Changing isonymic relationships in Fylingdales parish, North Yorkshire, 1841-1881.

Lasker's coefficient of relationship by isonymy was used to analyse surname data taken from the 1841-1881 Census returns from Fylingdales parish, North Yorkshire. Relationships were measured between each of the occupational groups: mariner, fisherman, shipowner, farmer, agricultural labourer, alum works labourer and 'other'--with and between census years in each decade. Broadly, there is a clear differentiation of the population genetic structure in the parish over this whole period, and distinct clusters of 'maritime', 'agricultural' and 'other' jobs can be identified. In finer detail, the gradual breakdown of this pattern of genetic differentiation can be observed, as the fishing industry declined, the alum works closed, and as new farming families moved in to the parish.