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
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.
First, the good: bananas are healthy, packed with nutrition and energy, they
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
is Wal-mart’s number one selling item. Not the potato chip, not Coca-Cola,
not Fifty Shades of Grey, bananas. They appear to be so perfect for human
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
least the ones that you see at the store,
were created by people. Don’t get me wrong, there are wild banana plants – lots
of them – they’re native to South and Southeast Asia,
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,
you have… kinda. In cultivated bananas the seeds have pretty much stopped existing.
If you look closely you can see
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.
Unless you were alive in the 1960s (hats off to all those older SciShow viewers out there)
every banana you have ever eaten was pretty much genetically identical.
This is a Cavendish, the virtually seedless variety that we all eat today
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 –
they taste like the Gros Michel. The genetic monotony of the Gros Michel
crop was its undoing.
A fungicide resistant pathogen called the Panama disease began infecting Gros Michel crop.
By the time growers understood how vulnerable their crops were
the GrosMichel variety was all but extinct.
The entire banana industry had to be retooled for the Cavendish.
Since they’reseedless, the only way to reproduce them is to transplant part of the plant stem,
and for the last 50 years we’ve been good with the Cavendish,
cause it’s more resistant to the Panama disease. However somewhat terrifyingly a
strain of Panama disease that affects the Cavendish strain that we all eat has been identified.
A global monoculture of genetically identical individuals is a beautiful sight to a pathogen.
The fungus only has to figure out how to infect and destroy a single individual,
and suddenly there is no diversity to stop it,or even slow it down.
That’s led to a lot of scientists worrying about or even
predicting the outright demise of the Cavendish.
This wonderful most popular of fruits might completely cease existence.
The good news is we now have a much better understanding of genetics epidemics, fungi, and pathology.
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
while scientists are attempting to genetically engineer Cavendish plants with immunity to Panama disease.
Plus we learned a lot from the Gros Michel debacle.
Infected fields are quickly being destroyed and new crops are grown from pathogen-free lab-grown plant stock.
So thanks to the people who work tirelessly to grow and harvest bananas
and bring them to us
so that we can offer them inexpensively to our employees
and thanks to the growers and scientists working tirelessly to make sure that they don’t
go the way of the Gros Michel.
Thanks for watching this episode of SciShow, if you have any questions, comments or suggestions for us
you can find us on Facebook, Twitter
or in the comments below, and if you want to continue getting smarter this year at SciShow
you can go to YouTube.com/SciShow and subscribe.
[banana eating noises]
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