Science Friday - PFAS, Urban Evolution, Science Diction. July 27, 2018, Part 1

Episode Date: July 27, 2018

If you thought city life was stressful, imagine being a wild animal trying to outlive speeding cars, toxic chemicals and heavy metals, or even the unnaturally bright nights and din of traffic. Why stick around at all? Yet our urban areas still teem with wildlife. Pigeons, mice, lizards, moths, and plants all eke out their livelihoods in sidewalk cracks, subway tunnels, and building ledges. But how is city living affecting how these organisms evolve? Evolutionary biologist Menno Schilthuizen, author of Darwin Comes to Town, tells guest host John Danksosky tales from the front lines of urban evolution research. Plus: Did you know the word robot was only coined in 1922? And that quark was inspired by Finnegan’s Wake?Words like these weren’t just plucked from thin air… behind each one is a fascinating origin story. Scientists use words and language just like us, and encoded in the language they use are etymologies, histories, and stories that often stretch back centuries—some even bleeding into the words we use in our everyday life. SciFri digital producer Johanna Mayer joins John to talk about our project "Science Diction." States across the country are holding public hearings on what to do about contamination with a class of persistent chemicals known as PFAS. New Hampshire Public Radio environmental reporter Annie Ropeik tells us more in "The State of Science." And Tanya Basu, science editor at The Daily Beast, explains the top science headlines in the News Round-up. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm John Dankoski. Ira Flato is away. Later this hour, we'll be talking about urban evolution, how species have adapted to life in the big city. But first, one adaptation that humans have had to make this summer is to rising temperatures. Across the globe and the northern hemisphere, heat waves have been common in the summer. Even the Arctic is at all-time highs. Joining me now to talk about that and other stories from the week in science is Tanya Basu, senior editor for Science at the Daily Beast. She's right here in a New York student. Welcome back to the show. Thank you.

Let's start about this, talking about this heat wave. It's not surprising, of course, that we've got a lot of hot weather. Where's it really bad right now? It's really bad, I would say, all over the place. You know, there's been a lot of deaths in Japan. Japan has had, you know, temperatures go up to 100 degrees, 108 degrees. Greece, there's wildfires, and now it's hitting the Arctic. We're hitting a lot of the Scandinavian countries that usually don't go over 80 degrees

and are going closer to 90, which means that there are forest fires that are just raging there. They don't know how to deal with it because they've never had forest fires before. Yeah, very high temperatures in Quebec and other places that we're not expecting high temperatures. Now, are all these events connected and are they connected to climate change? Yeah, so definitely climate change is playing a role. There's also the fact that jet streams are very slow right now, and there's a little bit of atmospheric pressure just hanging out, which means that these forest fires are able to spread more.

So all these forest fires, although they're in different regions around the world, are definitely connected, and climate change plays a big role. Okay, let's move on and let's move to the move. specifically the ancient moon, and whether or not there was water on the moon way back when? Yeah, so there were two periods the scientists were looking at. One was four billion years ago, another was 500 million years ago, which is very recent considering that life on Earth began 3.7 billion years ago, and that means that there could have been water vapor that existed on the moon

that could have supported microbial life at the same time that we were here on Earth. Yeah, that's amazing. So where would this water have come from, do you think? So it probably came from underground. You know, there were a lot of volcanic activity going on at that time, and so there could have been things in water in addition to other things coming out from the moon that could have been able to support, you know, very, very basic creatures. Very basic creatures, very tiny creatures, not big ones. No, very, very tiny ones. I want to move on to some creatures that have been adapting.

A story about lizards and really rapid adaptation. This is fascinating. This is such a great story. Okay, so basically, last summer, this researcher goes to Turks and Caicos and is studying rats and. how they're affecting these lizards that are local there. And then Hurricane Irma hits, and then Hurricane Maria hits, and he's like, let me go back and see how these lizards have potentially adapted. And he finds that they've really changed in those few months.

So there's a lot of natural selection at work. These lizards are showing toe pads that are 6 to 9% bigger than usual. They're showing hind legs that are shorter, which is unusual, because you would think that they'd want to be larger so that they could jump away. But the shorter ones actually let them stick on to leaves longer. and therefore, you know, when there's a lot of wind going by, they can stick onto the leaves and protect themselves. This is within just one generation and one or base two hurricanes.

And they also found that a lot of these lizards that had smaller tow pads, which means that they couldn't stick to the leaves, actually got wiped out. So it's happening that quickly, and we'll be talking more about urban evolution and how quickly evolution can happen, but my goodness, that seems really fast. It's so fast. It's within less than a generation. One of the things about the study that I like so much is how exactly they figured out this and what they used to blow the lizards around. Oh, they used, what was it, a windblower? It's a leaf blower.

