Create your own conference schedule! Click here for full instructions

Abstract Detail


Tseng, Yu-Hsin [1], Chung, Kuo-Fang [2], Monro, Alex [3], Wei, Yi-Gang [4], Hu, Jer-Ming [5].

The historical origins and evolution of paleotropical intercontinental disjunction in Elatostema (Urticaceae).

Elatostema is distributed throughout subtropical and tropical Africa, Asia and Australasia but is absent from the Americas. Elatostema comprises four major clades: Weddellia, Pellionia, Afroelatostema, and core Elatostema. This intercontinental disjunction in African and Asian tropics is evaluated by four competing hypotheses: Gondwanan vicariance, boreotropical migration, Miocene geodispersal hypothesis and transoceanic long distance dispersal. We reconstructed historical biogeographic pattern of Elatostema to evaluate the possible factors in shaping modern tropical disjunctions and the evolution within the group. Bayesian molecular dating and Statistical dispersal-vicariance analysis in Elatostema were conducted by analyzing 99 taxa of Elatostema and 40 outgroups, using one nuclear marker (nrITS) and two chloroplast sequences (psbA-trnH and psbM-trnD). The results indicate that the evolutionary history of Elatostema encompasses several biogeographical scenarios. These include two intercontinental dispersal events from Asia to Africa. One is correlated with the origin of Afroelatostema clade from the early Eocene to the late Oligocene, which could be explained by the hypothetical boreotropical migration during the early Eocene thermal maximum. The second African-Asian disjunction falls within the core Elatostema clade and could be explained by the hypothesis of overland dispersal in Miocene from Asia via Arabia to Africa during the Middle Miocene Climatic Optimum. Within the core Elatostema clade there are at least five major dispersal events, including two routes from East Asia through Malesia to Australasia. In addition, the geographical phylogenetic structure was found within Elatostema, which could be explained by restricted gene flow caused by limited seed and pollen dispersal. Numerous narrowly distributed endemics with relatively few widespread species and geographical structure within Elatostema suggest that limited gene flow may be an important feature in speciation and evolution in Elatostema, as hypothesized for other species-richness genera.

Log in to add this item to your schedule

1 - Academic Sinica, Biodiversity Research Center, 128 Academia Road, Section 2, Taipei, Taiwan
2 - Academic Sinica, Biodiversity Research Center, 128 Academia Road, Section 2, Taipei, 11529, Taiwan
3 - Royal Botanic Gardens, Kew, Herbarium, Richmond, Surrey TW9 3AB, London, UK
4 - Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chin, Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain, 85 Yanshan Stree, Yanshan District, Guilin, China

intercontinental discontinuous distribution
species richness.

Presentation Type: Oral Paper
Session: 37, Biogeography II
Location: 103/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 8:45 AM
Number: 37004
Abstract ID:586
Candidate for Awards:None

Copyright © 2000-2016, Botanical Society of America. All rights reserved