The Astrobiology Primer 2.o, co-authored by PI Sara Walker, is an educational document reviewing the diversity of astrobiology research published in the journal Astrobiology! This is a follow-up on the highly successful Astrobiology Primer 1.0 project published 10 years ago. The 2.0 version is open-access and is available here. 

Emergence@ASU graduate students Harrison Smith and Tessa Fisher are attending a NASA-sponsored "workshop without walls" as part of the NASA Nexus for Exoplanet System Science (NExSS). The workshop is aimed at setting future directions in exoplanet biosignatures and has been profiled in Nature, and Scientific American. Emergence@ASU PI Sara Walker will deliver a plenary talk on "Statistical Signatures of Life" as part of the workshop. The full workshop agenda is available here and is open for remote participation!

Emergence@ASU graduate students Alyssa Adams, Tucker Ely, Tessa Fisher, Steven Glaser, Cole Mathis & Harrison Smith head to the Astrobiology Science Conference (AbGradCon), held Jul. 24-27th in Boulder, CO, to present their research. 



​Here's the full schedule of talks from group members:

7/27 1:15 PM Tessa Fisher - "Theory and Computation"
7/27 1:30PM Harrison Smith - "The Network Architecture of Metabolism on Earth"
7/27 2:00PM Cole Mathis - "Autocatalytic Sets and the Origin of Life"
7/27 2:15PM Alyssa Adams - "From Turing to Turtles: Theory of Biological Computation"
7/27 3:00PM Tessa Fisher - "The Origins of Life"

The full conference program is available here. You can catch the talks of our amazing grad students live SAGANet.org !

A preprint of our new paper on open-ended evolution, with lead author graduate student Alyssa Adams is now available! Read the paper here.

Formal Definitions of Unbounded Evolution and Innovation Reveal Universal Mechanisms for Open-Ended Evolution in Dynamical Systems
Alyssa M Adams, Hector Zenil, Paul CW Davies, Sara I Walker

One of the most remarkable features of the > 3.5 billion year history of life on Earth is the apparent trend of innovation and open-ended growth of complexity. Similar trends are apparent in artificial and technological systems. However, a general framework for understanding open-ended evolution as it might occur in biological or technological systems has not yet been achieved. Here, we cast the problem within the broader context of dynamical systems theory to uncover and characterize mechanisms for producing open-ended evolution (OEE). We present formal definitions of two hallmark features of OEE: unbounded evolution and innovation. We define unbounded evolution as patterns that are non-repeating within the expected Poincare\'e recurrence time of an equivalent isolated system, and innovation as trajectories not observed in isolated systems. As a case study, we test three new variants of cellular automata (CA) that implement time-dependent update rules against these two definitions. We find that each is capable of generating conditions for OEE, but vary in their ability to do so. Our results demonstrate that state-dependent dynamics, widely regarded as a hallmark feature of life, statistically out-perform other candidate mechanisms. It is also the only mechanism to produce OEE in a scalable manner, consistent with notions of OEE as ongoing production of complexity. Our results thereby suggest a new framework for unifying the mechanisms for generating OEE with features distinctive to life and its artifacts, with wide applicability to both biological and artificial systems.

Graduate student Alyssa Adams will give at talk titled "Quantifying Non-trivial Open-Ended Evolution Reveals Necessary and Sufficient Conditions" at the OEE2: The Second Workshop on Open-Ended Evolution held at Artificial Life XV in Cancun, Mexico. The talk is based on a paper Alyssa is lead author on. The paper is titled "Formal Definitions of Unbounded Evolution and Innovation Reveal Universal Mechanisms for Open-Ended Evolution in Dynamical Systems" and a preprint is available here.  Way to go Alyssa!
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A preprint of an essay by Sara Walker and Paul Davies, titled "The "Hard Problem" of Life" is now available on the arxiv preprint server. The essay is part of a collection to appear in a book titled "From Matter to Life: Information and Causality" published by Cambridge University Press and edited by Sara Walker, Paul Davies and George Ellis, due to appear later this year.

The "Hard Problem" of Life
​Sara Imari Walker, Paul C.W. Davies

Chalmer's famously identified pinpointing an explanation for our subjective experience as the "hard problem of consciousness". He argued that subjective experience constitutes a "hard problem" in the sense that its explanation will ultimately require new physical laws or principles. Here, we propose a corresponding "hard problem of life" as the problem of how `information' can affect the world. In this essay we motivate both why the problem of information as a causal agent is central to explaining life, and why it is hard - that is, why we suspect that a full resolution of the hard problem of life will, similar to as has been proposed for the hard problem of consciousness, ultimately not be reducible to known physical principles.
Read more here.

A new perspective by Sara Walker and Leroy Cronin titled "Beyond Prebiotic Chemistry" is available in this week's issue of Science. The perspective explores the dynamic properties of networks that might be necessary for the emergence of the living state, and proposes that uncovering ``laws of life'' might be necessary to solving its origins. The full text is available from Science.  

Postdoctoral scholar Hyunju Kim heads to Korea to give a talk on "Multilevel evolution of chemical reaction networks" at the NetSci2016 meeting held in Soeul 5/30 - 6/3. The full program may be found here.