Mongrels may be hot for a couple of generations but eventually should stabilize.  The goal should be to have a diverse, stable population where colony characteristics reproduce true from one generation to the next.

Take the feral dogs of India.  They originated from different domestic dog races but, over a course of many years of free reproduction (open mating), there is now a prevailing shape and size in the dog population [although you can still find different colors.]

You can take these feral dogs and start selective breeding to get back to the 'pure' races.  You may not get healthier dogs but you will get races that please certain people.  Humans often tend to breed animals to have/resemble human characteristics.

I believe the same happens with bees if there is a sufficient genetic diversity for a selective process in a given environment to go well.

Waldemar

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