Bioassay of kinship in northwestern Europe.

Kinship of Barra (Outer Hebrides) is bioassayed as 0.0096 relative to northwestern Europe, in reasonable agreement with prediction of 0.008 relative to Britain. The exponential decline of kinship with distance is similar to Scandinavia. Kinship of larger populations is consistent with predictions from isolates. Kinship is largely due to local drift rather than Norse admixture, the estimate of which is obscured by drift and appears highly unreliable. Other populations in northwest Europe, including Iceland, Lewis and Orkney, give estimates of kinship which reflect drift and geography, but also do not provide reliable estimates of admixture. Bioassay of kinship from gene frequencies gives observations to be explained in terms of migration and drift, but contributes nothing to the question of whether polymorphism in the species is maintained by neutral mutation or selection. Although the latter is on various grounds more likely, no calculations based on gene frequency distribution can provide critical evidence.