Create your own conference schedule! Click here for full instructions

The Virtual Conference is located at

Abstract Detail


Charboneau, Joseph [1], Cronn, Richard [2], Liston, Aaron [3], Wojciechowski, Martin [4], Sanderson, Michael [1].

Phylogenomic analysis of morphological homoplasy and its impacts on the classification of Neo-Astragalus (Astragalus L., Fabaceae).

Astragalus L. (Fabaceae) is possibly the most species-rich genus of seed plants with around 3,000 recognized species. Almost 500 of those species in the Americas are part of a clade called Neo-Astragalus that are estimated to have shared a common ancestor as little as 4.5 million years ago. Although disparity in growth form and climatic tolerances among Neo-Astragalus species is somewhat limited as mostly temperate, herbaceous perennials, the clade does show striking variation in vegetative and especially fruit morphological characters. Rupert Barneby considered the evolution of these characters in forming his morphology-based taxonomic system for North American Astragalus in the 1960s, which largely still stands. How well his attempted natural classification system reflects the phylogeny of Neo-Astragalus has remained unevaluated for the most part, however, because low levels of sequence variation have kept most phylogenetic relationships within Neo-Astragalus unresolved in previous studies. Using both genome skimming and target-enrichment sequence data from 90 Neo-Astragalus species representing 55 of 85 recognized sections in Neo-Astragalus, we begin to resolve recalcitrant backbone and species-level relations within this clade. Ancestral state reconstructions of morphological characters important to Barneby’s system on these improved phylogenies have revealed homoplasy to be nearly ubiquitous. Although this may have made it impossible to form a natural taxonomic system based on a relatively small number of morphological characters, high levels of homoplasy may have made it likely even closely related Neo-Astragalus species differ in character states, aiding in their differentiation. Neo-Astragalus thus provides a case study for examining how rates of homoplasy may have influenced the number of species assigned to genera as well as the circumscription of infrageneric taxa.

Log in to add this item to your schedule

1 - University Of Arizona, Department Of Ecology And Evolutionary Biology, 1041 E. Lowell St., Tucson, AZ, 85721, United States
2 - 3200 SW Jefferson Way, Corvallis, OR, 97330, United States
3 - Oregon State University, Department Of Botany & Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331, United States
4 - Arizona State University, School Of Life Sciences, PO Box 874501, Tempe, AZ, 85287, United States

Genome skimming
Target enrichment

Presentation Type: Oral Paper
Session: COOLII, ASPT Cooley Award Talks II
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 1:00 PM(EDT)
Number: COOLII003
Abstract ID:1071
Candidate for Awards:George R. Cooley Award

Copyright © 2000-2021, Botanical Society of America. All rights reserved