S3 Ep13. From Echidnas to The Epididymis: A Scientist's Journey with David Skerrett-Byrne

In this engaging episode of ABWilson's Heart of the Matter podcast, host Aderonke Bademosi Wilson welcomes David Skerrett-Byrne, a reproductive scientist, storyteller and community builder. David shares his groundbreaking work on sperm biology, framing it as a feminist endeavor to shift responsibility in reproduction toward men, whether they want children or not. 

He explains how sperm mature in the epididymis, gaining the ability to swim and fertilize eggs, and delves into epigenetics, showing how men's diet, lifestyle and even climate change can impact sperm quality, pregnancy outcomes and the lifelong health of the next generation. 

David highlights the global decline in sperm counts from about 100 million per ejaculate in the 1970s to 30 million today, linking it to environmental factors rather than genetics, and calls for better male sex education and routine sperm testing as a marker of overall health.

David opens up about his life across four countries, speaking three languages including Irish (Gaeilge), and his unexpected work with Australian wildlife like koalas and echidnas. He reflects on building communities in science through mentorship, emotional intelligence and showing up for friends in tough times like fertility struggles. 

From overcoming imposter syndrome during his PhD, his move to Australia and then embracing German work-life balance with structured holidays and Feierabendbier, David emphasizes resilience, vulnerability and honest communication. 

He critiques toxic masculinity, advocates for non-hormonal male contraceptives and envisions healthier narratives for men via outreach like Pint of Science. The conversation wraps with joys like time with his fiancée, book clubs and Alpine walks, inspiring listeners to prioritize reproductive equity and human connections.

https://www.abwilsonconsulting.com

https://abwilsonphotography.com

Transcript

Copy Transcript Copied

Aderonke Bademosi Wilson (00:00.893)

Welcome to another edition of ABWilson's Heart of the Matter, a podcast that uses overwhelmingly positive questions to learn about our guests, where every episode uncovers extraordinary stories of triumph, growth, and empowerment. Hi, I'm Aderonke Bademosi Wilson. My guest on today's show is David Skerrett-Byrne. David is a scientist, a storyteller, and a community builder. David, welcome to the show.

David A. Skerrett-Byrne (00:36.891)

Thank you for having me, Aderonke. And congrats on your 100th -- I just heard.

Aderonke Bademosi Wilson (00:40.875)

Well, thank you. Yes, 100 episodes. And I have to say, it's people like you who say yes that I can get to 100 episodes, right? Because if everybody said no, I would be sitting here talking to myself. So thank you. Thank you for being a guest on the show. And I want to start with your descriptors. Let's start with storyteller. Tell me about being a storyteller.

David A. Skerrett-Byrne (00:49.504)

Hahaha.

David A. Skerrett-Byrne (00:57.646)

Of course.

David A. Skerrett-Byrne (01:06.924)

Yeah, I don't know if it sounds pretentious, but I certainly hope not. I guess my kind of logic is that, you know, science, which is my field of work -- I think it's not enough on its own. You can be the best scientist in the world, but if you can't piece together that story, whether that's through papers or grants or conferences, it stays in the lab and it never reaches the world. So I cannot see storytelling as anything but a critical part of what I do. And I think historically, science and the arts have always belonged together. And I think that's still very true. And being able to take these complex ideas and make them understandable, relatable, and engaging for the general public, but also our peers -- so whether, in my case, it's explaining sperm biology or communicating research findings or even sharing the journey of being a scientist -- storytelling is what connects work and people.

Aderonke Bademosi Wilson (01:59.831)

And you've mentioned you're a scientist. Tell me about your work. What type of scientist are you?

David A. Skerrett-Byrne (02:07.154)

I'm a reproductive scientist. I work with biology. My specialty is sperm. And it may sound grandiose, but I like to think that my research program is a feminist endeavor. My whole work is trying to reposition men to be responsible when it comes to reproduction, whether you want kids or don't want kids, either which way. So my work is trying to understand what makes sperm good quality. And I think going hand in hand with that is, if you know what makes sperm good, then you can make contraceptives and take the burden off women. And the last part, and partly why I'm in Germany, is trying to understand how male experiences -- whether it's diet or climate change -- affect what's called the epigenome of a sperm, these small coding units of information, and how that affects pregnancy, the woman herself, and the lifelong health of the next generation. So I hope -- maybe it's not too grandiose -- to reposition men to be responsible.

Aderonke Bademosi Wilson (03:07.095)

So this is fascinating, right? Because I've never heard -- well, first of all, your description that you see it as a feminist endeavor -- I would never have associated feminism with sperm, right? I just didn't see that. And so I find that curious, and I want you to talk a little bit more about that. But good sperm and bad sperm and diets of men -- this is very curious. And so,

David A. Skerrett-Byrne (03:09.727)

I think so.

David A. Skerrett-Byrne (03:21.506)

Fair enough.

Aderonke Bademosi Wilson (03:35.573)

So let's start with the feminist part and then move into what makes a really good sperm.

David A. Skerrett-Byrne (03:41.676)

Mm-hmm. Yeah, I mean, so how do I see feminism in terms of what I do? I think the fact that -- I'm sure I don't have to convince you or the audience -- but I mean, historically and to this day, women bear the responsibility, whether it's physically on your body, emotionally, financially, while men don't really bear the repercussions of whether one chooses to delay having children or in fact having children. Like even a simple idea in the IVF setting, if you have to go... Because infertility is now one in four in Europe -- like, couples experience infertility, which is quite high. And first testing is all on women. Women get very invasive things. They get injections, they get all sorts of things, which is hard emotionally and physically. But a man may get his sperm tested, which in terms of tests you can do is not the most invasive thing to look at, in fairness. So I think it's about, again, repositioning and ensuring that we actually have equity between the two sexes -- across genders, really. Yeah, and I guess it's trying to, I hope, improve sex education for men to be aware of these things. I imagine most men, sadly when it comes to education, sex education -- are a bit more ignorant that they could play such a role. I don't mean that in a bad way, but we need better education in this sense. And I feel fortunate that, you know, I grew up with my mom being my real idol. And I think that's what's really helped me. To -- I don't know if you know, there's a poet called Emmett Kirwan. He's an Irish spoken word poet and he had this wonderful piece one time and he put it like: to be the best elements of femininity wrapped in a rebellious, feminine, but benign masculinity. And I think -- I hope -- that's kind of the concept I'm trying to embody.

