[Lucky Dog]

I distrust your "three possibilities in terms of natural selection: beneficial, detrimental, or benign."

I remain open to convincing argument otherwise. However, your post did not provide another category. Even assuming a range, as you postulated, a mutation must fit into one of my posited categories for the environmental natural selection pressure to select it for propagation to succeeding generations as a component of evolution.

Please see post 231

[Coyoteman]

I remain open to convincing argument otherwise. However, your post did not provide another category.

I don't see where a three-part limit is justified.

In just one trait, skin color, I discussed a cline (range of variation) from extremely dark to extremely light, to albino. This reflects a real-world condition.

There are many other traits involved in evolution.

These traits can be expected to vary, co-vary, and counter-vary in all sorts of ways. Some mutations will have both beneficial and detrimental results (sickle-cell anemia being one example).

I simply do not see a need to restrict the possibilities to only beneficial, detrimental, or benign. There will be "little bit beneficial-somewhat detrimental"; "mostly benign here, detrimental 2000 miles farther north"; "mostly benign here, advantageous 2000 miles farther south"; and so on and on and on.

That is why, when the climate changes, the range of variation within a population allows some to adapt better than others--they are already carrying the mutation from hundreds, thousands, or millions of years ago; it was benign but now (look at those darn glaciers!) its beneficial.

That's the way evolution works, and why simplistic mathematical models often come up with screwy results.