I saw your post in the admin change thread that referenced this one...
Are you aware of Galton's Polygon.
I can frame an, (my), understanding of *any* %IF% selection without variation in terms of this illustrated bio-change but in doing so I would have to go against SJ Gould's feeling that the "push" from outside in the model is not sufficient enough to be population genetic natural selection. You and I may disagree at this point but first are you aware of the figure and do you have anythhing to say about selection without variation in terms of this diagram that we could discuss. Others may simply deny that you do not look at regression as the majority but before jumping the gun lets us first see if we can speak from the same page. Sincerely, Brad. There would have to be torque however!