A leaf blower. Exactly. It's not the lowest tech possible way of trying to figure this out. I really love this. Okay, we're going to move from lizards to goldfish. You may have heard the story, but goldfish crackers is actually a problem with goldfish crackers. Oh, my goodness, what's wrong with them? And more, it's not just goldfish crackers.

There's also Ritz crackers. There's Swiss bros. commonly often referred to as ho-ho's. Basically, when a lot of manufacturers create these snacks, they use whey, which is dry milk. It's a way to create creaminess in these products without the cream. And it seems like there's salmonella, which is unusual. You think of salmonella is something with chicken, with eggs, but salmonella also occurs in dried milk and whey, and therefore a lot of these manufacturers are recalling them just so that we don't get sick. It's in ho-hoes, too? Yeah. Oh, oh. Yeah. Well, are these all coming from the

company? Is there one company that makes all the way? Yeah, it seems like there's one in Minnesota, and the FDA is investigating to see what exactly occurred, but all the way and these products are coming in from Minnesota. Okay, I've been waiting all week to talk about the story with you, and here's why, because I just adopted two brand new kittens. My life is being overrun by cats right now, and there's a story making the rounds about a parasite associated with cats. That doesn't sound good, but there's maybe a silver lining to the story. Okay, what are we I'm going to reassure you, but also before I do, it's a viral story about this cat parasite, a parasite that's found in their feces, basically, that can get into humans.

Now, nothing to worry about humans don't usually, you know, show any symptoms or anything, but these researchers found that some humans that have this infection in them might have signs of being able to take more risks or, you know, show signs of being in management and entrepreneurship. That's crazy a little bit. So I want to break it down a little bit if we can. Okay, please do. Yes, we've got some time. So this infection, basically what these researchers did was look at 1,500 university students, and they tested the saliva of them and saw that if you had signs of this infection within you, which is, by the way, usually asymptomatic, you were 1.7 times more likely to pursue management, and you were 1.4 times more likely to be a business major.

Now, those are pretty low rates. Sure. And there is a correlation. But, you know, there's a lot of things that could be different here. For example, we're talking that's a correlation. That means those facts are connected, but that's not that one causes the other. Just because I had a cat and I had this infection doesn't necessarily mean that I'm going to be a risk taker. So there's that.

There's also the idea of we don't exactly know what the pathway of exposure is. So, for example, it could be that I had a cat at one time, and then I decided, independent of that, even if I had the infection, that I wanted to be. you know, a business owner and to start a business of my own. So that's also another thing. You know, there is a connection that is interesting. It's something we should know. But... It sounds like one of the things that makes for a great viral story,

something to share on Facebook with your friends, but I don't know that I'd go to the bank with that one. No, no. Maybe don't. Maybe just play with your kittens independent of this. I will safely play with my kittens and enjoy them, but probably won't get any other benefits other than just the cuteness. Tanya Basu is Senior Editor for Science at the Daily Beast.

Thanks so much for taking the time to talk with me today. Appreciate it. Thank you for having me. And now it's time to check in on the state of science. This is KERNO. St. Louis Public Radio News. Iowa Public Radio News. Local science stories of national significance.

A class of chemicals known as PIFOS, short for per and polyfluoro-alkal substances, have been used since the 1950s in manufacturing. The most commonly known is perhaps Teflon, but there are lots of other. chemicals in the PIFAS class. They were often used to make one thing resistant to other things. Think heat resistant, water resistant, stain resistant, grease resistant, nonstick coatings, flame retardants, that sort of thing. In recent years, manufacturers in the U.S. have stopped using some of these PIFAS chemicals, but the resistance properties of PIFAS make them slow to break down. They stick around in the environment and they can move into the drinking water supply

and then into us. This stuff is all over the place. Today word came that drinking water in Harchment, Michigan, that city named for the paper mill there is contaminated. Now the EPA is holding hearings around the country on what to do about PFOS and the standards that should be involved. Joining me now is Annie Ropeak, Environment Reporter at New Hampshire Public Radio, a state with several PFOS hotspots and was recently the site of one of those EPA hearings. Annie, welcome to Science Friday. Hi, John. So why was New Hampshire the first place to get one of these EPA public comment periods? So New Hampshire, like you said, has a lot of PFAS hotspots. and our congressional delegation, a lot of our state officials,

have been really out in front on this issue and tried to sort of push the conversation forward at the Environmental Protection Agency on what to do about these chemicals. New Hampshire is also one of just a handful of states that has really any regulations at all on these chemicals and drinking water. And we've got some active cleanup situations going on. I was just at the site of one this morning.

