Cover art for podcast COMPLEXITY


59 EpisodesProduced by Santa Fe Institute, Michael GarfieldWebsite

Far-reaching conversations with a worldwide network of scientists and mathematicians, philosophers and artists developing new frameworks to explain our universe's deepest mysteries. Join host Michael Garfield at the Santa Fe Institute each week to learn about your world and the people who have dedic… read more


Natalie Grefenstette on Agnostic Biosignature Detection

Is there life on Mars? Or Titan? What are we even looking for? Without a formal definition, inquiries into the stars just echo noise. But then, perhaps, the noise contains a signal… To find life elsewhere in the universe requires us to wager a defined biology, to come to terms with what it means to be alive. Looking out is looking in, to ask the hardest question ever: How do we find something we might not recognize as what we’re seeking?

Welcome to COMPLEXITY, the official podcast of the Santa Fe Institute. I’m your host, Michael Garfield, and each week we’ll bring you with us for far-ranging conversations with our worldwide network of rigorous researchers developing new frameworks to explain the deepest mysteries of the universe.

This week we talk to SFI Program Postdoctoral Fellow Natalie Grefenstette, who works with SFI Professor Chris Kempes (whom we spoke to on Episode 17) on the multi-institution, NASA-funded Agnostic Biosignatures Project. Over the next hour we discuss how new approaches to astrobiological research may help science finally define the nature of living systems, and where and how to find them in the cosmos.

For show notes, research links, transcripts, and more, visit

If you value our research and communication efforts, please consider making a recurring monthly donation at, or joining our Applied Complexity Network at Also, please consider rating and reviewing us at Apple Podcasts. Thank you for listening!

Natalie’s website:

Natalie’s Google Scholar page:

"Adaptive properties of the genetically encoded amino acid alphabet are inherited from its subsets"

"Agnostic Approaches to Extant Life Detection"

"Agnostic Polymer Detection Using Mass Spectrometry for Astrobiological Samples"

"Mars Extant Life: What's Next? Conference Report"

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Podcast Theme Music by Mitch Mignano.

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