Abstract Detail

Systematics Section/ASPT

Berger, Brent A. [1], Sytsma, Kenneth [2].

Diversification of Metrosideros (Myrtaceae): Timing the Spread Across the Southern Hemisphere.

Oceanic islands, as opposed to continental islands or other “island” systems, are considered epicenters for studying patterns and processes of both evolutionary and ecological diversity, adaptive radiation, and biogeography. With regard to historical biogeography, oceanic islands present a special challenge because current paradigms and models are inherently vicariance-based, or with some dispersal permitted, when the overwhelming and dominant process that contributes to oceanic island biotas is long distance dispersal (LDD). The use of both molecular phylogenetics and time-calibrated chronograms to evaluate competing models of biogeography are often difficult in oceanic islands due to distant or unknown source origins, rapid and/or recent radiations, hybridization, and the general lack of close fossil taxa. We reconstructed the historical biogeography of the genus Metrosideros (Myrtaceae), centered on the southern Pacific and Hawaiian lineage, for which competing models of biogeography and age exist. Three major aims of our study were: 1) evaluate the relationships, temporal diversification and biogeographic patterns of major lineages within tribe Metrosidereae; 2) estimate using fossil evidence the timing of the spread of Metrosideros across the Pacific islands and its entry into Hawaii, and compare these results to previous models; and 3) test for support of a colonization from Hawaii back to the Marquesas Islands. We employed 11cpDNA and 2 nDNA markers, derived a chronogram in BEAST using Metrosideros and other Myrtaceae fossils, and evaluated biogeography using ML in S-DIVA and Bayesian Inference in BayesMultiState. Results support a monophyletic tribe Metrosidereae, crown radiation of Metrosideros s.l. at 26 Mya, the origin of Hawaiian Metrosideros out of a broadly paraphyletic M. collina and specifically from a lineage including Marquesan taxa at 5 Mya, and the extant radiation of Hawaiian taxa shortly after 3 Mya in the Pliocene.

Broader Impacts:

1 - St. John's University, Department of Biological Sciences, 8000 Utopia Parkway, Queens, NY, 11439, USA
2 - University of Wisconsin, Department of Botany, Birge Hall, 430 Lincoln Drive, Madison, WI, 53706, USA

Keywords:
biogeography
Metrosideros
Long Distance Dispersal
Hawaii
fossil
chronogram.

Presentation Type: Oral Paper:Papers for Sections
Session: 11
Location: Magnolia/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 4:15 PM
Number: 11011
Abstract ID:567
Candidate for Awards:George R. Cooley Award