P's Air Force Base on our sea coast region where the PFS levels are really off the charts in some places, and that was affecting some people's drinking water a few years back. So the chemicals stay in the environment for a long time. They enter into water supplies. Do we really know what they do to the human body? We know a little, and there's a lot left to learn. And, you know, these chemicals, a lot of officials describe it as plain whack-a-mole

because there's just so many of them, and it's so hard to get any definitive answers about their health effects that, you know, once you have any information about one, there's so many others and so many other questions to still answer. So we're really pretty early in that process right now still, but generally speaking, many of these chemicals have been linked to all kinds of serious health issues if you drink or ingest enough of them over many years, things like kidney disease, liver disease, cholesterol issues, testicular cancer, other kinds of cancer, immune deficiencies, developmental issues, issues in pregnancy and with childbirth. So really all kinds of things here. and you don't need to ingest a lot of them in order to see some health effects. It just kind of can take a long time to show up.

Well, so given all of this, you would think the government had really tight standards about how much is safe, how much is dangerous. What do the standards look like right now? You would think, wouldn't you? So these are, have been for what we call an emerging contaminant for a long time. They're not really emerging anymore. They're pretty much emerged. But these are like many other man-made chemicals. just hard to understand and they're a new issue.

And so the EPA took some steps initially when this first started to become an issue in places like West Virginia to stop manufacturers using the chemicals and stop importing them. So that was one step. And then they issued a health advisory, which is sort of this non-binding thing

that states could use to say don't have more than this much in your drinking water or there could be health problems. Now they're working on developing a hard limit, a national, hard limit on PFS in drinking water so that water companies would actually have to test for it before they send the water down your tap, and it's more of a proactive response than a reactive

response. So we've said already to these chemicals stay around for a long time, but they're not really in use anymore, at least some of them. There are more chemical compounds that are sort of like them that are still in production, though. Yeah, that's right. So, I mean, these play an important role in all kinds of manufacturing. Like you mentioned, you know, that was found near a paper mill in Michigan.

And here it was the firefighting foams that were used at Air Force bases. It came out of a plastics factory. You know, it's in just so many different things that they play an important role. And so they've come up with these new types of chemicals called next-gen compounds or gen X compounds. And they do the same thing, but theoretically, with fewer health risks. We don't know a lot about those still, though. And so that's another thing the EPA is working on in the next few years is studying those next generation of non-stick type of chemicals. to make sure that they really have solved the problem.

Annie Roe Peak is Environment Reporter at New Hampshire Public Radio, who's been following this story for us. Thanks so much for being with us. I appreciate it. Thank you, John. After the break, what would Darwin think about the mice, the pigeons, and so-called weeds that live in our cities, how urban animals are evolving to coexist with us.

It's coming up next. This is Science Friday. I'm John Dankowski. City life can be hectic. Your neighborhood is crowded and there's constant noise from traffic, sirens, or early morning garbage truck. Public transit doesn't always work in the summer breeze. Not exactly refreshing right now.

But if you find urban living tough, try being a mouse or a lizard or even a flower, trying to start a new generation in a crack in the asphalt. Your hazards include speeding cars, marauding cats, and water tainted by car exhaust, road salt, and who knows what. It sounds tough, right? Well, it could be the perfect laboratory for natural selection. That's what my next guest is here to talk about. As human cities continue to grow around the globe, a new wave of evolution. Biologists is looking at how our neighbors, the feathered, the furry, the photosynthesizing,

are learning to thrive? Are we even influencing the creation of new species? Menno Skilthausen is evolutionary biologist for the Naturalis Biodiversity Center in Leiden, Netherlands. He's also the author of Darwin Comes to Town, how the urban jungle drives evolution. So what's your favorite urban wildlife? Give us a call. Our number is 844-724-8255. That's 844-Sy-Talk, or you can tweet us at SciFri. Meno, welcome to Science Friday. Thanks so much for joining us. Thanks for having me.

So a lot of us might not feel like we're surrounded by wildlife when we step out the door. So why don't you paint a picture of what you see as the typical urban ecosystem? Well, yeah, of course there are some very obvious, very large animals in cities that we know here. In Europe, we've got foxes and in the U.S. you've got coyotes, lots of birds like, like Paragon, falcons, Swift, you know, your average duck, average duck in your city pond. But I think the majority of biodiversity in the city is actually much smaller and less obvious, things like little weeds and little insects and snails that are finding tiny, tiny niches in forgotten corners of the city.

And there's actually much more diversity, biodiversity in cities than we think. Yeah, that's the remarkable part. We think about the natural world being something. outside the city, but you write about this teeming life that's all around us that we probably just don't notice because it's right underneath our noses. Yeah, a lot of it, we don't notice unless we start looking for it. And actually, you need very little space to look for it. As long as you don't expect, you know, very large animals that you would normally find in wild nature, but smaller things, insects and snails and smaller plants and millipedes and

woodlides and spiders. They're everywhere. I mean, you probably in your basement, on your walls, in your carpets, outside. If you have a little yard, just pick up a stone or look behind a bush, and you'll find species, some of which are identical to the ones you would find outside of the city. But there's also lots of species of animals and plants that are really specialized in living in a city in an urban environment. So we mentioned already the hazards from cars and other urban toxins. There's some forces that might shape natural selection in cities. Yeah, cities are really, despite the fact that there's a lot of biodiversity in cities, they're also very extreme environment.

