6.1. Discussion

 The One-Island Model of Migration and Water Snakes in Lake Erie 

    The snakes that inhabit the islands and main land surrounding Lake Erie exhibit different camouflages that help them blend in with their specific environment. The snakes living on the main land typically have phenotype D, which is a striped phenotype. This allows the snakes to stay hidden in forrest streams. The snakes that inhabit the islands typically have phenotypes A, B, or C, which are reduced or no striped phenotypes. This allows the snakes to stay hidden among large slabs of rock. If A, B, and C phenotypes are selected for on islands snakes, then we shouldn't be seeing D phenotypes in those populations. However, that is not the case in the graphs below. We see some D phenotypes in the island populations because Migration is occurring. Snakes from the main land can move to the islands and introduce the D phenotype into the populations. The islands closer to the main land are more likely to have migration happen. This is why there is a larger number of D phenotypes in the Kelley's Island snakes than the other islands. 

    To summarize the consequences of migration for population is that it prevents the fixation or loss of specific phenotypes. The introduction of these new phenotypes could be harmful to the population because the phenotype is not best suited for that environment.