Unexplainable: Moon Genes – Episode Summary

Title: Moon Genes
Host: Meredith Hognaught
Guest: Rebecca Boyle, Science Journalist and Author of "Our Moon"
Release Date: April 16, 2025

Introduction: The Moon's Profound Influence

In the "Moon Genes" episode of Unexplainable, host Meredith Hognaught delves into the enigmatic relationship between the Moon and life on Earth through the insights of science journalist Rebecca Boyle. Boyle, whose award-winning work has been featured in prestigious publications like Nature, Science, and The New York Times, presents a compelling thesis: the Moon has been instrumental in shaping not only our planet but also the very essence of life itself.

Rebecca Boyle [02:13]: "My book is a story about the shared history between humanity and the Moon. I think there's a lot that we still don't actually understand about that relationship."

Earth and Moon: A Symbiotic Dance

Boyle explains that the Earth and Moon orbit a common center of gravity, emphasizing their intertwined existence in space. This mutual orbit is more than a celestial dance; it has tangible effects on Earth's environment and, by extension, on life.

Rebecca Boyle [03:09]: "Basically, life as we know it would not be possible without the moon."

This symbiotic relationship has stabilized Earth's tilt, leading to a stable climate conducive to life. The Moon's gravitational pull is responsible for over half of the ocean's tidal mixing, a process crucial for nutrient distribution in marine ecosystems.

Lunar Genes and Marine Life

A significant portion of the discussion revolves around the concept of "lunar genes"—genetic mechanisms in marine organisms that sync their behaviors with the Moon's cycles.

Rebecca Boyle [04:27]: "There is evidence that there are lunar genes that drive certain behaviors. And this is more obvious in marine animals, which makes sense because they rely on the tide."

One fascinating example Boyle highlights is coral reproduction. Corals release their sperm and eggs synchronously during full moons, an event sometimes humorously referred to as "the greatest orgy on Earth" by scientists.

Rebecca Boyle [05:18]: "One of my favorite ones is coral. Almost every species of coral responds to moonlight, at least to the lunar cycle."

This synchronization ensures successful fertilization, demonstrating the Moon's pivotal role in the reproductive cycles of marine life.

Lunar Influence on Plants

Beyond marine life, Boyle presents intriguing evidence of the Moon's impact on terrestrial plants. She cites studies involving the model plant Arabidopsis thaliana, which exhibited root movements synchronized with lunar cycles even when grown on the International Space Station under microgravity conditions.

Rebecca Boyle [06:37]: "There is a Scottish botanist who devoted a lot of his career to showing this connection between the moon and plant life... they found the same lunar cycle that they find on Earth, even when they're in space in microgravity."

This suggests that the Moon's gravitational presence may directly influence plant gene expression, hinting at a molecular connection that transcends mere visual or gravitational effects.

Potential Effects on Human Biology

The conversation takes a thought-provoking turn as Boyle explores the possibility that humans might also harbor genetic connections to the Moon. She discusses historical beliefs linking the Moon to human behavior and health, such as the origins of the word "lunacy."

Rebecca Boyle [08:25]: "I definitely think so. And I think this is one of these things that's been dismissed for the last century or so in medicine because it's hard to prove."

Boyle references studies that correlate lunar cycles with various human health metrics, including menstruation cycles, strokes, heart attacks, and even sleep patterns. Notably, she mentions a study published in Science Advances that found a strong correlation between lunar cycles and human menstrual cycles, with the average cycle length mirroring the Moon's cycle.

Rebecca Boyle [14:41]: "But if you look at the statistical averages of people over long periods of time that are tracking these things, the numbers are the same. It's 29 and a half days. And that's the length of a lunar cycle."

Moreover, Boyle discusses research indicating that full moons can disrupt human sleep, affecting both the duration and quality of rest even in controlled environments where moonlight isn’t directly visible.

Rebecca Boyle [16:37]: "And there’s evidence that people who have bipolar disorder experience heightened episodes of mania during full moons."

Challenges in Scientific Exploration

Boyle acknowledges the significant challenges scientists face in studying the Moon's impact on biology. The numerous confounding factors in human health and behavior make it difficult to isolate the Moon's specific effects. Controlled studies are particularly challenging, as it's impossible to shield human subjects entirely from lunar influences in natural settings.

Rebecca Boyle [18:34]: "There are so many confounding factors that it makes it really difficult. And I mean, any epidemiology is hard for that reason, but that doesn't mean it's not real."

Despite these obstacles, Boyle advocates for continued research, emphasizing the importance of understanding the Moon's role in Earth's history and evolution.

