Recent Topics Posters
Gonzalez, Lauren , Bell, Charles D. .
Ecological and Temporal Diversification in Symphoricarpos.
The major goal of this study was to investigate ecological and temporal diversification within Symphoricarpos (Caprifoliaceae; Dipsacales). We used a recently published molecular phylogeny along with GPS occurrence data to examine when Symphoricarpos may have arrived in the New World and if current distributional patterns can be explained by 1) ecological niche models (ENM) and 2) data on geological events. In order to investigate this we simultaneously estimated the phylogeny and divergence times within Symphoricarpos and related Caprifolieae species using BEAST. Next, we calculated ENMs for all currently recognized species of Symphoricarpos using maximum entropy (Maxent): combining GIS locality data and climate data. We then integrated ecological niche models (ENM) and phylogenies to examine degrees of climate niche evolution versus niche conservatism.In addition, we reconstructed ancestral areas using the dispersal-extinction-cladogenesis (DEC) method implemented in LAGRANGE. For Symphoricarpos, our phylogenetic results were in strong agreement with previous studies, with a well-supported clade containing the North American species that was sister to the lone Asian species. Our divergence time results suggest that the North American species of Symphoricarpos originated in the late Oligocene to mid Miocene (12-25 million years ago) and quickly diversified. DEC area reconstructions suggest that after entering the North American continent from Asia, species of Symphoricarpos became widespread across the continent, followed by range restrictions to that of what we see today. Although several recent studies have argued for the idea of phylogenetic niche conservatism as a general explanation for characterizing broad biogeographic patterns, our data support significant niche evolution within the North American species of Symphoricarpos, especially in regards to taxa found in the southwestern parts of the United States and Mexico. These observed biome shifts, from a mesic forest habitat to a much drier habitat, appear to have happened across the highly diverse landscape in which species of Symphoricarpos are found, and appear to be correlated with a shift in climate that has been proposed to have occurred throughout western North America during the duration of the clades existence in the continent.
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1 - University of New Orleans, Biological Sciences, 2000 Lakeshore Dr., New Orleans, LA, 70148, USA
ecological niche models
Presentation Type: Recent Topics Poster
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM