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This week of SciShow is supported by Brilliant! To learn more, go to Brilliant.org/SciShow.
本周《科学秀》由Brilliant赞助播出。登入Brilliant.org/SciShow了解更多。
I don't know if you've noticed, but animals kind of need oxygen.
不知道大家注意到没有，动物也是需要氧气的。
That's because animals generally get their energy from cellular structures called mitochondria,
因为动物一般从一种被称为线粒体的细胞结构中获得能量，
and those processes require oxygen to work.
并且那些过程需要氧气才能工作。
So if somebody stole all of the Earth's O2, things would end pretty quickly around here.
所以如果有人偷走了地球上的氧气，那么全球物种将迅速终结。
Except, as it turns out, there are at least some animals that would be perfectly fine.
但事实证明至少有一些动物会安然无恙。
Because in 2010, scientists published a paper announcing
因为在2010年，科学家发表了一篇论文宣布
that they'd found three species of them that straight-up don't need oxygen!
他们发现其中三个物种是不需要氧气的！
Now, to be clear, not all life needs oxygen.
更明确地讲，不是所有生命都需要氧气。
There are plenty of single-celled microbes that are anaerobic, meaning they can survive just fine without the stuff.
有许多单细胞微生物是厌氧的，这意味着没有氧气，它们也没事。
Instead of oxygen, these organisms can use other molecules like sulfate or nitrate.
相对于氧气，这些生物体可以利用其它分子，如硫酸盐或硝酸盐。
But for years, scientists thought a system like that wouldn't work for animals,
但多年来，科学家认为这样的系统不适用于动物
since their complex, multicellular bodies have higher energy requirements.
因为它们复杂、多细胞的身体需要更多的氧气。
Instead, they thought animals needed the more efficient energy production that takes place in mitochondria.
相反，他们认为动物需要发生在线粒体中的更有效的能量生产。
And then came back to 2010 paper. This discovery happened in the L'Atalante basin,
再回到2010年的论文上。这一发现发生在地中海三千米处的
three thousand meters below the surface of the Mediterranean Sea.
亚特兰大盆地。
L'Atalante is a deep hypersaline anoxic basin, meaning it's super salty and completely devoid of oxygen.
亚特兰大是一个深高盐缺氧盆地，这意味着这个地方超级咸，且完全没有氧气。
It's the kind of place you wouldn't expect to find animals.
这种地方是不可能有动物存在的。
And indeed, when a research team visited three times between 1998 and 2008, that's generally what they saw.
事实上，当一个研究小组在1998年到2008年间访问了三次时，他们看到的大致就是这样。
They did find a lot of single-celled organisms living in the basin,
他们确实发现在盆地内生活着很多单细胞生物体，
but most of the animals they saw were dead, the result of a so-called "rain of cadavers" from oxygenated waters above.
但他们看到的大部分动物都是死的，这是来自于上层含氧水所谓“尸体雨”的结果。
Most of the animals, but not all of them. Because the team also found an unusually high abundance of tiny,
绝大部分动物，而非所有。因为这个团队也发现了一种异常丰富的小型的
sediment-dwelling animals called loriciferans, and they were seemingly very alive.
居住在沉淀物内的动物，它们被称为铠甲动物且似乎非常活跃。
Loriciferans are pretty weird creatures to begin with.
铠甲动物是一种非常奇怪的生物。
Their heads are covered in spines, and their bodies are typically encased in a vase-like shell called a lorica.
它们的头部覆盖着体刺，它们的身体包裹在花瓶一样的壳内，这个壳子被称为兜甲。
But finding them in an oxygen-free basin was a whole new level of weird.
但在无氧盆地中发现它们就更加奇怪了。
The researchers observed that the loriciferans were still taking up nutrients, and that some had recently molted.
研究人员发现铠甲动物仍在吸收营养盐，并且一些最近还蜕皮了。
Some even had developing offspring inside them.
一些甚至正在孕育后代。
So these animals apparently spend their lives buried in this sediment,
所以这些动物显然是在这些沉淀物中度过了它们的一生
with no oxygen, not only surviving, but thriving. Part of this incredible survival might be down to their size.
没有氧气，不仅活下去了，还在茁壮成长。部分原因可能是由于它们的体型。
At less than one millimeter long, loriciferans have pretty low energy needs.
