Abstract Detail

Systematics

Brose, Caroline [1], Jabaily, Rachel [2], Shepherd, Kelly [3].

Diversification and Character Trait Analyses of the Core Goodeniaceae.

The Goodeniaceae is a family of angiosperms occurring primarily in Australia with more that 400 species in 7 genera, split into two major clades. The Core Goodeniaceae clade comprises more than two-thirds of the family and is primarily composed of two major genera: Goodenia and Scaevola. Molecular-evolution-based branch lengths, numbers of extant species, and morphological traits vary between them, but have not previously been studied with diversification rate analyses or other comparative methods. A recent comprehensive study on Goodenia has resolved the topology and altered taxonomy within the genus to reflect phylogeny. Scaevola has been poorly sampled in prior studies, but infrageneric taxonomic issues were identified. We conducted a comprehensive sampling of the monotypic genus Brunonia and the Core Goodeniaceae, with additional Scaevola species included, sampled from two different loci, nrITS and trnL-F. We generated a MrBayes tree and calibrated it in BEAST using new fossil information, dating the crown of the Core Goodeniaceae to about 47 Mya, which is slightly younger than previous studies. The crowns of Scaevola and Goodenia are 14 Mya and 39 Mya, respectively. We found a significant lack of monophyly within all levels of subgeneric grouping in Scaevola, along with a lack of consistent backbone support, which suggests the need for more molecular data and reexamination of the taxonomy of the genus. Previous hypotheses for drivers of diversification within Core Goodeniaceae suggested that the floral symmetry flexibility within Goodenia may allow for greater rates of speciation. In contrast, we found that the almost exclusively fan-flowered Scaevola had the highest rates of diversification when analyzed with BAMM. The lowest rate of diversification was found in Goodenia Clade B, which only has one fan-flowered species, and includes a singular species with woody habit in the otherwise-entirely herbaceous clade. Ancestral state reconstruction of fleshy fruits using Mesquite shows up to nine separate evolutions of this trait in Scaevola. These correspond directly to multiple dispersals outside of Australia, with only one extra-Australian species with dry fruits, and one small clade of fleshy-fruited Australian endemics. Future work seeks to increase phylogenetic resolution and explicitly test character-based diversification processes.

1 - Colorado College, Organismal Biology and Ecology, 14 E. Cache La Poudre St., Colorado Springs, CO, 80903, USA
2 - Colorado College, Organismal Biology & Ecology, 14 E Cache La Poudre St, Colorado Springs, CO, 80903, United States
3 - Western Australian Herbarium, Department Of Biodiversity, Conservation & Attractions, 92 Enfield Street, Lathlain, WA, 6100, Australia

Keywords:
Goodeniaceae
Asterales
Australia
Scaevola
Goodenia
systematics.

Presentation Type: Oral Paper
Number: SYST III009
Abstract ID:114
Candidate for Awards:None