They're just as extreme as, you know, a desert or a hot spring. There's lots of dangers, lots of challenges, lots of very unusual circumstances in cities. So, for example, you've got the urban heat islands. In cities, it's as, well, actually, I'm in Leiden where I live at the moment, it's very, very hot, and that's partly even exacerbated by the fact that it's a large city. You have got all this concrete that's absorbing heat and reflecting it. There's people producing heat. So in big cities, it can be up to 10 degrees centigrade hotter than outside.

So that's one aspect. Another aspect is that there's all these dangers like pets, for example, the density of predators in the city where you have a lot of cats and dogs. running around free, roaming free, that's a much denser predator population than you would normally find in an environment. Other things are like traffic, which kills off a lot of animals and plants and makes it much harder for weeds to germinate in between the cracks of the pavement, and so on and so forth. So cities offer a lot of opportunities because there is food, there is people concentrate a lot of food in cities, so there's for animals and also for

plants, there are lots of opportunities, but there are also many dangers, which are very different from non-urban environments. And that causes a very different kind of natural selection in cities than animals and plants are used to. You write this amazing story about blue tits in Europe learning how to get cream from milk bottles. And they plagued milkmen for decades. And in different cities, they seem to learn this independently of one another. And this really gets to the heart of what's in your book here, trying to figure out if this is evolution over time or just a behavioral change, some learned behavior by these animals. Right. Yeah, there's a couple of very famous examples of, and very cute examples also, of birds and mammals learning to manipulate us, basically. They figure out

how to get to a certain food source. So the famous example is already from the early 20th century when blue tits and gray tits, these little songbirds in Britain learn. how to open the caps of milk bottles that the milkmen at that time still deliver to people's door and left them there for a while until the inhabitant of the house would pick them up. And these birds would rush in and pack the lid open and steal some of the cream on the inside of the rim of the bottle. And this behavior, this trick to open these bottles spread very quickly through these populations of birds and it also appeared in different parts of the UK at the same time, more or less. A similar example is house crows in Japan, which have learned to use cars as nutcrackers.

They have these walnuts which they place in front of passing cars, and the cars crack open the walnuts, and they get to the flash inside. And again, this is something that seems to have, this behavior seems to have originated in one place and then spread, but sometimes it also is picked up by other house crows in a completely different place where they could not have learned it from each other. So this in itself is probably not evolution. There's not a gene for opening milk bottles. But there are genes for personalities of birds and also mammals.

So there are genes which make birds better at problem solving, less fearful of humans and other large animals, more inquisitive of novel objects. Those are all personality traits which have genes and which are to some extent genetic. And those sort of general personalities, they can evolve. So birds can become better at problem solving in cities because the genes for being clever in that way are selected.

Whereas in nature, probably they would not have much of an advantage because the way you crack open an acorn is always the same. But in cities, every year you have these new opportunities for birds and mammals and other animals to get to human-generated foods. So we're making the birds smarter. We're giving them harder problems to solve over time. Yeah, or new problems. I mean, you're only smart depending on your context. So in a city, it's smart to be curious about new objects.

in the forest is probably dangerous and not very smart to be curious about new objects because it usually means something something is dangerous if humans place a new object there. But in the city something new often means something that could provide food in a different way than the animals are used to before.

So being inquisitive and trying to figure out what that new thing is and how it works is smart in the city. A lot of people who took high school biology might remember the peppered moth. This is a classic example you write about of evolution in response to pollution during the Industrial Revolution. The moth, it is told, got darker to hide better on soot-stained surfaces.

So is this still the textbook example of the type of adaptation or evolution that you're talking about in the book? It is actually, yes. It's a very famous example, and it's still a very good example of how a change in the environment that's caused by humans drives the evolution in a wild organism. So just two years ago, it was figured out exactly which. bit of DNA is responsible for the color of those wings of those moths. It turns out it's a single sort of switch gene that turns on the melanin, this dark pigment in the wings of the moths. And there's just a little change in that gene that has caused these moths to become darker.

