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So I'm here today to encourage you to think about New York City,
今天，我在这里想鼓励你们去思考一下纽约这座城市，
and not just as one of humanity's greatest achievements,
它不仅是人类最大的成就，
but as home to native wildlife that are subject to a grand evolutionary experiment.
也是原始野生动物经历重大演化实验的家。
So take this forested hillside in Northern Manhattan, for example.
就拿这片位于北曼哈顿岛、树木丛生的山坡为例
This is one of the last areas left in the city where there's clean spring water seeping out of the ground.
这是城内最后一片净土，干净的泉水仍从地面涌出，
You could drink this out of your hands and you'd be OK.
你能以手接泉水直接饮用，不会生病。
These tiny little areas of seeping water contain huge populations of northern dusky salamanders.
这一小片泉水区住着数量庞大的北方脊口螈。
These guys were common in the city maybe 60 years ago,
以前这些小东西在城内很常见，大约六十年前还有，
but now they're just stuck on this single hillside and a few places in Staten Island.
但现在它们被困在这片山坡及史坦顿岛等几个地方。
Not only do they suffer the indignity of being stuck on this hillside,
被困在这片山坡上，它们不仅尊严受辱，
but we divided the hillside in two on two different occasions with bridges crossing from the Bronx into Manhattan.
我们还把这片山坡一分为二，中间用桥梁把布朗克斯与曼哈顿岛相连。
But they're still there, on either side of the bridges,
但它们还存在那儿，就在桥的两端，
where you see the red arrows -- about 180th Street, 167th Street.
就是你们看到的红箭头，大约位于180街，167街。
My lab has found that if you just take a few segments of DNA from salamanders in those two locations,
我的实验室发现，如果你拿几段取自这两处的蝾螈的DNA来看，
you can tell which side of the bridge they came from.
你能分辨出它们是从桥的哪一端来的。
We built this single piece of infrastructure that's changed their evolutionary history.
我们建造的基础建设改变了它们的演化历史。
We can go study these guys, we just go to the hillside we know where they are,
我们要研究这些家伙，只要跑去这片山坡就好，我们知道它们在哪里，
we flip over rocks so we can catch them.
我们翻下石头就能抓到它们。
There are a lot of other things in New York City, though, that are not that easy to capture, such as this guy, a coyote.
但纽约市还有很多其他的东西是没那么容易捕捉得，就像这个家伙，郊狼。
We caught him on an automatic camera trap in an undisclosed location; I'm not allowed to talk about it yet.
我们在某处的自动相机陷阱上拍到它，地点不能透露，我们不允许谈论这个地点。
But they're moving into New York City for the first time. They're very flexible, intelligent animals.
但它们将要首次迁移进纽约市。它们是非常灵活、聪明的动物。
This is one of this year's pups checking out one of our cameras.
这是一头今年出生的幼狼，在看我们的相机。
And my colleagues and I are very interested in understanding how they're going to spread through the area,
我的同事和我对弄清它们要如何在这片区域迁移、
how they're going to survive here and maybe even thrive.
它们要如何在这里生存、甚至大量繁殖很感兴趣。
And they're probably coming to a neighborhood near you, if they're not already there.
它们还可能去你家附近，如果它们还没占领那块地方的话。
Some things are too fast to be caught by hand.
有些东西跑太快，以至于手都抓不到。
We can't pick them up on the cameras, so we set up traps around New York City and the parks.
我们无法用相机捕捉，所以我们在整个纽约市及其公园设置了陷阱。
This is one of our most common activities.
这是我们最常见的活动。
Here's some of my students and collaborators getting the traps out and ready.
这是我的一些学生及合作者，他们正在把陷阱拿出去架好。
This guy, we catch in almost every forested area in New York City.
而这个家伙，在纽约市有树林的地方几乎都能抓到。
This is the white-footed mouse -- not the mouse you find running around your apartment.
这是只白足鼠，不是那种你在你的公寓里看到的、跑来跑去的老鼠。
This is a native species, been here long before humans. You find them in forests and meadows.
这是一种原生种，在人类出现前就已在这里生存。你能在树林及草原上看到它们。
Because they're so common in forested areas in the city,
由于它们在都市中有树林的地方非常常见，
we're using them as a model to understand how species are adapting to urban environments.
所以我们现在就以它们为模板，来了解物种是如何适应都市环境的。
So if you think back 400 years ago, the five boroughs would've been covered in forests and other types of vegetation.
如果你回想400年前，当时这五个城区都还被森林及其他植物覆盖。
This mouse would've been everywhere huge populations that showed few genetic differences across the landscape.
