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Mosquitoes suck. Not just literally, their bites are also itchy and annoying,
蚊子太讨厌了。不仅如此，被它们咬到也是又痒又烦，
and certain species transmit parasites and viruses like the ones that cause Malaria, Yellow Fever, and Zika
而且某些种类的蚊子还会传播寄生虫和病毒，比如那些每年导致几十万人
infecting and killing hundreds of thousands of people every year.
感染并死亡的疟疾、黄热病以及寨卡病毒。
And when we told you about the Zika virus two weeks ago, a lot of you had the same question:
两周前当我们告诉你们关于寨卡病毒时，众多人都有同样的疑问：
Why don't we just kill them all? All of them! Kill all the mosquitoes!
我们为什么不直接消灭所有蚊子？所有蚊子！杀光所有蚊子！
Humans are historically really good at making things go extinct.
历史上人类真的是非常擅长让物种灭绝呢。
So it shouldn't be too hard to get rid of these bloodsuckers,right? Yeah... not exactly.
所以要消灭这些吸血鬼也不会太难吧。是的...额...也不全是。
First of all, there are over 3,000 mosquito species worldwide, and only a couple hundred of them bite humans.
首先，世界上有三千多种蚊子，其中只有几百种咬人。
Mosquitoes have been around for a lot longer than people, millions of years,
蚊子先于人类存于世界百万年，
and have survived lots of predators and environmental changes.
它们逃过了许多捕猎者的捕食和活过了环境变化。
So that would be a lot of tough insects to kill, and a lot of bug deaths that wouldn't affect humans at all.
所以这是一种很难消灭的昆虫，并且很多细菌死亡完全不会对人类造成影响。
And we've tried to eradicate mosquitoes before,
我们之前也尝试过消灭蚊子，
mostly using chemicals that turned out to be awful for both the planet and us, like DDT.
大部分是使用化学制品，事实证明这种方法对地球和人类都是非常可怕的，比如滴滴涕。
But let's pretend that we were actually able to kill all the mosquitoes in some not-environmentally-apocalyptic way.
假设我们真的能够用一些环保的方法消灭所有蚊子。
Say, if I wished on a star, and the next day all mosquitoes just poofed out of existence.
比如，我向星星许愿，希望明天所有蚊子都灭绝了。
Would that be so bad for the Earth?
这样对地球而言会不会很糟糕呢？
Some scientists actually say no -- that if mosquitoes were suddenly ripped out of food webs,
事实上一些科学家会说，不会——如果蚊子突然消失于食物网中，
most ecosystems would heal pretty quickly, and other organisms would fill in those gaps.
大多数生态系统都会很快的治愈，其他生物体会填补这些缺口。
But other scientists argue that certain mosquito species do play important ecological roles.
但是其他科学家认为某些蚊子种类确实起到了重要的生态作用。
Take the mosquitoes that live in the Arctic of Canada and Russia.
就拿加拿大、俄罗斯北极范围内的蚊子举例。
They fly around in thick swarms and make up a huge part of the biomass there.
它们成群的飞来飞去，是该地生物量的巨大组成部分。
And these mosquitoes pollinate Arctic plants and are a major food source for migrating birds.
这些蚊子对北极植物授粉，也是迁徙候鸟的主要食物来源。
Removing these guys or other, more southern species that are food for fish, birds, and other insects
消灭这些家伙，更多作为鱼类、鸟类和其他昆虫食物的南方物种
could send a ripple through ecosystems, endangering many other plants and animals.
会通过生态系统传送涟波，危机许多其他植物和动物。
So we probably shouldn't kill all the mosquitoes. But, we also don't have to.
所以我们也许不应该杀光所有蚊子。但是也不必这样做。
We know which species are vectors, or carriers, of the worst viruses and parasites that can infect humans.
我们知道哪些种类是能够感染人类的厉害病毒和寄生虫的载体或携带者。
So lots of researchers are currently targeting these species,
所以很多研究员目前将这些物种定位目标，
and developing ways to kill them, or to kill the dangerous stuff inside them.
研究消灭它们的方法或是消灭其中的危险的那一类。
Take the genus Aedes, which transmits lots of awful diseases.
以传播许多可怕疾病的伊蚊属为例。
One particularly nasty species is Aedes aegypti,
一种尤为讨厌的种类就是埃及伊蚊，
which is the primary vector for the Yellow Fever, Dengue, Chikungunya, and Zika viruses.
它们是黄热病、登革热、基孔肯雅病以及寨卡病毒的主要载体。
A. aegypti is not just a pest, it's one of the most medically significant pests.
埃及伊蚊不仅仅是一种害虫，它们是医学上最重要的害虫之一。
So it's the focus of lots of recent experiments in targeted mosquito eradication.
