logo
episode-header-image
Jan 2022
27m 31s

Are humans running out of sperm?

Vox
About this episode
In 2017, researchers published an explosive finding: Sperm counts may be declining in some countries around the world. Media outlets began worrying about a potential Spermageddon, but other researchers have pumped the brakes. Because scientists know surprisingly little about sperm. Also, Noam created a list on the Hark podcast app where he talked about some ... Show More
Up next
Yesterday
Stopping the science that could stop the world
When scientists write their own rules for life, how do they know what could go wrong before it’s too late? This is the final episode of our new three-part series, Life from Scratch. Guests: Kate Adamala, associate professor at the University of Minnesota; David Relman, professor ... Show More
36m 12s
Aug 31
A breakthrough in synthetic life
Synthetic biologist Kate Adamala has been making major headlines as her lab creates cells that feed, divide, and grow — all from nonliving parts. It may sound like sci-fi, but Kate believes that these “not quite alive” cells are key to a renewable future. This is the second episo ... Show More
34m 16s
Aug 26
Life from scratch
Scientists stripped a cell down to its most essential genes in order to find out what makes life...alive. What they found was more bizarre than they could have imagined. This is the first episode of our new three-part series, Life from Scratch. Guests: Kate Adamala, associate pro ... Show More
29m 37s
Recommended Episodes
Jun 2023
Sperm counts
James Gallagher get's behind the hype to find out if sperm counts are really falling? There are plenty of headlines telling us they are, but also scientists who disagree - he unpicks the evidence with two of them. James also gets his own sperm sample analysed and meets a couple w ... Show More
27m 49s
Feb 2023
Sperm Counts
James Gallagher investigates whether there is a decline in male sperm including the results of his own sperm count analysis. He meets a couple who conceived after having treatment for a varicocele, enlarged veins in the testes that can heat the sperm up and the leading known caus ... Show More
27m 57s
Oct 2023
The Life Scientific: Chris Barratt
Reproductive science has come a long way in recent years, but there's still plenty we don't understand - particularly around male fertility. The reliability and availability of data in this field has become more of a concern in light of a study published this year, suggesting tha ... Show More
27m 16s
Dec 2023
These Researchers Put Sperm Through a Kind of 'Hunger Games'
The research focused on figuring out what enables certain sperm to gain some competitive advantage over millions of others fighting for the same prize. Learn more about your ad choices. Visit megaphone.fm/adchoices 
8m 7s
May 2025
Diagnosing Male Infertility with a Mechanical Engineering Twist
Male infertility is undercovered and underdiscussed. If a couple is struggling to conceive, there’s a 50–50 chance that sperm health is a contributing factor. Diagnosing male infertility is getting easier with at-home tests—and a new study suggests a method for testing at home th ... Show More
10m 39s
Aug 2025
Condoms and Vasectomies Aren’t Enough—Is a Male Birth Control Pill Next?
In this episode, host Rachel Feltman speaks with freelance science journalist Hannah Seo about a promising new development in male contraception: a hormone-free birth control pill that reversibly stops sperm production has just passed its first human safety trial. Seo explains ho ... Show More
9m 53s
Nov 2021
Am I Normal?: The Spermageddon is coming
"You should start thinking about kids at your age! Your biological clock is ticking!” When we talk about fertility, there's one section of the population that's consistently subjected to fear mongering: the people with the ovaries. But is that worry backed up by data? Should we b ... Show More
29m 11s
Mar 2024
Ep427 - Shanna Swan | Count Down: The Future of the Human Race
<p>Dr. Shanna Swan visits Google to discuss her book "Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race".</p> <p>In 2017, Dr. Shanna Swan and her team of researchers complet ... Show More
58m 43s
Apr 2019
Fertility Cliff: Is It Real?
We’re often told to have kids quickly, before our biological clock strikes and we fall off the fertility cliff. This week we find out if that’s true for women or men. And if the cliff is real, can you do anything about it, like freezing your eggs? Plus, the sperm-aggedon! We spea ... Show More
41m 55s