Science Friday - Beef Genetic Testing, Chasing Whales, Radiolab Gonads. June 29, 2018, Part 1

Episode Date: June 29, 2018

Whales are majestic, awe-inspiring animals. Some species can reach up to 150 tons and take in a living room-sized volume of water in one gulp. They can even dive thousands of feet into the ocean while holding their breath all the way down. It’s hard to imagine that the earliest ancestors of these graceful creatures of the deep were four-legged dog-like animals that lived on land. In his book Spying on Whales: The Past, Present, and Future of Earth’s Most Awesome Creatures, paleontologist Nick Pyenson examines their evolutionary story. Plus: Think back to your sex ed class in school. Chances are you were introduced to lots of new jargon too: Terms like spermatozoa, oviducts, chromosomes, germ cells and gonads. It was that last word, gonads—and a researcher who referred to them as “magical organs”—that sent Radiolab producer and host Molly Webster on a quest to respark our fascination with embryonic development, X and Y chromosomes, and reproduction. The first few episodes of the limited-run series called Radiolab: Gonads are out now, and Molly joins Ira here to talk about it. And Sophie Bushwick, senior editor at Popular Science, joins Ira to talk about the James Webb Space Telescope and other news from the week in science, including the FDA’s approval of a marijuana-based medicine,  the discovery of a nursery for manta rays, and research into just how wiggly the tongue of a T. rex actually was. 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 Ira Flato. A bit later in the hour, why the land animal most closely related to the whale is a hippo. We talk all about whales. It's kind of interesting. But first, this week, astronomers got some bad news. The launch date for the long-awaited James Webb Space Telescope is being delayed again. The launch is now planned for no earlier than March of 2021. Joining me to talk about that and other selected short subjects in science. Sophie Bushwick Senior Editor at Popular Science.

Welcome back, Sophie. Thanks for having me. So what's this time? What's the problem this time with the delay? So with all the delays, this was originally scheduled to go up sometime between 2007 and 2011 and now being pushed back, you know, a decade from that original optimistic view. NASA's had an independent review board look into just what's going on, and they've implemented a lot of their suggestions.

But as a result of testing out and trying to fix the problems, they've realized that they're actually going to be a year later than they thought they were last time they had delays. Did they do things wrong in maintenance? What were the delays about? They've pinpointed a few different things, including excessive optimism and just simple, simply dealing with such a complex system. But human error is another big one. So there's been incidents where some fasteners were not installed properly. and so during testing, screws came loose, and then they had to go back in and tighten the screws

and reinstall the fasteners or just situations where the excessive optimism is just where they just thought they would be able to do it and didn't make their estimate. To keep excessive optimism as a new kind of phrase for me. So why is the Hubble, as a successor to the Hubble, why is this so important? This is going to be able to look back

to when stars and galaxies were just forming like very soon after the Big Bang. So peering back into the history of not just the solar system, but of the universe, and so we can learn so much about how the universe formed, especially in those early days when everything was a lot more volatile. And that's just a really exciting time to look at. It'll also be able to look at the atmospheres of planets and to look at exoplanets in more detail because it's going to be a very powerful viewer.

Yeah, and they now have, what, 3,800 exoplanets? Yeah, it's an exciting avenue for us to explore. All right, let's move on to the FDA approving a new type of drug this week. Yes, the FDA has approved the first type of drug based on marijuana. So this is a drug called Epidilex. It's going to be used to treat two specific forms of epilepsy. And it's not entirely going to be ready for market yet. First, the DEA has to reclassify CBD or kind of BDIO.

which is the substance it's based on. So this is still classified as something without medical value by the DEA. So they're probably going to be reclassifying it in the next couple months before this can go to the market. So as you say, it is all the people who are waiting for this that's not going to happen any time, tomorrow or the next day. Right. They're going to have to wait a little bit longer for this to become available. But one of the forms of epilepsy it's supposed to treat is called Jarvese syndrome,

and there's no other medication on the market right now. so this could be enormously helpful. In trials, it's reduced the frequency of seizures by about 40%. And it also is going to change the conversation about medical marijuana, I imagine. Yeah, absolutely. I think right now people sort of self-administer and measure their own dosages for medical marijuana. And this is, it's been distilled into an oil with a very specific dosage. You know, there's specific times you would want to take it.

So it's sort of become regulated and brought into the official. pharmaceutical market. So this is a big difference from, I think, the way that medical marijuana is currently perceived. Yeah, and now we'll get big business involved. Absolutely. They'll change the conversation. It always does. Let's go on to other news about biologists have found a nursery from mantarays.