Aderonke Bademosi Wilson (05:26.487)

Repeat that. Say that again, please.

David A. Skerrett-Byrne (05:29.976)

To be the best elements of femininity wrapped in a rebellious, feminine, but benign masculinity. To be like the best parts of what is femininity, but as a man. That's at least how I feel I was raised and the life I've lived. I think that's what men should be striving towards.

Aderonke Bademosi Wilson (05:46.795)

Hmm, thank you. Thank you for that. And then what makes a good sperm?

David A. Skerrett-Byrne (05:50.222)

Of course.

David A. Skerrett-Byrne (05:55.694)

God, that's a good question. I mean, I'll put it simply in the sense that basically in most medical research, there's a sex bias. Most medical research focuses on men entirely, with the exception of reproduction. And I think that's because of our patriarchal society and how men can't be weak -- you know, any kind of vulnerability is seen as a weakness. So there's been great research on men's reproduction, but not as much as you'd hope. And it's certainly been placed on females. So I think most work -- you probably know sperm are made in the testis, right? Everyone knows this, but what you might not know is when sperm leave the testis, they can't swim, they can't find the egg. They're pretty useless, to be honest. And they go through this long tubule, which I work on, called the epididymis. And sperm cells are the only cell in the body that cannot create RNA or protein. And they move through this long tubule, which is about seven meters long when you're unwinding it, and they gain all these profound abilities to swim and bind eggs. And my work is understanding how they gain and lose proteins to gain these functions. So I think this is the key area that explains a lot of why fertility could be crashing in men and how we can help this.

Aderonke Bademosi Wilson (07:06.857)

And so if I understand correctly, it's the sperm's journey along the epididymis that gives them the power that they have in order to fertilize an egg.

David A. Skerrett-Byrne (07:20.268)

Yeah, their functional abilities -- in the testes, they get morphological maturation. So they look like you'd expect them to look. And then in the epididymis, they gain function. And as well as that, epigenetic coding information, which is this cool, very hot area at the moment, which I work in.

Aderonke Bademosi Wilson (07:37.067)

Hmm, okay. And I want to come back to this, because this is intriguing me. Your third descriptor: community builder. Tell me about that.

David A. Skerrett-Byrne (07:42.067)

Sure.

David A. Skerrett-Byrne (07:49.452)

Yeah, I think like anything, science -- and just life -- is built around communities. I mean, myself, I consider myself very extroverted and I really need people in my life. I think it's really fundamental to my happiness. And I think the focus on the science part -- I think we all have this idea of people in Cambridge and Oxford sitting in a dark room and figuring out all this great science. But I think that's naive, and true at one point, but it's completely entirely false. And science is really about connectivity and everyone working together. I think everything meaningful that's been built in science has been built on relationships with mentors, collaborators, students, friends. And I place a lot of value in trying to create such environments where people feel supported, where they can grow and feel safe to take risks and ask questions, which is what science is all about -- academic science. And I think this, again, applies to the lab inside and outside. And I think ultimately having strong communities not only makes us better scientists, but makes us more resilient and I hope more fulfilled as people.

Aderonke Bademosi Wilson (08:54.327)

Thank you, David. I would like our listeners to learn just a little bit more about you. Please share three interesting things about yourself that our listeners may not know and your friends will be surprised to learn.

David A. Skerrett-Byrne (09:09.07)

That's a good caveat at the end, because when I first read that I'm like, well, no, no -- so I can say anything. It's all new for them to learn. Yeah, I tried to think about this. I thought one thing I think is interesting, or has been good in my life, is that I've lived across four countries. And in terms of research, this is my sixth lab. So I think all that variation across people has shaped how I see the world and how I see my own work. I think each place brings a slightly different flavor or nuance to work, collaboration, and failure. And I think this has been a really valuable thing in my life. And I think everybody could benefit from living in different countries.

What else? If I'm generous with myself, I would say I speak three languages, which of course is English, as we're conversing; German, as I live in Germany; and -- you may or may not be aware -- I find most people outside of my home country, Ireland, don't realize that we have our own language in Ireland. And it's a completely separate branch on the Indo-European language tree. It's nothing like English. There's no relationship to it. And it's a wonderfully fierce, poetic language. And if you go to Ireland, you'll see every sign is in Irish, as we say in Irish. And I think it's a really wonderful ancient language that brings a lot of value. And last one -- the one thing I tell people they tend to always really enjoy -- is that, like I've just mentioned to you, I'm a sperm biologist and I'm interested in fertility, and obviously you think about humans, and that's definitely where most of my work is. But because I lived in Australia prior to Germany, I got to work with koalas and crocodiles and echidnas and all the weird and wonderful evolutions of Australia. And I can assure you as a small boy in Ireland, I never would have thought I would work with an echidna, which is like a little monotreme. It looks like a hedgehog, and it has a four-headed penis, which

David A. Skerrett-Byrne (11:18.572)

was quite an experience that I wasn't expecting. So you never know where life's going to take you.

Aderonke Bademosi Wilson (11:24.043)

And what is the animal?

David A. Skerrett-Byrne (11:26.958)

An echidna. It looks like a hedgehog, but it's not related.

