Monday, January 15, 2007

Survival of the Fittest

The animal kingdom constantly seeks to improve itself through "survival of the fittest". The feeble and diseased are preyed upon by predators, thus cleansing the stock, leaving behind the strongest to compete for the attention of mates in order to reproduce. One could argue that over many generations, this constant "improvement" would lead to super animals within a given species, but in fact it hasn't.

Ecosystems eventually reach an equilibrium with their environment, where the weak and diseased are still "trimmed" from the pack, but the overall strength of the entire system remains constant.

This all brings three questions to mind:

1) Is there some sort of external constant downward entropy that gets stronger as groups of animals improve? Such a thing would cause a natural limit to be reached.

2) Are their natural limits of the physical biology that the animals are hitting?

3) Are families of animals that exceed natural limits the ones who go on to speciate?


ydna said...

I think this limit is related to complexity and organization. A unit (or system) evolves and improves until it reaches a limit of complexity and then must transform to a higher level of organization (or abstraction, as I think of it related to system design). The original complexity is still there hiding below the abstraction. Animal, tissues, organs, cells, intracellular components, DNA, amino acids, base pairs, compounds, atoms, classic sub-atomic particles, and so on. It's turtles all the way down!

chuckwolber said...

So you saying that when a system exceeds the limit of its complexity, speciation occurs?

ydna said...

I'll offer two choices: speciation or extinction. No, that can't be right. If there's no evolutionary pressure (competition, environment, I don't know), then it's a dead end.

chuckwolber said...

Dead end? As in evolve or die? Or, given sufficient energetic input from the sun and sufficient isolation from perturbation, can't a species reach a plateau that they maintain indefinitely?

ydna said...

Well, the plateau is what I was referring to as a dead end. I made the assumption that ascending beyond the plateau or pushing through that complexity threshold is necessary or desirable. If a species is isolated, they could reach an evolutionary equilibrium with their environment regardless of any complexity limit. But as the galaxies wheel above and stir the pot, that isolation may be finite in time. The sea level drops and the land bridge forms, exposing previously isolated species to their neighbors and the competition and evolutionary pressure is on again. It's at those times that one might say, "Evolve or die."

I tell ya, this is a lot more fun to think about than waiting for dd_rescue to finish salvaging a bum partition right now.