Entropy and Evolution

There is a pervasive belief among some creationists that the second law of thermodynamics negates the evolutionist claim that more ordered systems can form through self-organization. Or in more simple terms, evolution violates the law of entropy. This is based on a flawed understanding of the second law of thermodynamics. The second law of thermodynamics states that in a closed system chemical, pressure, and temperature potentials tend toward states of equilibrium. Stated more succinctly, entropy increases in a closed or isolated system. Thus, some argue it is not possible for life to evolve from inorganic to organic chemical processes and onward to increasingly more complex life forms. This argument overlooks a key component in the second law of thermodynamics. Fundamental to the law is the statement that entropy increases in a closed or isolated system. The earth is not an isolated system. There is a constant stream of energy from outside the system in the form of solar radiation. The mass of the earth itself also contains a significant amount of energy in the form of heat that provides significant amounts of geothermal energy.

The average amount of solar energy reaching the earth is in excess of 300 watts per square meter per second. The peak solar energy in direct sunlight is slightly more than 1.3 kilowatts per square meter per second. This translates into 3.2-3.8 million exajoules reaching the earth's surface every year. This is not a trivial amount of energy. Such a steady input over the course of 4.6 billion years results in a significant amount of energy that could fuel evolutionary processes.

The solar energy reaching the earth is complemented by the geothermal energy provided by radioactive decay from within the earth. It is estimated that the earth contains 12.6 x 10²⁴ MJ of energy in the form of heat. In the process of continually releasing a portion of the original amount of energy found 4.6 billion years ago another substantial influx of energy has been provided. 


We observe the second law of thermodynamics in action with the earth and sun releasing vast amounts of energy. That energy will continue to be partially and steadily introduced into the earth's biosphere. In trillions of years all that we see in the visible universe may have dissipated into a cold, dark abyss. However, in the intervening billions of years, evolutionary processes will be well fueled. These processes on the earth will be cut short in several billion years by our sun swelling into a red giant. However, the sun's continually burning of hydrogen will have assisted, through the process of entropy, billions of years of fuel for evolution.