the increase of something required by an organism has a positive impact on that organism 's survival
evolution has effect_of_creating_new_species multicellular_organism_reproduction_event is organism_reproduction_event. joy is positive_stimulus. positive_outcome_of_undertaking is success. spouse has effect_of_happiness positive_stimulus is stimulation. controlling_organism's_diet is controlling_event. phototroph is living_organism. positiveness is amount. impact is consequence.