Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support

Geographic Variation in North American Colonies of Cepaea nemoralis

Peter F. Brussard
Evolution
Vol. 29, No. 3 (Sep., 1975), pp. 402-410
DOI: 10.2307/2407253
Stable URL: http://www.jstor.org/stable/2407253
Page Count: 9
  • Read Online (Free)
  • Download ($4.00)
  • Subscribe ($19.50)
  • Cite this Item
If you need an accessible version of this item please contact JSTOR User Support
Geographic Variation in North American Colonies of Cepaea nemoralis
Preview not available

Abstract

Starch gel electrophoresis of foot-muscle extracts from more than 1300 individuals of the introduced land snail Cepaea nemoralis collected from 30 different populations in 10 North American localities revealed nine scorable loci. Six of these showed no variation, one (PGM-1) was polymorphic at one locality only, and two (LAP-2 and PGM-2) were polymorphic at four and seven localities, respectively. Three hundred additional C. nemoralis, collected from three populations in Wales, were also examined. In addition to the enzyme loci, all snails were scored for shell color and banding phenotypes. Normalized genetic identities for all colonies were computed, based on the allozyme variability and on the previously established genetics of the shell polymorphisms. Genetic distances between each colony were ordinated to show their affinities by the Bray-Curtis method and by principalcomponents analysis. Both methods showed that the North American populations fall into two clearly recognizable groups: those living in the Piedmont and Valley of Virginia, and those found elsewhere. The latter group clusters with the Welsh snails. It is concluded that the North American pattern results primarily from different sources of introduction; the lowland Virginia snails have come from Italy, while all other North American C. nemoralis originated in northern Europe.

Page Thumbnails

  • Thumbnail: Page 
402
    402
  • Thumbnail: Page 
403
    403
  • Thumbnail: Page 
404
    404
  • Thumbnail: Page 
405
    405
  • Thumbnail: Page 
406
    406
  • Thumbnail: Page 
407
    407
  • Thumbnail: Page 
408
    408
  • Thumbnail: Page 
409
    409
  • Thumbnail: Page 
410
    410