Abstract Detail

Systematics Section/ASPT

Givnish, Thomas J. [1], Spalink, Daniel [1], Ames, Mercedes [2], Lyon, Stephanie P. [3], Hunter, Steven J. [4], Zuluaga, Alejandro [5], Iles, William J. D. [6], Clements, Mark A. [7], Arroya, Mary T. K. [8], Leebens-Mack, James [9], Endara, Lorena [10], Kriebel, Ricardo [4], Neubig, Kurt M. [11], Whitten, M. Mark [12], Williams, Norris H. [12], Cameron, Kenneth M. [13].

Orchid phylogenomics and multiple drivers of their extraordinary diversification.

Orchids are the most diverse family of angiosperms, with over 25,000 species, more than mammals, birds, and reptiles combined. Tests of hypotheses to account for such diversity have been stymied by the lack of a fully resolved broad-scale phylogeny. Here we provide such a phylogeny, based on 75 chloroplast genes for 39 species repre­sent­ing all orchid subfamilies and 16 of 17 tribes, time-calibrated against 17 angiosperm fossils. A supermatrix analysis places an additional 144 species based on three plastid genes. Orchids appear to have arisen roughly 112 million years ago (Mya); the subfamilies Orchidoideae and Epidendroideae diverged from each other at the end of the Cretaceous; and the eight tribes and three previously unplaced subtribes of the upper epiden­droids diverged rapidly from each other between 37.9 and 30.8 Mya. Orchids appear to have undergone one significant acceleration in net species diversifi­cation in the orchidoids, and three in the upper epidendroids. Consistent with theory, such accelera­tions were correlated with the evolution of pollinia, the epiphytic habit, CAM photosynthesis, tropical distribution (especially in extensive cordilleras), and pollination via deceit, euglossine bees, or Lepidoptera. The highest rate of net species diversification within the orchids is 4.9 times that at the Asparagales crown.

1 - University Of Wisconsin, Department Of Botany, Birge Hall, 430 Lincoln Drive, Madison, WI, 53706, USA
2 - Promega, Fitchburg, WI, USA
3 - Botany, 216 E Duncan St, Columbus, OH, 43202, USA
4 - University of Wisconsin-Madison, Botany, 430 Lincoln Drive, Madison, WI, 53706, USA
5 - University Of Wisconsin-Madison, 430 Lincoln Drive, UWisconsin-Department Of Botany, Madison, WI, 53706, USA
6 - University Of British Columbia, 3529-6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
7 - Centre for Australian National Biodiversity, Canberra, ACT, Australia
8 - Universidad de Chile, Santiago, Chile
9 - University of Georgia, Plant Sciences, Athens, Georgia, USA
10 - University of Florida, Florida Museum of Natural History, Gainesville, FL, USA
11 - University Of Florida, 4007 SW 20th Ln, Gainesville, FL, 32607, USA
12 - University Of Florida, Florida Museum Of Natural History, PO Box 117800, Gainesville, FL, 32611-7800, USA, 352/273-1964
13 - University Of Wisconsin, Department Of Botany, 154 Birge Hall, 450 Lincoln Drive, Madison, WI, 53706, USA

Keywords:
Andes
BAMM
BiSSE
New Guinea Highlands
Pleurothallidinae
speciation.

Presentation Type: Oral Paper:Papers for Sections
Session: 33
Location: Salon 10/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 11:30 AM
Number: 33014
Abstract ID:71
Candidate for Awards:None