Dr. Sara Imari Walker
Sara Imari Walker, Ph.D. is an Astrobiologist, Theoretical Physicist, and Professor at the School of Earth and Space Exploration at Arizona State University. She is Deputy Director of the Beyond Center for Fundamental Concepts in Science and Associate Director of the ASU-Santa Fe Institute Center for Biosocial Complex Systems.
Sara is an Associate Professor with joint appointments in the School of Earth and Space Exploration and the School of Complex Adaptive Systems. She is also a member of the External Faculty at the Santa Fe Institute, a Fellow at the Berggruen Institute, and leads the ASU Research Lab Emergence.
She is Cofounder of the astrobiology social network SAGANet, and on the board of directors for Blue Marble Space since 2011, a nonprofit education and science organization. As a science communicator, she is a frequent guest on podcasts and series, such as Through the Wormhole with Morgan Freeman — Are Aliens Inside Us?
Her research interests are in the origins of life, artificial life, astrobiology, emergence, self-organization, homochirality, life, and detection of life on other worlds. She seeks to develop new theories of physics to explain what life is, how it emerged, and what signs of life might look like on other planets.
Sara uses mathematical models to investigate chemical evolution and the development of networks on Prebiotic Earth. She looks at information flow in biotic and abiotic systems to further define life and its emergence. Read The Algorithmic Origins of Life, The informational architecture of the cell, and Beyond prebiotic chemistry.
At ASU since 2013, Sara has built a highly interdisciplinary research program to tackle the origin of life question from all sides. She leads one of the largest theory groups in the origins of life and astrobiology internationally.
Her team’s major contributions are in theoretical advances in the field of astrobiology, developing new approaches to the problem of understanding universal features of life that might allow a general theory for solving the matter-to-life transition, detecting alien life, and designing synthetic life.
Sara has studied the possible mechanisms of the origin of homochirality, which is a key problem in the origin of life. In her research, she has used several models, such as the Sandars polymerization model, the Langevin equation, and the activation-polymerization-epimerization-depolymerization (APED) model to imitate potential prebiotic conditions for autocatalytic polymerization networks. Read Toward Homochiral Protocells in Noncatalytic Peptide Systems and Punctuated Chirality.
Sara discovered that only networks with long polymers show the potential to produce significant spontaneous asymmetrical chirality in speculative early Earth conditions. She has also shown that the violent environment of prebiotic Earth would have continuously changed the chirality of reaction networks by a mechanism they termed punctuated chirality. This suggests that the origin of homochirality was not a singular event and that chiral selection occurred at the same time as the origin of life.
Sara and Marcelo Gleiser also revealed that homochiral proto-domains can form in the middle of racemic networks and that the slowdown of these networks through processes such as tidal motion or evaporating pools could have led to the stabilization of these structures on early Earth.
The results of these simulations have helped to reveal what possibly occurred during the origin of homochirality and its effect on the origin of life. Read An Extended Model for the Evolution of Prebiotic Homochirality: A Bottom-Up Approach to the Origin of Life.
Sara is the PI of a NASA Interdisciplinary Consortia for Astrobiology Research (iCAR) project focused on “Planetary Systems Biochemistry”, which provides a new set of rigorous, agnostic tools for NASA and other agencies to identify signs of life.
She is playing a key role in developing statistical frameworks for life detection and new approaches to the origins of life and was awarded the Stanley Miller Early Career Award by the International Society for the Study of the Origin of Life in 2021 for her international leadership in these areas.
Sara recognizes how understanding life at a deep level should have major technological and societal implications and therefore contributes to the tech transfer of her lab work. In this direction, she is part of a team awarded four highly competitive prizes from the National Institutes of Health to build a pipeline from prediction to design, discovery, and validation of new, non-addictive opioid drugs.
In 2024, Sara published her first book, Life as No One Knows IT: The Physics of Life’s Emergence. In her book, Sara argues that solving the origin of life requires radical new thinking and an experimentally testable theory for what life is. This is an urgent issue for efforts to make life from scratch in laboratories here on Earth and missions searching for life on other planets.
Sara serves on several steering committees and boards, including the Sloan Foundation’s Matter-to-Life Initiative, the LIFE mission concept, the NASA Network for Life Detection, and the NSF Origins of Life Coordination Network.
She is also heavily invested in public engagement in science and has reached thousands in person and hundreds of thousands remotely through lectures, podcast interviews, and other activities.
Previously Sara was NASA Postdoctoral Fellow at the NASA Astrobiology Institute, Adjunct Faculty Beyond Center for Fundamental Concepts in Science at Arizona State University, and Research Scientist at the Blue Marble Space Institute of Science.
Her papers include Autocatalytic Replication and Homochirality in Biopolymers: Is Homochirality a Requirement of Life or a Result of It?, Universal Sequence Replication, Reversible Polymerization and Early Functional Biopolymers: A Model for the Initiation of Prebiotic Sequence Evolution. Chiral Polymerization in Open Systems From Chiral-Selective Reaction Rates, Evolutionary Transitions and Top-Down Causation, Life’s Chirality From Prebiotic Environments, and The Chirality Of Life: From Phase Transitions To Astrobiology.
Sara earned her A.A. in Math/Science/Pre-Engineering at Cape Cod Community College in 2003. She earned her B.S. in Physics at the Florida Institute of Technology in 2005. She earned her Ph.D. in Physics and Astronomy at Dartmouth College in 2010 with the thesis “Theoretical Models for the Emergence of Biomolecular Homochirality.” She was also a postdoctoral fellow in the NSF/NASA Center for Chemical Evolution at the Georgia Institute of Technology between 2010 and 2011.
Sara was the 2023 Polymaths Award Winner. The award enables her lab to take theoretical ideas on the nature of life and its origins to practice, including applications like setting data standards for origins of life research, algorithmic agency detection, and designing planetary futures.
Watch What Is Life: The Secret to Understanding Ourselves?, Is Alien ‘Life’ Weirder Than We Imagine: Who Is Out There?, Rethinking Astrobiology’s Biggest Questions About Life Through New Physics with Dr. Sara Walker, Sara Imari Walker on Physics, Emergence, and Life on Other Planets | Closer To Truth Chats, Sara Walker, ASU | Unraveling Life’s Beginnings with the Cosmic Perspective. and Ask An Astrobiologist: Physics and the Origin of Life with Dr. Sara Imari Walker.
Watch Neil & Sara Imari Walker Discuss New Theories on The Origins of Life in the Universe on StarTalk, Sara Imari Walker on Aliens and the Origins of Life at Skeptic, and Joe Rogan Experience #2184 — Sara Imari Walker.
Listen to The Origins of Life with Sara Imari Walker and Sara Imari Walker on Information and the Origin of Life with Sean Carroll. Read her AEON Contributions Time is an object and Life ≠ alive. Listen also to The SciFri Book Club Talks ‘Dune’ and The SciFri Book Club Introduces Dune with Sara.
Read her Big Think Interview Sara Imari Walker: Using physics to rethink the definition of life. Read New way to look at dawn of life: Focus shifts from “hardware” to “software”.
Visit her LinkedIn profile, Academic page, Emergence Lab page, and Wikipedia page. Follow her on Facebook, Instagram, Academia, and Twitter.