Biodemographic characteristics of North-Western Italian population (Giaglione-Susa Valley) between 18th and 19th century.

For the study of genetic changes that occur over time in human communities (microevolution) anthropologists and biodemographers have favored the use of renewable flow, in particular the registers of marriage. Indeed they allow to easily estimate several biodemographic parameters (endogamy and exogamy; repeated pairs; immigration), even for long periods of time, since it is quite common to have consecutive series of documents relating to the marriage of a population. However, the sources of flow do not always allow to study in depth the factors that have given continuity to the community because they provide only partial information on demographic structure, the mode of aggregation of its members and the processes of change within families. A good alternative to sources of flow may be the use of sources of state, civil (censuses) or parish sources (the status animarum), which give a very detailed picture of the state of the population at a given time. The retrieval and analysis of census documentation assume therefore a primary role in order to obviate the intrinsic weaknesses of the sources of flow. In the perspective of biodemographic studies, the integration of the two types of sources is in actual fact the operating optimum. It must be remembered that it is quite difficult to find contemporary sorces of flow and of state fr the italian populations pf the past.