Abstract Detail

Phylogenomics

Ottenlips, Michael [1], Buerki, Sven [2], Mansfield, Don [3], Dodsworth, Steven [4], Forest, Felix [5], Smith, James [6].

Lewis’s lost Lomatium found: Investigating species boundaries in the rare plant species subcomplex, Lomatium packardiae/anomalum.

Speciation exists on a continuum beginning with genetic structuring to incipient speciation and finally distinct species. Understanding where to draw species boundaries is complicated by many factors ranging from theoretical issues dealing with the nature of the species unit itself to biological realities which confound morphological-based identification. Modern advances in genomics, including next-generation sequencing, bioinformatics processing, and phylogenetic reconstruction, allow researchers to model speciation more accurately than ever before. The Perennial Endemic North American clade of Apiaceae (PENA) is one of the largest and least understood plant radiations in Western North America. Lomatium is the largest genus, and as traditionally defined is polyphyletic. Recent Sanger-sequence based studies have resolved many evolutionary relationships and revealed a suite of homoplasy in previously thought to be taxonomically informative characters. The Lomatium packardiae/anomalum subcomplex embedded within the larger Lomatium triternatum complex could not be resolved with Sanger-sequencing and traditional concatenated-based phylogenetic analysis. Lomatium triternatum was first collected by Merriweather Lewis and the phylogenetic placement of his original collection has been the subject of debate. Morphological, ecological, and geographic differences in the L. anomalum/packardiae subcomplex do not agree with monophyletic groups in Sanger-sequence based studies. The recalcitrant nature of this subcomplex may be that the complex is one morphologically variable taxon or, alternatively, incomplete lineage sorting is causing the incongruences between morphological, ecological, and molecular data. A Bayesian coalescent-based technique (STACEY) performed on nuclear introns generated using the Angiosperm 353 baits uncovered three coarse and seven fine scale clades that correspond with geographic distributions and some previously recognized taxonomy. Climatic factors, morphological characters, and soil variables were measured in an attempt to uncover additional unifying features of monophyletic groups. Climatic niche and leaflet width and length were associated with coarse phylogenetic structure. Lomatium packardiae was found to be monophyletic in the molecular data and distinct in the PCA of reproductive characters with shorter umbel rays and fruit than other members of the subcomplex. The population (D. Mansfield 16078) of L. triternatum (the species collected originally by Lewis) is included in this analysis and for the first time belongs to a monophyletic group that agrees with non-molecular data sources (geography and morphology). A possible explanation is that the clades recovered with the STACEY analysis are the result of incipient speciation, which is cryptic due to the lack of any consistently reliable diagnostic traits besides geography. Currently, the best predictor of phylogenetic placement is geography.

1 - 2133 W Cesar Chavez Ln, 2133 W Cesar Chavez Ln, Apt 304, Boise, ID, 83725, United States
2 - Boise State University, Biological Sciences, 1910 University Drive, Ms1515, Boise, ID, 83725, USA
3 - College of Idaho, Biology, 2112 Cleveland Blvd, Cadwell, ID, 83605, USA
4 - University of Bedfordshire, Life Sciences, Luston, LU1 3JU, UK
5 - Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey, TW9 3DS, United Kingdom
6 - BOISE STATE UNIVERSITY, Department Of Biological Sciences, 1910 University Drive, Ms1515, Boise, ID, 83725, United States

Keywords:
incomplete lineage sorting
Angiosperm 353
target-enrichment.

Presentation Type: Oral Paper
Session: PHYL1, Phylogenomics I
Location: San Ignacio/Starr Pass
Date: Monday, July 29th, 2019
Time: 10:15 AM
Number: PHYL1009
Abstract ID:512
Candidate for Awards:None