Aderonke Bademosi Wilson (11:28.864)

An echidna.

Aderonke Bademosi Wilson (11:34.813)

And okay, so let's just go back. You said you've lived in four different countries. So that's Ireland, Germany, Australia. What was the fourth one?

David A. Skerrett-Byrne (11:43.63)

Well, I was hesitant to say four -- it's actually kind of controversial. Technically, I did my masters in the north of Ireland, which you may know as part of the United Kingdom. So Ireland, in my opinion, is one country, but of course we are segregated based on our history currently. So technically it's a different country, but culturally it's the same. Well, mostly. But that's a very complicated topic.

Aderonke Bademosi Wilson (12:04.725)

And okay. And then so tell me about the language. Tell me the name of the Irish language.

David A. Skerrett-Byrne (12:16.302)

So in Irish, it's Gaeilge.

Aderonke Bademosi Wilson (12:18.647)

Gaeilge. Okay, so you learned that language as a child?

David A. Skerrett-Byrne (12:20.014)

Perfect, nice.

David A. Skerrett-Byrne (12:28.896)

Yeah, so in school in Ireland, you need three languages to go to university. So you learn Irish from when you're four till you're 18, roughly, at varying degrees. You can go to a school all in the Irish language, or you can go in English, but obviously Irish is a key component. So you need English and Irish to go to university. And usually you do French, German, or Spanish.

Aderonke Bademosi Wilson (12:49.013)

Hmm, excellent. Thank you. Thank you so much. And can you tell us about a recent accomplishment or success that you're particularly proud of?

David A. Skerrett-Byrne (12:52.782)

Thank you.

David A. Skerrett-Byrne (13:02.626)

Yeah, there are a few that come to mind, I guess. I think one that I'm most proud of is -- as I get more senior in my career, it's nice to see all the younger researchers prospering. And in fact, just this last week, two students got their first first-author paper. So their name appears first on the paper, which is quite prestigious. And I just -- I don't know -- seeing how hard they work and just the absolute, pure, and deserved joy they get, I think that's really wonderful for me. I think it's such a pivotal moment in your scientific career where you go from contributing something to really owning a piece of work and putting it out into the world, and hopefully watching that transformation happen and seeing their confidence build -- I think that's the really awesome, rewarding thing. That's a really nice one. And then I was really, really lucky at the end of last year to have gotten a paper in The Lancet, which is quite a big, prestigious journal. But this was focused on the Western Pacific region, where they invited me to write about what the determinants of male fertility are and how lifestyle, environment, and biology all intersect -- and to explain that, you know, we may or may not know we have this worldwide crisis of sperm concentrations crashing. I'm trying to contextualize all that, but focusing on the Western Pacific -- like Southeast Asia, Oceania, all this part -- but it's applicable across the world. It's not unique to there.

Aderonke Bademosi Wilson (14:31.063)

Okay, so sperm is crashing. What does that mean? Men are creating less sperm?

David A. Skerrett-Byrne (14:34.68)

Mm-hmm.

David A. Skerrett-Byrne (14:38.304)

Yeah, exactly. That's really well put. Exactly. Essentially from the 1970s, we had about 100 million sperm in an ejaculate, and now it's crashed down to about 30 million. So we're really seeing this quite linear and quite rapid decrease across very recent generations.

Aderonke Bademosi Wilson (14:59.445)

And are you investigating why?

David A. Skerrett-Byrne (15:02.744)

Partly, yeah. So I think the real thing is people obviously focus on genetics -- you know, that's what people would think -- but genetics seems to only explain maybe 4% of what's causing infertility issues in men. So by focusing, in my opinion, more on protein and RNAs, you bring a whole different level of complexity to understand this. And that's where I think the epididymis is a really interesting component. And of course, it's environment. If anything happens really rapidly in time, you can tell it's our changing world -- not just... Humans have existed for a very, very long time and things are really happening in line with our industrial world and how we're changing our climate and the food we eat, the plastics in our society -- all these things intersect in one.

Aderonke Bademosi Wilson (15:47.005)

And so can I assume that you're looking at how to increase sperm count? Is that part of your research?

David A. Skerrett-Byrne (15:57.826)

I think part of it, in a sense, is maybe even from a sex education point of view. I think it's important that -- I think it's fair to say most men would assume they can have kids when they're 80. Robert De Niro did it, Charlie Chaplin did it. But you shouldn't. And there is a relationship -- the older the man is, the poorer the trajectory for your child and their fertility. And I think young men being aware of this through sex education is a really important thing. And this is probably a bit more idealistic speaking, but there's a wonderful professor in Australia, John Aiken. He always put it as: we keep trying to bend our fertility to our careers, but instead we should have -- in my opinion -- a more socially oriented, socialist-based society to -- you know -- put fertility first and have our careers bend to it, where you don't compromise educational opportunities because you didn't have an education at 20. Because our biology says one thing and our lives say a different thing. And I think having a model like Sweden or Finland would be a far better way to live, I think.

Aderonke Bademosi Wilson (16:57.697)

Hmm. And this may be out of your area of research, but are women's fertility levels decreasing at the same rate, or at all?

David A. Skerrett-Byrne (17:10.028)

That's a very good question. The same rate I couldn't say, but there's definitely issues because those women are also affected by our environment and these things. Women are even more complex in the sense that, you know, a man's sperm is generated all the time, but you are born with all the eggs of your lifetime, which essentially are affected from the time your mom is in utero with your grandmother. So it's a really complicated system of three things all at once. Men are at least, on balance, continuously producing sperm. There's definitely female fertility issues, not just men's. The problem really is that there's almost very little research proportional to men. And the expectation is to put everything onto women to solve it, when in fact there are, you know, two at play, let's say.

Aderonke Bademosi Wilson (17:53.463)

Thank you. I've got to tell you, I'm learning a lot.