所以它们也是目标蚊子根除计划内许多近期实验的焦点。
But some of the most promising research doesn't set out to kill mosquitoes outright -- instead, it genetically modifies them.
但一些最有希望的实验并没有彻底消灭蚊子的打算，相反是对它们进行基因改良。
In 2015, a British company called Oxitec created male A. aegypti mosquitoes with a self-limiting gene,
2015年，一家叫做Oxitec的英国公司发明了一种携带自我限制基因的雄性埃及伊蚊，
which basically means that the gene can stop their cells from functioning normally.
这主要意味着基因可以阻止细胞的正常运作。
When these genetically modified mosquitoes are released and mate with females in the wild,
当这些改良基因蚊子被放走并与野外的雌性蚊子交配时，
the self-limiting gene gets passed on to their offspring.
这种自我限制基因就会转接到它们的后代身上。
Those offspring usually can't develop properly and die before they become adults.
这些后代无法正常发育并会在成年前死掉。
No adult mosquitoes means no disease transmission.
没有成年蚊子就意味着没有疾病的传播。
Likewise, a team of scientists in California inserted modified genes into a species of Anopheles mosquitoes,
同样，加利福尼亚的一个科学家团队将改良基因注入按蚊种类之中，
which are vectors for the parasite that causes Malaria.
它们是携带引发疟疾的寄生虫。
The modified genes cause the mosquitoes to kill the Malaria-causing parasites that live inside them,
改良基因能够让蚊子在将导致疟疾的寄生虫传播给人类前
before they can transmit them to humans.
消灭它们体内传播寄生虫，
And as a bonus, these parasite-destroying genes are designed to be passed on to 99.5% of the mosquitoes' offspring.
作为奖励，这些消灭寄生虫的基因能够传递给99.5%的蚊子后代。
So, eventually, this entire species could be unable to transmit Malaria.
所以最终这整个种类无法传播疟疾了。
And scientists think that this same technology could be applied to other mosquito species,
科学家认为同样的技术也能用于其他蚊子种类
and other parasites and viruses -- like Zika.
以及其他寄生虫和病毒之中，如寨卡。
Lastly, some scientists are fighting fire with fire -- or fighting viruses with bacteria--
最后，一些科学家以火灭火或者说是以病毒灭细菌——
by intentionally infecting A. aegypti mosquitoes with a bacterium called Wolbachia.
有意地让埃及伊蚊感染上一种被称为沃尔巴克氏体属的细菌。
Wolbachia seems to stop most viruses from growing inside these mosquitoes.
沃尔巴克氏体属似乎阻止了蚊子体内多种病毒的生长。
So even if the mosquitoes bite somebody infected with, say, the Dengue virus,
所以即使蚊子叮咬了那些感染了，如登革病毒的人，
the virus wouldn't survive inside the mosquito long enough to be transmitted to a new person.
这些病毒在蚊子体内能够生存的时间不足以让蚊子将病毒传播给另一个人。
Now, because viruses mutate rapidly, scientists worry about accidentally creating deadly viruses that are resistant to Wolbachia.
现在因为病毒变异非常快，科学家担心不小心制造出了一种能够抵抗沃尔巴克氏体属的致命病毒。
But a study released this week suggested a strategy to superinfect mosquitoes with more than one strain of the bacteria at a time.
但是本周发布的一项研究提出了一种让蚊子一次重复感染多种细菌的策略。
This way, the viruses can't develop resistance to the bacteria as easily.
这种方法使蚊子无法轻松进化出抵抗细菌的抗体。
And we can keep infecting mosquitoes, to keep them from infecting us.
而且我们可以继续感染蚊子，让它们无法感染人类。
I mean, it's only fair.
我是说，一切变得公平。
So, basically, it would be incredibly difficult and possibly harmful to kill all the mosquitoes.
所以基本上消灭所有蚊子是相当困难且可能有害的。
But we may soon be able to focus on certain species and take away their ability to infect us, making the world a lot safer.
但也许不久我们就能够专注于某种种类并剥夺它们感染人类的能力，使世界更加安全。
But... not any less itchy.
但...并没有缓解蚊子叮咬的瘙痒。
Thanks for watching this episode of SciShow News.
谢谢敢看本期科学秀。
Thank you to all of the people doing this amazing research.
谢谢进行这项惊人研究的人员。
And thank you to our patrons on Patreon who support SciShow so it can always be freely available to everyone.
谢谢Patreon上支持科学秀的那些赞助人让大家都能免费观看科学秀。
If you want to help us keep making shows like this, you can go to patreon.com/scishow.
如果你想支持科学秀可以登录patreon.com/scishow
And if you just want to keep getting smarter with us, you can go to youtube.com/scishow and subscribe!
如果你想变得更聪明，你可以去youtube.com/scishow进行订阅！
