Imagine a parallel universe that coexists in the same place as our universe, in the same space, at the same time.
想象有一个平行宇宙，它跟我们的宇宙在同一时间、同一空间、同一地点共存。
This universe is overcrowded with life forms.
这个宇宙里充满了各种各样的生物形态。
It is invisible and intangible like the finest layer of reality, which we cannot notice.
它看不见摸不着，像物体的各个层一样，人们无法发现。
But it is there, and it maintains the functionality of our everyday world. Without it, we just wouldn't exist.
但是它就在那里，维持着我们这个世界每一天的正常运转。没有了它，我们就不复存在。
Now, would you be surprised if I told you that actually everything I said before is true? Because I'm about to tell you this.
如果我告诉你我刚刚所说的一切都是真的，你们会觉得惊讶吗？因为我下面要讲的正是这件事。
I'm talking about the world of microbes -- a separate world, yet so deeply connected to us.
我要讲述的主题就是微生物，它们生活在另一个世界，却与我们息息相关。
And the story of this connection expands far away into the past.
我们与微生物之间的故事要追溯到很远的过去。
But thanks to modern science, we are now able to read this story like a history book.
感谢现代科学的存在，我们现在就可以像读一本历史书一样去了解这个故事。
Ladies and gentlemen, I proudly present biomolecular archeology, the science behind this history book.
女士们先生们，请允许我向大家介绍生物分子考古学。
And I am here to share with you what fascinating things we can try to manage with this powerful modern science.
我来是为了跟大家分享有了伟大的现代科学，我们可以达到什么样的伟大成就。
But let's start with the term itself: biomolecular archeology.
我们先从这个术语本身开始：生物分子考古学。
It's not even easy to pronounce, not to mention to try to understand the essence of this phrase.
连发音都很难，更不用说理解这个短语的内涵了。
There might not be a problem with the archeology part, right?
考古这个词大家理解起来是没有问题的，对吗？
We've all seen it in movies, we know what it is about, but what is "biomolecular" anyway?
我们都在电影里面见过这样的画面，我们知道它是做什么的，但是生物分子呢？
The first thing that comes to mind: it is something about biology and molecules. And this is actually correct.
我们想到的第一件事就是，这是关于生物学和分子的科学。其实非常正确。
A biological molecule, or a biomolecule, is any molecule that is present in a living organism.
生物学上的分子，或者说生物分子，就是在一个活体器官里存在的分子。
Now, there are all sorts of molecules in your body, but undoubtedly, the most informative one is DNA.
人的身体中存在各种各样的分子，但毫无疑问的是，蕴含信息量最大的是DNA。
So, let's bring it back together.
让我们总结一下。
Biomolecular archeology enables us to study the DNA recovered from archeological samples.
生物分子考古学让我们可以阅读恢复后的考古样本中的DNA。
And not only native human DNA, which, of course, all by itself gives lots of study perspectives,
不仅是本地人的DNA，这当然可以给我们提供很多方向，
but also the DNA of microbes that lived side by side with that human. This science is relatively young.
还包括这个人周边微生物的DNA。这门科学其实相对年轻。
About ten years ago, a massive breakthrough happened in genomic research technology.
在大约十年之前，基因研究技术出现了一项巨大突破。
A method appeared which is called NGS, next generation sequencing,
人们研究出了一种叫做NGS的方法，全称是二代测序技术，
and this method significantly cuts time and costs of any genomic research.
这项技术大大的减少了基因研究所需要的时间和金钱。
For example, have you ever heard about the Human Genome Project?
比如，你们听说过人类基因计划吗？
It was quite a popular topic for science fiction some time ago.
有段时间这个计划非常受科幻片的欢迎。
This project launched in 1990 with the goal to decrypt all genomic information in a human organism.
这一计划发起于1990年，其目的是破解人类器官中所有的基因信息。
At that time, with the technology of the time, it took ten years and three billion dollars to reach the goals of this project.
在当时的技术条件下，人们花费了十年的时间和十亿美元的投入才达到这个目标。
With NGS, all of that can be done in just one day at the cost of 15,000 dollars.
而有了二代测序技术，所有这一切只需要花费15000美元就可以在一天之内完成。
On the fertile soil of next generation sequencing arose biomolecular archeology
在二代测序技术的基础上出现了生物分子考古学，
because there is a great lot of genomic information to be analyzed
因为有非常多的基因信息需要被需要进行分析，
and it just wouldn't be possible to manage such research with olden day technology.
而在老的技术条件下，我们无法进行这些研究。
Now we are able to manage such research OK, "But why?" you could ask me.
现在我们就可以进行了，“但是为什么要进行这些研究呢”，你可能会这样问。
"What benefits can we get out of this information? What can we use it for?"
“从这些信息中我们可以获得什么好处呢？我们拿它来做什么？”
The answer appears to be quite wide. Consider human health as a complex and dynamic system.
