I'd say more likely its equivalent to particle filters. Mold probably shoots spores all around the petri dish, and the spores that have better access to nutrien

I'd say more likely its equivalent to particle filters. Mold probably shoots spores all around the petri dish, and the spores that have better access to nutrients grow more, thus putting out larger proportion of spores in the next generation. A few generations later, all organisms that are either directly next to the nutrients, or next to another organism which has good access to nutrients survive.