铠甲动物不足毫米长，所以需要的能量很少。
But they also seem to have some unique adaptations. For one thing, they don't have mitochondria!
但它们也似乎有一些独特的适应性。首先，它们没有线粒体！
Instead, they have cellular structures that look a lot like hydrogenosomes.
相反，它们的细胞结构看起来很像氢化酶颗粒。
These are organelles that some microbes use to produce energy,
这是一些微生物用来产生能量的细胞器，
and they use hydrogen ions in place of oxygen. Alongside these structures,
并且它们利用氢离子来代替氧。除了这些结构，
the researchers also noticed shapes that might be microbes living inside the loriciferans' cells.
研究人员也注意到了一些可能是生存在铠甲动物细胞内的细菌的形状。
That's intriguing because some anaerobic, single-celled organisms
这很有趣，因为一些厌氧单细胞生物体
also have symbiotic microbes that live alongside their hydrogenosomes.
也有与氢化酶体共存的共生微生物。
All in all, it looks like these loriciferans have developed similar cellular structures to anaerobic microbes
总而言之，似乎这些铠甲动物形成了类似于厌氧微生物的细胞结构
for living in the same way, although it's not clear how they did this.
才能以同一方式生存，虽然还不知道它们是怎么做到的。
One option is that they retained these adaptations from an earlier ancestor more similar to anaerobic microbes.
一种可能是它们从类似于厌氧微生物的祖先身上将这些适应性保留了下来。
But it's also possible that their ancestors swiped genes from their microbial neighbors,
但也有可能是它们的祖先从它们的微生物邻居那里窃取了基因
allowing them to use the same cellular tricks for survival.
让它们利用同样的生存细胞把戏。
Of course, this is an extraordinary claim, and some researchers have doubts.
当然，这是一个很棒的说辞，一些研究人员也有疑虑。
For example, a study published in 2015 looked in the same basin
例如，2015年发表的一项研究观察了同一片盆地
and was unable to find independent evidence of living loriciferans.
且并未发现铠甲动物存活的独立证据。
The researchers of the original study are still confident in their results,
原版研究的研究人员仍对他们的结果非常有信心，
but it may take more confirmation to convince everyone.
但或许需要更多的证实才能说服所有人。
If these results do hold up, though, it could change how we understand the requirements of complex life.
不过，如果这些结果确实成立，它可能会改变我们对复杂生命需求的理解。
It would have implications for the diversity of animal life in the world today,
这将对当今世界动物生活的多样性
for scientists interested in how life got started on an oxygen-deficient early Earth,
对那些对早期地球上缺氧生命如何开始很感兴趣的科学家，
and maybe even for scientists looking for life elsewhere in the solar system.
甚至可能对那些在太阳系寻找生命的科学家将产生影响。
Ultimately, life is so adaptable and endlessly diverse,
最终，生活拥有超强适应力以及无穷无尽的多样性，
that we wouldn't be surprised if there are more surprises to be found.
如果还有更多的惊喜等着我们去发现，我们也不会感到惊讶。
Critical thinking in science is obviously a great thing, though,
科学中的批判性思维显然是一件很棒的事情
and that's why it's so important for researchers to check each other's work.
因此研究人员互相检查工作非常重要。
And if you want to brush up on your critical thinking skills, or just learn some really cool stuff,
如果你想重温你的批判性思维能力或是想学习一些很酷的东西，
the Daily Challenges from Brilliant are a great way to do that.
Brilliant的每日挑战是个不错的选择。
Every day, Brilliant has new challenge questions about math and science topics.
Brilliant每天都会出一道有关数学和科学的新挑战题。
They're short, fun, and you can access them every day of the week for free!
题目简短有趣，你可以免费做题！
Like, I just completed one about black body radiation in a real life setting: a campfire!
比如，我刚刚完成了一个关于在现实生活中黑体辐射的问题：营火！
If you become a Premium member, you'll also get access to the whole archive of questions.
如果你是会员，你可以查看所有问题。
Best of all, the first 200 people to sign up at Brilliant.org/SciShow, will get 20% off an annual Premium subscription.
最棒的是，前200名注册Brilliant.org/SciShow的用户将获得8折优惠。
And if you check it out, well, hey, thanks for supporting us!
如果你看了，谢谢你的支持！
