Abstract Detail

Empirical Approaches to Phylogenetic Comparative Methods in Plant Science

WHITTALL , JUSTEN BRYANT [1].

Wallflowers keep good company: Adaptive radiation in Erysimum (Brassicaceae).

Adaptive radiations typically follow dispersal to islands or island-like habitats. Alternatively, continental radiations are much rarer and frequently arise only after the origin of a key innovation. The wallflowers (Erysimum, Brassicaceae) represent an unusually fast, yet enigmatic continental radiation. Erysimum is the third largest genus in the Brassicaceae with over 220 species distributed across the northern hemisphere. We estimate the crown age of Erysimum at less than 3 million years based on over 8 kbp from seven loci spanning all three genomes. This radiation coincides with the origin of cardenolides, a unique defensive compound in the Brassicaceae. We test a range of comparative approaches to determine the likelihood of cardenolides as a key innovation. Following the advent of this defensive compound in the wallflowers, this lineage has diversified into a range of specialized habitats including serpentine, sandhills, sand dunes and talus slopes. We further examine patterns of habitat divergence within this recent adaptive radiation using phylogenetic comparative methods. Since Erysimum is the closest adaptive radiation to (the relatively slowly diversifying) Arabidopsis lineage, we are leveraging the wealth of tools available for Arabidopsis thaliana to gain further insights into the mechanism of adaptive radiation in the wallflowers.

1 - Santa Clara University, Department Of Biology, 500 El Camino Real, Santa Clara, CA, 95053, USA

Keywords:
adaptive radiation
Key Innovation
Erysimum
cardenolides.

Presentation Type: Symposium or Colloquium Presentation
Session: C1
Location: Summit/Boise Centre
Date: Monday, July 28th, 2014
Time: 1:45 PM
Number: C1002
Abstract ID:406
Candidate for Awards:None