There isn't any AI or genetic algorithms involved. It's actually using genetics modelled on how genes in the real world operate (although on a a vastly simplified scale as there are only about 3 dozens genes as opposed to hundreds of thousands). Some phenotypes operate using dominant/recessive pairings, while others are quantitative, meaning that they can have values any where within a range of options. When you breed plants together it samples the two parents' genes and blends them, which is why your crosses are not always identical. There is also a chance for the crosses to mutate from the original parent, although the rate and scale of the possible mutations is greatly exaugurated.