Placeholder Image

字幕表 動画を再生する

  • What if you spent most of your life in near  darkness, surrounded by the same walls,  

  • eating the same food, all alone?  

  • That's life inside a Mexican jumping bean…  and that's just how these creatures like it.

  • They're the same jumping beans you find in  markets all over Mexico and exported worldwide.

  • But they're not something you'd want  to eat. They aren't beans at all.

  • They're seeds of this scraggly shrub.  

  • It primarily grows in Mexico, in  the mountains of the Sonoran Desert.

  • There are three of them that make up this fruit.

  • Some of these sections have a stow-away –  

  • a tiny moth larva that burrowed into the  seed while it was still on the plant.

  • The larva devours the inside of the seed,  

  • hollowing out its new pad to  make room for its growing body.

  • Over the next 8-10 months our squirmy friend  lines the walls with a comfy layer of silk.

  • Just enough air and moisture sneak in  through tiny holes in the seed walls.

  • It's a cozy life.

  • Except for the sweltering desert sun.

  • That heat can dry out and  kill our sweet little larva

  • So, of course, it starts jumping.

  • A few hops out of the sun can mean  the difference between life and death.

  • Luckily, it's got wheelswell sort of.

  • The seed's shapewith two flat sides  

  • and one curvedeven allows the  jumping beans to travel uphill.

  • Inside, the larva is working hard.  

  • With its back legs, it grabs onto the silk lining  and thrashes its head against the seed wall.

  • The force topples the seed.

  • Researchers think these headbangers  aim themselves in the right direction  

  • using a finely-tuned sense of temperature.

  • Check out this experiment. One side  of the pan is warmed by a heat lamp,  

  • the other cooled by an ice pack.

  • Over time, the larvae move away from the heat.  

  • It's not always a smooth trip. If the seed  gets damaged, the larva springs into action,  

  • repairing holes with a dense patch of silk.

  • But the larva can't stay in  its comfort zone forever.

  • With sharp mandibles, it cuts a circular door  in the seed wall. But it doesn't open it.

  • It's doing its future self a favor.

  • When it's done it turns into a pupa.

  • And then transforms into an adult moth. It simply pushes itself through the  

  • pre-cut exit doorwhich is handybecause now its mandibles are gone.

  • The liberated moth has mere  days, maybe a few weeks,  

  • to quickly mate and lay eggs before it dies.

  • But after all, freedom isn't  really what this animal lives for.

  • For most of life, it's totally fine being  a young larva trapped inside a seed,  

  • just hopingand hopping  – for a place in the shade.

  • Hi, it's Laura. It's hard to grow  up. You know what's also hard?  

  • Giving birth. A female tsetse fly pushes outsingle squiggly larva almost as big as herself,  

  • which she nourishes with her own milk. That's  right: fly milk. Enjoy and see you soon.

What if you spent most of your life in near  darkness, surrounded by the same walls,  

字幕と単語

ワンタップで英和辞典検索 単語をクリックすると、意味が表示されます

B2 中上級

Why Did the Mexican Jumping Bean Jump? | Deep Look

  • 18 2
    shihwun に公開 2021 年 09 月 27 日
動画の中の単語