0:00:01.127,0:00:02.727
This is where I grew up.

0:00:03.159,0:00:05.452
A small village near the city of Rotterdam

0:00:05.476,0:00:06.912
in the Netherlands.

0:00:07.649,0:00:11.643
In the 1970s and 1980s,[br]when I was a teenager,

0:00:11.667,0:00:13.458
this area was still a quiet place.

0:00:13.482,0:00:16.054
It was full of farms and fields

0:00:16.078,0:00:17.675
and swamp land,

0:00:17.699,0:00:20.601
and I spent my free time there

0:00:20.625,0:00:21.783
enjoying myself,

0:00:21.807,0:00:24.189
painting oil paintings like this one,

0:00:24.213,0:00:26.834
collecting wild flowers, bird-watching

0:00:26.858,0:00:29.721
and also collecting insects.

0:00:29.745,0:00:31.816
And this was one of my prized finds.

0:00:31.840,0:00:33.537
This is a very special beetle,

0:00:33.561,0:00:36.077
an amazing beetle called an ant beetle.

0:00:36.442,0:00:39.371
And this is a kind of beetle[br]that lives its entire life

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inside an ant's nest.

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It has evolved to speak ant.

0:00:44.688,0:00:47.409
It's using the same chemical signals

0:00:47.433,0:00:50.387
the same smells as the ants do[br]for communicating,

0:00:50.411,0:00:53.583
and right now, this beetle[br]is telling this worker ant,

0:00:53.607,0:00:55.898
"Hey, I'm also a worker ant,

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I'm hungry, please feed me."

0:00:57.716,0:00:59.242
And the ant complies,

0:00:59.266,0:01:01.891
because the beetle is using[br]the same chemicals.

0:01:01.915,0:01:03.676
Over these millions of years,

0:01:03.700,0:01:08.870
this beetle has evolved a way[br]to live inside an ant society.

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Over the years,

0:01:10.736,0:01:12.379
when I was living in that village,

0:01:12.403,0:01:15.537
I collected 20,000 different beetles,

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and I built a collection[br]of pinned beetles.

0:01:19.120,0:01:23.397
And this got me interested,[br]at a very early age, in evolution.

0:01:23.421,0:01:25.802
How do all those different forms,

0:01:25.826,0:01:28.953
how does all this diversity come about?

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So I became an evolutionary biologist,

0:01:33.022,0:01:34.760
like Charles Darwin.

0:01:34.784,0:01:36.252
And like Charles Darwin,

0:01:36.276,0:01:38.572
I also soon became frustrated

0:01:38.596,0:01:43.149
by the fact that evolution is something[br]that happened mostly in the past.

0:01:43.173,0:01:46.597
We study the patterns that we see today,

0:01:46.621,0:01:50.033
trying to understand the evolution[br]that took place in the past.

0:01:50.057,0:01:53.918
But we can never actually see it[br]taking place in real time.

0:01:53.942,0:01:55.671
We cannot observe it.

0:01:55.695,0:01:58.322
As Darwin himself already said,

0:01:58.346,0:02:01.371
"We see nothing of these slow[br]changes in progress,

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until the hand of time has marked[br]the lapse of ages."

0:02:06.293,0:02:07.443
Or do we?

0:02:08.373,0:02:09.777
Over the past few decades,

0:02:09.801,0:02:12.134
evolutionary biologists[br]have come to realize

0:02:12.158,0:02:15.847
that sometimes, evolution[br]proceeds much faster

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and it can actually be observed,

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especially when the environment[br]changes drastically

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and the need to adapt is great.

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And of course, these days,

0:02:28.585,0:02:32.057
great environmental changes[br]are usually caused by us.

0:02:32.081,0:02:35.968
We mow, we irrigate, we plow, we build,

0:02:35.992,0:02:39.051
we pump greenhouse gases[br]into the atmosphere

0:02:39.075,0:02:40.574
and change the climate.

0:02:40.598,0:02:43.387
We release exotic plants and animals

0:02:43.411,0:02:45.434
in places where they didn't live before,

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and we harvest fish and trees and game[br]for our food and other needs.

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And all these environmental changes[br]reach their epicenter in cities.

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Cities form a completely new habitat[br]that we have created.

0:03:03.175,0:03:06.516
And we clothe it in brick and concrete[br]and glass and steel

0:03:06.540,0:03:08.690
which are impervious surfaces

0:03:08.714,0:03:12.175
that plants can only root in[br]with the greatest difficulty.