答案可以很广泛。我们把人类的健康想象成一个非常复杂的动态系统。
Apart from genetically determined factors that are stored in our DNA,
除了储存在我们DNA中的那些由基因决定的因素，
our health is severely influenced by many other factors, like our lifestyle, our diet, and our fellow microbes.
我们的健康还受到很多其他因素的影响，比如生活方式、饮食和我们身体内的微生物。
One hundred trillion cells, one and 14 zeros, that's the approximate number of microorganisms in your body,
一百万亿，一个一后面加十四个零，这就是你体内微生物的大概数量，
ten times greater than the number of your own cells.
比你体内细胞的数量还要多十倍。
Your microbial baggage occupies almost 2% of your body weight,
所有的微生物占据了你体重的大约百分之二，
that's about one and a half kilograms, approximately the weight of your liver. Or your brain.
也就是大约一点五千克，相当于你肝脏的重量。或者是你大脑的重量。
And all these are microbes. Just think about it for a second!
所有这些微生物。请大家想一想。
Human microbiome, that's the modern term for all microbial communities inhabiting your body,
人体微生物是对居住在你体内所有微生物的现代称呼，
has earned a close attention over the last decade.
在过去十年他们获得了密切关注。
It seems that we are only beginning to discover the mysterious role that is given to microbes in the performance of our health.
而相对于这些微生物对我们健康的影响，我们仿佛只是刚刚开始研究这个神秘的团体。
In 2007, the National Institutes of Health of the U.S. launched the Human Microbiome Project
2007年，美国国家卫生研究院启动了一项人类微生物计划，
to finally study its relation to our health conditions.
要对微生物与我们的健康状况之间的关系做最终的研究。
And since then, it has only become clearer that our notion about our fellow microbes is inexcusably poor.
从那时起，我们对于体内微生物的了解程度过低这个问题越来越明确。
Francis Collins, the director of the National Institutes of Health,
弗朗西斯·柯林斯，美国国家卫生研究院的主任，
even compared the researchers involved in the project with the 15th century explorers discovering the outline of a new continent.
甚至把参与这个项目的研究人员跟十五世纪那些发现新大陆的探索者相提并论。
It is now being suggested that a range of modern, widespread diseases, starting from obesity, Crohn's disease,
现在的研究表明，很多现代普遍发生的疾病，包括肥胖、克罗恩病、
other gastrointestinal problems to all sorts of allergies, autoimmune diseases,
其他的肠胃疾病、各种过敏、自身免疫系统疾病，
or maybe even cancer, may appear to be consequences of microbiome changes.
甚至癌症，可能都是由于微生物发生改变的结果。
But where do these changes come from? When did they first appear? What was the triggering factor?
那这些改变是怎样发生的呢？它们第一次出现是什么时候？原因是什么？
These are the questions we are trying to find answers to at the moment.
这些都是我们当下想要找到答案的问题。
This topic always triggers a memory of my first conscious experience with the microbial world around.
这个话题总是让我想起我第一次意识到微生物世界的时候。
My mother, like any attentive parent, tried her best to warn me against the invisible dangers of the world,
我的妈妈，就像其他负责任的父母一样，努力想要让我避开世界上那些看不见的危险，
and she told me a story that every time I do not wash hands before eating something,
每次我不洗手就吃东西的时候，她都会讲给我一个故事，
I become a reason of global microbial migration.
故事里我变成了全球微生物移民的结合体。
An uncountable number of microbial families come together, pack their suitcases, their TVs, their favorite toys,
数不清的微生物家庭一起，带上行李箱、电视、它们最爱的玩具，
and leave their houses forever to move to a new area which is thought to be my body.
永远的离开家，搬去一个新地方，就是我的身体里。
Now, I was a child with a very vivid imagination,
我是一个想象力非常丰富的孩子，
and this story influenced me so much that I was obsessed with handwashing for a really long time.
这个故事对我的影响太大了，所以在很长的一段时间里我一直很喜欢洗手。
It actually took me years to overcome the thought that I'm doing something wrong when I initiate this microbial migration,
我花了好几年时间才克服每次引起一场微生物移民的时候就觉得自己做错了什么事的想法，
and to understand finally that they are actually willing to come, they've got friends there waiting for them.
我最终理解了它们其实很愿意来我的身体里，因为有朋友在等着它们。
I'm not trying to convince you not to ever wash your hands again, of course not.
我不是要告诉你们再也不要洗手了，这当然是错误的。
But let's try to be moderate with it. We lack this microbial diversity nowadays.
但是请保持一个适中的态度。现在我们面临着微生物的多样性的缺乏。

And as we know from ecology, the most diverse systems are the most stable ones.
从生态学中我们知道，最多样化的系统才是最稳定的。
This might be one of the reasons for our so-called diseases of civilization.