David A. Skerrett-Byrne (17:56.43)

I'm glad you think so.

Aderonke Bademosi Wilson (18:00.311)

David, please tell us about a time when you made a difference in another's life. What were the circumstances? Paint a picture for me, please.

David A. Skerrett-Byrne (18:10.978)

I have to admit, I found this one exceptionally difficult. I don't know -- it felt -- I don't know, I feel too young to have known that I profoundly changed someone in some way, or maybe I'm being modest. I'm not really sure. I found this hard to grapple with. So I kind of thought that maybe it's not a single defining moment for me, but rather a pattern of being present for people having difficult times. Like when friends are going through challenging experiences, whether it's breakups or health scares -- or I mean, now all my friends are trying to have kids, like we're in our mid-thirties -- and this comes with those complications that we've just talked about, and those periods of feeling uncertain and overwhelmed. And I think what I've learned in my lifetime is that it's not always about trying to fix someone's problems, but more about giving them time to be heard and feel validated and just talk it through and get it out of your head -- word vomit if you have to.

I think people just need someone to show up consistently, to listen and sit with them when they need that space, without trying to immediately problem-solve from your perspective. And I've been told by my friends that I'm quite a reliable person. I take a lot of pride in that. I mean, I like being someone who people can call at 2 a.m. if they hit that crisis -- that's what they really need. Rather than someone who, you know, says "I hope you're okay" and then turns up weeks or months later. I think turning up is what matters the most. And I think sometimes we underestimate the impact of simply being steady in someone's life -- being that constant, not dramatic, not heroic, just there. I think in many ways that mindset has carried over into how I mentor my students and trying to create an environment where they feel supported, heard, and not alone in their struggles. And I think that's one of the most meaningful ways to make a difference, if I can put it like this.

Aderonke Bademosi Wilson (20:13.155)

And so thank you for that. And so what do you think are the key strengths and qualities you rely on to make a difference and, as you've said, show up when it matters most?

David A. Skerrett-Byrne (20:27.948)

I mean, I think for me, the biggest one is definitely emotional intelligence. I think being able to read a situation, understand what someone actually needs, and respond appropriately. And I think that often goes hand in hand with listening -- not listening just to reply, but listening to understand. I think it sounds simple, but it's surprisingly rare, I suspect. So I guess my really big strength is investing my time in

Aderonke Bademosi Wilson (20:28.919)

Thank you.

David A. Skerrett-Byrne (20:56.078)

trying to expand one's vocabulary and, you know, the atlas of the heart -- all this kind of thing. So I think that's a big one. And reliability, I think, is another one. I think trust is built over time and through consistency. And people know that if I say I'll be there, then I'll be there. And I think that creates a kind of -- I guess -- a psychological safety that allows people to open up. And I think hand in hand with that, I think I've always found that when you share something sincere about yourself, it makes people more willing to be open with you. And I guess lastly, later in life -- not that I'm particularly old, but later in my life -- I think I've found that I'm quite calm under pressure. And I think when someone's struggling, not amplifying their stress is something that really helps them to feel grounded, I find. Yeah, I think that's what I'd say.

Aderonke Bademosi Wilson (21:51.753)

Okay, thank you so much. Can you recall a situation where you overcame a challenge that led to personal growth? What did you learn from that experience?

David A. Skerrett-Byrne (22:07.278)

Yeah, I also tried to take some time to reflect on this question. They're surprisingly hard questions. They're wonderfully positive, like you say, but I had to really try and be thoughtful about it. I think the most formative challenge for me was moving halfway across the world. So when I was 24, I moved to Australia -- and honestly, you can't go any further on the globe without returning back to Ireland. Ireland's a wonderful country. It's not about Ireland. I think it was just time to go somewhere and do something different. You know, arriving in a whole new environment without an established community and trying to navigate different cultures -- not to say Australia is dramatically different to Ireland, but enough that those nuances and those cultural references, people don't understand what you're saying -- while also trying to prove myself academically. I moved for a PhD, so you're trying to impress, but you're also trying to survive. And I think those two things compounded each other. And at the time, I had to be, I think, really self-sufficient. I think that's when I really learned about my extrovertedness -- in the sense that I really need people to be happy. And at the same time, I think I'm quite good at forcing myself upon people in the nicest of ways to try and build something. And you know, it happens in funny ways. My first week, the PhDs all wanted to go to a Comic Con convention, which is not my thing necessarily, but I wanted friends, so I dressed up as Ron Weasley. I've got strawberry blonde hair. I think it worked and it just went -- and it was a curious experience. But yeah, I think that experience really helped me to build relationships more intentionally, to be open to curious things like Comic-Con, and to, I think, delve deeper into emotional intelligence. I think that was a really helpful thing for me. I became more aware of how important it is to understand people and not just work with them. And I think it gave me a good sense of resilience -- not in the sense of just pushing through for the sake of it, but understanding when to lean on others, when to step back and maintain perspective. And I think that really shaped how I am now and how I approach others, both personally and in the workplace.

Aderonke Bademosi Wilson (24:29.469)

And you've mentioned Australia. I understand that you're getting ready to return to Australia. Do you want to talk about that a little?

David A. Skerrett-Byrne (24:39.148)

Yeah, sure. I mean, I'm very lucky to have received quite a prestigious fellowship in Australia, which allows me to spend the next five years developing a team between Helmholtz Munich here in Munich, Germany, and the University of Melbourne in Australia, which is a new city for me. And yeah, it's going to be really exciting and cool, trying to tackle all these questions I mentioned -- about what makes good sperm, non-hormonal male contraceptives, and how male experience affects the next generation. And it's really cool because in Munich you've got all this critical mass in epigenetics information. And in Melbourne, I'm going to work with an amazing team led by Professor Natalie Hannan, who is not only just a wonderful soul, but just someone who -- I don't know -- I think it's always impressive when you see -- and I know it sounds terrible to say, but you know what I mean -- a female scientist who's a professor and leading a department. You don't see it too often, but I think she's a wonderful inspiration. It's just a cool thing I want to be part of. And they focus on the placenta, looking at preeclampsia and fetal growth restriction. I'm trying to bridge those two worlds -- these pregnancy complications and how men affect these things. So I'm super excited, and it's not bad to live between two different countries.

