Evolution and the 2nd Law of Thermodynamics

[hackenslash]

Just posted a new blog post. This is a slightly updated version of an essay I wrote for the Ratskep sci-writing competition some years ago, and deals with what entropy is in thermodynamics, information theory and statistical mechanics, and why it doesn't constitute a problem for evolution.

http://reciprocity-giving-something-back.blogspot.com/2016/04/order-order.html

Will be posting more old stuff over the next few days while I decide what to write about next.

All comments/questions welcome.

There are other posts there as well, about the KCA, pre-big-bang cosmology, philosophy and logic, etc.

[Tank]

Thanks Hack.

Sitting here with a stinking cold hardly up to reading your post. I'll read the blog when I feel a lot better!

[Claireliontamer]

I haven't really looked at all this since uni but I thought the reason evolution still obeyed the second law of thermodynamics was that you need external forces for evolution to happen.  The external forces being natural selection. 

The second law of thermodynamics can say that the universe as a whole will become disordered with time but within the universe you can have areas that become more disordered and some that become less disordered.  For example we can all take a pile of straws and arrange them in neat rows so we can create order from randomness but in doing so we need to do work and so we release heat energy creating more disorder in the particles directly around us as the thermal energy ultimately increases the internal energy of the molecules that make up the air.  The same thing happens with evolution, things appear to become more ordered but in doing so the organisms interact with their environment and have external selection pressures so it's not a closed system.

There's an analogy I've read before about a card game:

consider a simple analogy: a poker tournament. In poker, good hands are less likely to be dealt than bad ones - for example, the odds of getting three of a kind are much less than the odds of getting two of a kind. So in a poker tournament, most people will be dealt bad hands and only a few will be lucky enough to be dealt good hands. But it is the people with good hands who will be more likely to win and "survive" to the next round. So the "outside forces" (in this case, the rules of poker) acting on a random distribution (all the poker hands that were dealt) will tend to select out the best, least likely ones.

[Waski_the_Squirrel]

For anyone dealing with a lay person on this issue, just point out that the sun is constantly adding energy to the Earth system. But, thank-you for the detailed article. I bookmarked it to read this weekend.

[Crow]

For anyone dealing with a lay person on this issue, just point out that the sun is constantly adding energy to the Earth system. But, thank-you for the detailed article. I bookmarked it to read this weekend.

What does the sun have to do with the second law of thermodynamic in relation to a misinterpretation by evolution deniers?

[Ecurb Noselrub]

Entropy (2nd Law) applies universally, but locally you can have pockets of self-organization, as exemplified by evolution.  The universe is winding down, but locally it can be building up.

[Tank]

^^^ What he said.

[Waski_the_Squirrel]

For anyone dealing with a lay person on this issue, just point out that the sun is constantly adding energy to the Earth system. But, thank-you for the detailed article. I bookmarked it to read this weekend.

What does the sun have to do with the second law of thermodynamic in relation to a misinterpretation by evolution deniers?

People claim that the entropy should increase. Evolution suggests the opposite. They forget that the sun continually adds energy to the Earth.

[hackenslash]

In actual fact, the correct answer is more subtle than that. Life and evolution are actually manifestations of the 2LT. In other words, they're an example of increase in entropy.

Now, I can hear the objections already, and I know this is extremely counter-intuitive, but grasping shit like this is why they pay me the small bucks.

Let's start with a really simple example to explain.

This is a hydrogen explosion. What's actually happening here is that hydrogen and oxygen are in their lowest energy state (highest entropy), but their energy state can get lower still if they bond. The problem is that the energy contained in the hydrogen and oxygen separately is not quite sufficient to make them bond and get to a lower energy state. Inputting a tiny bit of energy makes it possible for them to get over the hump of the energy gradient so that they can shed energy and get to a lower-energy, higher entropy state.

Life is doing the same thing, because it's entirely blind to the energy budget elsewhere. Adding a little bit of energy allows entropy to increase locally at a much higher rate, and at the cost of increase in entropy overall.

So, life is simply a manifestation of the tendency for entropy to increase. Evolution is life's way of finding ever more efficient ways to increase entropy locally.

Still only half-way through my first cup of coffee, so apologies if any of that isn't clear.

[hackenslash]

New blog post: Evolution and Entropy Revisited:

A treatment of life and evolution as a manifestation of the second law of thermodynamics.

http://reciprocity-giving-something-back.blogspot.com/2016/05/evolution-and-entropy-revisited.html

This is a more complete treatment of the topic inspired by responses in this thread.