biology evolution computation philosophy
Definition
Life
Life is self-modifying computronium arising from selection for dynamic stability; it evolves through the symbiotic composition of simpler dynamically stable entities.
Perspectives on Life
Traditional biology textbooks often define life through a list of functions: eating, metabolising, excreting, breathing, moving, growing, and reproducing. However, this definition is often challenged by edge cases such as viruses (which cannot reproduce on their own) or sterile organisms (which cannot reproduce at all).
The Computational View
From a functionalist and computational perspective, life is not defined by its physical substrate (e.g., carbon chemistry) but by what it does. John von Neumann demonstrated that any complex machine capable of self-reproduction must contain:
- Machine A (Universal Constructor): A mechanism to follow instructions and build a replicator.
- Machine B (Copying Machine): A mechanism to copy the instruction tape.
- The Tape (Instruction Set): A “Standard Description” of the system (e.g., DNA).
Thermodynamic Lens
Life appears to locally violate the Second Law of Thermodynamics by maintaining low entropy. This is achieved by exploiting free energy to achieve dynamic kinetic stability. In this view, a more effective replicator is more stable than a less effective one, making evolution a predictable outcome of statistical processes.
Observation
The boundary between life and non-life is not strictly defined. Systems such as the gaia hypothesis (homeostatic planetary systems) and even human technology can be viewed as “alive” when considered as part of a larger symbiotic network of functions.