Abstract Detail

Phylogenomics

Valderrama, Eugenio [1], Sass, Chodon [2], Guan, Clarice [3], André, Thiago [4], Maas, Paul J. M. [5], Maas-van de Kamer, Hiltje [5], Skinner, David L. [7], Specht, Chelsea [8].

Phylogenomics of the Neotropical spiral gingers (Costaceae) .

One of the most widely recognized patterns in ecology and evolutionary biogeography is that lineages tend toward species-richness in tropical regions; however, the mechanisms that originate such patterns of diversity are still poorly understood. In addition, richness is not uniform across the tropical regions - with ca.32,000 species of flowering plants in tropical Africa, ca.50,000 in Southeast Asia and ca.90,000 in the Neotropics. Hypotheses addressing higher species richness in the Neotropics include opportunities for allopatric speciation, the availability of new habitats through uplift of the Andes, and major habitat and climate shifts prompted by shifts in the Amazon river drainage and closure of the Panama isthmus. Possibilities for prezygotic reproductive isolation driven by shifts in pollination syndromes, adaptation to local conditions leading to ecological speciation, or the effects of polyploidization on diversification rates of Neotropical lineages are additional mechanisms proposed to explain the relatively higher diversity of Neotropical plant lineages compared to their Paleotropical congeners.
The family of pantropical Spiral Gingers (Costaceae Nakai; ca.125 spp.) can be used as a model to enhance our understanding of the mechanisms underlying Neotropical diversity. Costaceae has higher taxonomic diversity in South and Central America (ca.65 Neotropical species, ca. 30 African, ca.23 Southeast Asian), particularly due to a radiation of Neotropical species of the genus Costus L. (50spp.). The Neotropical species of Costus show multiple shifts in pollination syndromes, with closely related species that are associated with either insects or birds demonstrating rapid ecological isolation. However, a well-supported phylogeny of the Neotropical Spiral Gingers, including thorough sampling of proposed species encompassing their full morphologic and geographic variation, is lacking. Here we use a phylogenomic approach to estimate the phylogeny of Neotropical Costaceae (incl. Costus and Chamaecostus C.D.Specht & D.W.Stev.) species using a targeted enrichment approach. Baits were designed to capture conserved elements as identified from genomic sequences of Costus species and relatives. We sampled the vast majority of described and newly defined species, with multiple samples from widespread and enigmatic species covering observed morphologic and geographic variation. DNA was extracted from living collections, field collected material, and herbarium samples where required to include type specimens and population-level diversity. The resulting phylogeny of the Neotropical Spiral Gingers will shed light on the taxonomy of this lineage and will enable us to test multiple hypothesis addressing the mechanisms underlying the diversity of the family.

1 - Cornell University, School for Integrative Plant Sciences, Section of Plant Biology and the L.H. Bailey Hortorium, 510 Mann Library, Cornell University, Ithaca, NY, 14853, USA
2 - University and Jepson Herbaria, 1001 Valley Life Sciences, Berkeley, CA, 94720, USA
3 - Cornell University, Plant Biology, 237 Mann Drive, Ithaca, NY, 14853, USA
4 - Universidade Federal do Oeste do Pará, Programa de Pós-Graduação em Biodiversidade (PPGBEES), Herbário de Santarém HSTM), Santarém, Pará, Brasil
5 - Naturalis Biodiversity Center, Leiden, Netherlands
6 - Naturalis Biodiversity Center, Leiden, Netherlands
7 - Le Jardin Ombragé, Tallahassee, FL, USA
8 - Cornell University, Plant Biology, Ithaca, NY, 14853, USA

Keywords:
Costaceae
Costus
Chamaecostus
Neotropical
phylogenomics
taxonomy.

Presentation Type: Oral Paper
Session: PHYL2, Phylogenomics II
Location: Tucson F/Starr Pass
Date: Wednesday, July 31st, 2019
Time: 3:00 PM
Number: PHYL2007
Abstract ID:900
Candidate for Awards:None