Sara Walker

About

Professor Sara Walker is an astrobiologist and theoretical physicist with research interests in the origins of life, artificial life, and life detection on other worlds. Since joining Arizona State University in 2013, she has developed a highly interdisciplinary research program aimed at understanding the origin of life from multiple perspectives. She has mentored numerous early career scientists and leads one of the largest theory groups in origins of life and astrobiology internationally. Her team's major contributions include theoretical advances in astrobiology, developing new approaches to understanding universal features of life, detecting alien life, and designing synthetic life. At ASU, she serves as Deputy Director of the Beyond Center for Fundamental Concepts in Science and as Associate Director of the ASU-Santa Fe Institute Center for Biosocial Complex Systems. She holds joint appointments in the School of Earth and Space Exploration and the School of Complex Adaptive Systems, and is a member of the External Faculty at the Santa Fe Institute. Her work includes leading a NASA Indisciplinary Consortia for Astrobiology Research project focused on planetary systems biochemistry, which provides tools for identifying signs of life. She has been recognized with the Stanley Miller Early Career Award for her leadership in life detection and origins of life research. Additionally, she contributes to tech transfer initiatives, including projects aimed at developing…

Research topics

• Computer Science
• Artificial Intelligence
• Physics
• Astrobiology
• Philosophy
• Epistemology
• Astronomy
• Computer Security
• Data Mining
• Computational biology

Selected publications

• Identifying molecules as biosignatures with assembly theory and mass spectrometry

  Nature Communications · 2021 · 166 citations

  The search for alien life is hard because we do not know what signatures are unique to life. We show why complex molecules found in high abundance are universal biosignatures and demonstrate the first intrinsic experimentally tractable measure of molecular complexity, called the molecular assembly index (MA). To do this we calculate the complexity of several million molecules and validate that their complexity can be experimentally determined by mass spectrometry. This approach allows us to iden…

  DOI

• Assembly theory explains and quantifies selection and evolution

  Nature · 2023 · 160 citations

  . We present assembly theory (AT) as a framework that does not alter the laws of physics, but redefines the concept of an 'object' on which these laws act. AT conceptualizes objects not as point particles, but as entities defined by their possible formation histories. This allows objects to show evidence of selection, within well-defined boundaries of individuals or selected units. We introduce a measure called assembly (A), capturing the degree of causation required to produce a given ensemble…

  DOI

• Intelligence as a planetary scale process

  International Journal of Astrobiology · 2022 · 73 citations

  Senior authorCorresponding

  Abstract Conventionally, intelligence is seen as a property of individuals. However, it is also known to be a property of collectives. Here, we broaden the idea of intelligence as a collective property and extend it to the planetary scale. We consider the ways in which the appearance of technological intelligence may represent a kind of planetary scale transition, and thus might be seen not as something which happens on a planet but to a planet, much as some models propose the origin of life its…

  DOI

• Detectability of Life Using Oxygen on Pelagic Planets and Water Worlds

  The Astrophysical Journal · 2020 · 34 citations

  Abstract The search for life on exoplanets is one of the grand scientific challenges of our time. The strategy to date has been to find (e.g., through transit surveys like Kepler) earthlike exoplanets in their stars’ habitable zone, then use transmission spectroscopy to measure biosignature gases, especially oxygen, in the planets’ atmospheres (e.g., using James Webb Space Telescope (JWST)). Already there are more such planets than can be observed by JWST, and missions like the Transiting Exopla…

  PublisherOA PDFDOI

• Revealing the structure of information flows discriminates similar animal social behaviors

  eLife · 2020 · 24 citations

  Senior authorCorresponding

  are governed by different communication protocols. Our discovery reconciles the diverse ultimate causes of tandem running across these two taxa with their apparently similar signaling mechanisms. We show that bidirectional flow of information is present only in ants and is consistent with the use of acknowledgement signals to regulate the flow of directional information.

  DOI

Recent grants

• Emergent Computation in Collective Decision Making by the Crevice-Dwelling Rock Ant Temnothorax Rugatulus

  NSF · $596k · 2016–2020

Frequent coauthors

• Edward W. Schwieterman

  69 shared

• Paul Davies

  Arizona State University

  34 shared

• Shawn Domagal-Goldman

  31 shared

• Nancy Y. Kiang

  31 shared

• Harrison B. Smith

  Blue Marble Space

  31 shared

• Marcelo Gleiser

  26 shared

• Hyunju Kim

  Kyungpook National University

  24 shared

• Cole Mathis

  Arizona State University

  24 shared

Labs

• Sara Walker LabPI

Education

• Ph.D., Physics and Astronomy

  Dartmouth College

  2010

• B.S., Physics

  Florida Institute of Technology

  2005

• Other, Math/Science/Pre-Engineering

  Cape Cod Community College

  2003

Awards & honors

• Stanley Miller Early Career Award by the International Socie…

Similar researchers at Arizona State University

• Stephanie Forresth-81
• Upmanu Lallh-75
• Manfred Laubichlerh-43