Sometimes there are donuts. Sometimes there are nuts. Sometimes dried mango.

But the one thing that never sticks around and is

gone as soon as we can buy it is the wonderful,

beautiful, noble banana. Unfortunately for us, they may not be around forever.

[Intro Music]

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

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.

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.

They're just not the ones we eat. Some those species, as you might suspect,

have seeds, 'cause that's what fruits are, they're fleshy bodies containing seeds.

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,

and they're not fertile seeds. If you plant them, nothing grows.

Today's bananas are sterile mutants. I'm not trying to be mean, that's just the truth.

Unless you were alive in the 1960's (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. Until the 1960s,

everyone was eating the same banana, it was just a different banana -

the Gros Michel, a bigger, sweeter fruit with thicker skin. You might notice that

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 Gros

Michel variety was all but extinct.

The entire banana industry had to be retooled for the Cavendish. Since they're

seedless, 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.

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]

[music]