect for human
以至于Kirk Cameron曾试图用它们来证明上帝存在论。
consumption that Kirk Cameron attempted to use them to prove the existence of God.
当然啦 香蕉不是上帝创造的 甚至都不是大自然的产物
Of course this banana was not created by God, or really even nature. Bananas, at
至少在商店里你所见到的那些香蕉
least the ones that you see at the store,
曾经是人工生产的不要误解 确实有野生香蕉植物—
were created by people. Don’t get me wrong, there are wild banana plants – lots
而且有很多—他们生长于南亚和东南亚
of them – they’re native to South and Southeast Asia,
种类品种繁多
and there are dozens of species and thousands of varieties.
只是 这些并非供人类品尝 你可能有所疑问 为啥那些品种
They’re just not the ones we eat. Some of those species, as you might suspect,
有种子 因为那是水果的本质 新鲜的果肉应该包含着种子
have seeds, ’cause that’s what fruits are, they’re fleshy bodies containing seeds.
那么 你可能会好奇 为什么你从来没吃到过香蕉籽呢?嗯
So you might wonder, why have you never eaten a banana seed? Well,
其实你多少会吃到……在培植的香蕉中籽基本不存在了
you have… kinda. In cultivated bananas the seeds have pretty much stopped existing.
如果你仔细观察 可以看见
If you look closely you can see
细小的黑点 那些就是被遗留下来的
tiny black specks. Those are all that’s left,
不育种子 如果你把它们种在地里 什么也不会长出来
and they’re not fertile seeds. If you plant them, nothing grows.
今天的香蕉是不育突变体 我不是毒舌 但事实就是那样
Today’s bananas are sterile mutants. I’m not trying to be mean, that’s just the truth.
除非你在20世纪60年代生活过(向年长的科学秀观众致敬)
Unless you were alive in the 1960s (hats off to all those older SciShow viewers out there)
那时你吃过的每一根香蕉 它们基因完全相同
every banana you have ever eaten was pretty much genetically identical.
这是一根卡文迪什香蕉它实际上是无籽的那种 是我们今天都在吃
This is a Cavendish, the virtually seedless variety that we all eat today
但我们也不总是吃这种香蕉
but it wasn’t always our banana of choice.
直到20世纪60年代 每个人都吃着同种香蕉 这是一种不同香蕉—
Until the 1960s,everyone was eating the same banana, it was just a different banana –
名字叫大麦克香蕉 它是一种更大 、更甜、皮更厚的香蕉 你可能会注意到
the Gros Michel, a bigger, sweeter fruit with thicker skin. You might notice that
香蕉味儿的东西和真的香蕉比口感上还是差了一点 没错 确实如此
banana flavored things don’t really taste like bananas. Well they do –
它们尝起来像大麦克香蕉 大麦克香蕉作物遗传的单一性
they taste like the Gros Michel. The genetic monotony of the Gros Michel
失去了香蕉的口感
crop was its undoing.
杀真菌剂耐药病原体巴拿马病（香蕉枯萎病）开始抑制大麦克香蕉作物
A fungicide resistant pathogen called the Panama disease began infecting Gros Michel crop.
当种植者们知道了他们的作物是多么脆弱时
By the time growers understood how vulnerable their crops were
其几乎绝迹了
the GrosMichel variety was all but extinct.
整个香蕉产业不得开始培植卡文迪什香蕉
The entire banana industry had to be retooled for the Cavendish.
因为它们是无籽的 培植它们的唯一方式就是移植其一部分的茎
Since they’reseedless, the only way to reproduce them is to transplant part of the plant stem,
50年来卡文迪什香蕉都长的很好
and for the last 50 years we’ve been good with the Cavendish,
因为它更能抵抗巴拿马病 然而令人恐惧的是
cause it’s more resistant to the Panama disease. However somewhat terrifyingly a
已经证明巴拿马病会影响我们吃的卡文迪什香蕉
strain of Panama disease that affects the Cavendish strain that we all eat has been identified.
全球范围内单一培植相同基因的个体这给病菌带来可乘之机
A global monoculture of genetically identical individuals is a beautiful sight to a pathogen.
真菌只需要找出如何感染并破坏单个的个体
The fungus only has to figure out how to infect and destroy a single individual,
然后突然间 并没有其余品种来阻止或者减缓其发生
and suddenly there is no diversity to stop it,or even slow it down.
这让许多科学家担心
That’s led to a lot of scientists worrying about or even
甚至预言卡文迪许香蕉会彻底绝种
predicting the outright demise of the Cavendish.
这种美妙的、最受欢迎的水果可能会完全消失
This wonderful most popular of fruits might completely cease existence.
好消息是我们现在对遗传学、流行病、真菌和病理学都有了更深刻的了解
The good news is we now have a much better understanding of genetics epidemics, fungi, and pathology.
科学家们和种植者们已经开始采取措施来保护卡文迪许香蕉了
Scientists and growers have already taken steps to protect the Cavendish.
一些种植者正在创造不同基因的香蕉 如果卡文迪什香蕉绝种 这个可能会取代它
Some growers are creating genetically different bananas that might replace the Cavendish crop if it fails
而科学家也正在试图对卡文迪许香蕉进行基因工程改造 让它对巴拿马病免疫
while scientists are attempting to genetically engineer Cavendish plants with immunity to Panama disease.
而且我们从大麦克香蕉的失败中学到的许多东西
Plus we learned a lot from the Gros Michel debacle.
受感染的区域正在迅速被销毁 并且新的作物正在无菌的实验室被培育
Infected fields are quickly being destroyed and new crops are grown from pathogen-free lab-grown plant stock.
所以多亏了那些人不知疲倦的种植和收割香蕉
So thanks to the people who work tirelessly to grow and harvest bananas
并且将其带到我们身边
and bring them to us
因而我们可以廉价地买到它们并带给我们的员工品尝
so that we can offer them inexpensively to our employees
还要多亏了那些种植者和科学家们不知疲倦的工作 以免再
and thanks to the growers and scientists working tirelessly to make sure that they don’t
重蹈大麦克香蕉的覆辙
go the way of the Gros Michel.
谢谢观看这一期的科学秀 如果你对我们有任何疑问、评论或者建议
Thanks for watching this episode of SciShow, if you have any questions, comments or suggestions for us
你可以通过Facebook Twitter找到我们
you can find us on Facebook, Twitter
或者从评论下方找到我们 如果今年你想变得更加睿智
or in the comments below, and if you want to continue getting smarter this year at SciShow
你可以去YouTube.com/SciShow观看科学秀 订阅我们
you can go to YouTube.com/SciShow and subscribe.
[吃香蕉的声音]
[banana eating noises]
[片尾曲]
[music]