Name: Kale, Cauliflower, and Brussels Sprouts Are the Same Species
Uploaded: 2020-03-30T03:36:08.000Z
Duration: 5 min 48 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

One of the most extraordinary things about dogs

Like, we took one wolfy species and made over 200 breeds

from adorable wrinkly pugs to lanky, powerful greyhounds.

And we didn't just do this kind of whole-body-tinkering with dogs.

Just about all the fruits and veggies you can buy at the supermarket

Most look totally different than their wild ancestors.

But there's one plant species that's produced

so many different varieties that it's known to biologists

hat's right, those are all the same species of plant.

Foodie favorites like kale and cauliflower

or human-modified and grown varieties, of Brassica oleracea.

from the logarithmic spiral of romanesco broccoli to the distinct,

And you might think tons of variety is just

what happens when humans selectively breed something for generations.

After all, we've been growing and breeding lettuce

and yet, all lettuce varieties look pretty lettuce-y.

It turns out that B. oleracea is kind of a special plant.

It was so transformable because it underwent some massive genomic event

The story of why we have such a variety of this kind of plant

Back then, an ancient Brassica ancestor did something quite remarkable—

That massive genome was whittled back down to a more reasonable size

as its own species about four million years ago.

Still, it meant that wild cabbage ended up with a lot more genetic variation

You see, broccoli and kale and brussels sprouts don't just look different.

And we're not just talking little tweaks to genes.

the genomes of 9 different cultivars to construct the plant's pangenome—

the total genetic variation that exists in the species.

And they found nearly 20% of the genes in that pangenome

So not only do cultivars have a lot of mutational differences,

they also have whole genes that aren't present in other members of their own species,

even though they all came from the same wild cabbage.

originated in the coastal areas of southern and western Europe.

We don't know exactly when our species first grew and domesticated it,

but genetic evidence suggests it may have been around 2000 B.C.E.

The earliest written records come from ancient greece,

and they suggest the first cultivars were leafy—

And the Greeks weren't the only ancient people who tinkered with wild cabbage.

Scientists are pretty sure that the plant was domesticated many times in several locations.

Some of these domesticated varieties found their way back into the wild,

became feral, and then were re-domesticated,

adding even more to the species' genetic diversity.

And all that genetic diversity eventually allowed people

to magnify different structural parts of the plant.

The variety we now call cabbage, for example,

seems to have arisen sometime before the tenth century

when people bred a kale-like plant to have larger buds on the tips of its stems.

Brussels sprouts are also enlarged buds—

the buds that grow all around the length of the stem.

And scientists aren't quite sure when the cultivar first emerged,

but it was definitely being grown in Belgium by the end of the 18th century.

Then there's kohlrabi, which literally means cabbage turnip in German—

presumably referring to its bulb-like enlargement at the base of the stem.

It's not clear when it first came about, either,

but historical literature suggests it was grown throughout Europe by the 1500s.

Both get their unique florets—the yummy parts we eat—

In broccoli, those mutations lead to a lot of flower buds packed tightly together.

Cauliflower has a lot of tightly packed flowering structures, too,

Instead, the white, pre-bud flower tissue replicates itself as it grows,

it's thought that one came from the other, but it's still not totally clear which came

As of 2018, genetic research seemed to be leaning toward team broccoli.

In fact, scientists are still trying to piece together

how we got all of these amazingly different versions of Brassica oleracea

Trouble is, the same genomic shuffling events which gave this species so much genetic diversity

also make it challenging to figure out a precise timeline for these cultivars

Researchers are eager to figure out as much of that as they can,

because it will also help them better understand how the different varieties tolerate different