Factors influencing the shell pattern polymorphism of cepaea nemoralis (L.) in east yorkshire: A test case

Abstract

This paper considers the shell pattern polymorphism of Cepaea nemoralis on the east Yorkshire Wolds. Patterns of variation in shell colour, but not shell banding, can be related to habitat differences. On the basis of interpretations given in other regional surveys, the predominant morphs do not suggest that climatic selection is an important factor. Patterns of morph frequency cannot be related to topographic effects. Morph frequencies on the Yorkshire Wolds are similar to those in the geologically variable surrounding area and to those on the geographically separated Lincolnshire Wolds. © 1976 The Genetical Society of Great Britain.