Aderonke Bademosi Wilson (25:58.647)

So your work will ultimately continue to look at increasing fertility -- is that correct?

David A. Skerrett-Byrne (26:10.194)

I think creating the right situation for fertility -- maybe that's the best way to put it. If you want to have kids, then thinking about being more thoughtful about it. So if you're a man, the way I like to think about it is: your sperm today is you about six weeks ago. So if you're honest with yourself, have you been healthy in that timeframe? And could you be setting yourself up with the right coding information in your sperm to give your offspring the best opportunity? And as well as your partner -- because there is a relationship, although not completely concrete I should say, between miscarriages and pregnancy complications. And it's not just the pregnancy, but your partner as well. Are you giving them the best opportunity? So I think it's a collaborative thing between both people.

Aderonke Bademosi Wilson (26:56.983)

Hmm. And so -- I know you can get tested, men and women, on fertility. And as you've said, some of it is quite invasive. Are there new tests coming online around that?

David A. Skerrett-Byrne (27:16.268)

Well, I think for women, there are definitely things developing to try and use blood instead, to be less invasive than a biopsy, which is obviously quite intense. And if you're trying to figure out how many eggs you have left, that's quite an invasive thing. And you lose an egg in the process, essentially. And I'm not an expert on the female side, though I do go to conferences -- but there are people talking about biomarkers that are a bit more reasonable or routine to take. But for men, in my opinion, I think giving a sperm sample is really not remotely on the level of invasiveness as what women suffer. And I think it should be a normal thing, because honestly, there are these really wonderful epidemiology studies that show that if you have two poor sperm parameters in a man -- to say your sperm doesn't swim well -- you have the same mortality risk rate as a smoker. So in reality, it's kind of like a canary in the coal mine. What's in your sperm is reflective of your systemic health. So it should be a normal thing to do at the GP -- to see how your overall health is, as well as your fertility. Because as you can imagine, from a purely biological, evolutionary point of view, your body is -- I guess -- built both to sustain your mind and to pass on genes to the next generation. So if your systemic health is not good, then why would you invest in sperm that would perpetuate some problem, theoretically?

Aderonke Bademosi Wilson (28:38.775)

There was so much in your last comment. All right, so let's go back to what you said near the beginning. If you have two sperm that swim poorly...

David A. Skerrett-Byrne (28:45.378)

Sorry.

David A. Skerrett-Byrne (28:55.614)

Sorry -- two poor sperm parameters. So the parameters usually are: do they swim well, or morphology -- do they look correct -- and how many you have. These are kind of the basic WHO standard parameters.

Aderonke Bademosi Wilson (28:58.335)

Okay, sorry, I misunderstood that.

Aderonke Bademosi Wilson (29:10.377)

Okay, but if two of those parameters are not healthy, your mortality is the same as a smoker.

David A. Skerrett-Byrne (29:20.131)

Mm-hmm.

David A. Skerrett-Byrne (29:25.846)

Your risk score, I guess -- your probability towards disease.

Aderonke Bademosi Wilson (29:34.049)

So is that being used a lot? Is that being used a lot for men's health to determine their overall health?

David A. Skerrett-Byrne (29:34.518)

Wild, you know?

David A. Skerrett-Byrne (29:42.826)

Not at all. Not at all. And it absolutely should be. And there are wonderful papers -- I can happily direct you to people writing amazing stuff -- showing that there is this relationship, and it needs to obviously be invested in more. But there are big epidemiological studies across North America and across Europe showing these relationships. Like I said, my old professor Brett put it to me: that's the canary in the coal mine. And that analogy has stuck very well with me, but it's not really been pounced upon by people -- but it should be. It's not a particularly invasive biomarker to test. I think it's more about men not being willing to give their sperm, which again, I hope is thanks to an older generation and an older idea of masculinity. And I hope this shifts with every generation.

Aderonke Bademosi Wilson (30:33.591)

So if we're looking at a man's sperm and it's not necessarily healthy, but healthy enough to reproduce, to make children -- does any -- well, and I guess I'm answering my own question -- these things pass on to the next generation, right?

David A. Skerrett-Byrne (30:54.616)

Please.

David A. Skerrett-Byrne (30:58.19)

Mm-hmm. Can do.

Aderonke Bademosi Wilson (31:03.735)

And so now I want to get into DNA, because I've heard you could change DNA structure and do all sorts of things to -- I guess -- an embryo, or even before it becomes an embryo. Does that factor into your research? Like, what can be manipulated?

David A. Skerrett-Byrne (31:24.526)

Mmm.

David A. Skerrett-Byrne (31:34.478)

That's obviously very controversial. I mean, I understand gene editing from the point of view of someone lacking a certain gene or a certain point mutation. Like people who develop diabetes -- type one -- there are certain ones that are just a very specific gene. People do really nice pre-clinical models, which means animals -- mice predominantly -- and you can prove that it works. That makes sense to me. At other levels, if it comes to this idea of -- I don't know -- celebrities or wealthy people wishing to have an ideal child, this is crazy talk, and shouldn't be explored. We don't know the consequences. But maybe a good way to put it is: you probably know DNA is the core fundamental of who we are, right? But it's kind of the simplistic blueprint, because there are only 25,000 protein-coding genes in the DNA. But when they become RNA, 25,000 becomes 100,000 possibilities. And when RNA becomes protein, it becomes 1 million possibilities. So there's a complexity beyond our knowledge.