And also to become lighter again, because in the 1960s, the legislation to remove suit from the air was introduced. The air got cleaner again, the trees got lighter again, and these moths became lighter again. So you have a very beautiful seesaw of evolutionary change, where the moths first in the 19th century became darker and almost completely took over the light moths. And then the reverse happened in the late 20th century. And today, the moths in UK and in Europe look exactly the same way they did before the Industrial Revolution. So I think it's still a textbook example, except that, of course, it's a single gene. It's a very simple. It's about the simplest kind of urban evolution that you can think of. It's a single factor in a single gene that changes these

moths. We don't see a new species appearing. And there are other examples nowadays of animals that are changing, are evolving because of urbanization that involve many genes, and they evolve lots of different parts of the genome, and where you see something that you could really say is the evolution of a new species. We're talking with Minot. It was Bill Housen about his new book, Darwin comes to town. Let's get to a phone call. Jeff is calling from St. Louis, Missouri. Hi, Jeff.

Hi, how are you? Good. What's on your mind? I'm the lucky guy that gets to band Paragrin Falcon Chicks in St. Louis. We've got three pairs, three pairs in downtown St. Louis. And I've got males and females, adult males and females on these territories that have been there for many years now. And I've always wondered how they've adapted to the glass buildings. Glass buildings kill millions of birds a year in big cities here in the United States.

Yet the peregrines seem to have adapted to the city lifestyle, and it is rare for them to hit buildings and be found dead. And I know that these females and males are the same ones because we have auxiliary bands on them so we can see the numbers and the letters on these auxiliary bands from quite a distance. So it's very interesting to me that they've adapted and not been able to or not hit these buildings like most of the other birds do, or many of the other birds do in this city. Jeff, thanks so much for that. It's interesting, huh?

It is very interesting. I think, yeah, you're right that glass and also reflecting steel and also lights at night kill a lot of birds and also a lot of insects. I mean, the death toll is enormous. We're talking about billions of birds and gazillions of insects that are dying because of that. And, you know, when you have a lot of death, you also have a lot of natural selection. There's a very high premium on being able to avoid that cause of death. So in insects, we're seeing that they're now beginning to avoid lights, actually, in areas where there's a lot of artificial light. We don't have any evidence yet that birds are doing the same with either light or.

or glass buildings, but you would expect that that sort of evolution would be going on. And it could very well be that peregrins and maybe other birds also are beginning to get better at recognizing glass buildings and not because they're learning, but because maybe their eyes are changing. We don't have any evidence for it, but it wouldn't be, it wouldn't surprise me because the death toll in some species of birds is enormous. You talked about the massive deaths from lights and insects, and light pollution is one of the big features of the urban landscape.

Yeah, that's, of course, very pervasive human-generated change in the environment, and it's a very new change. I mean, there's never been artificial light at night for some other aspects of the urban environment you could find parallels in natural conditions, but in nature, the only light at night has always been the moon and the stars, and only less than 200 years ago, suddenly we had all these other lights appearing at night, and all the animals that are active at night and were using the moon to navigate

started to get confused because of this artificial light at night. So, you know, insects, for example, they have always used the moon as a beacon to fly in a straight line at night. So if they keep a fixed angle with the moon, they fly in a straight line. But they've tried to do the same thing with something that they think is a moon,

but it's actually a street lantern, and then they end up going in ever-decreasing circles around that street lantern, and they probably die because of the heat of the light or they just sit there and waste time that they should be spending feeding or looking for mates. So I think that this light at night is definitely a very important selection pressure,

or something that could drive evolution and the evolution you would expect to happen is that these insects start being less attracted to lights, start losing their tendency to use light at night for navigation. And there is some evidence that insects are actually doing that, that the city insects are ignoring light much more than rural insects do. I'm John Dankowski, and this is Science Friday from WNYC Studios. I want to get to another phone call quickly here.

Bex is calling from Santa Cruz, California. Hi there, Bex. Hey there. Hi, what's in your mind? Thanks for having me on. I wanted to contribute a couple of my favorite urbanized animals. And here in Santa Cruz, the UC Santa Cruz, it's confusing. considered a city on the hill. And I like to consider our deer a little subspecies where they will cross the street in the crosswalks.

They will eat grass a few feet from a jackhammer. You can walk just a few feet away from them where I know coming from the mountains, that would be dinner. And they don't seem to have a fear at all. We also have this wild turkey. We call Hank. And Hank has, I believe, like a territorial protective instinct, particularly against male delivery, like UPS man, the mailman, and then, I mean, just cars, he'll chase, he'll stop traffic, and peck at tires, and sometimes even people. It's really cute and confusing behavior, and it's, I've never seen anywhere else. Well, thank you so much for those two stories, and I want to ask about both those. Other people are tweeting about deer getting less skittish than they were before.

and I've heard a lot of stories, Meadow, about Turkey's taking on really aggressive personalities in urban areas all across America. What do you see there? What do you think is happening? Yeah, like I said before, there's probably some sort of general personality change in many of these animals. And to some extent, of course, there's more specific things they could simply learn and pass on to each other.