0:03:13.141,0:03:15.982
Also in cities, we find[br]the greatest concentrations

0:03:16.006,0:03:17.585
of chemical pollution,

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of artificial light and noise.

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And we find wild mixtures[br]of plants and animals

0:03:24.140,0:03:26.725
from all over the world[br]that live in the city

0:03:26.749,0:03:28.814
because they have escaped[br]from the gardening

0:03:28.838,0:03:31.029
and aquarium and [unclear].

0:03:31.585,0:03:35.347
And what does a species do

0:03:35.371,0:03:39.459
when it lives in a completely[br]changed environment?

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Well, many of course, go sadly extinct.

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But the ones that don't go extinct,

0:03:46.508,0:03:49.213
they adapt in spectacular ways.

0:03:50.188,0:03:52.569
Biologists these days[br]are beginning to realize

0:03:52.593,0:03:56.776
that cities are today's[br]pressure cookers of evolution.

0:03:56.800,0:04:00.022
These are places where wild[br]animals and plants

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are evolving under our eyes very rapidly,

0:04:03.466,0:04:06.752
to suit these new, urban conditions.

0:04:06.776,0:04:10.425
Exactly like the ant beetle did[br]millions of years ago,

0:04:10.449,0:04:12.822
when it moved inside an ant colony.

0:04:12.846,0:04:17.584
We now find animals and plants[br]that have moved inside the human colony

0:04:17.608,0:04:19.674
and are adapting to our cities.

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And in doing so,

0:04:21.585,0:04:23.259
we're also beginning to realize

0:04:23.283,0:04:26.743
that evolution can actually[br]proceed very fast.

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It does not always take[br]the long lapse of ages;

0:04:30.173,0:04:32.839
it can happen under our very eyes.

0:04:33.680,0:04:35.125
This, for example,

0:04:35.149,0:04:36.882
is the white-footed mouse.

0:04:37.355,0:04:40.696
This is a native mammal[br]from the area around New York,

0:04:40.720,0:04:43.799
and more than 400 years ago,[br]before the city was built,

0:04:43.823,0:04:45.934
this mouse lived everywhere.

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But these days, they are stuck[br]in little islands of green,

0:04:50.259,0:04:55.774
the city's parks, surrounded by a sea[br]of tarmac and traffic.

0:04:56.893,0:05:02.015
A bit like a modern-day version[br]of Darwin's finches on the Galapagos.

0:05:03.744,0:05:05.990
And like Darwin's finches,

0:05:06.014,0:05:10.188
the mice in each separate park[br]have started evolving,

0:05:10.212,0:05:13.307
have started to become[br]different from each other.

0:05:13.331,0:05:15.553
And this is my colleague,[br]Jason Munshi-South,

0:05:15.577,0:05:17.307
from Fordham University,

0:05:17.331,0:05:18.815
who is studying this process.

0:05:18.839,0:05:21.339
He is studying the DNA of the mice,

0:05:21.363,0:05:22.680
the white-footed mice,

0:05:22.704,0:05:24.839
in New York City's parks,

0:05:24.863,0:05:28.506
and trying to understand[br]how they are beginning to evolve

0:05:28.530,0:05:31.069
in that archipelago of islands.

0:05:31.093,0:05:33.769
And he's using a kind of[br]DNA fingerprinting, and he says,

0:05:33.793,0:05:35.688
"If somebody gives me a mouse,

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doesn't tell me where it's from,

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just by looking at its DNA,

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I can tell exactly[br]from which park it comes."

0:05:42.157,0:05:44.690
That's how different they have become.

0:05:45.395,0:05:49.140
And Jason has also discovered[br]that those changes,

0:05:49.164,0:05:50.498
these evolutionary changes,

0:05:50.522,0:05:53.315
are not random, they mean something.

0:05:53.339,0:05:56.490
For example, in Central Park,

0:05:56.514,0:05:58.996
we find that the mice have evolved genes

0:05:59.020,0:06:02.258
that allow them to deal[br]with very fatty food.

0:06:03.258,0:06:04.956
Human food.

0:06:04.980,0:06:07.805
Twenty-five million people[br]visit Central Park each year.

0:06:07.829,0:06:10.583
It's the most heavily visited park[br]in North America.