Mantarays? Mantarays. So these are these really large rays. They can have a wingspan of about 23 feet. And they're these incredible animals, but we know very little about their early lives. And researchers have never seen mantas give birth in the wild. They don't really know how they develop. And so this discovery of a nursery in the Gulf of Mexico is super exciting because they can look at the natural

life cycle of these animals. It's not where tourists are going. No, you have to travel a long distance to get here. This is a place where scientists are focusing. It's a marine reserve. They're hoping to study these very young. So when they're young, the mantras are only about seven feet across, so they're kind of puny. But they're hoping they can live a lot.

Seven feet is kind of small. Exactly. By Vanta standards. Elsewhere in Biology, New Yorkers got a bit of a treat this week. Let's take a listen. Oh, blah. It smells musky and, like, damp, but distinctly rotten. It was like a dead mouse, I think.

I've only smelled Roadkill once before, and this is exactly what it smells like. I honestly didn't think it was that bad. I got right up there, and it just smelled like dirty, What were they talking about? They are talking about a lovely corpse flower. Yeah. So corpse flowers, they spend about a decade building up to get ready to bloom. And when they do, the result smells, like, as people were describing, like rotting meat, like corpses, like sweaty socks.

There's lots of great descriptions for it. It's a very exciting moment. You know, I think I recognize some Science Friday staff member voices in there. And they actually went up. They took the train up. there and we had a scientist showing them around and they said, how bad was the smell? The scientist said, you know, we opened the door in the morning and three of our own staff people threw up because I had accumulated overnight so bad.

It was really kind of cool. Yeah, I prefer to observe it through the radio. That's what we're doing. Get close to the radio. I mean, we humans don't like it, but carrion beetles love this smell. So the whole... Oh, is that right? Right.

The reason these flowers release this terrible smell is so they can draw these carrion beetles and they come and they gather pollen. from the flower and next time they wander off, they could go pollinate other flowers. That answers the question of how this reproduces. I didn't know that. Thank you, Sophie, for that. And lastly, the important question of how wiggly a T-Rex's tongue was. What's the burning issue here? Well, if you look at dinosaurs in fiction, you know, you often, you know, you'll see them with these long, waggily tongues, sort of like a lizard tongue. And so researchers decided, you know, let's see once and for all what their tongues really would have been like.

So they looked at the hyoid bones of fossils. The hyoid is a bone that kind of anchors the tongue in place. And then they were comparing fossils to the hyoids of birds and of reptiles. And they found that dinosaur hyoids are probably closer to crocodile ones than anything else. And crocodiles have these kind of short, stubby tongues, nothing that you would see wagging out as a dinosaur roars. So they've unraveled this tongue mystery. No lizard-like tongue coming out of a... T-Rex, Al.

No, which honestly I'm kind of thankful for it. That's pretty scary to picture. Well, wait for the remake of the movie. Sophie, thank you. Sophie Bushwick, senior editor at Popular Science. 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 import, and when you choose a steak, there are a lot of factors to consider, right? Do you like yours as medium or rare? T. Bo and a ribeye. Long before that steak gets to your plate, farmers and ranchers are making decisions of their own. And increasingly in the beef cattle world, these decisions are being shaped by genetic testing with farmers selecting specific traits that they hope to see in future generations of cattle.

Joining me now is Christopher Husted. He's Harvest Public Media Reporter at KBIA in Columbia, Missouri. Welcome to the program. Hey, thanks for having me. So tell us about this new way. So what sorts of genetic traits are beef producers looking for? Right. There's a lot they're looking at.

One of the biggest ones is birth weight or waning weight, things that farmers depend on. They want to know how quickly their cattle are going to grow. They're also looking at how their rib-eyes are developing, how much marbling is in their meat. So there's a variety of things that they're looking at. Wow. And how does this work? As you say, is there a catalog that now I can try? choose my cattle. I can basically decide what steak I want to grow. Essentially, yeah, you look at

your herd, you look at whatever its weaknesses, and then you can select the things that can help strengthen your herd, whether you want to have cows that grow a lot faster or have higher feed efficiency, and those traits can get incorporated into your genetic pool and your herd and strengthen that, and ultimately help save farmers a lot of input costs. So what's the, What's been the drive behind this? Right. So actually a couple years ago in 2012, there was a big drought that took out a lot of the cattle inventory in the U.S. So people have been trying to build back their herds.