But there's more general personality traits that are evolved. evolving if they are genetic. And we know that many behavioral characteristics of mammals and birds are genetic. So in the case of aggression in Turkey's and in Europe, we often see it with large moot swans, which are in cities, which are also seem to become more aggressive and more territorial. Also, tameness. I mean, the color just described that deer are much tamer in the city. We also see that in birds that the same species of bird outside of the city would fly off if you get within 40 yards from them,

whereas in the city they stay on the floor until you're just a few yards away from them. And those things are they're repeatable, and you can actually measure them, and you can see that there are genetic changes in these animals. So it seems that in cities, they evolve their personality, the personality that was outside of the city was very beneficial, namely being scared of people in the city often people are not as dangerous. It's actually better to be closer to the people. Coming up after the break, more stories from the urban evolution jungle, plus how one researcher is untangling the story of pigeon evolution.

That's right, pigeons in New York and all over the east coast that's coming up. This is Science Friday. I'm John Dankoski. We're talking with evolutionary biologist Menoskielhausen about the evolution of our urban wildlife neighbors, how mice, mosquitoes, and even flowers are responding to the pressures of urban living. But first, ever try to shoe a group of pigeons that crossed your path? Tired of dodging close flyovers of pesky gray birds?

The urban pigeon may feel like another city nuisance, but there's a lot that can teach us about how wildlife is adapting to coexisting with us. The science is there, if you can just chase it down. Sci-Fry producer Christy Taylor recently joined a biologist's pigeon hunt in New York City. And here's a story. Elizabeth Carlin would be the first to tell you she has understanding. friends. They're quite used to going into my freezer to get ice and seeing blood samples or a dead bird or a dead mammal. They'll even text her when they see dead pigeons on the streets of New York

City so she can snip off a sample. Sometimes it's the whole foot. Generally it's just the toe or a couple toes. Her car and clothes are constantly covered in feathers too and sometimes bird poop, but it's all part of the job because Carlin is a biologist who studies evolution. urban evolution in the common city pigeon. These feral, ubiquitous birds are the descendants of wild cliff-dwelling doves from Europe in North Africa. And they seem to like living with us. They moved into most major cities around the globe.

And that sets up the perfect experiment in adaptation and evolution in harsh, dangerous, sometimes toxic environments. We're starting to realize that animals rapidly evolve much faster than we thought. And that means that organisms are able to adapt to cities, these very new ecosystems, this new habitat. To look for answers in New York City, step one is to get in the car. Carlin meets me in Inwood, the northern tip of Manhattan. Our mission, find and capture some pigeons and then sample their blood. Our getaway vehicle, Carlin's silvery gray Subaru hatchback. She has a stash of birdseed in the trunk, a full tank of gas, and we're ready to roll.

So mostly what I'm looking for is a lot of pigeons that are close together and that are feeding and kind of distracted. This is harder than it sounds. We have not really seen any big flocks on the ground. They all just flew away as soon as we drove up. We're just stopped for no reason. I am really not seeing any pigeons. No, that just scared him away. So a guy just walked up and pulled up his cane and totally scared them off.

They're definitely in the neighborhood. Why are they not here? I never thought it would be this hard to find a pigeon in New York. But we finally luck out on the Upper West Side, 20 or 30 gray, brown, and white birds just pecking away at a stash of food someone's left in a park. We sneak up on them, and Carlin pulls out her secret weapon, a net gun. It looks kind of like a long black flashlight,

but it shoots out a net, capturing as many as 13 pigeons in a shot on a good day. The birds scatter, except for a few choice research subjects. We got two this time, which is great. We're going to head back to my car so I don't get a ticket. We have the birds. Now it's time to collect the data. Remember Carlin's bird seed-filled trunk?

It's also a traveling lab, packed with test tubes, bloodletting needles, and brown paper grocery bags, where the birds can wait calmly until it's their turn to be processed. And in just a matter of minutes, she's gotten everything we spent the whole morning hunting. She weighs each bird. So this guy is about. 410 grams. She notes its location and color, gingerly draws a small blood sample from a vein under its wing. So then I just slowly insert the needle up against the vein. And fits a small

lavender identification band around one leg. These blood samples will go in her freezer, along with those cut off toes from Roadkill pigeons. And in the DNA of all those samples, she's hoping to find clues as to why pigeons thrive in big, busy cities. Are urban pigeons genetically more tolerant of toxins, noise, or light pollution? Are there genes helping them digest our junk food? How are birds in New York related to birds in Boston or D.C.? We don't even know how many are out there, and DNA can help biologists count. Then, the last bird in her hands, Carlin asks me a question. Do you want to let them go? Yes.

By the way, I'm someone who loves New York's pigeons. They feel like my neighbors. Seeing them hopping along on the sidewalk in the morning gives me this little burst of dopamine, Like we're all in this crazy city together, rushing to get to the train on time. So holding this calm little bird in my hands... This is really great. It's kind of a dream come true. How are you doing, bird?

