Animals are an integral part of the Earth's ecosystem. Each organism in the ecosystem plays a role in supporting the ecological community, which means that animals play a vital role as well. Each organism in the ecosystem depends on the other organisms in the system to play its role. Without animals, there would be dysfunction within the system and human life would be disrupted.
An ecosystem is a community of living and nonliving organisms working together. The air, plants, animals, soil and even bacteria are interconnected. They work together to support the ecosystem. If the plants die, the small animals that depend on them for food die as well. If the small animals die, then the larger animals that eat the smaller animals are likely to die. According to How Stuff Works, the biodiversity of a community is very important because it adds a variety of food and minerals to the ecosystem. Without the biodiversity of plants and animals, human existence would be in jeopardy. Since animals are an integral part of the ecosystem, removing a species or animals completely would upset the system and throw it out of balance.
If an animal species is removed or becomes extinct, other animals that depend on the extinct animal for food or another purpose must look elsewhere. In other words, removing one animal or organism from the ecosystem upsets the equilibrium of the entire system. This means that if animals are removed, human life is disrupted as well.