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Sperm
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Sperm carry half the genes needed for human life. In this hour of Radiolab, some basic questions and profound thoughts about reproduction.
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Save $4 on GE LED 100 count string lights. Now just 5 DOL 98 Lowe's. We help you save valid through 12. 3. Selection varies by location. Select locations only while supplies last. See lowe's.com for more details. You're listening to Radiolab from Public Radio, WNYC and npr. Hello, hello, hello, Hello. Today, I want to start the show by telling you about a guy. Well, a very, very, very important man. Probably one of the most important guys in. In guydom. Yes. Okay, tell me the correct pronunciation on I'm not Dutch. Leo Kenhuken. The way that you should say it is something like Leeuwenhoek. And here, thankfully, to help with our pronunciation and to fill in the details, is Professor Matthew Cobb. I'm the program director for zoology at the University of Manchester, and I've written a book about this called generation the 17th century scientists who Un of Sex, Life and Growth. Okay, so Leeuwenhoek. Yeah, that's fine. Okay, so what did he do? He was a draper. A draper? Yeah. So he just sold cloth? Oh, he had no scientific training whatsoever. He was interested in microscopes. Why would a draper be interested in microscopes? It was his hobby. It's what he did. He made these microscopes and he was actually really good. That's right. Although you have to keep in mind that microscopes at that point in time, talking 1670s here is not exactly how we think of them now. Back then, they were just tiny balls of glass. And that's it. And science itself was just a wee little baby. You gotta just really put yourself back. Okay, There was Leeuwenhoek doing really well with these microscopes. And pretty soon scientists all over the place were asking him to look at stuff. For example, what's in blood or what's in sweat or what's in semen. Dun, dun, dun. This is where it does get rather sordid. Okay, so Jad, before you do that, this is a point where we should tell our audience that some of the references from here on in will be a bit graphic. If you don't want to hear that kind of stuff. No, if you don't want to hear that stuff, now go out to the garden and, you know, check out the rabbits. Okay, now getting back to the story. It's 1667, just imagine, and Leeuwenhoek has just received a letter from the Royal Society of London, this big group of scientists asking him to take a look at, at a drop of human semen, just to see what's in there. And not to be graphic, but one Autumn Day, autumn 1677, he is in his bedroom having conjugal relations with his wife Cornelia. He's got his microscope ready, plus a little vial. And then as he put it within six beats of the pulse, after he ejaculated, he'd got the semen and he put it into this very thin capillary tube, rushed over to the window. His wife's lying there thinking, what the hell are you doing? Not again. Come on, will you? Enough with the microscopes already. And then he looks into the semen and he can clearly see that there's a thing, there's something in there, some kind of small structure. He squints and he focuses and he can see all these wriggling things. It is just full, absolutely full of these tiny eel like things. He says a vast number of living animalcules. Animalcules. Their bodies were rounded and furnished with a long, thin tail. They moved with a snake like motion of the tail, as eels do when swimming in water. Whoa. So what was he thinking at this point? Do we know? I don't know. Putting myself in his place, I think, wow. Cause here's the thing, at this point in time, people didn't really understand where babies came from. They knew it had something to do with sex. But the notion of heredity was still very fuzzy. And how a baby developed was a total mystery. What's life? How would you know if something's alive? In those days, one of the main things that they associated with life was movement. If stuff moved, it was alive. So if movement is the key, you can imagine what Leeuwenhoek must have been thinking, staring at these wriggling little beasts in the vial. Because they moved. That's right. Oh, boy, did they move. These things are trying to get somewhere. They're thrashing, they're desperate. Maybe in this vial is the secret to life, to the soul. This is what people thought. It didn't take long before a pretty fantastic idea began to circulate, which is that not only is the sperm the vehicle of the soul, but if you could somehow zoom all the way down into its little head, you would find in there a little man. Hello, Hello. This little chap all hunched up, a little tiny guy, tiny human, thinking was that one day when the microscopes got better, you'd actually be able to see that tiny little human with your own eyes. Because it had to be there. Because if the sperm was the sole source of life, then there must be something in there that looked pretty much like a human being. One problem, though. What if you were one of these folks who believed that the sperm was the soul? Well, then you had to ask yourself, what does this say about God? Because it would mean he was creating all these souls and then he was just wasting them. Leeuwenhoek did a calculation. He worked out that there were more semen, more spermatozoa in an ejaculate of a cod. He got a cod and he opened it up and saw how many sperm there must be in its ejaculate. And he said he was pretty much right. There are more sperm in this ejaculate than there are human beings alive on the planet. And that's just in one cod. We what? That's true. Yeah. Holy moly. So you imagine all the men producing all this stuff all the time. That's an awful lot of souls if they're all potential human beings just dying. Well, all but one. How many sperm are in a human ejaculate? About 180 million. Oh, see, that's nothing these days. Yeah, it's like Brooklyn. You just live there. All right, this is Radiolab. I'm Chad Abumra. I'm Robert Krulwich. And our program today is about. By the way, 180 million is still a lot. It's not a lot considering that you only have a couple of egg. Eggs. Who has a cup. Eggs? I don't know. The lady has a couple of eggs. She's got a finite number, whereas the guy is making millions Every day. Oh, right. Well, that's right. Anyhow, our program today is about sperm. Yep. Stick around. Okay, in all seriousness, before we get started for real, just want to tell you that the CIS program does actually contain strong sexual material. Nothing too graphic. But this is your warning. Stick around. It'll be great. Okay, for those of us who remain, let's get back to our basic question, the why so many? Question. Yes. Why is there such a startling asymmetry between the number of sexual cells produced by a male and the very relatively few eggs in the female? Well, of course, this is the question. I put the question to. