Simulation

Hybridization in turn can play a role in the fitness of a species .Below is a simulation I generated for a 200 individual population of rainbow trout on the left and a 50 individual population of cutthroat trout on the right. The graphs show the change in genotype and allele frequency over 200 generations.

                                      200 rainbow trouts                        50 cutthroat trouts

From the graphs it's evident that with the smaller population of cutthroat trout had a lot more fluctuation in genotypes while the rainbow trout genotypes were much more stable.

As with any normal habitat there are also other factors that can come into play such as reduced resources and predation. Below is a simulation of what could happen as hybridization takes place along with increased predation on the cutthroat trout because of their decreased fitness. In this scenario rivers have been stocked with invasive rainbow trout so that their population is already much greater than the cutthroat trout. Let's see what happens when they begin to hybridize with predation also being a factor in allele frequency. The graphs on the left are for the population rainbow trout at 200 and they are able to disperse easily among the cutthroat trout because their population is so high. The graphs on the right are for the cutthroat trout at 50 individuals and they are not able to disperse with the rainbow trout because they are more heavily predated. This simulation was carried out over 200 generations.

                                    200 rainbow trout                                50 cutthroat trout

These graphs show the negative impact hybridization has on the native population of cutthroat trout as they are being predated. While the genotype and allele frequency for the rainbow trout did vary over time their change are very different from the cutthroat population. At around generation 80 the aa genotype was at carrying capacity while the AA genotype was non existent. For allele frequency, it was also not evident at generation 80. 

From these simulations and the graph I found through my research it is clear that hybridization does negatively impact the cutthroat trout that are found in their native habitat.