demes

You have a model with 3 demes, with the deme having the lowest proportion of A-individuals being killed.

You maintain diversity through demes and use incremental evolution?

There's no real theoretical underpinnings that would make it possible, either, because there's just too much gene flow between demes (...partially isolated breeding populations) to allow selection to happen.

I am working on a language currently and wonder what gives you that impression as a user who seems knowledgeable and demes to have a preference for one style verses the other.

The wise have always understood this - hence the electoral college and the incredibly convoluted system designed by Cleisthenes at the birth of democracy - trytties and demes were designed to break up traditional kinship based-allegiances which would have smothered the baby at birth.

It's a little tough to explain without resorting to a level of math nerd that is hard to type out here, but the basic problem with it is that there's too much gene flow between demes (partially isolated intra-breeding populations), and that swamps the relatively weak effects of natural selection.

Sometimes you can get GA/GP systems that escape local maxima and find much more clever and interesting solutions by setting up a selection function that adjusts its strictness curve based on measured diversity (we jokingly called this affirmative action), or by creating an environmental topology that encourages diversity (many compartments / demes, etc.).

Two of the simplest techniques are using mass extinction events and separating the larger population in to a number of smaller populations (called "demes", "islands", or "subpopulations") and is generally referred to as "the island model".