And since then, genetic testing has also progressed. And this is a much more predictable way to pick and select what you want in your herd. Not having to spend a ton of money trying to figure out if your cow is going to be better at eating grain versus hay versus grass, whatever it might be, it takes a lot of the gamble out for farmers. So you can put in a little more money on the front end to get your cow genetically tested, so you know what more of those traits are going to be like in predictability. Is the science mature enough to really know how well? You're spending your money on this, how successful you're going to be?

Right. You can't rely completely on this just yet. It's still just one tool in the toolbox, as the cliche goes. but it is becoming more important because there's more traits that are getting tested. So there's more DNA markers that scientists are looking at to help select for different types of traits that we don't look at right now that could help farmers be even more specific and precise with what they're looking to add to their herd. So I'm reminded of when we hear horses, you know, champion horses, they go out to stud, their bread because they run really fast. This is the next step, it sounds like.

You're not just looking at the total horse or the total cow or the beef cattle here. You're looking at a specific trait. I want a T-bone steak. I'm going to breed this for a T-bone steak. Exactly, exactly. You essentially are going to be able to choose what type of meat. I mean, I'm sure there'll be the all-around perfect general cow, if you will. But there will be ones that have specific traits that are better for a tri-tip versus a,

a rib eye, yeah. So this is a big business. I mean, there must be international interest in this. There is a lot. You know, we have developing economies in China and India, and with those growing middle classes, we have more people interested in buying beef. So a lot of interest is coming from overseas, and that's driving a lot of the uptake in beef across the world, and mostly with America genetics. So in 2017, I think it was $170 million worth of bull semen was actually sold, exported out of the U.S. That's triple in the past 20 years. So American genetics and beef, at least, is getting distributed all over the world. Well, speaking of butchering, forgive me for butchering your name, Christopher. Christopher Hustead is a Harvest Public Media

Reporter at KBIA in Columbia. Thanks for taking time to be with us today. We have a story about beef genetic testing on our website at Science Friday.com slash bulls. We're going to think about whales when we come back, so stay with us. This is Science Friday. I'm Ira Flato with the holiday weekend coming up. Maybe you're going to do a little whale

watching. Is that on your agenda? Because, you know, it's very exciting. People love to go watch for whales because they're majestic and awe-inspiring animals and some of the largest creatures on Earth, reaching up to 150 tons. Listen to this. They take

in a living room size volume of water in one gulp. They can dive thousands of feet into the ocean while holding their breath all the way down. But all of these details also make their existence improbable, according to my next guest, because whales, after all, are mammals like us, and they evolved from a four-legged dog-like animal that roamed around on the land. So how did all this happen? Nick Payanson chases the story of whale evolution in his new book. He's the author of spying on whales, the past, present and future of Earth's most awesome creatures, is also the curator of fossil marine mammals at the National Museum of Natural History in Washington, D.C. Welcome to Science Friday.

Hi, Ira. Happy to be here. Thank you. A great book. It's a terrific read. I learned so much from this book. You said that you've never had a, you've never been a whale hugger, so to speak, that whales aren't your destiny. How did you get in the world? involved in this? Yeah. So I think for a lot of people how they get interested in different kinds of science is a bit of a chronicle of happenstance and unique opportunities.

I was always interested in evolution and I was always attracted to fossils and certainly the big skeletons of dinosaurs that you see in museums. I just thought the material evidence for evolution was really compelling. And I had the right opportunities at the right time. especially in college, that exposed me to knowing a bit more about the fossil record of whales. And that got me really excited about knowing about evolution through this kind of vehicle, whales. And I just kind of kept with it. Was there like a Jurassic Park moment where you saw something?

He said, oh, I want to do that? You know, I think not for me at least. It was small moments. One was finding a dead dolphin on a beach once on a college ecology field trip. And watching it decay was actually fascinating for me. I mean, I didn't love it, but it was still, it made me start thinking about how the remains of organisms enter the fossil record. How do we get fossils in the first place? And then I was also fortunate to also get to do some real research on CT scans of fossil.

skulls belonging to whales to try to understand how their brains evolve through time. Whales being, of course, some of the more fascinating creatures to study in terms of their behavior, which is really sophisticated. Our number 844724-8255, if you'd like to talk about whales, and then there's a lot to talk about. 844724-8255, you can also tweet us at SciFri. You know, it's so fascinating the history of whales because as you write in your book, Whale started out, evolutionarily speaking,

it's sort of like big dogs on land, right? Right, right. How do they get from there to there? Right. So if we look at, let's just take DNAs. Assume we don't know anything about the fossil record, and we just try to figure out who are whales most related to among all the species of mammals on the planet,

if we go with our observations and recognize that whales are mammals in the first place. And I'd say that, you know, they're hardly like the mammals that we see on a daily basis. You have to watch them for more than a few minutes to recognize that they breathe there, that they nurse their young. And so once you realize that, then if you look at their DNA, they're most closely related to even-toed hoofed mammals. So cows, deer, pigs, camels, whales are really different from their nearest relatives. And what that tells us is that there had to have been a lot of evolutionary change in their history.