There are other factors in play, but the key one, I think, is epigenetics, which plays the role between DNA and RNA. This is kind of the key one. And it's called -- I believe it's Greek, if I'm not mistaken -- "epi" means "over." So it's the regulation between these two worlds. And epigenetics is where you're able to see very rapid evolution, because genetics can't explain -- you know -- the 1970s to now is not a long time in the span of evolution, but epigenetics is this area where you can rapidly change things. And the way we always think about it is the epididymis. Sperm pass through there for two weeks -- that's all it takes. And we've shown here in Munich that when you give mice a high-fat diet for two weeks only, that sperm causes glucose intolerance in the next generation. Or we did heat stress and we saw effects to the placenta and how fast embryos grow, which has an effect on metabolism. So even those small, short windows can change the landscape -- again, allowing for rapid change. So I think epigenetics is the space to really think about.

Aderonke Bademosi Wilson (33:43.009)

David, you've got me dead curious about this. And I think I want to sit down -- come to either Germany or Australia -- and sit down and have a conversation or at least learn, maybe educate myself a little bit more about this, because I've never really given it a lot of thought, just generally.

David A. Skerrett-Byrne (33:43.564)

It's cool, right?

David A. Skerrett-Byrne (33:54.158)

Good choices.

David A. Skerrett-Byrne (34:11.596)

Yeah, I mean, I'm really happy you say that, because I think it exactly points to the thing -- I think it's taboo to some degree in our societies to talk about these things. And it shouldn't be. It's a very common, fundamental human aspect. Again, whether you want kids or don't want kids. And I just think we should talk about this more openly. I think we need to improve sex education, particularly for men. At least I can only speak from my own experience in Ireland. And obviously I grew up thankfully during a very pivotal change in Ireland -- obviously conservative, Catholic Ireland and now Ireland, which I would say is super progressive in the best way. But when we had sex education, they separated boys and girls, which is crazy. There's no reason we should be separated. And, you know, we're told, "your balls will drop and you'll grow some hair" -- and that's about it. This is insane. And I remember when I came home, I told my mom and she was like, "No, you need to learn about periods and menopause. You need to know about these things." Half the population are women -- of course we have to be aware of these things.

Aderonke Bademosi Wilson (35:14.839)

David, thank you. You are listening to ABWilson's Heart of the Matter podcast.

Welcome back to ABWilson's Heart of the Matter. My guest today is David Skerrett-Byrne. David, we have talked about epigenetics, we have talked about good sperm, we've talked about feminism and sperm, we've talked about where you are planning to go in your research. What self-care practices or strategies help you to sustain your energy and motivation while navigating your journey?

David A. Skerrett-Byrne (35:58.39)

Yeah, I mean, a great and really important question. I think for me, it's really about work-life balance, which I know sounds easy to say, but I really think this is essential -- not only to sustain your career in something particularly demanding like academic research, but just to function as a person. And that's where cultural experiences are really important. And living in Germany has really reinforced that. I really think the Germans are such a wonderful people and they have such a strict importance placed on work-life balance. In fact, in Germany they have strict regulation, depending where you work -- if you work over hours, the government will basically sue your employer. There are strict labor laws to protect people in Germany, which I think is amazing and a really healthy thing. And as you can probably imagine, the Germans are super organized and they love planning. And when you meet a friend, you meet for a Termin, which means an appointment, which I always think is very funny -- the idea of having an appointment with friends -- but that's how they do it. And I can show you my calendar now: it's just full of appointments and structure. And I think it's really nice, because what stood out to me is usually in January, or a bit before, most Germans will sit down and plan their holidays for the entire year -- and it's done. And I think it's really nice because you don't have to think about, "Yeah, I just got to get through Easter and then I'll have a break" -- but you don't even do it. And I think that's an easy way to burn out. But if you really structure your year, then other things can't get in the way because your holiday is booked. You've made your plans, it's happening, and it gives you something to look forward to and you kind of space it out. So I think that's been a really cool, healthy thing to learn. And also in Germany, they have a wonderful word, I think -- which is Feierabendbier -- which means like when you finish at the end of the day and you go for a beer together. Like, they have a word to encapsulate that whole thing, which I think is just nice. It's just to mark that you celebrate the end of work. You go together -- it's a cultural connection. I think this is just so nice. So I feel like Germany has been really good for me in further emphasizing those things. And I'm sure it applies across the board, but in academia I've had many friends who work crazy hours, they work weekends, and they're amazing scientists.

David A. Skerrett-Byrne (38:17.87)

But they lose out because, unfortunately, you know, funding in Australia is less than 9%. In the United States, Trump is canceling all sorts of funding. All these things have issues. And I think working extra hours -- I don't think there's a line between working extra hours and being successful. I don't believe in this. And I would much rather just work nine to five, not work weekends. And if my career ends, at least I was happy. That's sort of my approach. I think it's a healthier way to go about it than pushing my health to god knows what kind of limits.

Aderonke Bademosi Wilson (38:52.203)

Thank you for that. And I didn't know about the rules around working long hours in Germany. That's a revelation for me.

David A. Skerrett-Byrne (38:58.798)

Yeah, they've really good trade unions, good strict labor laws. I think that's the way it should be.

Aderonke Bademosi Wilson (39:08.511)

How might sharing your experiences of success and growth create a positive ripple effect in your family, community, the world?

David A. Skerrett-Byrne (39:19.65)

Big question. Yeah, it's something I've had to ponder on a bit lately because I'm at a point in my career where I'm known as a mid-career researcher. So I'm usually speaking to a lot of younger PhDs and younger researchers. And it's been really nice. And I think what I've taken from it is: I think just sharing your experiences and being genuinely honest about them -- I think that has the most powerful ripple effect.