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Another. There's a lot of English people in this show today. I'm Tim Burkhead. I work at the University of Sheffield in the department of Animal and Plant sciences and he is an on sperm in birds. How did you choose this line of work? Ever since I was a teenager, I was obsessed by birds. I was also obsessed by sex and I managed to combine the two into an academic career. Isn't that lucky? In any case, he says, this question of waste. Why on earth did God make so many sperm? It just didn't seem very sensible. Well, this question not only troubled the church, it felt flummoxed Science. Flummoxed is, I think, the right word, flummoxed scientists for a very long time. It really wasn't until about the 1970s that finally the large numbers of sperm that males transfer to females finally began to make sense. What happened in the 1970s? Well before the 1970s, bird scientists assumed that if a female chose a spouse for the season, she would stick to the spouse for the season, she would be faithful. But in the 70s, when they looked a little more closely, they found there was. Well, more to this story. Springtime in Somerset. The female bushy tailed whippoorwirl is always present in woods like this, always searching for that springtime joy of love. Her love song is very beautiful, as is his. Here he comes. And there is the act of love consummated rather quickly. And now he's off to get his new sweetheart, Juicy worm. She's alone for a time and she. Well, actually she's hopping off to to another branch where there seems to be another male. She of course, will remain loyal to this first partner. Copper tape. Prior to the 1970s, if people saw females behaving promiscuously, they assumed that there was something wrong with them. What is wrong with this bird? Do you have another bird? Hey Lance, have you got another Bird hormone imbalances or some kind of misunderstanding. But then they discovered DNA fingerprinting, the DNA test, which provided a completely unequivocal test of paternity. They'd go to a nest, say, and look at the five eggs in the nest, test the DNA and discover that some of those eggs came from different dads, indicating that the female had mated with more than one male. One of these four men is the father, but she doesn't know which one. DNA fingerprinting gave us the evidence that, in fact, the majority of animals, the females, are promiscuous. Really? I mean, this is like chimp babies, chickadee babies, chipmunk babies. It's almost ubiquitous. Let's find out the truth. You are not the father. At the moment, I'm only talking about non humans. Right, but what does this female promiscuity thing have to do with the. Why so much sperm? Catch everything. Everything. Because once people understood that that was going on, well, then the level of competition between males gets actually much more complicated. What do you mean? Well, if I am chasing a lady now, not only do I have to worry about a competitor, but I have to worry about all the people I've never met who have been having sex with my girl. There's a whole level of. Oh, you mean like the sperm is competing? The sperm is competing. Not just the makers of the sperm, but the sperm itself. The sperm itself. So there's outdoor competition, but now there's indoor competition. Exactly, if you get my drift. And one very effective way of competing is simply to produce more sperm than the next guy. Okay, I think we need to step back a little bit. If females are promiscuous, natural selection is going to favor the male that wins and fertilizes that particular female's eggs. As a consequence of that, males have evolved the most staggering array of adaptations to minimize their own chances of being cuckolded. What does cuckolded mean? Cuckolding means your wife is cheating on you and you don't know it. Oh. So what he's saying is that animals will go to elaborate lengths to be not cheated on. In fact, let me give you three spectacular illustrations as never before heard on our program. We're going to begin, which includes most things with sperm competition as displayed by first, the rolled beetle. These beetles are amazing. When the male beetle, the male rove beetle, has sex with a female, says Tim, they transfer the sperm in basically a package of sperm called a spermatophore. Once it's inside the female, it starts to swell, expand Like a balloon. Yeah. In swelling and expanding, it pushes out or away any rival sperm. Hey, hey, hey. But the sperm is stuck in a balloon. It's gotta get out. Oh, yes, well, but the lady rove beetle has a little structure, a structure like a tooth that will puncture the spermatophore, releasing the male's sperm. No kidding? Yeah. It's kind of like science fiction. But if you think the rove beetle has got something going on, let's meet the dragonfly. In dragonflies, males have the most elaborate and bizarre penis. It's covered with backward pointing spines, hundreds of backward pointing spines. Kind of like, you know, bristles on a pipe cleaner. And a very clever guy called Jeff Wagy did a very clever experiment. He allowed male dragonflies to mate with females and separated them at different stages during their rather process, protracted copulation. And what he found was halfway through the copulation, the male, before he actually does the act, is actually removing his penis from the female. And it's covered with sperm from the previous male that inseminated that female. Oh, so he's brushing out the other guys. Exactly. That's rather shocking. Yep. But better still, better still is the duck. The duck? The duck. Most birds don't have a penis. Male birds. Ducks do. That's it. No, it goes on across different duck species. The penis size varies from very small to about 14 inches. Something absolutely astronomical on a relatively small duck. And the thing about the duck is. I don't quite know how to put this. Ducks engage in forced extra pair copulations. What he's really saying is that the males are. They're raping the females. Oof. But wait, because the females have a strategy of their own. A couple of years ago, we were dissecting a female duck and a postdoc called Patty Brennan called me into the lab and she said, look at this. I've just found this funny structure in the female's vagina. And what it was was a side branch, meaning instead of one clear highway right to the egg, this one had a kind of off ramp. Off ramp? Yeah. I phoned a colleague in France who was a duck expert and he said he'd never seen such a thing, but give him and he'll go and check. So he obviously went off and dissected his own duck. Phoned me back and said, my God, you're right there. It was an off ramp in the French duck. By which time we'd finished our dissection. And in fact, when the British took a look at their duck in the duck that we looked at, there were two or three separate side branches. Patty then went on to do a comparative