Biological Invasions

, Volume 10, Issue 1, pp 1–6

How to Use Genetic Data to Distinguish Between Natural and Human-Mediated Introduction of Littorina littorea to North America

Original Paper

DOI: 10.1007/s10530-007-9099-8

Cite this article as:
Cunningham, C.W. Biol Invasions (2008) 10: 1. doi:10.1007/s10530-007-9099-8


The rapid range southward expansion of the periwinkle Littorina littorea from the Canadian maritimes has fueled a long-running debate over whether this species was introduced to North America by human activity. A reappraisal of the mitochondrial DNA sequence evidence finds considerable endemic allelic diversity in the American population. The degree of endemic genetic diversity is higher than expected from human-mediated colonization, but not so much to suggest that it survived the last glacial maximum in America. Coalescent estimates of population divergence agree that colonization of America preceded European contact. A reappraisal of the ITS nuclear sequence data finds extensive recombination. Taking this recombination into account strengthens the genetic case against human-mediated introduction. Finally, a reappraisal of conflicting allozyme studies from the 1970’s supports a claim of limited divergence between American and European populations. This is consistent with post-glacial colonization, but the allozyme data cannot distinguish between natural or human-mediated colonization. Taken as a whole, the DNA sequence data supports the many sub-fossil reports of an American L. littorea population in the Canadian maritimes that preceded even the first visits by the Vikings.


Haplotypes diversity Invasive Species ITS Mitochondrial DNA 

Copyright information

© Springer Science+Business Media, Inc. 2007

Authors and Affiliations

  1. 1.Biology DepartmentDuke UniversityNorth CarolinaUSA