Okay. Okay, so yeah, just open the door and then open your hands. Okay. Let me bird. And it just went. It just went. It just went.

And that's the gift. Carlin wants to give other city dwellers too. This sense that pigeons, they're not just a nuisance clogging up the sidewalk, eating our trash, or pooping from building ledges. They're our nature, our wildlife,

and part of our shared urban ecosystem. So why not take a minute? Look up from the crowded sidewalks and screeching traffic and the weird smell of garbage in the wind and just watch a few of these graceful birds wheeling about in a bright blue sky. In New York, I'm Christy Taylor.

You can see pictures from Christy's pigeon exploration at cyfry.com slash pigeons. We're talking with biologist Menno's skillthouse, an author of Darwin comes to town. It's such an interesting story. What else can you tell us about pigeon evolution,

Meno? Yeah, John, I think that was really a great report on the city pigeon. I think they're really wonderful animals, and most people wouldn't consider pigeons as wonderful animals, but they're ideal for studying this urban evolution. So there's some evidence now

that the wings shape of city pigeons has changed, but also that their colors are evolving. You may have noticed that in cities you can have these light gray and dark gray pigeons. And it seems that the larger the city is, the more of these dark gray pigeons you have. And there are genes for the color of their wings and their plumage. So there's also genes for dark gray pigeons and for light gray pigeons. And it turns out that the ones that have dark gray feathers, they have more melanin, this dark pigeon pigment in their feathers. And melanin also helps them to basically detox their bodies.

Melanine binds to heavy metals, lead and zinc, of which there is a lot in cities because there's a lot of pollution in the past, of course, lead from fuel. Today, a lot of zinc also from lampposts and electricity poles. And the animals ingest this accidentally, and it's dangerous for them. And they can get rid of that zinc by basically incorporating it in their feathers. and then it's harmless and it's bound to the melanin.

So the dark-wing, the dark-feathered pigeons are better at getting rid of these metals from their bodies. And that's why these dark ones do better and you see more of them in big cities. I'd like you to quickly, though, tell a story that our pigeon-loving producer, Christy might not like so much. A story you tell about France where catfish are jumping out of the water to eat pigeons.

Yeah, that's, of course, much of the things I've talked about and also much of the things I talk about in my book have to do with the physical and chemical aspects of the city. And that's the thing you think of immediately. But there's also a very interesting biological thing going on in cities in the sense that cities are places where all these species of animals and plants come together that have never met each other. We introduce animals and plants in cities.

They start thriving there and they start building an ecosystem together with species that come from all over the world, from different parts, from rainforests, from deserts, from cities in Asia, Africa, Europe. And in France, for example, they have introduced, well, the rock pigeons are there, which are originally from southern Europe and from Africa, North Africa. And they've introduced catfishes from Eastern Europe for angling, for fishing. And these catfishes, normally, they are very large freshwater fishes, and they tend to rustle up clams and worms from muddy river bottoms.

but in a city in France in Albi in southern France they have figured out that you can actually catch as a catfish you can also catch pigeons these pigeons these city pigeons are bathing are preening on the water's edge of the big river that flows through the city

and these catfishes sneak up on them like orca sneaking up on sea lions on a beach and they grab them by their feet and pull them under and swallow them which is something that catfishes are not supposed to do but they have an opportunity in a city and they take it and in this sense they've created a new ecological relationship between pigeons and catfishes that wasn't there before

and that could be the start of a new evolutionary process. You mentioned something earlier that I wanted to loop back to about whether or not someday we might see entirely new species that live just in cities. Yeah. Of course, we humans have been creating cities not for a very long time yet. I mean, we've started doing it a few thousand years ago, but it's really taken off only in the past century. so animals and plants that are adapting to cities haven't had much time to evolve. What we see now is really the beginning of evolution.

So not really completely new species are evolving. But there are one or two examples that seem to go a little bit towards new species evolving. And new species being organisms that have a lot of different genes in their genome that are evolving. So blackbirds, for example, the European blackbirds which have invaded cities, and they were one of the first birds to do that. In the early 19th century, in Rome and in Germany, they started invading cities. And they've continued doing that throughout the 20th century. And we now see that these blackbirds have a whole range of genes in which they are different.

They sing at a different pitch. They have differences in their intestines. Their beaks are shorter. They don't migrate anymore. So they breed much earlier in the year than the forest blackbirds do. So their personalities also have changed. also in the genetic level. So we have a whole range of differences

between the forest blackbirds, the ancestor of the city blackbird and the urban blackbird. And you could argue that they are on the way of becoming a separate species, some sort of turdus urbanicus, turdus muralized, the scientific name of the forest blackbird.