study of a lot of different duck species. And what we found was that in species where the male had an enormous phallus, the female had the most enormous complex vagina we'd ever come across. Some had two or three side branches and a very long spiral like a corkscrew at the end of the vagina. If you think about it, what seems very likely here is that the female has got these structures to deflect the male. If she's being raped, she might contract part of her reproductive tract to send the male off down a blind alley. If he avoids that, she can just tighten up this spiral so his sperm can't get to the right place. So what you've got here is a kind of warfare. The male says, all right, I'm coming in there, like it or not. And then the female as well. You're getting nowhere. Like it or not. Go. Female ducks, remarkable case of females evolving counter adaptations to keep males at arm's length. Or penis length, so to speak. So this is Maverick and Buckles. They are African geese. The British male scientist section of our program is coming briefly to a pause so we can meet an American and a female. My name is Joanna Ellington. Joanna ellington. I'm a PhD in reproductive physiology. We spoke with her at her farm in. Yes, Washington state. So we have 70 acres here. And I was a veterinarian before I did my PhD. You are an andrologist? Yes, an andrologist. The study of male reproduction. Andro for man. And ology is study of. Yes. Where are the pigs? They're. Right. The pigs are over here sleeping. They're going to be bred today. We actually have semen flying in from the bathroom. And we're gonna go down here to the chicken coop. And while she's walking to the chicken coop, let me just say we finally come to a human sperm expert to ask about us. Yeah. And I mean, this competition thing, does it work like that with us? Ginger. Ginger. No bark. Well, that's the real surprise to me. I mean, we've all seen the sex education films. You know, when you're in fourth or fifth grade, the woman's own defense system attacks the sperm. They are unwelcome cells from another organism, and they are potential enemies. But when Joanna gave me her version of all this, it was not like that at all. Let me start from the beginning. First, the sperm have to get through the cervix. The woman's cervical mucus Has a lot of fibers in it that are crisscrossed. So you'd think there'd be this big mesh barrier they couldn't get through. The barriers are new, humorous. But when the woman ovulates, the hormones in her body make all those fibers in the cervical mucus line up. Oh. And they basically make a little highway that the sperm can swim through. Zip, zip, zip. Not only is she welcoming them in, she's making sure later that they don't get a lot. They're directed to the side that has the egg on it. Oh. Because there's some tubes with eggs and some tubes without. Wait, one. One fallopian tube leads to the waiting egg, the other to an empty tube, except for the woman's body. Says, over here, guys, this site. And most surprising of all is that halfway through the journey, there's a rest period in what's called the fallopian tube. The fallopian tube says, oh, great, we know that you guys are here. We know that you're pretty fragile, guys. So we're gonna change the type of sugar proteins that we make. We're gonna make sugar proteins that you're bathed in, and you just hang out here until an egg comes. Oh, so we're now in the waiting room. Yes. And we're being sugared. Yes. This sounds nice. It is nice. Sounds like a little Roman moment. Everybody's lying down and kind of getting a towel wash or something. They're very quiet at that point. Metabolically, they're quiet. The female is essentially telling them, shh. Wait, not yet. Not yet. They can live in the fallopian tube for two, three, four days, maybe even a week. A week? No kidding. Until her egg is ready. That's when she says, hey, we just ovulated. You need to let the guys go. And the sperm are released and start swimming up the track. They swim in dense bunches to meet the egg in search of the egg and the rest of it, of course, you know, never heard about the sugar room before. I mean, that seems like news. You had the fallopian tomb. Yeah, neither had I. This had been discussed by scientists, but there was no evidence to prove that it was, so. But Joanna, as a good scientist, she was the first to provide the evidence. You said, after I had my last son, I told my doctor, I said, my husband and I are going to have intercourse. You are going to do my tubal ligation and cut out my tube. And we're going to get pictures of the sperm stored in the human fallopian tube. So we Did. So you counted your husband's guys? Yes. At the gate? Yeah, there weren't very many there, just a few. How many were there? He had about 20 in the fallopian tube that we looked at. Oh, man, that seems like a fragilely low number. Well, it is, but you have to remember that you only need one. Wow, that blows my mind. I mean, that's like 20 little potential souls lost at the gate. The cool thing is that, yes, there is this level of competition still, but underneath there is this substrate of male female cooperation. It's much more an act of teamwork than one would have supposed. Hazel's sperm just arrived. Thought I'd let you guys know. Come on, girls. Yeah, they're gonna get pregnant. Hazel. Who's Hazel? Actually, that's her pet, Hazel. Is it a big box or what is it? It's a white Styrofoam cooler. Go ahead and scratch Hazel's back, Seij. We'll end up putting probably about a half a cup into Hazel. Wow. How long did it take Mr. Pig to make a half a cup? Pigs make a lot of sperm, Robert. We gotta leave the farm. No, come on, come on. We gotta go to grave. Sorry. So you're missing some stuff about the pig. Radiolab will continue in a moment. Message 1. Radiolab is funded in part by the Alfred P. Sloan foundation, the Corporation for Public Broadcast and the National Science Foundation. Radiolab is produced by WNYC and distributed by National Public Radio. End of message. My friend just got married and is thinking about starting a family. But her doctor never mentioned checking her hormones and her cycles are super irregular. It's Black Friday, so I told her to grab Mira, the baby making machine at the lowest price of 2025. She could never confirm ovulation on her period app, but Mira did it in 16 minutes, tracking four hormones like a lab and pinpointing her full fertile window so she can conceive much faster. Get 30% off Miro for Black Friday at mirrorcare.com it's never too early for Lowe's Black Friday deals. Snag some of our biggest savings of the season right now. Like 25% off. Select Pre lit artificial Christmas trees and get yourself free. Select Dewalt cobalt or Craftsman tools when you buy a spot select battery or combo kit before the Black Friday rush. Because everyone loves free stuff, right? Lowe's. We help you save valid through 123 while supplies last. Selection varies by