A new criterion for demarcating life from non-life

Area of Science:

• Astrobiology
• Origin of Life Studies
• Synthetic Biology

Background:

• Defining life is crucial for identifying extraterrestrial or synthetic organisms.
• Existing criteria for life are often too restrictive or too broad.
• Understanding life's origins and evolution requires robust demarcation criteria.

Purpose of the Study:

• To propose a novel, more effective criterion for distinguishing living from non-living systems.
• To provide a framework for assessing candidate life forms in diverse contexts.

Main Methods:

• Introduced the concept of 'active causation' as a defining characteristic of life.
• Defined active causation as the organism's use of its Darwinian fitness estimate to modulate stochastic changes.
• Described a feedback loop where changes inform future fitness estimates.

Main Results:

• Living systems are characterized by their capacity for active causation.
• Active causation involves a feedback loop modulating hereditary and behavioral changes based on self-estimated fitness.
• This mechanism results in a combination of predictability and unpredictability in life's trajectories.

Conclusions:

• The proposed criterion of active causation offers a more precise definition of life.
• This framework helps differentiate living systems from non-living matter.
• Active causation underlies the self-directed agency observed in living organisms.