Placeholder Image

字幕列表 影片播放

  • "That a boy, Dopey,

  • kill'er good and dead."

  • Citronella,

  • netting,

  • DEET.

  • All the things we use to arm ourselves

  • against a pesky foe,

  • the mosquito.

  • There are over 3,000 species

  • of these arthropods in the world.

  • If you're in North America,

  • you can be bitten by 175 different types.

  • These blood-sucking pests carry diseases

  • such as malaria and the West Nile virus,

  • and they cause an average of 2 million

  • deaths around the world each year.

  • Our attempt at curbing the population

  • of mosquitoes has, so far, failed.

  • One of the reasons this disease-carrying bug

  • is so dangerous is because of its size.

  • We usually don't know when a

  • mosquito is biting us,

  • and even if we do, it's too late.

  • Like vampires, mosquitoes are known for blood-sucking.

  • But they don't do it for nourishment.

  • Like many other bugs,

  • mosquitoes need sugar from nectar to survive.

  • So why do they suck animal blood?

  • Female mosquitoes need a particular protein

  • and lipid only found in animal blood

  • in order for them to lay eggs.

  • A standard mosquito weighs just 2.5 mg,

  • but they need a sizeable 1 mg of blood

  • just to produce 40 eggs.

  • And, they can lay up to 300 eggs

  • during their average lifespan of 2 to 6 weeks.

  • This is why only female mosquitoes bite and draw blood.

  • So what would happen if they were the size of humans?

  • For starters, transmitting diseases would be the last thing you'd worry about.

  • If a female mosquito were 79 kg (175 lbs)

  • and still required almost three times her

  • body weight in blood over her life cycle,

  • then she would need 237 kg (525 lbs) of animal blood

  • to lay those 300 eggs.

  • In other words,

  • she would need to suck every last drop of blood from your body.

  • And from 236 other people, too.

  • Yikes.

  • At the very least,

  • it could become difficult for female mosquitoes

  • to get enough blood to lay her maximum amount of eggs,

  • so the population might begin to decrease quickly.

  • And we'd probably want to kill as many as possible.

  • Maybe scientists would develop some sort

  • of pesticide that only harmed mosquitoes and not humans.

  • Or maybe they'd become another

  • big game target to hunt down.

  • It's also possible that predators

  • would begin to eat mosquito eggs and larvae,

  • further curbing the population.

  • A mosquito has an exoskeleton,

  • meaning it has to molt as it grows.

  • This period of transition would be a vulnerable

  • time and could make killing them much easier.

  • Human-sized mosquitoes would be bad news,

  • and not just because they could easily kill us.

  • They would likely target cattle, horses,

  • and large wild mammals,

  • creating chaos in both the meat industry and nature.

  • But would a mosquito even be able to survive at 79 kg (175 lbs) in our current atmosphere?

  • Probably not.

  • Arthropods breathe through openings

  • called spiracles that connect to a

  • branching network of trachea.

  • This network of tubes diffuses

  • oxygen throughout their body.

  • Because of this system,

  • the amount of oxygen in the air limits their growth.

  • At that time, arthropods were huge!

  • But today, the oxygen in our atmosphere is only 21%.

  • That's not enough for a human-sized mosquito.

  • Even if it was,

  • mosquitoes would need to develop a much

  • stronger exoskeleton to support all that extra weight.

  • And because they'd need more

  • nectar to sustain themselves,

  • many would likely starve.

  • We might not see human-sized mosquitoes any time soon,

  • but we could see a rise in giant mosquitoes called 'Gallinippers'.

  • These mosquitoes are 20 times larger

  • than their cousins and are native to North America.

  • They are so large, they are able to bite through clothing!

  • Since mosquitoes are cold-blooded,

  • they need temperatures over 26 °C (78.8 °F).

  • With global temperatures on the rise,

  • Gallinippers could easily expand their range and population.

  • Another possibility is that the growth of mosquitoes

  • could also spur the growth of their natural predators.

  • Just imagine giant spiders roaming the Earth.

  • But that's a story for another What If.

"That a boy, Dopey,

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

B1 中級

如果蚊子和人類一樣大呢? (What If Mosquitoes Were the Size of Humans?)

  • 0 0
    林宜悉 發佈於 2021 年 01 月 14 日
影片單字