0:06:10.607,0:06:13.392
And those people leave behind snack food,

0:06:13.416,0:06:15.996
and peanuts and junk food,

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and the mice have started feeding on that,

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and it's a completely different diet[br]than what they're used to,

0:06:21.046,0:06:22.212
and over the years,

0:06:22.236,0:06:25.878
they have evolved to suit[br]this very fatty, very human diet.

0:06:27.180,0:06:29.426
And this is another city slicker animal.

0:06:29.450,0:06:31.776
This is the European garden snail.

0:06:31.800,0:06:32.982
Very common snail,

0:06:33.006,0:06:36.751
it comes in all kinds of color variations,

0:06:36.775,0:06:40.307
ranging from pale yellow to dark brown.

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And those colors are completely determined

0:06:43.339,0:06:44.823
by the snail's DNA.

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And those colors also determine[br]the heat management of the snail

0:06:50.445,0:06:52.379
that lives inside that shell.

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For example, a snail[br]that sits in the sunlight,

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in the bright sun,

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if it has a pale yellow shell,

0:06:59.020,0:07:05.266
it doesn't heat up as much as a snail[br]that sits inside a dark brown shell.

0:07:05.290,0:07:09.316
Just like when you're sitting[br]in a white car, you stay cooler

0:07:09.340,0:07:12.196
than when you're sitting[br]inside a black car.

0:07:12.220,0:07:15.348
Now there is a phenomenon called[br]the urban heat islands,

0:07:15.372,0:07:18.315
which means that[br]in the center of a big city

0:07:18.339,0:07:21.014
the temperature can be[br]several degrees higher

0:07:21.038,0:07:22.434
than outside of the big city.

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That has to do with the fact

0:07:23.839,0:07:26.529
that you have these concentrations[br]of millions of people,

0:07:26.553,0:07:28.783
and all their activities[br]and their machineries,

0:07:28.807,0:07:30.022
they generate heat.

0:07:30.046,0:07:33.720
Also the wind is blocked[br]by the tall buildings,

0:07:33.744,0:07:38.053
and all the steel and brick[br]and concrete absorb the solar heat

0:07:38.077,0:07:39.678
and they radiate it out at night.

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So you get this bubble of hot air[br]in the center of a big city,

0:07:42.990,0:07:46.806
and my students and I figured[br]that maybe those garden snails,

0:07:46.830,0:07:49.522
with their variable shells,

0:07:49.546,0:07:53.850
are adapting to the urban heat islands.

0:07:53.874,0:07:55.660
Maybe in the center of a city,

0:07:55.684,0:07:58.557
we find that the shell color is evolving

0:07:58.581,0:08:02.017
in a direction to reduce[br]overheating of the snails.

0:08:02.367,0:08:05.870
And to study this, we started[br]a citizen science project.

0:08:06.210,0:08:08.805
We built a free smart phone app

0:08:08.829,0:08:11.034
which allowed people[br]all over the Netherlands

0:08:11.058,0:08:14.027
to take pictures of snails[br]in their garden, in their street,

0:08:14.051,0:08:15.870
also in the countryside,

0:08:15.894,0:08:19.403
and upload them to a citizen[br]science web platform.

0:08:19.427,0:08:22.474
And over a year, we got 10,000 pictures

0:08:22.498,0:08:25.133
of snails that had been photographed[br]in the Netherlands,

0:08:25.157,0:08:27.647
and when we started analyzing the results,

0:08:27.671,0:08:31.363
we found that indeed,[br]our suspicions were confirmed.

0:08:31.387,0:08:33.751
In the center of the urban heat islands,

0:08:33.775,0:08:36.261
we find that the snails have evolved

0:08:36.285,0:08:39.776
more yellow, more lighter-colored shells.

0:08:42.341,0:08:45.309
Now the city snail and the Manhattan mouse

0:08:45.333,0:08:51.093
are just two examples[br]of a growing list of animals and plants

0:08:51.117,0:08:54.434
that have evolved to suit[br]this new habitat,

0:08:54.458,0:08:57.450
this city habitat that we have created.

0:08:57.832,0:09:00.705
And in a book that I've written[br]about this subject,

0:09:00.729,0:09:02.236
the subject of urban evolution,

0:09:02.260,0:09:03.681
I give many more examples.

0:09:03.705,0:09:06.466
For example, weeds that evolved seeds

0:09:06.490,0:09:08.960
that are better at germinating[br]on the pavement.

