Closed community
A closed community intentionally limits links with outsiders and outside communities. Closed communities may be of a religious, ethnic, or political nature. Governance of closed societies varies. Typically, members of closed communities are either born into the community or are accepted into it. The opposite of a closed community is an open community, which maintains social relations with external communities. Development. Frederic Clements was an American ecologist and pioneer who studied vegetation formation and development, he created the idea that plants are supposed to birth, grow/mature, and decay. Their life cycle is similar to that of a  human being. Clements also tested a theory known as "climax community"; he used areas of vegetation in comparison to actual communities. The community (fauna or human) is always constant and thriving, even if there were to be a catastrophic event, an individual or small group can manage to survive and regrow or rebuild in the same area they originated or relocate else where and succeed. The concept of many plants and animals coexisting together, having an ecosystem and building upwards was the theory he aimed for (example: rain forest). The general theory later failed due to the fact that there  was little or extremely basic comparable information about the logic of a being, the concept worked more in favor towards smaller organisms. Also, the theory became outdated and later on replaced with new sociological facts or science theories. Cons. In a 1957 article published in the "Southwestern Journal of Anthropology", archaeologist Eric R. Wolf argued that the organization of subsistence farmers into "closed, corporate communities" is a recurrent feature "in two world areas, widely separated by past history and geographical space: Mesoamerica and Central Java." Medicine in closed communities. Infectious disease presents particular challenges to closed communities; external action (from  the government or outside medical personnel) may assist in stopping the spread of the disease. Religious and cultural communities. Some religious or ethnoreligious communities are considered closed. For example: