Abstract Detail

Phylogenomics and evolution of Superrosids

Cai, Liming [1], Davis, Charles [1], Liu, Liang [2], Xi, Zhenxiang [1], Rest, Joshua [3], Lemmon, Emily [4], Lemmon, Alan [4], Must, Austin [4], Buddenhagen, Christopher [4], Amorim, André [5], Sugumaran, M [6].

Dissecting the genomic evolution of Malpighiales—whole genome duplication, incomplete lineage sorting, and introgression.

Malpighiales is a large and diverse clade that remains one of the ‘thorniest’ angiosperm nodes to resolve. This order alone includes nine of the top ten most unstable nodes in angiosperms (Smith 2013). The application of genomic data to phylogenetic investigations have revived hope of resolving recalcitrant relationships but also revealed extensive gene tree heterogeneity. Gene tree variation of this nature can shed important light on evolutionary events. I will discuss a variety of phylogenomic data sets used to explore the early evolutionary history of this large and ecologically important clade. First, using transcriptome data we identified 24 ancient whole genome duplications widely distributed across the order. These events are clustered around the super-greenhouse period during the Paleocene-Eocene Transition (~54 Ma). This finding provides further supporting evidence that polyploidization may be important for surviving periods of global upheaval. Second, we apply a sequence capture data set to examine gene tree–species tree heterogeneity contributing to the recalcitrant relationships in Malpighiales. We developed a novel method to quantify the relative contribution of factors influencing gene tree heterogeneity, including incomplete lineage sorting, gene tree estimation error, and gene flow. We identified a deep history of gene flow, likely involving a single promiscuous clade, which we hypothesize may play a key role in our ability to resolve this group. This research highlights the critical need for more sophisticated phylogenetic models that do not strictly enforce a single, bifurcating species tree.

1 - Harvard University, OEB, 22 Divinity Ave, Cambridge, Massachusetts, 02138, United States
2 - University of Georgia, Department of Statistics and Institute of Bioinformatics, 120 Green St., Athens, GA, 30602, USA
3 - Stony Brook University, Department of Ecology and Evolution, Stony Brook, NY, NY 11790, USA
4 - Florida State University, Department of Biological Science, 319 Stadium Dr, Tallahassee, FL, 32304, USA
5 - Universidade Estadual de Santa Cruz, Departamento de Ciências Biológicas, Ilhéus, Bahia, 45.662-900, Brazil
6 - University of Malaya, Institute of Biological Sciences, Kuala Lumpur, 50603, Malaysia

Keywords:
Malpighiales
phylogeny
gene tree-species tree conflict
Evolutionary radiation.

Presentation Type: Colloquium Presentations
Session: COL07, Phylogenomics and evolution of superrosids
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 3:45 PM
Number: COL07003
Abstract ID:225
Candidate for Awards:George R. Cooley Award