0:09:09.903,0:09:13.410
Grasshoppers that have evolved a song

0:09:13.434,0:09:16.966
that has a higher pitch[br]when they live close to noisy traffic.

0:09:17.553,0:09:22.887
Mosquitoes that have evolved[br]to feed on the blood of human commuters

0:09:22.911,0:09:25.252
inside metro stations.

0:09:25.276,0:09:28.037
And even the common city pigeon

0:09:28.061,0:09:31.005
that has evolved ways to detox themselves

0:09:31.029,0:09:35.259
from heavy metal pollution[br]by putting it in their feathers.

0:09:35.743,0:09:38.085
Biologists like myself all over the world

0:09:38.109,0:09:41.156
are becoming interested[br]in this fascinating process

0:09:41.180,0:09:42.347
of urban evolution.

0:09:42.371,0:09:46.299
We are realizing that we're really[br]at a unique event

0:09:46.323,0:09:48.221
in the history of life on earth.

0:09:48.245,0:09:50.752
A completely new ecosystem

0:09:50.776,0:09:55.772
that is evolving and adapting[br]to a habitat that we have created.

0:09:57.181,0:09:58.840
And not just academics,

0:09:58.864,0:10:02.650
we're also beginning to enlist[br]millions of pairs of hands

0:10:02.674,0:10:05.038
and ears and eyes[br]that are present in the city.

0:10:05.062,0:10:08.135
Citizen scientists, school children,

0:10:08.159,0:10:09.343
together with them,

0:10:09.367,0:10:12.405
we are building a global[br]observation network

0:10:12.429,0:10:16.786
which allows us to watch this process[br]of urban evolution taking place

0:10:16.810,0:10:18.135
in real time.

0:10:19.323,0:10:20.522
And at the same time,

0:10:20.546,0:10:22.799
this also makes it clear to people

0:10:22.823,0:10:25.561
that evolution is not just[br]some abstract thing

0:10:25.585,0:10:28.431
that you need to travel[br]to the Galapagos to to study,

0:10:28.455,0:10:31.338
or that you need to be[br]a paleontologist for

0:10:31.362,0:10:33.099
to understand what it is.

0:10:33.123,0:10:36.186
It's a very ordinary biological process

0:10:36.210,0:10:39.633
that's taking place[br]all the time, everywhere.

0:10:39.657,0:10:42.228
In your backyard,[br]in the street where you live,

0:10:42.252,0:10:44.252
right outside of this theater.

0:10:44.729,0:10:48.783
But there is of course,[br]a flip side to my enthusiasm.

0:10:48.807,0:10:51.482
When I go back to the village[br]where I grew up,

0:10:51.506,0:10:56.529
I no longer find those fields and swamps[br]that I knew from my youth.

0:10:56.553,0:10:58.450
The village has now been absorbed

0:10:58.474,0:11:01.156
by the growing[br]conglomeration of Rotterdam,

0:11:01.180,0:11:03.656
and instead, I find shopping malls

0:11:03.680,0:11:06.791
and I find suburbs and bus lanes.

0:11:06.815,0:11:10.410
And many of the animals and plants[br]that I was so accustomed to

0:11:10.434,0:11:14.442
have disappeared, including[br]perhaps that ant beetle.

0:11:15.449,0:11:18.553
But I take comfort in the fact[br]that the children growing up

0:11:18.577,0:11:20.581
in that village today

0:11:20.605,0:11:24.468
may no longer be experiencing[br]that traditional nature

0:11:24.492,0:11:25.680
that I grew up with,

0:11:25.704,0:11:27.950
but they're surrounded[br]by a new type of nature,

0:11:27.974,0:11:29.815
a new type of ecosystem,

0:11:29.839,0:11:33.903
that to them might be just as exciting[br]as the old type was to me.

0:11:33.927,0:11:37.625
They are living in a new,[br]modern-day Galapagos.

0:11:37.649,0:11:41.182
And by teaming up with citizen scientists

0:11:41.206,0:11:44.558
and with evolutionary[br]biologists like myself,

0:11:44.582,0:11:48.344
they might become the Darwins[br]of the 21st century,

0:11:48.368,0:11:50.748
studying urban evolution.

0:11:51.114,0:11:52.281
Thank you.

0:11:52.305,0:11:54.503
(Applause)