这种老鼠其实随处可见，整片土地庞大的老鼠族群基因差异很小。
But if you look at the situation today, they're just stuck in these little islands of forest scattered around the city.
但如果你看看今天的情况，它们就只能待在这几个城内少数有树林覆盖的小块地区。
Just using 18 short segments of DNA, we can pretty much take a mouse
仅仅只用18段短的DNA片段，我们就大致上能把一只老鼠--
somebody could give us a mouse, not tell us where it was from, and we could determine what park it came from.
某人会给我们一只老鼠、但没有告诉我们它是从哪来的--我们就可以判断出它是从哪个公园来的。
That's how different they've become. You'll notice in the middle of this figure, there are some mixed-up colors.
那就是它们之间演化的差异。你会注意到，在这段有颜色的条纹中间有一些混杂的颜色。
There are a few parks in the city that are still connected to each other with strips of forest,
这个城市内有几个公园仍然连接在一起，以带状森林方式相连，
so the mice can run back and forth and spread their genes, so they don't become different.
所以老鼠可以跑来跑去，并散布它们的基因。所以它们没有差异。
But throughout the city, they're mostly becoming different in the parks.
但以整座城市来看，它们在公园间已变得相当不同。
So I'm telling you they're different, but what does that mean? What's changing about their biology?
我告诉了你它们是不一样的，但这代表什么？它们在生物学上有什么变化？
To answer this question, we're sequencing thousands of genes from our city mice
要回答这个问题，我们为我们城市的老鼠定序了数千个基因，
and comparing those to thousands of genes from the country mice,
并与乡下老鼠的数千个基因进行比较，
so, their ancestors outside of New York City in these big, more wilderness areas.
它们的祖先在纽约市外围，住在这些较大较原始的区域。
Now, genes are short segments of DNA that code for amino acids.
基因是小片段的DNA，是组成胺基酸的密码。
And amino acids are the building blocks of proteins.
而胺基酸是蛋白质组成的元件。
If a single base pair changes in a gene, you can get a different amino acid,
如果某个基因里有一对硷基配对变了，你就会得到不同的胺基酸，
which will then change the shape and structure of the protein.
这样就会跟着改变蛋白质的形状及结构。
If you change the structure of a protein, you often change something about what it does in the organism.
如果你改变了某种蛋白质的结构，你通常就会改变它在生物体里的功能。
Now if that change leads to a longer life or more babies for a mouse, something evolutionary biologists call fitness,
那么，如果这种改变会使老鼠的寿命更长或生更多宝宝，跟演化有关，生物学家就称之为适存度，
then that single base-pair change will spread quickly in an urban population.
那么那对配对的改变就会在城市的族群中快速散播。
So this crazy figure is called a Manhattan plot, because it kind of looks like a skyline.
所以这张怪怪的图，其实是叫曼哈顿散布图，因为它看起来有点像建筑物的轮廓。
Each dot represents one gene, and the higher the dot is in the plot,
每个点都代表一个基因，在这图上的点越高，
the more different it is between city and country mice.
其在城市与乡村老鼠间的差异就越大。
The ones kind of at the tips of the skyscrapers are the most different, especially those above the red line.
这些在轮廓顶端的是差异最大的，尤其是在红线之上的那些。
And these genes encode for things like immune response to disease,
这些基因是免疫系统如何对抗疾病等的编码，
because there might be more disease in very dense, urban populations;
因为可能有更多的疾病出现在密度高的都市族群里；
metabolism, how the mice use energy; and heavy-metal tolerance.
以及代谢作用，也就是老鼠如何使用能量；还有重金属耐受性上。
You guys can probably predict that New York City soils are pretty contaminated with lead and chromium and that sort of thing.
你们大概可以预见到纽约市的土壤很大程度上会受铅、铬这类东西的污染。
And now our hard work is really starting.
现在，我们辛苦的工作要真正开始了。
We're going back into the wilds of New York City parks,
我们要回到纽约市公园的荒地，
following the lives of individual mice and seeing exactly what these genes are doing for them.
追踪个别老鼠的生活，并且看看这些基因究竟是如何在他们身上运作的。
And I would encourage you guys to try to look at your parks in a new way.
我会鼓励大家试着以新的方式来看待你家附近的公园。
I'm not going to be the next Charles Darwin, but one of you guys might be, so just keep your eyes open. Thank you.
我不会变成第二个查尔斯·达尔文，但你们在座的都可能会，所以千万要睁大你的眼睛，谢谢。
