The Purpose Podcast

Around the mid twentieth century Barbara McClintock revolutionized the way we study cells. She was studying corn or maize and developed a way to look at their chromosomes. These are large DNA molecules containing multiple genes packaged into a single structure. Most people have between 45-47 chromosomes in ever cell of their body. McClintock identified different part of the chromosomes and what they might be doing. But her most controversial work happened in the 1940s and 1950s when she was cross-breeding maize to understand why some kernels had different colors. Based on her results, she proposed that this happens, when some genetic elements—basically bits of DNA— jump to a different chromosomal position. Science is always conservative and any new idea is challenged, and because she was a woman, it was probably a little worse for her. But the idea was solid. It survived the scrutiny. In 1984, she was awarded the Nobel Prize for Physiology and Medicine. The only woman to have won it unshared. And the idea that bits of DNA can jump around is well accepted. These things are called transposable elements and they are far from rare. By some estimates, they are about 40-50% of our DNA and in some plants they might be even more.

But what is less settled is what they are doing in our cells.

They might have some function. But could they also just be rogue elements that are out for themselves?

Researchers have gone back and forth on this debate for a while.

In today’s episode, I will be talking to Stefan Linquist about a different idea. You see selfish genetic elements or transposable elements they don’t always jump around, but in some cells in some species, they are more active. Why? According to Stefan, we might begin to understand this by looking at the cell through the eyes of the selfish genetic element – an ecosystem approach, if you will.

References

• Linquist, S. et al. Transposon Ecology and the Octopus Genome. BioEssays 48, e70124 (2026).
• Bonar, M., Elliott, T. A., Ahmadi, M. A. M., Cottenie, K. & Linquist, S. Biological Implications of a Detailed Repeat Annotation in Octopus vulgaris. Genome Biology and Evolution 18, evag137 (2026).

Podcast production was supported in part by the Consortium for Advancing a Science of Purpose (#63716; John Templeton Foundation). The opinions expressed are those of the participants and do not necessarily reflect the views of the John Templeton Foundation.

We live in a social world as full of cooperation as it is of competition. How should ecologists and evolutionary biologists tell them apart?

Podcast production was supported in part by the Consortium for Advancing a Science of Purpose (#63716; John Templeton Foundation). The opinions expressed are those of the participants and do not necessarily reflect the views of the John Templeton Foundation.

In the 1960s the search for alien life inspires the chemist James Lovelock to imagine that life, if it occurred anywhere in the universe would be accompanied by an atmosphere that was in constant flux. He called this the Gaia hypothesis. Since then the idea has been subject to constant misinterpretation. In this episode, Siddhant talks to Richard Boyle about what the Gaia hypothesis is, what it isn't how planetary scale dynamics interact with life and natural selection.

This episode assumes some knowledge of earth systems and evolution.

Richard's paper describing an attempt to Darwinize Gaia

https://royalsocietypublishing.org/doi/reader/10.1098/rstb.2024.0087

Podcast production was supported in part by the Consortium for Advancing a Science of Purpose (#63716; John Templeton Foundation). The opinions expressed are those of the participants and do not necessarily reflect the views of the John Templeton Foundation.

Does Earth’s habitability for life exist due to or in spite of Darwinian evolution by natural selection? (#63450; John Templeton Foundation)

https://youtu.be/Bs4ne_PBylY?feature=shared

David Oderberg is a professor of philosophy at the University of Reading. In this episode he talks about why he got into philosophy, why philosophy is important for the study of living things and the theory of mistakes he's developing along with the rest of the Mistakes in Living Systems team.

Find out more about his work - https://www.davidsoderberg.co.uk/

Host Siddhant Pusdkekar speaks to Joanna Masel about how she stumbled upon a 4 billion year old trend and a problem that evolution has been trying to solve since the beginning of life

Papers referenced in this episode

Genes from Junk DNA

https://www.nature.com/articles/s41559-022-01925-6.pdf

Papers on directionality in evolution by Joanna Masel

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7153934/

https://elifesciences.org/articles/57347

https://academic.oup.com/genetics/article/211/4/1345/5931507

Emilie Snell-Rood convinces people that studying weird animals can be useful for designing things. Jessica Rossi-Mastracci is looking forward to playing with bioinspired designs, one of which may or may not be a butterfly wing wallpaper

In this episode of The Purpose Podcast we meet a designer and an evolutionary biologist who are working together to bring light into a dark corner of the University of Minnesota

Artwork by Bernie Cook, who is open to requests (nardcook13@gmail.com)

The Purpose podcast is hosted and produced by Siddhant Pusdekar (pusde001@umn.edu) and is brought to you by the Biological Purpose Project (https://www.biologicalpurpose.org/) funded by The John Templeton Foundation

Music (In order of appearance)

Aimless Walk by Silicon Transmitter

Emotions Are Alright With Me by Geb

Sourced from the Free Music Archive

Ramray Bhat is an associate professor at the Indian Institute of Science in Banagalore, India. He studies how collectives of cancer cells migrate and metastasize to new organs within the human body.

To learn more about the Biological Purpose Project visit - https://www.biologicalpurpose.org/

Podcast produced by Siddhant Pusdekar

Episode cover art by Bernie Cook

Music (In order of appearance)

Aimless Walk by Silicon Transmitter

Where everything begins by drób

Emotions Are Alright With Me by Geb

Sourced from the Free Music Archive