The Role of Exchangeability in Biology, Genetics and Medicine

In the context of various models appearing in biology, genetics and medicine, the concepts of exchangeability and its extension partial exchangeability are discussed. It is pointed out that these concepts appear either as a basic assumption in some models or are inherent in the composition of a population (or subpopulations). That is, when the population is homogeneous as a whole or can be partitioned to several subgroups which are homogeneous within themselves. Also extensions of some of the existing results in the literature are carried out.