这也许就是我们所谓的文明病的原因之一。
And this is exactly the type of hypothesis for biomolecular archeology to deal with.
并且这正是我们生物分子考古学研究的假说之一。
It turns out that there is a unique archaeological material that so preciously
我们发现了非常珍贵的独特的考古材料，
stores the enormous amount of information related to ancient human microbiome, and this material is ancient dental plaque,
它们储存着大量的古代人体微生物群的信息，这个材料就是古老的牙菌斑，
thanks to the fact that oral cavity hygiene was not on the list of top priorities for humans of the past.
谢天谢地，过去的人们并没有把口腔健康问题放在第一位。
Their oral microbiome has already been partly fossilized during their lifetime in the form of dental calculus, which, in turn,
这些口腔的微生物群已经部分变成了牙结石，进而变成了化石，
stays in soil as well preserved as the skeletons themselves.
它们跟人体的骨骼一样被好好的保存在土壤里。
Sadly, we can't help these fellas anymore.
遗憾的是我们再也帮不到这些人了。
But they can help us by providing unique and precious information about their microbes and their health,
但是他们可以帮到我们，他们可以提供独特的关于这些微生物群和他们健康状况的珍贵信息，
and maybe we will have a chance to help others in the future thanks to them.
因为他们，也许我们还有机会在未来帮助其他人。
There is one more vast human health-related aspect where biomolecular archaeology takes its rightful place,
还有一个跟人类健康相关的生物分子考古学可以大显身手的地方，
and this field of research expands into the valley of ancient deadly pathogens.
这个领域的研究涉及到古代那些致死的病原体。
It is true that the vast majority of microbes either provide us some kind of benefit
大部分的微生物要么可以给我们提供一些好处，
or do not really care whether there is a human around.
要么就根本不在意周边是不是有一个人类。
But there are some ancient deadly microbes that still remain an urgent problem nowadays all around the world.
但也有一些古老的致命的微生物存在于这个世界上，并且成为了现代一个非常紧急的问题。
For example, Mycobacterium tuberculosis. One and a half million deaths in 2014.
比如结核杆菌。它导致了2014年150万人的死亡。
And OK, OK, I know, the first reaction I always get is like, "Wait, aren't there antibiotics?"
是的，当然，我知道说出这句话时你们的第一反应总是：“等等，难道没有抗体吗？”
or "I heard there is even a vaccine; is this disease still dangerous to us after all?"
或者“我听说我们已经有疫苗了；这种病对我们还有威胁吗？”
The answer is yes; tuberculosis is closer than you think.
答案是：是的，结核病离我们的距离比你们想的要近。
Because of some mysterious genetic phenomenon,
由于一些神秘的遗传因素，
there are people that can carry around this microbe their entire lives without developing any symptoms,
有些人在自身没有任何症状的情况下，可以把这种微生物带到世界的任何地方，
and there are people that develop symptoms straight ahead after infection.
也有一些人在感染之后马上就出现了结核病的症状。
Let me give you a real example of a tuberculosis microepidemic. Let's say a person somehow got infected.
我来讲一个结核病的真实的例子。比如有一个人感染了。
He works as a teacher in a junior school. Half a year later, one of his pupils develops symptoms.
他在一个中学里面当老师。一年半以后，他其中一个学生出现了这种症状。
A few months later, the older sister of the pupil. A few more months later, two friends of the sister.
几个月后，这个学生的姐姐出现了症状。又几个月后，姐姐的两个朋友也出现了这种症状。
This is how it spreads. When I was just starting my research on this topic,
这就是它的传播方式。当我刚开始研究时，
I myself was very surprised to know that tuberculosis worldwide remains one of the major health concerns,
我很惊讶的发现，结核病在世界范围内居然还是大家担心的一个主要问题。
that on the list of infectious diseases, it is the second most common death cause after HIV. Yes, the fight continues.
在传染病的清单上，它是仅次于艾滋病的第二常见的致死原因。是的，战斗还在继续。
Did you know we have a tuberculosis clinic right here in Latvia, just outside Riga,
你们知道吗，就在拉脱维亚，我们有一个结核病治疗中心，在里加旁边，
where many doctors and other specialists fight tuberculosis on a daily basis?
每天有很多的医生和其他的专家在对抗结核病？
To finally beat this harmful bacteria, it is crucial to understand how it evolved,
他们想要最终打败这种有害的细菌，我们要理解它如何进化，
how it developed resistance to antibiotics, how it spread.
如何对抗抗体产生抵抗力，如何蔓延，这是至关重要的。
And these are the questions where biomolecular archaeology can help us a lot.
这就是生物分子考古学起作用的地方。
At the moment, working in the Latvian Biomedical Research and Study Centre,
现在，我们正在拉脱维亚生物制药研究中心工作，
we have managed to identify Mycobacterium tuberculosis in one archaeological sample from the 17th century.
