Abstract Detail



Macroevolution

Mason, Chase [1], Goolsby, Eric [2], Edwards, Robert D. [3].

Towards understanding environmental drivers of diversification rate in the North American Asteraceae.

Understanding the role of environmental pressures in shaping plant diversification is a major goal of plant evolutionary ecology.  The largest family of flowering plants, Asteraceae, has repeatedly colonized North America, with each colonizing lineage diversifying into a large number of species occupying a wide variety of habitats. This pattern makes Asteraceae an ideal model system to understand how the abiotic environment drives diversification across the continent, and to ask whether evolution proceeds in a predictable manner in response to similar sets of complex environmental gradients. This work uses a set of phylogenetic comparative methods to perform diversification analysis in each of multiple tribes of Asteraceae, assessing and comparing the relative role of climate, topography, soil conditions, and geochemistry on diversification rate. First, calibrated phylogenies were generated for North American members of each Asteraceae tribe using publicly available sequence data. Second, detailed plant species locality data was derived from multiple databases of digitized herbarium records. Third, environmental attributes were extracted for each locality from a large suite of climate, topography, soil, and geochemisty data layers. Individual linear and nonlinear phylogenetic generalized least squares (PGLS) regression was performed for each environmental variable of interest in each tribe, followed by model selection to determine the most appropriate shape to describe the relationship between environmental predictors and diversification rate. Subsequently, multiple PGLS regression and model selection were performed on variables demonstrating significant individual predictive power for diversification rate. Results give insights into which environmental pressures most drive diversification within each tribe, the interaction among different environmental pressures, and how well such pressures together predict observed diversification in the most diverse plant family on Earth.


Related Links:
Mason Lab website
Eric Goolsby website
Bort Edwards website


1 - University Of Central Florida, Department Of Biology, 4110 Libra Dr, Orlando, FL, 32816, United States
2 - Yale University, Department of Ecology and Evolutionary Biology, 165 Prospect St, New Haven, CT, 06511, USA
3 - Smithsonian Institution, National Museum of Natural History, 10th St. & Constitution Ave. NW, Washington, DC, 20560, USA

Keywords:
Asteraceae
diversification rate
North America
Adaptation
climate
soil geochemistry
Phylogenetic Comparative Methods.

Presentation Type: Oral Paper
Number:
Abstract ID:261
Candidate for Awards:None


Copyright © 2000-2018, Botanical Society of America. All rights reserved