[单项选择]
SOCIAL BEHAVIOR IN ANIMALS
1 Social behavior is communication that permits a group of animals of the same species to become organized cooperatively. Social behavior includes any interaction that is a consequence of one animal’s response to another of its own species, such as an individual fighting to defend a territory. However, not all aggregations of animals are social. Clusters of moths attracted to a light at night or trout gathering in the coolest pool of a stream are groupings of animals responding to environmental signals. Social aggregations, on the other hand, depend on signals from the animals themselves, which stay together and do things together by influencing one another.
2 Social animals are not all social to the same degree. Some species cooperate only long enough to achieve reproduction, while others--such as geese and beavers--form strong pair bonds that last a lifetime. The most persistent social bonds usu
A. To show how social behavior benefits each individual in a group
B. To point out the role of the environment in social organization
C. To give examples of groupings that do not represent social behavior
D. To explain how not all social behavior has the same purpose