我们在17世纪的一个考古样本中发现了结核杆菌的存在。
We are now in the process of defining its whole genome,
现在正在判断它的整体基因组，
so we can understand what type of tuberculosis reigned at that time over the Latvian territories and where it came from.
这样就能帮助我们理解当时的拉脱维亚国土上生存的是哪一种结核杆菌，又是从哪里来的。
Obviously, biomolecular archaeology impacts humanities as well, such as history and anthropology.
很显然，生物分子考古学也会对人文学科产生很大的影响，比如历史学和人类学。
These, for example, are the excavations on the Saint Ģertrūdes Cemetery a few years ago. They started very spontaneously.
这是几年前从圣格特鲁德墓地中挖掘出来的。这是偶然发现的。
There was an idea to build a shopping center in that area,
当时的人们本来想在这个地方建一座购物中心，
and there was also information that there might be some medieval burial sites.
有人说那个地方可能是中世纪的一块墓地。
So the Latvian Institute of History received a request to check it out.
于是拉脱维亚历史研究院被邀请去进行检查。
And they did actually find a medieval burial site, quite a massive one.
他们确实发现了一块中世纪的墓地，规模很大。
Our archaeologists dug out over 500 skeletons, and found 2,000 more skeletons buried separately in a giant wooden box.
我们的考古人员挖出了500具骨骼，另外还有2000具骨骼分开埋在一个巨大的木盒里。
But what was it? This couldn't be war because the skeletons lacked war lesions on their bones. Was it hunger? Epidemic?
但是到底是什么呢？不是战争导致的，因为骨头上没有战争造成的伤痕。那是饥饿导致的吗？还是传染病呢？
Archaeology itself cannot take this research any further, we have to intervene with biomolecular methods.
因为考古学无法进行更加深入的研究，于是我们采用了生物分子研究方法。
Only then can we trace the true reason.
只有这样我们才能找到真正的原因。
The research process that implements the goals of the science is fascinating, even by itself.
实现科学目标的研究过程是很吸引人的，甚至就其本身而言也是如此。
It all starts with ancient bones and teeth from cemeteries all around Latvia.
从拉脱维亚墓葬中发现的古代的骨骼和牙齿中开始。
We then cut out small pieces of these bones and shred them in special scientific mills to get bone powder.
我们切开了小片的骨骼，进行了科学研磨，从而得到骨粉。
We then extract all the DNA that is captured in a specific bone powder sample, and then we sequence it.
然后从一份骨粉样本中提取了所有的DNA，进行测序。
Sequencing is the process where the machine reads the DNA code and translates it into a four-letter code.
测序的过程就是用机器阅读基因密码，并把它翻译成一个四个字母组成的密码的过程。
By the way, it is absolutely fascinating how all genetic information of human beings and all other living creatures on the planet Earth
顺便提一下，这件事真的很神奇，地球上人类和所有其他生物的基因信息，
can be written down using the alphabet containing four letters only.
都可以写作只包含四个字母的密码。
It's absolutely not surprising that the result of the sequencing is absolutely unreadable
测序的结果阅读不出来，这不奇怪，
gigabytes of text consisting of these four letters.
它的内容就是由包含四个字母的密码组成的字节。
It then takes time and effort to analyze these data with a variety of computational methods and programming approaches.
再用各种电脑技术和编程手段花时间对数据进行分析。
And at the very end, we get a pretty readable list of all the microorganisms from a specific sample.
最后就会获得一份可阅读的从样本中发现的所有微生物的清单。
The field of my research contains three sciences at once: archaeology, biology and computer science, all mixed, merged and connected.
我的研究领域包含三门科学：考古学、生物学和计算机科学，它们互相混合、共生、连接。
It's like the science itself merging and connecting humanity throughout centuries.
就像数个世纪以来科学与人类的共生和连接一样。
Science is like a pyramid: you cannot lay the upper block without a foundation of the blocks beneath.
科学就像金字塔：没有底下的砖块做基础，就无法搭建上面的砖块。
And building this pyramid of healthcare throughout the entire human civilization,
在搭建这座贯穿整个人类文明的健康金字塔的过程中，
I believe biomolecular archaeology just opened up a new frontier for us.
我相信生物分子考古学给我们打开了新的大门。
Where do we go from here? It's a question of choice, but I believe that any destination holds fascinating discoveries.
我们要去向何方？这是一个选择的问题，但我相信任何一个目的地都会带来惊人的发现。
But just for now, please remember that you are never alone.
而此刻请记住，你们永远不孤独。
You've got a hundred trillion friends that are always there for you.
有数百万亿个朋友永远陪着你。
Think about it next time you want to wash your hands. Thank you.
下次想洗手时请记得这一点。谢谢大家。