And that's the way that we know about that directly is through their early evolutionary history that's in the fossil record. So we're fortunate to actually have these fossils early on that show us how they transformed from land ancestry into something a bit more aquatic. And so did they start out with, you know, living by the shore and then their feet, legs changed because they were getting, you know, spending more and more time in the water? What happened? Right. So we see this in, if we look at the family tree of whales, and if we include all the fossil relatives, especially for the earliest whales. And these are, if you looked at these fossils, and you can actually go walk into the Smithsonian's Natural History Museum in the Saint Ocean Hall, we have this great exhibit of whale evolution. And you can see what some of these earliest whales look like. They have a pelvis that is tightly sutured to the backbone. They have weight-bearing limbs. They have a skull that looks more like, the skull of a land mammal than it does like any kind of whale that we see today. And through time, as we go up in the rock sequence, so getting younger in time, we're fortunate in having found fossils that show us the transformations that happen as we get

into whales that evolved more and more to life in the water than life on land. Now, why that is, there's potentially 18 different reasons why that could be. And some of them are testable, some of them aren't. The fossil record is really hard to bear on those why questions. But the how questions, that's something that we definitely know for the early evolutionary history of whales. Yeah, because what is the motivating factor? You know what drives somebody to leave the shore or an animal and, you know, take up residence in the ocean? There's a variety of reasons.

You might want to escape predators. Maybe there's more resources that you alone can, can, can, pursue in the water. And we also have to remember the setting, too, which is really important. At that time, and the earliest whales only come from a specific part of the world. This is what is now Indo-Pakistan, but 40 to 50 million years ago, over 50 million years ago, this part of the world was more like an island archipelago in an equatorial sea. So that's the kind of setting that we see the first, we imagine how the first earliest whales would have lived.

You're talking about a time right after the dinosaurs died out. Did that, was that a catalyst for them to evolve? Yeah, so the oldest whale on the planet that we know of is some 53 million years old. And that's over 10 million years after the end-Cretaceous mass extinction that wiped out all the dinosaurs that didn't evolve into birds. So there's roughly 10 million years when. In the oceans, there weren't the large marine predators that there were during the Cretaceous. So these marine reptiles like mosasors and ichthyosaurs and pleasosaurs, you would not have wanted to go on a scuba trip in the Cretaceous ocean. But, you know, so the seas were relatively empty.

There were a few sharks and sea turtles. So in some ways, yes, there was vacancy in the Eocene. oceans. You're right that whales did not undo 300 million years of terrestrial modifications. Instead, this story is far more interesting. Please explain what you meant by that. Right. So if we recognize that whales had terrestrial ancestry, so they had ancestors that once lived on land, adapting to life in the water isn't just about magically evolving gills. There's constraints in evolution, but there's also opportunities. So what we see from the fossil record tells us slowly,

episodically, these changes that happen in the skeletal system, and what we infer happens to, to their ecology, from changes to their sensory systems. What that shows us is how exactly limbs transform from weight-bearing structures into flippers. They start flattening out. They stop bearing weight. We see their tails,

become locomotion devices, being able to actually power their bodies through the water. And then the dramatic changes that happen to their skull. I don't know if you've ever seen the skull of a dolphin or a whale, but they look nothing like those of a land mammal. So we can read a lot of the story of evolution in their skeletons. And why are some whales so big? Boy, that's a great question. So with some colleagues, we tried to address this,

at least for one group of whales, the filter-feeding whales, baleen whales. They include some of the largest whales ever, blue whales, fin whales, bowhead whales, right whales. And that's kind of the first amazing point is that those are some of the largest, heaviest animals to have ever evolved in the history of life on Earth. There are no 200,000-pound dinosaurs in the fossil record. So we are living in an age of giants. That's the first peculiar fact. The second is it looks like when you start mapping these traits on an evolutionary tree of an. evolutionary family tree of these whales. We see them all get big at about the same time,

