Understood - and I was just making the observation that the expressions produced during the process were junky in a way that's characteristic of the way they ar

Understood - and I was just making the observation that the expressions produced during the process were junky in a way that's characteristic of the way they are evolving : Mixing together two honed expressions would produce much more extreme deviations in 'children' than the offspring of two of these hairy expressions. Not only are the expressions tending to get more accurate with each generation, but their degree of 'evolvability' is also being selected for.