There are occasions when, either by choice or by circumstances, human beings are driven to temporary or permanent isolation from other people. Some of the examples are working in a lighthouse, serving a prison sentence, or doing research in less populated areas. The same can happen to entire human populations, although this may seem quite improbable in an era which provides ever-increasing means of communication and transport. However, the gap between those who have access to these technological advancements and those who do not is increasingly widening. The number of people living in isolated communities, and whose isolation from other populations is constantly increasing, is largely underestimated.