The Second Law of Thermodynamics and Evolution

Just a quick question that has been troubling me. How do experts explain the seemingly inherent paradox between the 2nd Law of Thermodynamics, which states that entropy increases in a system over time, and evolution, which implies that order increased over time? It seems to me that if the 2nd law of thermodynamics were true, immediately after the big bang there would be the highest probobility for life, and that life would break down and become chaotic as time passed. Please tell me where im wrong.

The 2nd law applies to closed systems. The earth is an open system, deriving much energy from the sun.

The caricature of 2LoT peddled by creationists would also prevent an acorn growing into an oak tree and would prevent solar panels from working.

In the case of members of the public who believe this, most of them simply don’t understand what it is they are talking about; in the case of creationist authorities who talk about this, most of them are wilfully misrepresenting the case.

The Second Law is true of an enclosed system, which the Earth very definitely is not. Local increases in order can arise so long as the total order does not increase (which is why your refrigerator works!).

The Solar System is more like an enclosed system. Any increase in order on Earth is paid for many times over by the increased disorder due to the sun “burning down” and supplying the Earth with energy.

As for the universe as a whole, it is true that order was maximum close to the initial singularity. However, life requires rather a lot more than mere “order”, and the high temperatures and Hydrogen/Helium monotony (“interesting” atoms only came later, manufactured by stars) precluded the possibility of life.

Try this.

One could argue that the combined gene pool is a closed system. But I don’t know the mathematics of applying the second law of thermodynamics to a discrete information system.

Not with respect to energy, one couldn’t.

They are simply different subjects. One could no more apply thermodynamical theory to genetics than the other way around.

(An ideal gas breeds with a Bose-Einstein condensate. What is the specific heat capacity on the offspring at 300K?)

One would be talking bollocks. Any “mathematics” allowing one to apply 2LoT to a “discrete information system” would be pseudo-science at best.

Geeze Jurph, way to slam Claude Shannon!
Here’s a snippet on the second law in molecular information theory.

Because the experts aren’t fooled by the strawman that creationists put up. Here’s another article about the 2LoT and evolution.

The above link is a good place to start, and finish.

Even in a closed system (e.g., the universe), the second law only refers to entropy on a global scale. On a local scale, order may increase. It’s exactly what SentientMeat said, only there’s no requirement for an open system.

Information-theoretic entropy is a different beast from thermodynamic entropy, and while they are related, it would be a mistake to assume that they’re the same.

Boy, if that’s the case. I refuse to clean my house anymore; it would violate teh second law of thermodymanics.

Hmmm, using the term ‘global’ in reference to the universe doesn’t exactly clarify much. :slight_smile:

You cannot evaluate evolution and life in energy terms without also including the source for nearly 100% of all energy used by life. Otherwise your equations are never, ever going to balance. That energy doesn’t just appear from nothing as a free gift. That means the including the Sun.

All life on Earth in terms of energy is just a tiny fraction of the energy converted to a chaotic state by the Sun (i.e. what we call ‘shining’). The solar system is gradually moving from an ordered state to a chaotic state. The Earth, life and evolution is just a tiny and temporary blip on the chart.

The 2nd Law is certainly not being contradicted.

Others have dealt with the 2nd Law aspect here; I am more interested in addressing the “evolution…implies that order increased over time” part.

Simply put, evolution implies no such thing. How does one state objectively that a rhinoceros is more “ordered” than a flatworm? The former is certainly more complex, but that has little to do with the entropic states of either critter.

Entropy is a measure of how energy moves throw a system. Evolution says nothing at all about how that happens. Really, entropy as a physical concept is no more relevent to evolution than is, say, gravity. Sure, evolution is limited by both concepts in the sense that it is limited by physics in general, but neither plays an active role in the actual mechanisms of evolution.

Now, if you want to talk about ecology, then entropy becomes something of a more active player…

Just out of curiosity, I wonder if the “Hovi” in the OP’s screen name derived from “Hovind”.

Not a chance in Hovinds hell. it’s just a nickname.

And great links Sentinent and Meatros. I had been unable to find anything relating directly to this in the past.

BTW, I was in no way going to argue that my question was a refutation of evolution (or the 2nd Law). The question just popped into my head the other day while reading some Hawking, and coming from a family where i was the only non-creationist, I figured it was only a matter of time before one of them posed it to me. I appreciate yall clearing it up for me though.

An acquaintance of mine is a professor of biology in England, who was doing some research into the relationship between rigidty in molecules and their level of “chaining” (for lack of a better word.)

this was several years ago, but basically he said that it appeared that as organic molecules grew in size and complexity, they became less rigid… so entropy has its day in the sun, so to speak.

Don’t have any personal clue on this, I took the biology at my uni with the football team, the class was more interesting.


There is a thread in GQ now “Thermodynamics Question” which addresses Gibbs free energy, i.e. Delta G = Delta H - T x Delta S. The change in enthalpy dwarfed the potential change in entropy. Thus, any attempt to “crystallize” would be blown apart by the huge changes in enthalpy (components include kinetic energy.) I know this is in simplistic terms, but it seems obvious …

And this is why the earth must be destroyed you see. It’s filling the universe with disorder and chaos. Hmm… Maybe this is the reason the aliens will offer to us before they blow us up to make way for the hyperspace bypass.

Since you brought up creationists, here is a creationist’s rebuttal (not mine personally, but I’ve seen this response on other forums):

An open system and an adequate external source of energy are necessary, but not sufficient conditions, however, for order to be generated and maintained, since raw undirected, uncontrolled energy is destructive, not constructive.