Abstract Detail

Biogeography

Simpson, Andrew [1].

Relationships between dispersal, geographic range, and diversity in the Rosales: evidence for lineage selection?

The origin – and demise – of biological diversity is a question that has long interested biologists and paleontologists alike. Recent approaches to this problem focus on systematic comparisons, although ecological comparison remains a common practice and the fossil record remains the best source of information on past diversity available. Relationships between geographic range, diversity, and taxon survivorship have been demonstrated in paleontological studies as well as in extant populations, but the mechanisms that link the ecological traits of a species with its geographic range are still not well understood. I here use the Rosales, a diverse group of flowering plants possessing a wide range of life history traits and dispersal modes, as well as a good fossil record, in order to quantify the relationships between different modes of dispersal, life history traits, and geographic range using herbarium specimens and museum collection databases. In addition to uniting modern phylogenetic methods with a paleobotanical prospective, this study also compares the three-way relationship between ecology (dispersal), macroecology (geographic range size), and lineage selection and diversification together possibly for the first time. Phylogenetic correlation is controlled for using the QuaSSE method (Maddison & Maddison), and also in order to elucidate differences between character state proliferation resultant from differential net diversification rates (lineage selection) as distinguished from selection at the individual level (character state change rates). Phylogenies used are APG III and Potter et al.’s (2007) phylogeny of the Rosaceae, with Rosaceae sequences acquired from Potter et al and other Rosales augmented via GenBank. Preliminary results using Mesquite (Maddison & Maddison 2011) suggest a three-way positive association between animal dispersal, geographic range, and net diversification rates in the woody Rosales. This association is also correlated anecdotally with a decline in range size of fossil Rosaceous genera (e.g. Lyonothamnus) that lack animal dispersal seen through the fossil record. Because long-lived woody plants would have fewer generations between Milankovitch or sub-Milankovitch scale climate events than short-lived herbs, I would predict that effective long-range animal-mediated dispersal would be more favored in woody taxa than in herbs. More rigorous analysis of a more complete dataset including over 90% of Rosalean genera using QuaSSE implemented through Diversitree (Maddison & Maddison) is ongoing, and will be presented at the meeting.

Broader Impacts:

1 - University of Maryland, Department of Biological Sciences, Biopsychology Building, College Park, MD, 20740, USA

Keywords:
Geographic range
Dispersal
Rosales
QuaSSE
Comparative methods
Lineage selection.

Presentation Type: Oral Paper:Papers for Topics
Session: 50
Location: Magnolia/Riverside Hilton
Date: Wednesday, July 31st, 2013
Time: 5:15 PM
Number: 50015
Abstract ID:490
Candidate for Awards:George R. Cooley Award