and that time frame is relatively recently in their entire geologic history. So in the last few million years, whales seem to get really, really big. When we see multiple things happening at once on different branches of the tree of life, that tells us about external factors. That's telling us something about how the world is is influencing their evolutionary history. And what my colleagues and I argued was that it probably has something to do with Ice Age seas, that changes in how productive Ice Age seas were from millions of years before it fueled a richness and abundance of patchy prey. So getting these kinds of aggregations of krill and fish, the kind that you see on natural history programs, or these big bait balls, fish swimming together in a tight school,

that's a relatively recent geologic phenomenon. And that's what led to the right kinds of setting the stage for whales to take advantage and move beyond just being very large to truly Titanic size classes. That's why we think at least the bailing whales got so big. There are, of course, other kinds of whales, sperm whales, killer whales. They each happen to be the largest members of their individual groups. So there's something a bit more complex about what's going on in the past few million years that still hasn't been resolved. On number 844-724-8255. We're talking about what we're going about. Wales with Nick Payinson, who is author of Spying on Wales.

It's a great book, Nick. It's a great read. Let's see if we go to Manhattan and go to Amy in New York, New York. Hi, Amy. Oh, hi. The audio dropped out for a few seconds there. Story of my life. Yeah.

I was wondering, well, two things. One is that I thought I had read, this is a long time ago, but that whales evolved from animal that were, from land mammals that were like cattle. And now, I think there are two different things. At one point, I heard that they came from common ancestors with dogs and another time with hippos. But I'm wondering if either was the cattle hypothesis proved, or are there close to relations between cattle and hippos, say, then? Okay.

Okay. And I knew. All right. Thanks for the call. Sure, Amy. So what I would say is that we can look at DNA. And if we just look at the DNA relationships of all these mammals that you mentioned, hippos are the closest living species of mammal to all whales.

And that's kind of a peculiar thing because hippos live a large part of their life underwater. We do have a fossil record for hippos. And they show us that they were probably living on land, much more so in the past. than they do today. But that still doesn't answer exactly who are they most closely related to. And especially that's true for paleontologists. So we've known about the DNA evidence for these relationships for many decades. But paleontologists know about the extinct branches on the tree of life much better than almost anybody else.

And so they recognize there's potentially a lot of other candidate relatives out there that are completely extinct. that look sure a lot like the earliest whale fossils. So this was a debate for many years was what piece of evidence do you believe? Do you look at the DNA evidence and say, well, that's what it's got to be? And they're not really mutually exclusive. And what it took was finding complete skeletons

of the earliest whales where ankle bones were preserved intact along with all the other bones in the skeleton so that you knew that the ankles belonged to this species of early whale. And once that was determined, those ankle bones look like they belong to no other group of mammals, aside from those of the even-toed-hoved mammals, to which hippos belong. So that evidence that was found almost 20 years ago now, 15, 20 years ago, from Indo-Pakistan for the earliest whales, shows us that all whales nest within the family tree of even-toed-hoffed mammals, which include cows and dears and pigs. So, Amy, I think you're kind of half right.

All right, we'll give her a batting average of 500. Talking to Nick Piant, an author of Spying on Whales on Science Friday from WNYC Studios. You say whales have a culture that's influenced their development. What do you mean by that? Well, if we have a broad definition of culture, I'm a paleontologist, so I get to paint it. at broad scales here. If culture is information that's transmitted between or among individuals or through the generations, but outside of the body, if it's some kind of song, for us, it's usually

written down or visual, but it can also be oral. If that information is transmitted outside the body through generations across individuals, through time and space, then it looks like a lot of other species on the planet have culture besides us. And there's a lot of studies out there for primates, for elephants, and also for cetaceans. And that's the really crazy thing, I think, is that you can look at the whale family tree. And there is great evidence for culture in baling whales, in toothed whales. So humpbacks seem to have songs that have been traded in a social network through time and across the ocean. sperm whales seem to have specific dialects that unite their family groups.

And certainly killer whales, too, in the Pacific Northwest, where they've been studied probably the best. It's clear that their individual calls create these boundaries among populations that are very, very restrictive. And those populations haven't interbred in over 100,000 years. So for killer whales, at least, it seems to be an example of speciation in. action before our eyes that's driven in large part by the cultural component. Killer whales could eat salmon or mammals or sharks, but there's specific groups. They're called ecotypes. So there's salmon eaters and marine mammal eaters and maybe shark eaters we don't really know for the offshore killer whales. But it seems that culture really restricts how they interact.

