Quote Originally Posted by halfeye View Post
I find the second of those more plausible by far. There can be all sorts of random accidents that lead to physical characteristics, they have to be selected, but there is a random factor in there.

I first became aware of the scientific basis for entropy and natural selection at about the same time, and I was impressed by their apparent similarity. They are both sort of inevitable, recursive and fractal seeming. I don't have the facility with maths to prove that they come from the same base, but I think it is highly likely that they do.
The Price Equation is the sort of posthoc inevitable account of natural selection. Basically, if you have a set of things with some attribute x, the total change in x from one time to the other can be written as the innate charge in x for each of those things, plus the correlation between x and the rate at which things are added or removed from the set.

It's kind of tautological if used post-hoc, like saying that 3 can be written as 1+2. But you can propose predictive, hypothetical mechanisms for both the drift and selection terms (like 'birth rate is proportional to metabolic efficiency') and then the equation will let you convert those into predictions about how the frequency of that attribute will change in the population.