The algorithmic origins of life

Abstract

Although it has been notoriously difficult to pin down precisely what is it that makes life so distinctive and remarkable, there is general agreement that its informational aspect is one key property, perhaps the key property. The unique informational narrative of living systems suggests that life may be characterized by context-dependent causal influences, and, in particular, that top-down (or downward) causation-where higher levels influence and constrain the dynamics of lower levels in organizational hierarchies-may be a major contributor to the hierarchal structure of living systems. Here, we propose that the emergence of life may correspond to a physical transition associated with a shift in the causal structure, where information gains direct and context-dependent causal efficacy over the matter in which it is instantiated. Such a transition may be akin to more traditional physical transitions (e.g. thermodynamic phase transitions), with the crucial distinction that determining which phase (non-life or life) a given system is in requires dynamical information and therefore can only be inferred by identifying causal architecture. We discuss some novel research directions based on this hypothesis, including potential measures of such a transition that may be amenable to laboratory study, and how the proposed mechanism corresponds to the onset of the unique mode of (algorithmic) information processing characteristic of living systems.

Can a Robot Have Free Will?

“…If they were, then switching would always be biased by the difference in energetic cost between e.g., switching on and off. Energetically unbiased switching is the physical underlying mechanism of "information abstraction" referred to by Walker and Davies [62]. In reality, switching (and state-changes in general) always have energetic consequences (more deeply, there is always an exchange of entropy between the system and an external energy source), which is one of the reasons an autonomous agent must complete work cycles as Kauffman [63] specifies.…”

“…A less obvious, but crucial property of the switch for the physical embodiment of computation is "thermodynamic indifference". Walker and Davies [62] focus on computation in explaining the origin of life, referring to genetics-first theories as "digital-first", emphasising the need for "programmability" and its provision by informational polymers (the genetic oligomers RNA, DNA etc.). By programmability they meant that components of a system are configured so that the system state can change reversibly, approximately independent of energy flow: i.e., changes of state are not accompanied by substantial changes in potential (stored) energy.…”

Proper activity, preference, and the meaning of life

“…That represents only one such controversy from the past year. For metabolic definitions, Sara Walker has tried to mathematically characterize top-down causation and information control in a way that would objectively reduce self-regulation (Walker and Davies 2013;Walker et al 2012). She has also run into difficulties formalizing an objective metric.…”

“…The question of exactly how we are to conceive of biological activities within this framework remains unresolved. Over the past century, scientific definitions of life have included two prominent schools of thought: metabolic and evolutionary (Chao 2000;Fleischaker 1990;Tirard et al 2010;Walker and Davies 2013). 2 The activities in question have remained the same, with extensive refinements in how they are characterized.…”

“…Maintenance is central, with a preference for optimized processing. Walker and Davies (2013) use explicit computer analogies. Within such a framework, the binary character of life is a processing unit, the range is processing speed, and the preference is for higher speeds and robustness in the system.…”