Well, that must mean. Culture implies that they're able to pass it on from one generation to the next. Absolutely. And this is something that can be documented if you look long enough over time. You can photo ID these animals from their dorsal fins, drop an acoustic probe in the ocean, and you can listen to their specific calls in acoustics, and record that. And that's something that can be identified and logged through time. So I think that, to me, that satisfies the criteria for culture. Wow. We're going to take a break and come back and talk lots more with Nick Pianton, author of Spying on Whales,

the Past President and Future of Earth's Most Awesome Creatures. You can read an excerpt from his book on our website at ScienceFriday.com slash whalebones. ScienceFriiday.com slash whale bones. More conversation and tweets. We'll take them after the break. People want to know what your most magical whale moment discovery in the field was. So think about that, and we'll talk to you about it after the break. Nick, stay with us.

We'll be right back. I'm Ira Plato. This is Science Friday. We've been talking with the paleontologist Nick Biance, and author of the new book Spying on Whales, if you'd like to call us, the number's 844-8255. We're going to be talking more about whales.

Let's go to the phones to Skyler in Fort Collins, Colorado. Hi, Skyler? Hi, there, go ahead. Hey, I'm wondering how the whales deal with salt in their system drinking only ocean water. Yeah. I'm a weird question, but... No, no, I actually think about that all the time,

and this is a good time. We'll see if we can get an answer. for you. Nick, they gulp in all the salt water. It would make me sick, wouldn't it? Yeah, I think the solution to that is they don't actually swallow that salt water. That would be a mistake. Now, they certainly get some amount of salt water into their bodies. And what we do know is they get most of their water from their diet. So from fish, from squid, from whatever they eat, they're somehow able to process that water,

which gives you a sense, you know, it's summer. You tend to be thirsty. Imagine if your only source of water was the food you ate. So what that tells us that they have to have certain physiological mechanisms to deal with that. And we can look at the shapes of their kidneys. They certainly have the same kinds of adaptations shape. It almost look like a cluster of grapes that's wrapped in a bag. That looks a lot like the kidneys from other marine mammals.

So it tells us these solutions for dealing with saltwater are held in common, but you'll notice I'm not really answering the question. because we quickly get to the limits of knowledge of how marine mammals are able to make their living. They're incredibly logistically challenging to study, whether they're whales or seals or sea lions. And we don't always get to see what they do for their entire lives because they live remotely. Whales live 99% of their lives underwater. And they're not really great experimental animals either. So, you know, we can infer some specific things about how they deal with that, but this is still part of the mysteries of these animals. I heard people who believe in the aquatic ape theory of people.

Humans went to the ocean and they came back. They say that we have tear ducts that are vestigial parts of when we were ocean mammals. And that whales and dolphins, they also have teard ducks. That's how they get rid of their water. Is that true? Well, so for any of these hypotheses about adaptations telling you how organisms are dealing with any kind of feature they have that's special or unique, you always have to frame that in their evolutionary history to understand exactly how they might have, exactly how that trait might have come about. So for humans, we'd want to look at their nearest relatives and see who among them have teardocks and who, don't and then start clicking through that part of their family tree to really determining what

our hypothesis should be about when that might have evolved and whether it truly is unique to humans. There are a lot of traits that are unique to humans, just as there are with whales. But what I would say is the aquatic ape hypothesis is too special of a hypothesis when we have other explanations that do just fine. Here's a tweet from Meg who says, what was your most magical? whale moment. Yeah, so I was thinking about this before the break. I've been really fortunate in being able to participate in field work all around the world, not just digging up fossil whales, but

going on tagging boats to tag with suction cup removable tags on living whales. And those are all amazing and tremendously exciting moments in my professional career, some of which I talk about in the book. But I'd say that the most special one was discovering the fossil whale graveyard in the Otacama of Chile, because that was a surprise, because we weren't planning on finding that. And how we dealt with that, I think, is a really instructive example of how science works. So we were in the Otocama of Chile doing field work looking for fossil whales and other sea animals that preserve the record of the Humboldt current over millions of years. We want to understand how the Humboldt current and its fauna had changed through time.