location. The headlines never stop and it's harder than ever to tell what's real, what matters and what's just noise. That's where Pod Save America comes in. I'm Tommy Vitor, and every week I'm joined by fellow former Obama aides John Favreau, John Lovett, and Dan Pfeiffer to break down the biggest stories, unpack what they mean for the future of our democracy, and add just enough humor to stay sane. Along the way, you'll also hear honest, in depth conversations with big voices in politics, media and culture like Rachel Maddow, Gavin Newsom, and Mark Cuban that you won't find anywhere else. New episodes drop every Tuesday and Friday with deep dives every other weekend. Listen wherever you get your podcasts, watch on YouTube or subscribe on Apple Podcasts for ad free episodes. Hello, I'm Jad Abumrad. I'm Robert Krulwich. This is Radiolab. Our topic today is sperm. Actually, that's right. And what is a sperm if not one teeny, tiny little dad? Oh, it's much more than that. It's the soul. It's everything. Well, we're gonna just leave you in the garage and turn to Kathleen LaBounte, who a few years ago sat down to try to draw a picture of her dad. And this is the picture that I drew a picture of a sperm. It wasn't very impressive. It was like a cartoon sperm with blue eyes and brown hair and a little bit of a mustache. And then I had a really big question mark behind the sperm, and that was to represent the fact that I don't know this man's identity. This might sound like your typical man, Magic Marker paints a sperm donor story, but it's really not. And here to tell us about it is reporter Ari Daniel Shapiro. Should I just kind of take it from the top? Yeah. Okay. Kathleen lives in Houston, and when she was 8, her mom began telling her rather repeatedly, kathleen, there's something special about you. And I really wasn't that curious. But she kept saying it so many times that eventually I just said, okay, what is it that makes me different? So she took me upstairs, sat me on my bed, and she just said that the man who raised you is not your biological father. We had to go to his sperm bank and that a very nice man gave us his sperm so that you could be born. And then she said that I could still consider my dad to be my father, even though he wasn't my biological father. Right afterwards, I just ran downstairs and I threw my arms around my dad's neck and he was on the computer and I just told him that I left him and he didn't know that I had just been told that I wasn't his biological daughter. So she just took it in, and it was a source of joy for her. Initially. It felt kind of magical. It felt magical? Yeah. It was just unique. Yeah. It didn't completely sink in at first. Things started to change as she got older. She just became aware of all these things that were different between me and my family. Okay. So I've got the picture out of me and my cousins. So in family photos, I kind of don't blend in. The obvious thing is my height. I'm 5:2, and all of my cousins are between 5:10 and 6:5. Wow. So that's like a foot taller. Right. So that was one thing. And then there were lots of other things. Like she had blue eyes, whereas the rest of her family had mainly brown. And she had these drawing abilities. My mom, she can barely draw a stick. Figures. She's a vegetarian, the only one in my family. And so I was kind of wondering if that desire to take care of anything living maybe came from him. I just became more curious about how this man contributed to who I am. What did you know about him? The only information that I got is that he attended Baylor College of Medicine. Baylor is where? Texas, in 1981 when I was conceived. But I don't know if he was a first year, second, third or fourth year student. And that's it, Correct? That was. That's not very much. Yeah. So when she was a teenager, she contacted the clinic trying to request medical records, and I was told that they were destroyed years ago. Hmm. I felt like I had lost part of me. So can she solve this in any way? What is she gonna do? Well, one night when she was in college, and this was a few years later, her mom just happened to be watching TV. Every year, 30,000 children are born in this country to mothers who have been artificially inseminated with sperm from an anonymous donor. And she saw a special about the donor sibling registry called the donorsiblingregistry.com. oh, it's a website. It's a website to try to help donors and donor offspring and half siblings find each other. CBS News, 60 Minutes. So after my mother saw this show, I decided to register. So she logged on Press Clinic, and she put into the search engine Baylor College, Baylor College of Medicine. And there was actually a girl around my age, a young woman named Jessica, which means they could be sisters. So she and I got in touch and started to talk. Right away, they noticed that they had a lot of Things in common. We both had polycystic ovarian syndrome, which is a genetic syndrome that you would inherit. And we were on the exact same medication and the same dosage. And that seemed like more than a coincidence. Just kind of sparked our curiosity. And so they decided that they would meet up. She came and spent a weekend with me. By the time she left, we had come up with a list of a hundred similarities. A hundred on our list. We have that. We can't roll our tongues. Both born in 1982. We both have curly hair. We both had high cholesterol. We don't have any sense of direction. Oh, I know what this is. This is what you do when you want something to be true. We both had butterfly tattoos. Absolutely. We have the same taste in music. When you, I think, want to believe. We were both very thoughtful. All these things that would otherwise, I think, maybe escape detection. We thought that our handwriting was pretty similar. All of a sudden become really important. It just goes on and on. So they decide to have a DNA test and. And the results come back. They called her, and then she called me. I mean, you can hear people's disappointment and sadness. So I knew before she said anything. I think it was a.001% probability that we were sisters. Just like that, this possibility was gone. I began to feel loss and grief. Like, I look in the mirror and I see a stranger looking back at me. Okay, so fast forward now a couple of years. She goes to a library. A library in the medical. She walks over to the stacks, pulls out the old Baylor yearbooks. The old Baylor what? Yearbooks. She figured as long as he showed up to get his picture taken on picture day, he'd be in one of those books. Exactly. So I took them off the shelf and I photocopied every page in those yearbooks. The 1979, 1980, 81, 82, 83, and 84 yearbooks. And she took him home. I was expecting just to flip through it and not see any similarities with any of the men, and then get to one picture and think, okay, this is the man. But that's definitely not what happened. Instead, I realized that I looked like