Carnivorous plants turn carnivorous because they can't get enough nitrogen from the soil usually. Thus, in these populations, it's likely that the additional ge

Carnivorous plants turn carnivorous because they can't get enough nitrogen from the soil usually. Thus, in these populations, it's likely that the additional genes favoring carnivory evolved first and then, with that in place, the genes for nitrogen absorption would not confer any advantage or disadvantage so would be slowly lost by genetic drift.