and yellow; with brown being more dominant than pink and yellow. Furthermore, banding variation can be described as unbanded and banded, with banded individuals differing from another by the number of bands. One of the conclusions that could be drawn out of this research is that in grasslands, yellow individuals had a higher survival rate and were more abundant in these grasslands. This means that natural selection acted on the shell colour, which means that shell colour is the interactor in this example. Furthermore, they found that the brown individuals were more abundant and had a higher survival rate in woodlands than the yellow individuals. Moreover, a specific form of natural selection called thermal selection showed that shell colour worked in the interaction with the environment by yellow shells being more abundant, so more adjusted to reflect heat, in warmer places. References Science and Selection, David Hull, 2001 (http://assets.cambridge.org/97805216/43399/sample/9780521643399ws.pdf) Replication and Reproduction, David Hull, 2001 (https://plato.stanford.edu/entries/replication/) Color polymorphism in a land snail Cepaea nemoralis (Pulmonata: Helicidae) as viewed by potential avian predators, Adrian Surmacki & Agata Ożarowska-Nowicka & Zuzanna M. Rosin, 2013 (https://link.springer.com/content/pdf/10.1007/s00114-013-1049-y.pdf) On the Origin of Species, Charles Darwin, 1859 External links The Role of Behavior in Evolution Interactors is also an IT Company Evolutionary biology