Abstract Detail

Biogeography

Xiang, Qiu-Yun(Jenny) [1], Harris, AJ [2].

Accounting for phylogenetic uncertainty and fossil distribution in biogoegraphic analysis using S-DIVA - a case study in Cornales and comparison to LAGRANGE.

Phylogenetic uncertainty poses a major limitation in biogeographic analysis using conventional methods. Incorporation of fossil evidence into biogeographic analysis is essential for accurate estimation of ancestral ranges, but infrequently practiced. Two complementary methods of Bayes-DIVA were recently developed to account for phylogenetic uncertainty as well as to handle optimization uncertainty in reconstructing biogeographic histories using DIVA. Both methods have been newly implemented in the S-DIVA package (Statistical Dispersal Vicariance Analysis) . We used the S-DIVA program to reconstruct the biogeographic history of Cornales using 4500 Bayesian trees with fossil distributions included and excluded. Initial analyses were run using the 1/N method to estimate the frequency of occurrence of a range at each node on each tree, where N is the total number of optimal ranges at the node. Results from the analyses showed that adding fossil distributions resulted in highly supported ancestral distributions at eight of ten nodes which were unresolved when fossil distributions were omitted. Additional analyses of the two clades with unresolved ancestral distributions were performed using the i/Rt method to determine the actual frequency of a range at each node on each tree. These additional analyses resolved distributions at the two nodes but with relatively low support. S-DIVA is a fast, user-friendly program with a graphical interface. We compared the results with those from the likelihood-based method on LAGRANGE. The ancestral ranges of Cornales from S-DIVA are comparable to those from LAGRANGE. LAGRANGE requires longer computation times, and performing a "Bayes-LAGRANGE" analysis comparable to that of Bayes-DIVA requires analysis of one tree at a time and subsequent assimilation of results from all trees using external means.

Broader Impacts:

1 - North Carolina State University, Department of Plant Biology, Campus Box 7612, Raleigh, NC, 27695-7612, USA
2 - Oklahoma State University, Department of Botany, 104 Life Sciences East , Stillwater, OK, 74078-3013, USA

Keywords:
Cornales
Biogeography
S-DIVA
LAGRANGE
fossils
DIVA
Bayes-DIVA.

Presentation Type: Oral Paper:Papers for Topics
Session: 3
Location: 551A/Convention Center
Date: Monday, August 2nd, 2010
Time: 8:15 AM
Number: 3002
Abstract ID:463