Abstract
Relationships involving progenitor and derivative species pairs have been documented for a number of plant taxa. In this study, we used starch-gel electrophoresis to examine the probable relationship between Cirsium pitcheri, an endemic thistle restricted to the shorelines of the Great Lakes, and Cirsium canescens, a closely related species of the central Great Plains (U.S.A.). The species shared the same enzyme loci but differed greatly in levels of genetic diversity. C. pitcheri was genetically much less variable than its congener, with fewer polymorphic loci and significantly lower heterozygosity. The genetic variation in C. pitcheri represents a depauperate subset of the alleles present in C. canescens, consistent with the hypothesis that the two species represent a progenitor-derivative species pair. We suggest that C. pitcheri migrated into newly created dune habitats in the Great Lakes region near the end of the Wisconsin glaciation and that its low genetic variability results from repeated and probably prolonged population bottlenecks which accompanied its movement.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Evolution; international journal of organic evolution
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
