Just another Reality-based bubble in the foam of the multiverse.

Thursday, March 10, 2005

Evolution and Entropy

Think of it this way: which requires more food- a cold blooded 300 lbs crocodile that eats every week, or a warm blooded 300 lbs tiger that eats every day?

Both are highly evolved; but from our perspective, the more advanced tiger beats the croc every time. This is because the tiger has specialized in a set of tools that enable it to use more of its environment's energy. Here, the energy is in the form of the living material that constitute its prey.

All energy in our biosphere derives from the sun.

At some point, a billion years ago on a world where the core is constantly torn between the gravitational influence of a large moon and its solar primary, water oscillates wildly between gas, liquid, and solid phase. The churning, electrostatically charged atmosphere and the turbulent heated mantle interact at the surface, releasing energy that provided an environment where organic molecules could stabily replicate themselves. The molecules that formed complexes that did it the best used the energy in the environment to release heat.

Only a few of the infinite combinations did this well, so they predominated. The ones that survived best in this world were those that were able to propagate an advantage for themselves, and so the long road to evolution began. This evolutionary process is driven by entropy, because the more evolved organisms have an advantage over their resource competitors that enable them to better utilize their environment and propagate themselves through space and time.

The ones that are less efficient soon cease to exist- or find a niche that no longer competes with the organisms with the selective advantage.

From the acquisition of mitochondria to utilize oxygen in eukaryotes, to the aquisition of chloroplasts in plants, to the development of multicellularity, or a backbone, or the ability to use air as an oxygen source, each mutation that survives confers an advantage to the organism.

There are poor mutations that confer disadvantage that are quickly weeded ot.

There are mutations that are neither helpful nor a problem: and the genetic mechanism is again selected that retains these diverse elements in the population against the day an ice age begins, or insolation increases or decreases, or some unforseen novel event makes a neutral mutation bouncing around the gene pool a sudden advantage.

And again, what constitutes an advantage in the Jungle of Life? A trait that enables an organism to better utilize the energy present in the environment for survival and propagation. Living systems must use an energy source to run their bodies that releases free energy, creates heat, and increases entropy. This is called the Gibbs Free Energy relation: dG = dH - T(dS).

Energetically, the second law of thermodynamics favors the formation of the majority of all known complex and ordered chemical compounds directly from their simpler elements. Thus, contrary to popular opinion, the second law does not dictate the decrease of ordered structure in its predictions, it only demands a "spreading out" of energy in all processes.

In short: evolution, like life itself, requires an increase in entropy and is always accompanied by an increase in entropy.

It's just that the laws of thermodynamics that make most macroscopic events possible are such a given in our perception of the universe that we don't have to write them down.

This has to do with most of the silly things Creationists say.

Take, for example, their confusion about phenomena like the Sun. A creationist will point at the Sun and say there's surely an example that the Will of God violates all our scientific mumbo-jumbo. I say it's more a case of the misunderstanding of the ignorant being unable to decipher what the mumbo-jumbo means.

The laws of thermodynamics- or gravity- or evolution- are manifestations of the special cases of the natural laws that a Newton or a Darwin could percieve in our 4 dimensional universe.

A particle physicist would tell you that there are more dimensions than 4 that make up our universe. Exactly how many is something for people that understand the math to argue about. A big problem is that we're limited to the scale of the universe we can intuitively grasp, and by what the neuronal wetware in even the brightest of our skulls can process.

Presumably if intelligence keeps getting selected for, we'll keep getting smarter- or at least the ones of us that survive to reproduce will.

But something like the Sun or any thermonuclear reaction is a great example of a macroscopic event that's heavily dependent of those quantum dimensional interactions.

Energy isn't created- but the particle interactions on a scale we're incapable of intuitively understanding make the energy release inevitable.

[ posted as a comment to a post of DarkSyd's ]

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