In academia -- and again, I'm sure it's across fields, not just the academic world -- there's often a perception that everyone else has it figured out, that success is linear, that confidence comes naturally, and that struggles are something you keep to yourself. And I think that's just not real and completely false. And I think when you talk openly about these challenges -- like whether it's imposter syndrome, moving to a new country, all the setbacks, whether your paper didn't get published, you didn't get your grant, you didn't get your promotion -- I think this normalizes the experience for people and gives them permission to feel what they're feeling without thinking they're failing. Because of course that's not true. We obviously learn far more from what doesn't work out than when everything just works perfectly -- we learn nothing from that. And I think it's been really helpful. And even for me -- when I see a professor give a talk and they give an amazing talk and I'm blown away, and I'm like, "Wow, that's so great," and they say, "I was so nervous" -- just knowing that they're still nervous is just such a nice, reassuring thing for me to hear.

And I guess I've really seen this with, again, these students and early career researchers -- just knowing that someone ahead of them has faced similar challenges and how they may have managed it, I think is just incredibly reassuring. And yeah, I think in my field, we're trying to shift that kind of conversation to be more open about our failures. And I've seen some people give talks about all the things that went wrong for them, all the things they failed in. Because while you have those one or two big successes that are impressive, you don't see the trail of failure. I think that's a super helpful thing to hear. So I guess I hope when I take this through mentorship and conversations with people, that people just feel more seen. I hope that's my positive effect.

Aderonke Bademosi Wilson (41:39.031)

Thank you. What exciting opportunities do you see on the horizon? How do these opportunities align with your passions and aspirations?

David A. Skerrett-Byrne (41:50.478)

Well, I think I've kind of touched on that a bit -- which is really, for me, the most exciting thing is starting to build this team between Munich and Melbourne. And I won't repeat myself too much, but I think trying to really dig into these questions I've outlined. But I think maybe what's exciting -- I hope -- is again, this kind of broader societal context. I mean, perhaps you or your listeners might have recently watched Louis Theroux's documentary on Netflix. I love Louis Theroux. I don't know if you know him -- he was on the BBC. He did amazing stuff. And he had one on the "manosphere," as he called it. And he's interviewing all these hyper-masculine influencers, who in my opinion are just really awful and toxic. Think Andrew Tate -- this is what I'm talking about. And I think trying to create healthier narratives around masculinity is what we really need, rather than this harmful misleading of young men.

And I think I'm really interested and excited about offering this alternative -- one that combines, I hope, responsibility, empathy, and engagement in your reproductive health. I mean, on a very simple level -- right -- I'm just thinking aloud. Like, a woman would see a gynecologist regularly enough, but a man never sees a urologist or an andrologist. And this is kind of crazy, right? Again, for the reasons I outlined -- it's tied to our systemic health. But why don't we look at our sperm? It just seems so easy. Who doesn't want to live a long, healthy life? So I think -- that's what I'm excited about. My research questions. And I'd like to get more involved in sex education or some sort of societal outreach, which is why I'm very excited to talk to you. And I hope people hear this and engage in these topics. And I try my best to participate in -- have you heard of Pint of Science? I'm not sure if it's in the US or not.

Aderonke Bademosi Wilson (43:43.584)

No, no, no.

David A. Skerrett-Byrne (43:43.694)

It's like this thing -- it's in like 50 countries or something, I think. Basically you get scientists and you put them into a bar, and you have a few drinks and you give a presentation to laypeople on your topic. They get a good 30-minute presentation and you stay around and you just converse. And when I give these talks, the amount of young men who approach me -- they're like, "God, I didn't know anything about this. I didn't consider these things. And of course I don't want my partner to take a pill and risk stroke on a daily basis -- I want to be part of this." And that's really good and encouraging to hear. And if we don't -- I think sometimes as scientists, we live in our own world. And if we don't tell the community, how would they know? Because politicians, as well-intentioned as they are, they don't move at the same pace or with the same knowledge. So we have to have this interface between community and scientists. So I think those things kind of excite me.

Aderonke Bademosi Wilson (44:37.313)

Thank you. And what brings you joy?

David A. Skerrett-Byrne (44:42.502)

That's a really lovely question. I think -- I kind of touched on this -- I think it's people. People more than anything bring me the greatest joy. My friends, my family, and particularly my fiance. I think she's genuinely the coolest person I've ever met in my life. And I'm always just so wonderfully enriched when I'm around her. And I think that's what brings me the greatest joy. But in general, again, just being with people -- whether it's just meeting up for a coffee and chatting, or -- I have a wonderful book club that I left behind in Australia. These sorts of things are just so joyful. And yeah, I guess those moments are what keep everything grounded. I really love being outdoors. So if anyone hasn't been to Munich, it's obviously an incredible city. We have the Alps, which I can see from my window, which is just incredible. Just the other day I went for a 10K walk with my good friends along the Isar, which is the river here. And it's just breathtaking. I think being near water is really important, which is why Australia was so cool. And being near mountains and the outdoors -- I think that just, I don't know, puts the world in perspective. That doesn't sound too pretentious. Yeah. And then I guess besides that, just those social moments -- like in Germany, there's a lot of emphasis around beer, and as an Irishman, that's quite nice. And we have these big festivals, and I think they're just wonderful community affairs -- most of them really are from the community. They're not strictly commercial. I think that's nice.

Aderonke Bademosi Wilson (46:18.197)

Hmm. David, we're nearing the end of our conversation -- this fascinating, science-focused, sperm-driven fertility and feminist conversation. And I am in deep gratitude to you for sharing some of your work with us and giving me an opportunity to ask questions.

David A. Skerrett-Byrne (46:24.984)

Thank you.

