Pedigree and marriage data from the population of Sanday, in the Orkney Islands, Scotland, were used to assess temporal trends in isolation by distance. All data were analyzed for three time periods, defined by the year of birth for married males: 1855-1884, 1885-1924, and 1925-1964. Random kinship ((f)) was determined by computing the average inbreeding coefficient of all potential mates of each married male. Potential mates were selected on the basis of age and marital structure of the population. Estimates of the parameters of the isolation by distance model reveal a decrease in local isolation and an increase in short range and long range migration over time. Comparison with other published estimates show Sanday experienced isolate breakdown over time. Measures of the fit of the model decrease over time, showing that the degree to which geography acted as a determinant of kinship diminished over time. Comparison of values of random kinship ($) with observed inbreeding (F) shows that consanguinity avoidance occurred at all distances, but was more pronounced at closer distances
Relethford, John H. and Brennan, Ellen R.
"Temporal Trends in Isolation by Distance on Sanday, Orkney Islands,"
2, Article 13.
Available at: https://digitalcommons.wayne.edu/humbiol/vol54/iss2/13