And I had a colleague who kept on telling me about this fossil site that had all these whale skeletons. And for a lot of reasons, I didn't believe them. And that was a mistake until one day when we rolled up to the site, which had been uncovered through road expansion right along the Pan American Highway. And I remember that moment when we rolled up and saw whale skeleton after whale skeleton under these blacked. tarps, and we just flip open a black tarp, and you'd see these complete whale skeletons, fossil whale skeletons, preserve nose to tip yards away, sometimes on top of one another. And so that was a little bit terrifying because I don't really wish a whale skeleton on anyone. They're enormous burdens in terms of the logistics of dealing with them, how you study them,

and there weren't just one or two. There were dozens, and we didn't have much time to come up with some kind of game plan. for how we were going to study them. And this is where the Smithsonian's 3D digitization lab came in and really provide a technological solution to a scientific need. Wow. Let's talk about the future a little bit. Sure.

With climate change, the oceans are evolving. They're changing in their chemical makeup, you know, getting more acidic, getting more currents are moving in places they haven't been before. How is that going to affect the whales? Right. So whales have been around for 50 million years. and they've been in the water for over 40 million of those years. So they've experienced a lot of changes in the past.

But what I think is different about what's happening now is that the Earth is changing in geologic scales and rates within human lifetimes. I think the best examples, the bellwether of the Arctic. Summer sea ice is at a low in the Arctic, and it's been at a low for the last decade on a decreasing trajectory. So if you extrapolate just on a linear basis, draw that line down. We're looking at no summer sea ice for most of the Arctic in about 15, 20

years, assuming there's no nonlinear response to that. And so what that means is the Arctic Ocean will become a true ocean. And probably for many kinds of whales, that means more productivity, more light, more food, but it also means more human activity. That means the Arctic will become a shipping lane. And we know that in urban areas along the coast of the United States, ship strike is a major source of mortality for many large species of whales that simply can't get out of the way of a cruise ship or a cargo ship. Equally, entanglement in fishing lines is another huge source of mortality, especially for North Atlantic right whales, which have not recovered from over 10 centuries, nearly 10 centuries, of whaling throughout the North Atlantic. So there's kind of this mixed bag of

a future for whales where there's both human activity and major changes to ecosystems, and it's complicated for whales that have the ability to move large distances and have a variety of prey that they can pursue, they probably are going to be adaptable, whereas the other species that are in marginal areas. So think about river dolphins. Some species of river dolphins are living right in rivers right along major urban areas. And so human modification, to their habitat is a big threat to their continued existence. And I'm thinking about the Ganges River Dolphin or the Yangtze River Dolphin, which is probably extinct. Fascinating stuff, Nick, thank you for taking time to have to write this book and being a guest on Science Friday.

Absolutely. Thanks much. Great read, Nick Pyerson. If you're looking for, you know, some summer reading, this is it. Nick Payanson, author of the new book Spying on Whales, the Past President and Future of Earth's Most Awesome Creatures. and we have an excerpt on our website up at ScienceFriday.com. Our celebration of Oceans Month comes to an end today, but you can still read about underwater subpilots, get your fill on corals and kelp.

It's all up at our website at sciencefrily.com slash whalebones. ScienceFriiday.com slash whale bones. Now, if you want to dial back on the way back machine, to this next one, I want you to think back to school, right? You're sitting in the sex ed class, health class, maybe for some of you, where movies like this one may have been the soundtrack. The spermatazor, shed by the male during mating, appear like tiny little fish, or shall we say, tadpoles.

Very active squirming fellows. Notice the large head, the lashing, whip-like tail, and the streamline effect in general. These organisms are built for speed. Yeah, I remember that one. And then the next lesson, chromosomes, right? Your X and your Y, the formation of an embryo. You got to terms like germ cells and gonads.

Well, well, it was that word gonads. And a researcher who referred to them as magical organs that sent a radio lab producer and host Molly Webster on a mission, a quest to re-spark our fascination with human development, X and Y embryos, and her new limited run series. It's out now. It's called Radio Lab Gonads. Welcome to Science Friday.

Good to talk to you again. Hey, Ira. How are you? You were once an intern on our show. You've gone so far. I was. I was, yes. I was thinking, oh, this is what it was like when I set up other guests.

You are now one of them. It's a life-imitating art. Let's talk about a few years back. You reported the story on the surrogacy, donated wounds and sperm, and that sort of ignited this curiosity for you? Yeah, it was a story. about a sort of international surrogacy, like how folks were trying to create families across borders. So it was a same-sex male couple got eggs and then got surrogate women in India who then moved to Nepal and created a family. And in the middle of reporting that story, I realized, wow, there is a lot going on with how we think about families and how we understand just simple questions like, what is a mother or who is a parent? Or, what is a sibling, it felt like there were a lot of like open-ended definitions all of a sudden, and science was changing so much at that time that it felt like an interesting world to stand in.