dozens, if not hundreds of the men. Let's see. And I would think that I had one man's nose and this guy, another man's eyes. Here's another one. Another man's chin. Even this guy. I mean, I think it's possible because of the rounded eyebrows and bigger eyes. I just got overwhelmed. So she decided to enlist some help. Right? So I had my mom and three of my closest friends take sticky tabs and flip through the photos of all of the men. He has blue eyes. They might say, well, you kind of look like this man, or you kind of look like this other man. Our smiles are similar. And then they would mark the men who they thought resembled me the most. She then decided she would draft a letter. A letter. Dear Dr. It is after much thought that I am contacting you. I was thinking, well, I'll write the men who were consistently picked out. I was conceived May 4, 1981, by an anonymous sperm donation through a Baylor College medicine student. I tried to think, okay, if I were a donor, what would my concerns be? I want to assure you that I am emotionally stable and financially secure. I provide additional reassurance to donors. I have been using a non legally binding DNA test that cannot be used in court. And then I just explained, in many ways, I tried to give an overview of who I am. I have large, almost navy blue eyes. I barely reach five' two. Both my mother and I have a positive blood. I am attaching my photographs to see if you recognize my face. And then I just said, thank you for your time. Sincerely, Kathleen. And so she actually sends it out. The letter? Yeah. A round of 25 letters to the men that looked most like her. Another round of 50. My biggest fear was that my letters would not be acknowledged. I had been told for so long that my donor wouldn't want to know about me. He wouldn't care that I exist. And I thought if I sent out 25 letters, maybe one would take the time to respond to me. Did she get anything back? She did. What did they say? Well, I mean, some of them were what you might expect. Wow. Your letter was unexpected. Dear Kathleen, take me off your mailing list and do not ever contact me again. I remember just before my shift started, it was at 10:30am I rummaged through the mailbox and saw a letter that was addressed to myself, Dr. Daniel Zak. I live just outside Seattle, and I remember practicing emergency medicine. Opening the letter and the first sentence or two, I thought, uh, oh, oh, see, here's one that's handwritten. I was assured that it would be anonymous and that there would be no way for anyone to track me down even if they wanted to. Though your motivations may be innocent, please consider the ramifications for others by the knowledge you seek. I felt that I would never be contacted. But then there were others, like this guy. I think I called her right away. I'm Merriman Baker. I'M an orthopedic surgeon who lives in the Houston area. And I said, well, I was a donor, I think 25 years ago and I never thought this day would come. What does that mean? I wrote this one line down that he said. He said, that's how really good things happen. Usually the way really good things happen, they come out of the blue. I'm 51 now and I don't have any kids. Not having kids would be the last thing I would have guessed 35 or 40 years ago from my own perspective. But I've always been very work oriented. All of a sudden you kind of look up and a few years have passed by and you don't have any kids yet. So the prospect of having a daughter out there somewhere that I didn't know about was, quite frankly, kind of a rush. He called me and we just talked about our interests and our personality and we started finding similarities. Her mother had requested a blue eyed donor, which I am. She has a positive blood which would be compatible with mine. It gets even more eerie, the fact that we both studied psychology, my major in college, and our cumulative grade point average was identical. She certainly could be my daughter on many fronts. I spoke with my mother at length. She was extraordinarily excited at the prospect of having a grandchild and she prepared a place for her at Christmas dinner with her name on it. Wow. Did they get the DNA test? Not exactly. They just kept waiting. Probably subconsciously. I almost didn't really want to know. Right. You know, let's just not even open up the results of the test. Let's just assume that we're, it's a match. We get along so well, why does it matter? But at the same time, we both knew that we needed to know the truth. In the end, they finally went through with it. I mean, it was kind of a running lottery about, you know, what do you think? And I was pretty impressed at the fact that it was probably going to be positive. The results come back from the lab and it, this is what a DNA test looks like. Yellow is basic information. It has this information about this and that. In terms of the DNA, I have no idea what, blue, green, gray, pink. Then at the bottom it's, you know, kind of yes or no. The probability equals zero percent. It was like zero percent chance that it was positive. He wrote me and he said, I'm heartbroken, I'm so sorry, this was negative. And, and I think it took him about three or four weeks before he felt up to speaking to me again. Yes, you Know, I mean, I've always thought I'd be a good dad. And, you know, I guess it was kind of like, it would have been kind of nice to have a child out there who's well adjusted, intelligent person, you know, it's kind of all the things you'd want your kid to be. And that's what all of this made me stop my search. So did she stop then for the. She does exactly the opposite. I wrote every single male who went to Baylor from 79 to 84. Which is how many males? 600. Yeah. Out of those 600, 250 responded. Wow. Wow. Half of them fight her back. Yeah. That's so weird. Exactly. That was exactly my reaction. Weirder still, not only did they respond, but they were very supportive. Dear Ms. Leboune, you are clearly someone who thinks and feels deeply. That makes you special. One guy sent me a Christmas card. You sound and look like a remarkable young woman. This one says, I would claim you in a second. I'm trying to read his handwriting. Doctor's handwriting. Dear Kathleen, I've waited 26 years to receive a letter like this. And this is a man who's actually a friend of mine. Now I've met him, and I've met his wife. This one's really sweet, too. Well, wait a minute. What about that guy? At the beginning, the guy went, uh. Oh, Dr. Dan Zak. Yeah, him. Even he came around. As time has progressed since I initially read the letter. Now I'm almost sorry that she's not my biologic daughter. That would have been kind of fun. And of all those, has anyone else agreed to do a paternity test? All told, she's had 16 DNA tests. Have they all turned out negative? Every. Every test came back as negative. But I still feel like I probably have the answer in front of me. I just don't know which page is his. Just. Just