Recently, Yellowstone National Park reintroduced wolves into their park. The wolves have completely changed not just the food chain, but the entire ecosystem. This is a sign of a “trophic cascade,” as the video calls it. A trophic cascade is when a change at the top of the ecosystem causes a change at the very bottom. The wolves, at the top of the food chain, have caused a chain all the way down to the bottom of the ecosystem, the rivers. The wolves eat the deer and prevent the remaining deer from continually walking along the rivers. This causes the riversides to be more firm in their soil and vegetation, which in turn causes other wildlife to flourish, as well as making water flow more easily instead of spreading out. In class we talked about changes in an ecosystem and how simply adding one thing may mean complicating other situations. An example was imposing hunting laws on the locals of a rural area who had spent their whole life hunting. Some of the locals’ food source was dependent on hunting. A potential change in the laws would allow deer populations to flourish, but hunters to suffer. It was always a give an take situation, which is why this article about Yellowstone is so interesting. Reintroducing wolves into the population benefited every single aspect of the ecosystem. Once we are able to rely on natural solutions rather than imposing into mother nature, we will likely create a sustainable environment where both animals and humans can function effectively.