Yeah, well, let's talk about, speaking of interesting, the first episode of this series, you ask a bunch of people, do you do a bunch of people on the street, what does the word gonads mean to you? And all these people, we hear on this bit of tape say testicles, like gonads has become the slang term for men. And I want to play a clip of that vox pop because then you ask them this. Did you know that ladies actually have gonads also? That gonads are both testes and ovaries? Oh, really?

That it's actually for men and women. Really? I did not know that. I did not know that. Did not know that. 90% of the people I talked to didn't know that. They didn't know it. Who would have thought women and men both have gonads?

Culture, they've stolen the word and made it. And I think it's time we reclaim this word. Like, as a citizen, as a human, as a lady, as a science lover, I'm taking the word back. And that's what you did. Well, I'm trying to, Ira. So what does the term gonad then actually mean? Yeah, so gonad is actually a very serious science term that researchers don't giggle at when you talk to them about it. It means sort of two things in this interesting way.

One, it's just ovaries or testes, so men have them and women have them. They also use the term gonad when talking about very, very, very early in development before you have developed either ovary or testes when you're sort of like a bi-potential creature and gonads are just starting to develop. I'm Ira Flato. This is Science Friday from WN119. studios. Speaking of WNYC, we're talking about GONADS with Molly Webster, who is also a producer and host of Radio Lab. So your first, your adventure in this adventure, it's a great segment of Radio Lab,

but you talk about the journey of the gonads early on? Tell us about that. Yeah, yeah. So it's, the GONAD sort of develop in two parts. You have the actual, what I call like the house of GONAD, which is the testis or the ovary, and that is developing sort of in the center of the embryo. But then you have this other part that is the primordial germ cells, which are these cells that will ultimately become egg or sperm, right? They're the cells that are required for like the survival of the species. And those cells don't actually start in the embryo. They start out in what we call and what scientists have referred to as like the trash

fin of the embryo, which is sort of the place where the actual developing body of an embryo is then connected to the placenta and uterus. And so what ends up having to happen is those primordial germ cells need to get to their final resting place, right, which is going to be the organ. And so they go on this weeks-long sort of migration journey against all odds through an embryo that's trying to make them become liver cells and heart cells and lung cells and they try and like eyes on the prize get get to the gonad that's great and you have we're going to make a whole line of t-shirts i have a lot of gonad slogans at this point well maybe you can put the x's and y's on there too because i know you have a new episode coming out this weekend that questions the idea we were all

taught in school which is xx means girl and x y means boy yeah it's interesting and one of the things i found out about when I was looking into this is one, that is actually not right. I mean, there are many instances where X-X will lead to a boy and X-Y will lead to a female. And the reason behind that is because it's not so much chromosomes that give us biological sex, but genes. In fact, one very individual, important gene called S-R-Y that was discovered in the, like, 1989, 1990. And it is actually this gene that as it floats around and attaches to different chromosomes will drive production towards male. And if you don't have that gene, you will go generally down a female path. So the chromosome is sort of just like a boat for the gene to hide in or

be transported in. It's interesting. One of the things I found out is there's actually a lot of different genes that are involved in sex, and they're not all located on X's and Y's. They could be on making this number up, but like chromosome 17. It's spread out throughout your DNA. Wow. Okay. Well, I'm glad we wound up talking about sex on Friday afternoon. I know.

You've been waiting for years. It's good to have you back, Molly. Molly Webster is a producer and host of Radio Label and that episode will be this weekend? Coming up this week? Yes, yeah, yeah. We're hoping to get it out for folks on the Saturday. Okay, thank you for taking time to join us, Molly.

Good luck with the show. Yeah, thanks so much, Ira. One last thing before we go. Cy Fry is headed to Hawaii next week. We've got two great shows for you in Honolulu and on the Big Island, July 6th and 7th, talking about Hawaii's endangered species. What's like to live on a simulated Mars habitat,

a way to survey coral reefs from the air? so you can get your tickets and info at ScienceFriiday.com slash Hawaii. ScienceFriday.com slash Hawaii. We're going to be there July 6th and 7th. Charles Berkwist is our director, senior producer Christopher and Taliatta. Our producers are Alexa Lim, Christy Taylor, Katie Haller. Our intern is Lucy Wong, and we had technical engineering help from Rich Kim and Sarah Fishman. And, of course, we're active all week on Facebook, Twitter, Instagram, all the social media.

You can have your smart speaker even play Science Friday for you if you ask them to do it. So have a great and safe Fourth of July. I'm Ira Flato in New York.