One of the things that humans do in their lives is create relationships. They usually have some with other humans, but sometimes with animals too. In some cases it is not always a good relationship and in these scenarios one of them ends up injured or dead, but mostly between animals and humans. There are some relationships that can be explained in the life of a human being. A relationship is mutualism in which both organisms benefit from something they do. Humans can have a relationship like this with both other humans and animals. This relationship is safer between human and human because they can cooperate easily and don't have to worry about predators trying to eat them. An example of mutualism is usually jobs where someone does a favor for someone else and in return the person who did the favor receives money. Both people benefited because one did a job and the other got money to buy food and other important things. Another example of mutualism is when a farmer feeds a cow. Both of these organisms will benefit because the cow has received nutrients ...