Abstract Detail

Phylogenomics

Xiang, Qiuyun (Jenny) [1], Du, Zhiyuan [2], Cheng, Jing [3], Zhou, Wenbin [4], Wang, Qing-Feng [2], Soltis, Douglas [5], Soltis, Pamela [6].

An updated phylogeny, biogeography, and PhyloCode-based classification of Cornaceae based on three sets of genomic data.

A major goal of systematic biology is to uncover the evolutionary history of organisms and translate the knowledge into predictable and stable classification systems. Phylogenetic relationships, taxonomy, classification, and biogeographic history of the dogwood family Cornaceae (defined here to include only Cornus L. s. l.) have all remained either incompletely resolved or controversial despite previous investigations. In this study, we integrate three sets of genome-wide sequence data to resolve phylogenetic relationships and then reconstruct the biogeographic history of Cornaceae. Based on the robust phylogeny obtained, we produce a classification scheme using the Phylocode to stabilize the names of this taxonomically highly controversial group. Specifically, we conducted phylogenetic analyses using data from 312 single copy nuclear genes and 70 chloroplast coding genes obtained from Angiosperms353 Hyb-Seq coupled with numerous loci from RAD-seq. We then integrated fossils into the phylogeny using morphological data and the fossilized-birth-death model to produce a complete dated phylogeny for biogeographic analysis using the DEC method with a time sliced dispersal model. We found support for the monophyly of each of the four previously recognized major clades (BW or Swida[P], CC or Macrocarpium[P], DW or Arctocrania[P], BB or Benthamidia[P]) and the main topology of (BW, (CC, (DW, BB))) was strongly supported. Relationships within each major clade were resolved and well supported in species trees but conflict among gene trees was observed for a few nodes involved in rapid divergence. Based on the nuclear species tree, we named strongly supported clades following the PhyloCode using existing names that were previously applied as genera or subgenera. Biogeographic analyses supported an origin and rapid diversification of Cornaceae into four morphologically distinct major clades in eastern Asia during the T/K boundary period. Rapid divergence within the Swida[P], Macrocarpium[P], and Benthamidia[P] clades during different periods of the Paleogene was observed. Evidence supports a complicated and dynamic biogeographic history of Cornaceae involving many range expansion, restriction, and extinction events in the Northern Hemisphere. The modern African and South American outliers of the family appear to have been derived from dispersals from eastern Asia along the Tethys Seaway in the Paleogene (to Africa) and from Central America along the Panama Isthmus in the late Neogene or by long distance dispersal during the early Neogene (to South America), respectively. Our biogeographic results support frequent exchanges along the Tethys Seaway, the Bering Land Bridge, and the North Atlantic Bridge during the early Paleogene and Neogene connections between eastern North America and Mexico-Central America and between Europe and eastern North America, congruent with fossil evidence. Our study provides an example of integrating genomic and morphological data to produce a robust, “complete” explicit species phylogeny including fossil taxa and then translating these data into a predictable and stable classification scheme using the PhyloCode.

1 - North Carolina State University, Plant And Microbial Biology, 100 Derieux Place, Gardner Hall 2115, Raleigh, NC, 27695, United States
2 - Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hupei, 430074, China
3 - Beijing Forestry University, College of Biological sciences and Biotechnology, Beijing, 100083, China
4 - North Carolina State University, Plant & Microbial Biology, Box 7612, 100 Derieux Place Gardner Hall 2115, Raleigh, NC, 27695, United States
5 - University of Florida, Florida Museum of Natural History,, 3215 Hull Road, P. O. Box 2710, Gainesville, FL, 32611, USA
6 - University Of Florida, Florida Museum Of Natural History, Gainesville, FL, 32611.0, United States

Keywords:
phylogenomics
RAD-Seq
Angiosperms353 Hyb-Seq
Cornaceae
Classification 
Historical biogeography.

Presentation Type: Oral Paper
Number: PHYLO III001
Abstract ID:85
Candidate for Awards:None