Distribution of Cepaea nemoralis according to climatic regions in Spain

• Published in: Heredity 1987-02, Vol.58 (1), p.145-154
• Main Authors: Mazon, L I, de Pancorbo, M A Martinez, Vicario, A, Aguirre, A I, Estomba, A, Lostao, C M
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cepaea nemoralis; Cytogenetics; Ecology; Evolutionary Biology; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Human Genetics; Invertebrata; original-article; Plant Genetics and Genomics; Population genetics, reproduction patterns
• ISSN: 0018-067X; 1365-2540
• DOI: 10.1038/hdy.1987.19

121 Populations of Cepaea nemoralis were sampled in Spain. In an area which extends from the coast of the Bay of Biscay to 182 km inland, following the meridian 3° west of Greenwich, and which has a width of approximately 40 km. In this study, we analysed the relationships between the populations and some selective agents, such as predation by Turdus ericetorum and climatic factors. These latter are represented by indirect parameters, such as altitude and distance from the sea, and direct parameters such as rainfall or temperatures. Visual selection is unimportant in the sampled populations. It was observed that our area of study is subdivided into 3 zones: Zone 1. Transitional and Zone 2, which have very different phenotype frequencies. What is more, these Zones correspond to very different climatic regions. Zone 1 is located in the climatic region known as “Green Iberia”. The most frequent phenotypes of Cepaea nemoralis are the pale ones. Zone 2 is located in “Brown Iberia”, and the most frequent phenotypes are the dark ones. Therefore we believe that in the populations sampled, one or more climatic factors are operating, and presumably causing the subdivision of these populations into Zones 1 and 2.