Abstract Detail


Abair, Alexander [1], Godden, Grant [2], Sun, Miao [3], El-Bahawy, Ahmed [4], Soltis, Douglas [5], Soltis, Pamela [6].

Assembling and Dating a Near-Comprehensive Phylogeny of Lamiaceae.

Building and dating nearly comprehensive phylogenetic trees for large clades remains a monumental task.  Lamiaceae are the sixth largest flowering plant family with over 7,000 species, and despite wide interest in the family, a comprehensive phylogenetic framework is still lacking.  The Open Tree of Life has made great strides connecting subtrees based on disparate data types from molecular, morphological, and taxonomic studies across the tree of life, including Lamiaceae, for which it presents a phylogeny of roughly 5,000 species.  However, half of the species are placed solely on taxonomy because of insufficient molecular data.  Recent phylogenetic analyses of focal clades, coupled with analyses aimed at deep divergences, have provided new data that can contribute to both assembly and dating of this large clade.  Here we describe a strategy for assembling, vetting, and dating the most comprehensive tree yet for Lamiaceae, using the mint clade from the Open Tree of Life as a framework.  We downloaded the Lamiaceae clade from the Open Tree of Life and adjusted this ~5000-species phylogeny by constraining the topology to a recently published transcriptome-based Lamiaceae backbone.  We then carefully examined species placements and either removed species that did not align with current taxonomy or adjusted their positions.  We then used penalized likelihood methods in conjunction with several fossil calibration points to date a subtree (~2700 species) for which molecular data are available.  We used available genetic data and imputed branch lengths across the large tree, applied the dates from the small tree to the corresponding nodes in the large tree, and further estimated nodes in the large tree. By including outgroups from Lamiales, we are able to provide new insights regarding the age of Lamiaceae and key clades within the family. Based on our analyses, the age of Lamiaceae is estimated at 82 million years, and the subfamilies (as recircumscribed to be monophyletic) range in age from 10-68 million years.  The dates for these clades will be of utility in several downstream analyses.  Avenues for future work include analyses of diversification coupled with chemical and morphological evolution in the mint family.  Although the phylogeny reconstructed in our study provides some novel age estimates, there are improvements to be made.  More fossil calibrations will produce more accurate dates throughout the phylogeny.  As more molecular studies are conducted, and gaps in the Lamiaceae phylogeny are filled, a more comprehensive phylogeny with a stronger backbone will be developed.

1 - University Of Florida, Department Of Biology, 1659 Museum Rd, Gainesville, FL, 32611, United States
2 - University Of Florida, Florida Museum Of Natural History, Dickinson Hall, PO Box 117800, Gainesville, FL, 32611, United States
3 - AARHUS UNIVERSITY, BIOSCIENCE, NY MUNKEGADE 114, Jutland, BUILDING 1540, Aahrus, 8000, Denmark
4 - University Of Florida, Biology, 1659 Museum Rd, Gainesville, FL, 32608, United States
5 - University Of Florida, Florida Museum Of Natural History, Dickinson Hall, Gainesville, FL, 32611, United States
6 - University Of Florida, Florida Museum Of Natural History, Po Box 117800, Gainesville, FL, 32611, United States


Presentation Type: Oral Paper
Session: SYS1, Systematics I: Asterids I & II
Location: Virtual/Virtual
Date: Monday, July 27th, 2020
Time: 11:00 AM
Number: SYS1005
Abstract ID:491
Candidate for Awards:None

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