Geneological records are an important resource for the study of human genetic change over short periods of time. The primary objective of this research is to utilize the archival records of the Aland Islands, Finland, for such two such analyses. First, excellent archival records are available for the past 250 years, facilitating long-term demographic studies as well as the construction of multigenerational pedigrees. Second, this population has high frequencies of several genetic diseases that are very rare in other populations. The investigators are interested in determining the evolutionary forces responsible for these disease frequencies. The initial goal of this project is to complete the computer entry of archival records from Aland so that they can be used in a computerized construction of pedigrees for the entire population. This will allow the analysis of inbreeding levels, nonrandom mating, the degree of genetic isolation, and the extent to which individual ancestral founders may have made disproportionate genetic contributions to the current generation. These studies will have evolutionary significance, and they will help to explain why the Aland Islands population has a high incidence of some genetic diseases.