Abstract Detail

Patterns and Processes of American Amphitropical Plant Disjunctions: New Insights

Simpson, Michael [1], Guilliams, C. Matt [2], Whittall, Justen Bryant [3].

Patterns and Processes of American Amphitropical Plant Disjunctions: New Insights.

A fascinating aspect of plant biogeography is the occurrence of a number of closely related plant groups in temperate, desert, or polar regions of both North America and South America, but rarely intervening tropical regions. This distribution, which may be termed American Amphitropical Disjunction (AAD), has long been recognized by phytogeographers as a recurring pattern, mainly among herbaceous angiosperms. The primary research question remains: how did various plant groups come to have an AAD pattern of distribution? This question can be tackled as several corollary questions: 1) What is the mechanism by which plant groups have attained an AAD distribution: vicariance and/or long-distance dispersal? 2) How frequently and when did these dispersal events occur? 3) What are inherent features of AAD lineages that might have enabled them to attain an AAD distribution? 4) Can similar patterns of AAD distribution be correlated with common historical climatic or geological events? 5) What selective forces may have permitted the survival and radiation of dispersed plants and how are these reflected in morphological or reproductive traits? The current hypothesis accepted by most workers for most plant groups is that of long-distance dispersal, most likely by migratory birds, and at multiple times in the past, with a general north to south bias. However, with modern phylogenetic and comparative methods, these topics can be addressed more explicitly. This symposium will provide an opportunity to synthesize phylogenetic results from several angiosperms lineages - both from phylogenetic analyses of specific taxonomic groups and from comparative analyses of data from systematics, geology, and climatology.

1 - San Diego State University, Department of Biology, San Diego, CA, 92182, USA
2 - Santa Barbara Botanic Garden, Conservation & Research, 1212 Mission Canyon Road, Santa Barbara, CA, 93105, USA
3 - Santa Clara University, Department Of Biology, 500 El Camino Real, Santa Clara, CA, 95053, USA

Keywords:
none specified

Presentation Type: Colloquium Presentations
Session: C2, Patterns and Processes of American Amphitropical Plant Disjunctions: New Insights
Location: 204/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 1:30 PM
Number: C2SUM
Abstract ID:1006
Candidate for Awards:None