Abstract Detail



Systematics

Ackerfield, Jennifer [1].

A Prickly Puzzle: Phylogeny and Evolution of the Carduus-Cirsium Group (Cardueae: Compositae).

A basic goal of evolutionary biology is to understand the factors shaping phenotypic diversity, particularly within radiations.  Within Compositae, the Carduus-Cirsium (“thistle”) group is useful for the study of diversification for the following reasons.  First, it constitutes a radiation by having an accelerated period of diversification and speciation.  Second, within North America, species have diversified into a wide array of heterogeneous abiotic conditions and correspondingly have extensive phenotypic diversity.  In addition to constituting a continental radiation, North American thistles are one of the most difficult taxonomic groups within North America and many species delimitations are controversial or unclear. 
In this study, a phylogeny for the Carduus-Cirsium group was inferred to resolve relationships among North American thistles.  In addition, ecological niche modeling was used to test for evidence of phylogenetic niche conservatism or biome shifts within the continent-wide radiation.  Results demonstrate a prevalence for phylogenetic niche conservatism among sister species, as well as a convergence of characteristics in association with similar ecological niches.  This study builds upon our understanding of the factors contributing to diversification within North America and one of the largest families of flowering plants.


1 - Colorado State University, Biology Dept., 1878 Campus Delivery, Fort Collins, CO, 80523, United States

Keywords:
Cirsium
Evolution
ecological niche modeling
convergence
radiation
Thistles
Compositae.

Presentation Type: Oral Paper
Number:
Abstract ID:430
Candidate for Awards:George R. Cooley Award


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