Aderonke Bademosi Wilson (46:45.527)

What book recommendation do you have? It can be a book you've read recently or something that has stayed with you over the years.

David A. Skerrett-Byrne (46:54.742)

Yeah, I tried to think about this. I mean, I feel like I've been a bit bad for reading lately, but I do read quite a lot. But the book that I decided to focus on -- and maybe because I recommended it to a friend just recently -- I'm not sure if you've read Normal People by Sally Rooney. She's an Irish author. Her book blew up over COVID and they made a TV show -- it was a whole thing. But it's a really beautiful book. And I think for me, it was important because -- I don't know -- COVID was an interesting time in Australia. Very fortunate, to be honest, because Australia closed their whole borders, as they're an island. So no one could get in, and we basically didn't have COVID, strictly speaking, in my area for nearly two years. So while it was really cool, I couldn't go home. And this book is based in Dublin. And I think just the characters walking in the streets -- all these things -- was so important for me to feel like I was in my own country, just those feelings. But the reason I really picked the book is that I think on the surface, it's a story about a relationship. But what really struck me -- what the book is really about -- is communication, or the lack of it. And I think these two people who clearly deeply care about each other, but they struggle to express what they're feeling or to say the things that actually matter in those moments when you so desperately want to tell this person this thing, but you assume their reaction is that they don't actually think this. And then you dig into your own little hole. And I think those small misunderstandings really compound into a much bigger issue. And I think that book resonates beyond just relationships -- but friendships, family, and I guess even work environments. So many problems arise, I think, because people think others don't care, or they just don't express what they think or their expectations. And so much is lost between those two things. And I think that book really beautifully touches on this and on how important your mental health is. Yeah, I just think it's a wonderful book. I think Sally Rooney is just a beautiful writer. I feel like I'm only pushing Irish artists on this podcast, but we like to think we're an island of saints and scholars. I really think I'd encourage anyone to read her books. I think she's wonderful.

Aderonke Bademosi Wilson (49:15.605)

David, is there anything else? Do you have any final thoughts?

David A. Skerrett-Byrne (49:20.628)

Probably too many to say out loud, but I was trying to think about this too. If I could leave everyone with one overarching thought, I guess it would be that I think both for me, science and life are just fundamental human endeavors. And sometimes we focus too much on our outputs and work, but I think it's really about people -- people navigating uncertainty, building relationships, dealing with failure, and just trying to find meaning in what we all do. I think that's the big one. And otherwise, men should play a more active role in our reproductive health. Again, whether you want kids or don't want kids, I think it's important that this is a shared endeavor moving forward.

Aderonke Bademosi Wilson (50:11.991)

And I'm just writing that down because I want that to be one of my takeaways, and to reiterate what I see as one of the appreciation nuggets I'm taking away from our conversation. So David, thank you so much. Thank you so much. You've given me a lot of appreciation nuggets and things that I hadn't considered, right? So one of them that I'm taking is what you've just said: men should play a more active role in reproductive health -- not just their own, but also in giving thought to what having children means, and hopefully lessen the burden on the woman in terms of all things reproductive.

David A. Skerrett-Byrne (51:00.461)

Do you...

David A. Skerrett-Byrne (51:05.07)

Mm-hmm.

Aderonke Bademosi Wilson (51:09.643)

You've also said that your sperm today is you six weeks ago. And so I think having said that, what that kind of reminded me of is women breastfeeding -- what did you eat, and how is it impacting the baby?

David A. Skerrett-Byrne (51:19.502)

Yeah.

David A. Skerrett-Byrne (51:34.336)

Hmm. Yeah, true.

Aderonke Bademosi Wilson (51:40.179)

And then trying to remember not to eat that if it adversely impacts the baby in terms of digestion and reaction.

David A. Skerrett-Byrne (51:40.536)

Yeah.

David A. Skerrett-Byrne (51:46.446)

Yeah.

Aderonke Bademosi Wilson (51:52.599)

You talked about yourself as a friend. And one of the things you said is turning up is what matters most when somebody is in need and wants to talk about a situation or a problem that they're facing. Just showing up is important -- to help people, to let people know that you understand, even if all you're doing is listening. And listening is critical.

David A. Skerrett-Byrne (52:20.11)

Thank you.

Aderonke Bademosi Wilson (52:21.663)

And then the third nugget I'm taking away is the importance of your work -- the importance of your work for humankind. Because if male sperm count has reduced drastically in the last 50 years, what's going to happen in the next 50 years if it's not addressed? And will we have people in 100 years if these things -- if sperm and just general male reproductive health -- are not addressed, at least

David A. Skerrett-Byrne (52:53.527)

Mm-hmm.

Aderonke Bademosi Wilson (52:56.639)

the same as it is for women? And I think more research needs to be done on both. I don't know if you'll agree with that, but this is what I'm taking away.

David A. Skerrett-Byrne (53:03.404)

Yeah, 100%.

David A. Skerrett-Byrne (53:09.152)

Wonderful. I'm really, really glad you think so. And just on that last point -- if you're interested, there's a wonderful book called The Infertility Trap, which talks about exactly this: crashing fertility rates, not just in men, and what that means for the global population. Because you need to always think about these things as having a 30-year delay -- because you're having a kid now, and then they're having kids. There's a big gap between those. And the truth is, while we think about the world as billions of people, global populations are actually declining. We just don't see it because we see the number rather than the drop. So it's a very good point you raise.

Aderonke Bademosi Wilson (53:46.039)

So David, I appreciate you taking the time to join me on ABWilson's Heart of the Matter, a podcast dedicated to asking overwhelmingly positive questions as we uncover incredible stories of wisdom and people you may know. David Skerrett-Byrne, thank you so much for your time today.

David A. Skerrett-Byrne (54:09.07)

Thank you so much.