Maybe in a few hundred years we could speak of tortoise urbanicus, the city blackbird. I want to end on this, and I think it's fascinating. Whenever we think about an animal in what we call the wild outside the city, if we have some sort of impact on it and it starts to decline in number, we we wring our hands about what we should do to bring it back or preserve it. How do you think about this within the context of this urban environment in which there's so many animal and plant species that are living amongst us? How should we prioritize what is important and less important to make sure we preserve?

Yeah, I think, well, we tend to think in terms of individual species. We tend to think we have to preserve this species or that species or this species is doing poorly, so we have to help it. But I think what's much more important, and we're starting to see that in conservation also, that people are focusing more and more on the ecosystem as a whole rather than the individual species. And of course, in cities, you have very few species that are rare. or endangered often they are common species or invasive species or exotic species which usually don't have much conservation value but together they form a very well

functioning urban ecosystem and I think that ecosystem itself is something that we should preserve and stimulate and we can do that by creating cities in which there is space for for urban nature by creating bits of vegetation small bits large bits by creating sometimes maybe creating corridors between between parks sometimes maybe not creating corridors, planting, let's say not planting parks with species from a catalog of a garden center, but letting them be colonized by urban plants naturally.

In all those sorts of ways, I think you can stimulate that these urban ecosystems will thrive. Menosklethausen is evolutionary biologist at the Naturalis Biodiversity Center in Leiden, Netherlands. He's the author of this new book, Darwin comes to town, how the urban jungle drives evolution. Thank you so much for joining us.

I really appreciate it. Thank you, John. I'm John Dankowski, and this is Science Friday from WNYC Studios. And now it's time for a little lesson in science diction. And no, we're not going to teach you how to enunciate cryptosporidium. I did it.

I'm talking about diction as in the words we choose when we speak about science. Words like Zero and Robot. We're just plucked from thin air. Behind each one is a fascinating origin story, which you can read about in Science Friday's new weekly

science diction newsletter. And here to tell us more about it is Science Friday digital producer Johanna Mayer. Johanna, thanks for joining us. Thanks very much for being here. Hey, John. So what are we saying when we use words like zero or robot? So science is everywhere. Science is encoded in the words that we use and it's baked into our surroundings.

And zero is a really great example of a word with tons of historical and cultural backstory. So the numerical concept of zero originated in India. But our English word zero comes from the Arabic word zephyr, if you'll excuse my poor pronunciation. But that's the same root that gives us the English word cipher, which has this connotation of covertness or secrecy. And there's an interesting link there because the concept of zero as it worked its way through the Middle East, up through Northern Africa, eventually landed in zero during the time of the Christian Crusades. So not really great timing. And Zero and all Arabic numerals were actually banned in Florence, Italy, for a period of time in the 13th century. So we almost lost Zero altogether, but it's back now. It's been back for a while.

It's back. It took until about the 15th century for Zero to be widely accepted in the Western world. And that's largely thanks to merchants, because who wants to do complicated arithmetic with Roman numerals? I don't, and I'm sure those merchants didn't either. Okay, so, well, let's move on to today's word. The word is robot. Where does the word come from? Yeah, that's a relatively new word to the English language. We didn't get it until 1922.

And it comes from the famous Czech play, Rossum's Universal Robots, or R-U-R, by Carol Capic. And the premise of that play is that there's this company that manufactures this fleet of biomechanical workers that are tasked with essentially doing everything that humans don't feel like doing. So Capic needed a word for these workers, and he drew upon the church-Slavonic word, Robata. which means servitude or forced labor or drudgery. Interesting. So in that word, not some other word that could have meant the same thing. Well, he originally called them Labore, which comes from the Latin for labor. But that just doesn't really have the same ring to it.

He thought it was a little too bookish. So at the suggestion of his brother, Yosef, we have robot. Yeah, I think saying Labore and science fiction movies wouldn't be as much fun. Not quite. Okay, so how do you sign up? Where can you dig into all these past issues? And all the work that you're going to do moving forward in science diction. Yeah, head on over to science friday.com slash science diction.

You can read past issues, see tons of photos and images related to these words. How are you choosing these words? You know, it's just curiosity and calling up experts and diving into the words that are around us. Okay, well, thank you. Johanna Mayer. She is Science Friday Digital Producer. Thanks so much for being here. I appreciate it.

Thank you, John. And once again, it's sciencefriady.com slash science diction. that is Diction with a D. Charles Bergquist is our director. Our senior producer is Christopher Entaliata, and our producers are Alexa Lim, Christy Taylor, and Katie Hiler. Our intern is Lucy Wong.

We had technical and engineering help today from Rich Kim and Sarah Fishman. We're active all week on Facebook, Twitter, Instagram, all the social media places. And if you've got a smart speaker, ask it to play Science Friday, whatever you want, because every day is now Science Friday. You can email us.

The address is SciFri at Science. Friday.com. IRA is back next week in New York. I'm John Dankoski.