The Moon's Unacknowledged Role

Boyle laments that the Moon's significance is often overlooked in modern scientific discourse. She argues that recognizing the Moon's contributions is essential for a comprehensive understanding of Earth's ecological and biological systems.

Rebecca Boyle [19:42]: "It's one of the primary features of Earth, and I don't think it's really thought about in that way. But it's as much a part of Earth as the ocean and the atmosphere and plate tectonics."

She also reflects on human achievements related to the Moon, such as the Apollo missions, while expressing a desire for a deeper appreciation of the Moon's intrinsic value beyond its scientific utility.

Rebecca Boyle [20:38]: "The Moon is a world. The moon is a place that is very special and unique. There's no other place like it in our solar system or anywhere else we've ever looked."

Conclusion: A Call for Reverence and Understanding

In wrapping up the episode, Boyle articulates her hope that her work will inspire a renewed appreciation for the Moon's role in sustaining life on Earth. She envisions a future where the Moon is not only celebrated for its exploratory milestones but also revered for its ongoing influence on our planet and biology.

Rebecca Boyle [21:37]: "Hope I did right by you, Moon. I hope people care a little more now."

Unexplainable concludes by directing listeners to Boyle's book, Our Moon: Earth's Celestial Companion Transformed the Planet, Guided Evolution, and Made Us Who We Are, encouraging a deeper exploration of the Moon's enigmatic influence.

Notable Quotes with Timestamps

• Rebecca Boyle [02:13]: "My book is a story about the shared history between humanity and the Moon. I think there's a lot that we still don't actually understand about that relationship."
• Rebecca Boyle [03:09]: "Basically, life as we know it would not be possible without the moon."
• Rebecca Boyle [04:27]: "There is evidence that there are lunar genes that drive certain behaviors. And this is more obvious in marine animals, which makes sense because they rely on the tide."
• Rebecca Boyle [05:18]: "One of my favorite ones is coral. Almost every species of coral responds to moonlight, at least to the lunar cycle."
• Rebecca Boyle [06:37]: "There is a Scottish botanist who devoted a lot of his career to showing this connection between the moon and plant life... they found the same lunar cycle that they find on Earth, even when they're in space in microgravity."
• Rebecca Boyle [14:41]: "But if you look at the statistical averages of people over long periods of time that are tracking these things, the numbers are the same. It's 29 and a half days. And that's the length of a lunar cycle."
• Rebecca Boyle [16:37]: "And there’s evidence that people who have bipolar disorder experience heightened episodes of mania during full moons."
• Rebecca Boyle [18:34]: "There are so many confounding factors that it makes it really difficult. And I mean, any epidemiology is hard for that reason, but that doesn't mean it's not real."
• Rebecca Boyle [19:42]: "It's one of the primary features of Earth, and I don't think it's really thought about in that way. But it's as much a part of Earth as the ocean and the atmosphere and plate tectonics."
• Rebecca Boyle [20:38]: "The Moon is a world. The moon is a place that is very special and unique. There's no other place like it in our solar system or anywhere else we've ever looked."
• Rebecca Boyle [21:37]: "Hope I did right by you, Moon. I hope people care a little more now."

Key Takeaways

1. The Moon's Role in Earth's Stability: The Moon not only orbits Earth but together they create a stable environment essential for life through tidal forces and gravitational balance.

2. Genetic Synchronization with Lunar Cycles: Marine organisms, such as corals, have developed genetic mechanisms to synchronize reproductive activities with lunar phases, ensuring environmental cues align for successful propagation.

3. Plant Responses to the Moon: Terrestrial plants exhibit growth patterns and root movements that align with lunar cycles, indicating a possible genetic or gravitational influence beyond mere light perception.

4. Human Biological Connections: There are intriguing correlations between lunar cycles and various aspects of human health and behavior, including menstrual cycles, sleep patterns, and the incidence of certain medical conditions, though causation remains elusive.

5. Scientific Challenges: Isolating the Moon's specific effects on biology is fraught with methodological difficulties due to numerous confounding variables, necessitating innovative research approaches.

6. Appreciating the Moon's Legacy: Beyond its scientific contributions, the Moon holds cultural and existential significance, embodying a unique celestial companion that has shaped Earth's biological and environmental narrative.

Further Exploration

Listeners interested in delving deeper into the Moon's influence on life and Earth are encouraged to read Rebecca Boyle's Our Moon, which offers an extensive exploration of the topics discussed in this episode.

Produced by Meredith Hognaught with contributions from the Unexplainable team, this episode underscores the Moon's mysterious and potentially profound role in shaping life on our planet.