Evolution and Thermodynamics
Name: Mike Spanel
Date: Around 1993
My friend stated that the first and second laws of thermodynamics
contradict the theory of evolution. Also what are stated in the first and
second laws of thermodynamics?
Your friend is wrong, but he /she is in good company. A lot of
people misunderstand thermodynamics and think that they contradict the theory
of evolution. Here are some basic definitions: The First Law: Heat put into
a system + work done on a system = increase in internal energy of the system,
or dQ + dW = dU. This is just conservation of energy; if you take a system
and heat it, and do work on it, you will increase its internal energy. The
Second Law: If a system is changed by doing work on it or by heating/cooling
it, the entropy will either increase or stay the same. Notice that in the
above definitions, I have not yet said what a "system" is. The main thing to
remember is that although the total entropy of a system must increase or stay
the same, local fluctuations can be positive or negative. For example, by
cooling water, we can make ice. Water, a liquid, has a higher entropy than
ice, a solid. So by freezing water we DECREASE the water's entropy.
Therefore, it is possible to raise or lower the entropy of a system, as long
as it is an OPEN system (one that can exchange energy with its surroundings).
The earth is an open system, and so is a biological system (like a frog or an
ape). So evolution does NOT violate thermodynamics.
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Update: June 2012