Does evolution violate the Second Law of Thermodynamics? This article examines the relationship between thermodynamics and evolutionary processes.
Quick Answer
Evolution does not violate the Second Law of Thermodynamics because the Earth is an open system that receives a constant influx of low-entropy energy from the Sun and radiates heat to space. Local increases in order are routine when energy flows through a system.
The Claim
The Second Law of Thermodynamics states entropy (disorder) increases in isolated systems. Some argue this means complex life cannot arise by evolution.
The Facts
The Second Law applies to isolated systems. The Earth is not isolated; it constantly receives low-entropy solar energy and emits heat to space.
Local entropy decreases are normal when energy flows: snowflakes crystallize, embryos develop, and ecosystems organize—while total entropy still increases.
Evolution changes populations over time via variation, selection, drift, and recombination; none of these require violating thermodynamic laws.
Everyday Examples
Refrigerators create local order by dumping more heat outside.
Plants build complex tissues using sunlight (photosynthesis) while increasing entropy overall.
Key Evidence (Numbers)
Massive energy input: Earth absorbs ~1.74x1017 watts of solar power on average, which maintains far-from-equilibrium conditions required for complex structures.
Measured global energy budget: Energy flows in and out have been quantified and tracked by satellites and surface networks.
Formal analyses: Multiple physics papers show that evolutionary processes are fully compatible with the Second Law and quantify entropy changes.
Analysis of the Claim
The Earth exchanges energy with its surroundings, allowing ordered structures to form without violating thermodynamic principles. Evolutionary processes occur within this energy budget.