Abstract
The Orkney Islands, as an isolated rural community were assessed for the dermal traits of digital pattern-type and ridge-count, together with the comparative areas of Shetland and parts of the Scottish mainland. Sample numbers observed ranged from 1889 in Orkney (981 male: 908 female), 423 in Shetland (201 male: 222 female) 537 on Scottish mainland (407 male: 130 female) and 105 half-Orcadian (those with only two grandparents born in Orkney) , giving a total sample for Scotland of 2954 (1640 males: 1314 females). Using computer analysis percentage frequencies were calculated for geographical localities throughout the three groups to observe the degrees of variation within and between the Scottish population. Samples from Cumbria, Northumbria and the South Midlands were compared with the Scottish data to give general trends of frequencies of pattern types and total ridge count throughout Britain, indicating some regional difference and local, sometimes significant, variation. Such variation observed throughout the different areas assisted in explanation of the evolutionary processes of "drift" and "selection"' within and between the local and regional groups. Pattern types observed for digit preference indicated similar distributions throughout the Scottish sample. Pattern type correlations with ridge-count showing the distributions of loops and whorls over a range of ridge-count indicated a surprising bimodal distribution of radial loops. Detailed analyses of pattern form, direction and ridge-count correlation with particular reference to family studies may help to indicate the genetic factors influencing dermatoglyphlc inheritance. P. T. C. tasting various blood groups and secretor status were tested over a varying range of individuals throughout the areas visited in Orkney and Shetland, together with colour vision, eye colour and nasal bridge hair. Laterality dominance was assessed using a wide range of criteria whenever possible. These genetic traits were observed in an attempt to assess the possible genetic isolation of Orkney and the degree of homogeneity with historically-linked papulations, such as Shetland, Scandinavia and areas of Scandinavian colonisation in western Europe.