| Abstract Detail
Biogeography Givnish, Thomas J [1], Spalink, Daniel [2], Ames, Mercedes [3], Lyon, Stephanie [4], Hunter, Steven [3], Zuluaga, Alejandro [5], Doucette, Alfonso [3], Giraldo, Giovanny [3], McDaniel, James [6], Clements, Mark [7], Arroyo, Mary T. K. [8], Endara, Lorena [9], Kriebel, Ricardo [10], Williams, Norris [11], Cameron, Ken [6]. Orchid historical biogeography, diversification, Antarctica, and the paradox of orchid dispersal. Orchidaceae is the most species-rich angiosperm family and has one of the broadest distributions. Until now, the lack of a well-resolved phylogeny has prevented analyses of orchid historical biogeography. Here we use such a phylogeny to estimate the geographic spread of orchids, evaluate the importance of different regions in their diversification, and assess the role of long-distance dispersal (LDD) in generating orchid diversity. Analyses use a phylogeny including species representing all five orchid subfamilies and almost all tribes and subtribes, calibrated against 17 angiosperm fossils. We estimated historical biogeography and assessed the importance of different regions for rates of speciation, extinction, and net species diversification. We evaluated the impact of particular LDD events on orchid diversity by asking how many species evolved in the new range subsequent to those events. Orchids appear to have arisen in Australia 112 Ma then spread to the Neotropics via Antarctica by 90 Ma, when all three continents were in close contact and apostasioids split from the ancestor of all other orchids. The ancestors of vanilloids, cypripedioids, and orchidoids + epidendroids appear to have originated in the Neotropics 84-64 Ma. Repeated long- and short-distance dispersal occurred through orchid history: stochastic mapping identified a mean total of 73 LDD events, or 0.8 Ma-1. Across orchid history, Southeast Asia was the most important source and maximally accelerated net diversification; across epidendroids, the Neotropics maximally accelerated diversification. More than 97% of all orchid species appear to have evolved following one or more LDD events. Our analysis provides the first biogeographical history of the orchids, implicating Australia, the Neotropics, and Antarctica in their origin. LDD and life in the Neotropics – especially the Andes –had profound effects on their spread and diversification; > 97% of all orchid species are restricted to individual continents.
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1 - University Of Wisconsin, Department Of Botany, Birge Hall, 430 Lincoln Drive, Madison, WI, 53706, USA
2 - University Of Wisconsin-Madison, Department Of Botany, 430 Lincoln Drive, Madison, WI, 53706, USA
3 - University of Wisconsin-Madison, Botany, Madison, WI, 53706, USA
4 - Botany, 216 E Duncan St, Columbus, OH, 43202, USA
5 - Universidad del Valle, Biology, Cali, Colombia
6 - University Of Wisconsin - Madison, Botany, 430 Lincoln Drive, Madison, WI, 53706, USA
7 - CSIRO, Centre for Australian National Biodiversity Research, Canberra, ACT, 2601, Australia
8 - Universidad de Chile, Institute of Ecology and Biodiversity, Santiago, Chile
9 - University of Florida, Biology, Carr Hall, 217, PO Box 118525, Gainesville, FL, 32611, USA
10 - University of Wisconsin-Madison, Botany, Madison, WI, 53706, US
11 - University Of Florida, Florida Museum Of Natural History, PO BOX 117800, Gainesville, FL, 32611-7800, USA, 352/273-1964
Keywords:
Asparagales
BioGeoBears
BiSSE
long-distance dispersal
Neotropics
Southeast Asia.
Presentation Type: Oral Paper
Session: 37, Biogeography II
Location: 103/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 8:00 AM
Number: 37001
Abstract ID:407
Candidate for Awards:None |
