Radiolab Episode Summary: "Everybody's Got One"

Radiolab, hosted by Lulu Miller and Latif Nasser, delves deep into the enigmatic world of the placenta in their March 21, 2025 episode titled "Everybody's Got One." This episode unravels the complex relationship between the placenta, the fetus, and the mother's body, blending scientific inquiry with cultural insights to present a comprehensive exploration of this often-overlooked organ.

1. Introducing the Placenta: More Than Just a Bridge

The episode begins with the hosts introducing the placenta as an entirely new organ that develops during pregnancy. Lulu Miller reflects on the common misconceptions surrounding pregnancy, highlighting how the placenta is central to fetal development.

Notable Quote:

Molly Webster [04:09]: "When you're pregnant, you don't just grow a baby, you grow an entirely new organ."

2. Meet Harvey Kleiman: The Placental Scientist

Central to the narrative is Dr. Harvey Kleiman, a physician and scientist at Yale University, who has dedicated his career to studying the placenta. The episode introduces Kleiman's fascination with placental stem cells, emphasizing his groundbreaking work and the extensive placental collection he maintains.

Notable Quote:

Harvey Kleiman [05:25]: "We need another cabinet."

3. The Placenta: An Unwelcome Invader

Delving into the science, the hosts explain that the placenta is genetically distinct from the mother, carrying DNA from both the mother and the father. This genetic difference makes the placenta immunologically foreign to the mother's body, setting the stage for a biological tug-of-war.

Notable Quote:

Harvey Kleiman [09:52]: "Exactly."

4. Evolutionary Origins: The Viral Catalyst

The episode traces the evolutionary history of the placenta, revealing that a virus infection in an ancient mammalian ancestor led to the development of the placenta. This mutation transformed eggshells into a permeable layer within the body, facilitating a direct nutrient exchange between mother and fetus.

Notable Quote:

Molly Webster [16:11]: "A virus infected an ancient proto mammal and changed its DNA so that eventually... the eggshell transformed from a hard shell that exists outside the body to a sort of permeable layer that exists inside the body."

5. The Biological Battle: Nutrient Scavenging vs. Maternal Survival

A significant portion of the episode is dedicated to illustrating the placenta's aggressive quest for nutrients. The placenta secretes hormones like PP13 and human placental lactogen to manipulate the mother's body, ensuring a steady supply of nutrients for the growing fetus. This manipulation can lead to conditions like preeclampsia, where the mother's blood pressure becomes dangerously high.

Notable Quotes:

Harvey Kleiman [18:09]: "PP13 is blowing up the grocery store... the placenta's digging claws bust through."

Molly Webster [20:10]: "Preeclampsia is very, very scary. It's basically when the mother's blood pressure spikes so high that she can actually die."

6. Cultural Reverence: Indigenous Practices Surrounding the Placenta

Beyond the biological aspects, the episode explores the cultural significance of the placenta in various indigenous communities. Tina Delisle, a history professor, shares insights into how native cultures view the placenta as a companion or guardian, leading to rituals like proper burial to ensure the child's protection and connection to the land.

Notable Quote:

Tina Delisle [26:25]: "In native cultures, the placenta is a friend, a companion, grandmother."

7. Emotional Reflections: Hosts' Personal Connections

Throughout the episode, the hosts express a mix of awe and emotional response to the placenta's role. From handling a freshly delivered placenta to contemplating its journey out of the body, their reflections add a personal dimension to the scientific narrative.

Notable Quote:

Becca Bressler [25:11]: "I just wish I could meet it and thank it."

8. Conclusion: The Placenta's Enduring Legacy

The episode concludes by emphasizing the placenta's crucial role in human reproduction and its often-overlooked contribution to fetal development. The hosts highlight the placenta's seamless exit from the body post-birth, leaving no scar—a testament to its specialized function.

Notable Quote:

Molly Webster [24:03]: "And what's kind of cool is it leaves no scar. It's like one of the only things like this in the body."

Final Thoughts

Everybody's Got One sheds light on the placenta's intricate and often conflicting relationship with the mother's body. By intertwining scientific exploration with cultural practices, Radiolab offers listeners a profound appreciation for this vital organ, challenging preconceived notions about pregnancy and maternal-fetal connections.

Notable Quotes with Timestamps:

• Molly Webster [04:09]: "When you're pregnant, you don't just grow a baby, you grow an entirely new organ."
• Harvey Kleiman [05:25]: "We need another cabinet."
• Harvey Kleiman [09:52]: "Exactly."
• Molly Webster [16:11]: "A virus infected an ancient proto mammal and changed its DNA so that eventually... the eggshell transformed from a hard shell that exists outside the body to a sort of permeable layer that exists inside the body."
• Harvey Kleiman [18:09]: "PP13 is blowing up the grocery store... the placenta's digging claws bust through."
• Molly Webster [20:10]: "Preeclampsia is very, very scary. It's basically when the mother's blood pressure spikes so high that she can actually die."
• Tina Delisle [26:25]: "In native cultures, the placenta is a friend, a companion, grandmother."
• Becca Bressler [25:11]: "I just wish I could meet it and thank it."
• Molly Webster [24:03]: "And what's kind of cool is it leaves no scar. It's like one of the only things like this in the body."

This comprehensive summary encapsulates the essence of Radiolab's "Everybody's Got One," providing listeners with an in-depth understanding of the placenta's biological significance and cultural reverence.