real question, so I realize it's 12 now. The. The song. I don't know if you. Yes. I mean, yes. I was just thinking about that, too. Go ahead and play some of it. Okay. I just need to get a little. Whenever I've heard somewhere out there, ever since I was a kid, it would remind me of my biological father. That he's out there. When I was a kid, sometimes I'd look up at the sky and I would think that I literally know nothing about my father except that we were both looking at the exact same sky. Yeah, this is as far as I got. What do you mean, that's as far as you got? I Never learned the ending. I'm still working on it. That's a story from Ari, Daniel Shapiro and Lulu Miller, our producer. Time for a break. Radiolab will continue in a moment. This is Adrian Stein from New Brunswick, New Jersey. Radiolab is supported in part by the National Science foundation and by the Alfred P. Sloan Foundation. Enhancing public understanding of science and technology in the modern world. More information about Sloan@www.sloan.org. my friend just got married and is thinking about starting a family. But her doctor never mentioned checking her hormones and her cycles are super irregular. It's Black Friday, so I told her to grab Mira, the baby making machine at the lowest price of 2025. She could never confirm ovulation on her, but Mira did it in 16 minutes, tracking four hormones like a lab and pinpointing her full fertile window so she can conceive much faster. Get 30% off Mira for Black Friday at miracare.com@ lowe's. Before the holidays is the perfect time for upgrades and upkeep. During Black Friday, get up to 50% off, select major appliances and buy more to save more with up to an additional 25% off when you bundle select major appliances plus grab select Dewalt 20 volt max drill or impact driver kits for just $99 Lowes we help you save. Valid through 12 3. Selection varies by location while supplies last. See Lowes.com for more details. Hello, I'm Jad Abumrad. And I'm Robert Krilwit. This is Radiolab. Our topic today is sperm. Yeah. A little wiggly cell that along with male pattern baldness, seems to describe everything you need to know about being a male. Speaking of which, let's ask now one of the bigger questions that you can ask in a show about sperm, which is why are there sperm? Why are there men? What? Why are there men? This is a real question, a biological question, which is completely baffling, that is. Steve Jones. Hi. Hello. I'm professor of genetics at University College London. He wrote a book called the Descent of Man where he speculates about how we men got our start and why we've managed to stick around so long. That's the real question. Here's his theory. Well, let's imagine ourselves in the primeval soup. Okay. 3,000 million years ago was actually minestrone because it was lumpy by then and the lumps were cells. Hello. And to reproduce these cells, what they'd have to do is gather up their energy and all on their own, split in half. Hello. Hello. Made copies of of themselves, which Are more or less identical most of the time. The normal flow of events as these cells are coming and cupping. Every so often, there would be a copying error. Hello. A mutation. These were happening all the time. Hello, hello, hello. Hello. Hello. Most were harmless. Hello. But let's imagine that one of these mutations caused the cell that received it to behave in a different way. This new cell. How you doing? Through the randomness of nature, it had acquired a talent. Instead of dividing on its own, it figured out that it could save some energy if it could swim up to another cell. Hello. How you doing? Burrow its way in and force that second cell to divide. How you doing? By so doing, not only was it avoiding a lot of work, it was copying its own genes. And at that moment, males were born. Howdy, howdy. Do it. Howdy. Do it. Howdy, howdy, howdy, howdy. Do it. That's what you're saying is that guys are essentially moochers, like they. Well, that's how we got our start. According to this theory, males began with selfishness. These little cells began to mooch off a other cells. Then they figured out, you know, over time, they could mooch better if they got smaller, as small and faster and as mobile as they possibly can, because then they can fuse with more and more of the other kind of cells and persuade them to divide. So now, if you want a definition that encompasses all males everywhere from oak trees to elephants to humans, to fish, there's only one real universal definition of what it means to be male. It's the sex that makes small sex cells, and often lots of them. That's it. We make the small sex cells. That really is the mark of the male having a tiny sex cell, meaning you, me, Steve, at the core of it, our maleness is defined by these little tiny swimming packets of genes, what we now call sperm. But you know, you know what I don't understand? If all males are. Are parasites. Yeah, yeah. Why would the female cells allow us to do that? Why don't they just say, go away? And that's a. A big question. Because there are some species that have dispensed with males altogether. Really? Yes. The one that comes to mind is a Californian lizard, which is quite common. It's called the whiptail lizard, and they live in the Mojave desert and they're all female. As far as we can see, there have been no males around for a long, long time. It's kind of strange because they actually court each other, and one female gets on top of the other and tries to mate with it. So there's some kind of remnant of male behavior there. But they're all female. But how is it it that they make little lizards? They just produce eggs which develop into lizards? Oh, they just don't bother with males. So the baby is identical to the mommy. So we're talking about cloning here? Yeah, plenty of birds can do that. I mean chickens often lay eggs which develop and haven't been fertilized. Frogs, he says there's some frogs that can do it too. But here's the thing. Even though making babies without men is, according to some scientists, the most efficient way to do it to reproduce, it's still pretty rare. There are very few land vertebrates which are all female. Which brings us back to your question. Why? Why do females not make huge efforts to escape from it? That's what I want to know. Why are we here? Why have males hung around this long? I mean, we shouldn't be doing this program. Somebody named Alice and someone named Laura should be here. Hi, I'm Alice Abumra. And I'm Laura Krelwich. And this is Ray. Hey, not so fast ladies. Wait, we're still here. Now as for why we're still here, eh, there are tons of theories. Steve's best guess is that, you know what? We're not just parasites. We do offer the ladies one thing in return. Like what? Well, Lulu going back to the soupy days at the beginning. Just imagine, says Steve, what if that soupy sea is changing? The water's getting warmer and the water's getting saltier. So let's say