the most obvious evidence for this model is that carnivorous plants tend to grow in habitats where water and light are abundant and where competition is relatively low: the typical bog. those that do not tend to be even more fastidious in some other way. "drosophyllum lusitanicum" grows where there is little water, but it is even more extreme in its requirement for bright light and low disturbance than most other carnivores. "pinguicula valisneriifolia" grows in soils with high levels of calcium but requires strong illumination and lower competition than many butterworts.