RAPID ADAPTIVE DIVERGENCE IN NEW WORLDACHILLEA, AN AUTOPOLYPLOID COMPLEX OF ECOLOGICAL RACES
| Autor: | Alexander V. Robertson, Justin Ramsey, Brian C. Husband |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Northwestern United States
Achillea Molecular Sequence Data Population Adaptation Biological Biology Polyploidy Monophyly Genetics Amplified Fragment Length Polymorphism Analysis education Phylogeny Ecology Evolution Behavior and Systematics education.field_of_study Achillea millefolium Base Sequence British Columbia Ecotype Ecology DNA Chloroplast Sequence Analysis DNA Reproductive isolation biology.organism_classification Biological Evolution Phylogeography Genetics Population Cladogenesis Evolutionary biology General Agricultural and Biological Sciences |
| Zdroj: | Evolution. 62:639-653 |
| ISSN: | 1558-5646 0014-3820 |
| DOI: | 10.1111/j.1558-5646.2007.00264.x |
| Popis: | Adaptive evolution is often associated with speciation. In plants, however, ecotypic differentiation is common within widespread species, suggesting that climatic and edaphic specialization can outpace cladogenesis and the evolution of postzygotic reproductive isolation. We used cpDNA sequence (5 noncoding regions, 3.5 kb) and amplified fragment length polymorphisms (AFLPs: 4 primer pairs, 1,013 loci) to evaluate the history of ecological differentiation in the North American Achillea millefolium, an autopolyploid complex of "ecological races" exhibiting morphological, physiological, and life-history adaptations to diverse environments. Phylogenetic analyses reveal North American A. millefolium to be a monophyletic group distinct from its European and Asian relatives. Based on patterns of sequence divergence, as well as fossil and paleoecological data, colonization of North America appears to have occurred via the Bering Land Bridge during the Pleistocene (1.8 MYA to 11,500 years ago). Population genetic analyses indicate negligible structure within North American A. millefolium associated with varietal identity, geographic distribution, or ploidy level. North American populations, moreover, exhibit the signature of demographic expansion. These results affirm the "ecotype" concept of the North American Achillea advocated by classical research and demonstrate the rapid rate of ecological differentiation that sometimes occurs in plants. |
| Databáze: | OpenAIRE |
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