on one side of the there's a cell that mutates and suddenly it can handle warm water. On the other side there's a cell that mutates and suddenly it can handle salt. If this is an all female world, the wormies would copy themselves, the salties would copy themselves and every new member of both of these tribes would dive because the water's both warm and salty. Because they couldn't combine their talents. But if one of the say, salty cells is a male, how are you doing? Well, that male can swim up to a wormycell, do his mailing invader thing and in the next generation, anti warm and anti salt can get together. So that's what males do. They bring female lines together and allow them to mix their genes. And that may be, that may be so important, says Steve, that the only time you can do without males is if your world is static. Wait, what about the lizards? Yeah, well that's the interesting Question. And I think the answer is maybe. And we're kind of guesswork here. They live out in the desert. The desert doesn't change very much. Their enemy is always the same, which is heat, shortage of food. Their enemy isn't something like disease or parasites which are constantly evolving themselves. So they can afford to get one set of genes which are very effective, clone themselves by not having sex, whereas other creatures can't. Does that mean you think that if our world were like that, that if we'd somehow perfected it, that we wouldn't need men? That's arguably true. Um, and. Oh, God, there's somebody buzzing on the doorbell now. That's now stopped. Hang on. We got another bloody nuclear explosion going on outside here. Jesus Christ. This normally quiets the grave in here. Okay, right. True, if we lived in an unchanging world, maybe we wouldn't need men. But we don't live in a world that doesn't change. Look at the AIDS virus. Look at bird flu. They're out there, they're waiting to get you. And they're going to get lots of us sooner or later with a new epidemic which itself has changed genetically. And you're going to need the males to mix up the genes to make sure that the whole species doesn't disappear so that, you know. I think we males are due for a brief moment of quiet self congratulation. Robert, I've never told you this, but you're a really good guy and you are spectacular. Thanks. Yeah. The prospect of a world without men seemed remote until the invention of the deep freeze. Because you can freeze sperm and use it. I do like blue eyes. Look at that. Were Mensa. And it can be used after their death. Maybe I'm not ready yet. So that. Don't congratulate yourself that you're always going to have a world with men in it. You may just have a world with freezers in it. Steve Jones wrote the book why the Descent of Men, moving right along, the idea of like a world without men or a world where men have been replaced by freezers. It's not men replaced by freezers. It's sperm frozen in freezers. Yeah, yeah, whatever. That's frozen men in freezers. Frozen little baby men. I want to tell you a story that's gonna wipe that smile right off your face. Crawlish. It comes from one of our favorite reporters, NPR's Nell Greenfield Boyce. Hello, Radiolab. Hello. So should I just introduce this person? Yeah. Okay. My name is Leisha Nabel Taylor. Okay. And I live in Oshkosh Wisconsin. Basically, I love animals. Back in 1995, Leisha and her husband John were living in New York City in a mouse infested, cheesy little dump in Park Slope. They were this young couple in their 30s. She was working at like a daycare center. I did basically creative movement with little kids under five. And he was a super in this big apartment building on the Upper east side. And she and her husband both got some horrible flu. And I can remember laying in bed both of. And we were, we flipped a quarter to see who would go make the can of chicken noodle soup. And I said, what would we do if we had kids right now? And I can remember laying there in that bed. And John goes, we'd set, we'd set that child up right there on the floor and, and throw some toys down there and we'd both lean over the edge. I had never been so sick. Did she have any idea what made them sick? Nope, just one of those things. And, you know, she got better. What about him? He didn't get better. He was throwing up, cold cough. Did you guys think it was just like the flu? Flu, yeah. But he was getting sicker and sicker. And at some point he was like having trouble kind of breathing. And so Leisha was just like, we're going to the emergency room. They wheeled him into the emergency room. First nurse we see, she says, oh my God, John, why did you wait so long? All of a sudden he's like in the icu. Well, it's funny though, while John was in the hospital, I snapped three photographs of him. Was going to say to him, see what you put me through. See what the. See what you look like. Because I don't think he would have ever believed how many tubes and how many things were coming out of him. A couple days later, he had a cardiac arrest. And after that, he's brain dead. I went home that night. You know, I'm right across the street. I went home and I saw our whole lives go right out the door. It was as I looked out over that East River, I saw the kids. We weren't going to have that fear of, oh my God, I'm gonna lose everything. And then she remembered something, something that had happened about six months before. John and I had seen something on the news. Hours after Anthony Baez died in a confrontation with police, his widow told her sister in law, I want his baby. This one day before she went to work, she had seen this report about a man who had died, a young man who had died and when he was lying there in the morgue, family members of his wife actually said to the doctors, is there any way that you can save his sperm? The family called in a New York hospital urologist, Peter Schlegel. I'm Peter Schlegel and I'm urologist in chief at New York Presbyterian Hospital, who had removed sperm from many men before, but never a dead one. Had you been to the morgue before? Nope. It's probably not quite as clean as on tv. And certainly working with a dead body is different. Schlegel says Mrs. Baez would have an excellent chance of conceiving with the sperm he retrieved, if that's what she decides to do. Warren Levinson, New York. And I said to John, I go, wow, is that wild or what? What do you think of that? She said that John was like in the bathroom, you know, I mean, he was brushing his teeth, you know, in his usual rush to get off to work. And she said to him, like, if you died, would you be okay with me doing that? And he says, well, if it's really tragic, he goes, go for it. Then later on she went to work. Remember, she works at like this daycare kind of center. And she mentioned it to somebody at work. And one of the women who works there pointed to a kid and said, you see that kid? His father is the doctor who removed the sperm. Wow, no kidding. And so she's remembering all of this six months later. I went, oh, that little boy's dad. You know, her husband is brain dead at this point. And what she decides to do is go to work and find the name of that kid whose father had taken the sperm. So you pick up the phone and got an appointment with him right away that Wednesday. I went and saw Peter Schlegel on that Thursday, John. He died around 6 o'. Clock. I'm sorry. I'm really sorry. We were best friends. A team came in to his room. She waited outside. What do you actually need to do a procedure like this? Basically a vasectomy kit. They take a needle, put it into the man's body. One of the richest sources of sperm would be the VAs, the tube that normally carries sperm from the area around the testicles to the ejaculatory regions. They literally put the needle into that tube and suck the sperm out. So you're left with a little 1 inch tall conical tube that has tens of millions or maybe even hundreds of millions of sperm within it. You know, I can't help but ask myself the question, maybe I'll just ask you, would you do this? Absolutely. Really no question in my mind. I've been married eight years. I don't have children. I want to have children with my husband. And if he died, I would absolutely do it. And no ethicist at a hospital is going to be able to tell me no, because I got my husband to put it in his will. Why? So that there would be no question if he died, that I would have permission to do this. But why are you so certain? Isn't that a party that's a little hesitant about it, what it really means? What would it really mean? I don't know, that you're somehow. I mean, at the very least, it's a kid without a dad. And also, like, the kid would have your husband's eyes and his nose and his ears. And so it would be kind of like an echo of him. Reminder. There is nothing that I would want more, honestly. I mean, you know, if my husband died, there was no. Nothing I would want more than a child of his. But, you know, Peter Schlegel. What Peter Schlegel told me is that in most cases, women do not use the sperm. Women will not go forward and use those sperm. Really. They collect it. Time passes. Maybe they meet someone else and decide to move on with their life. That's interesting. And what about Leesha? Did she move on? Well, no. If I. If I was standing at 70 and looking back at my life, then I'd have to kick myself. If I didn't do this, it would have been out of fear that I didn't because everybody kind of looks at it like, God, that's weird. That's. What are you gonna tell this kid? Oh, you came from somebody dead. How would you explain this to your child? And simply, well, with the truth. I loved your father. He died. I saved his sperm post mortem so that I could bring you into the world. You are indeed a part of him and you are indeed a part of me. After John died, she moved back to Wisconsin and she waited for a while. Her life was moving on. She had relationships with other people, but she didn't let go of the idea. Finally, six years after her husband died, she decided that she was going to do it. I think it really came down to me making a decision about doing it on my own, you know, she called and she made an appointment at a fertility clinic back in New York. I had gone out in September, like the day before. The planes flew into the World Trade center and the city felt solemn. Felicia. It seemed like signs Were everywhere signs of fate. I guess there was just such a big part in the coincidences. Like what? Well, it was pretty amazing in that the in vitro center was in the building where John and I made love. I mean, it was in that building, you know, the doctor's office where she was getting the fertility treatments were in her old building. It was such a coincidence that she'd even seen that news report. The fact that it was the doctor's little boy I was teaching that her cat died, you know, while she was in New York. And she sort of had this idea that with this death, this life comes, things were dying, but there was going to be new life. I had all these eggs and the chances of it working were really big. I was for sure going to get pregnant. You know, all of these things just came together so it felt natural and right. Right. A fertility clinic technician thawed this frozen six year old sperm, injected it into the eggs, and then they waited. I mean, had you like gotten nursery stuff ready and stuff? Like, were you at that point level of certainty? I had gone out and shopped and yeah, I had it all picked out. But none of the eggs fertilized. None, None. It was like another death. I mean, it was just, it was like another death. She had told me that she had John cremated and that she had sort of half of his ashes still in her house and that she didn't know really what she was going to do with them, that she knew at some point she had to scatter them or something, but she hadn't really worked out a plan. And you know, I pointed out that, well, she's got the sperm stored too. Like, do you think that that's something that you want to somehow do something with or will it be there forever until there's a power outage? No. I'm so cynical. It doesn't amount to anything. It's the thing that's there that isn't. It's like the chair. It's, it's not who he is or was. Nell Greenfield Boyce. Thanks to her. Thank you to npr. To NPR Science desk, npr. Anything you heard today you can hear again on our website, Radiolab.org our email address is RadiolabNYC.org I'm Jad Abumrad. I'm Robert Krulwich. Thanks for listening. Radiolab is produced by Lulu Miller and Jada Bumrad. Our staff includes Serene Wheeler, Jonathan Mitchell, Ellen Horn, Amanda Aronchik, Jessica Benko and Elizabeth Giddens, with help from Anna Boyco, Wero, Ike Sriskhandaraja. And Si Chang Lin and original music from Jonathan Mitchell. Special thanks to Whitney Thompson and her students at Brooklyn, France. Bye Bye. Radiolab is supported by the National Forest Foundation, a nonprofit transforming America's love of nature into action for our forests. Did you know that national forests provide clean drinking water to 1 in 3Americans? And when forests struggle, so do we. The National Forest foundation creates lasting impact by restoring forests and watersheds, strengthening wildfire resilience and expanding recreation access for all. Last year they planted 5.3 million trees and led over 300 projects to protect nature and communities nationwide. Learn more@nationalforests.org Radiolab My friend just got married and is thinking about starting a family, but her doctor never mentioned checking her hormones and her cycles are super irregular. It's Black Friday, so I told her to grab Mira the baby making machine at the lowest price of 2025. She could never confirm ovulation on her period app, but Mira did it in 16 minutes, tracking four hormones like a lab and pinpointing her full fertile window so she can conceive much faster. Get 30% off Mira for Black Friday@mirrorcare.com.