Abstract Detail

Systematics Section

Moore, Michael [1], Bruenn, Riva [1], Drummond, Chloe [1], Joffe, Jonah [1], Mostow, Rebecca [1], Stalberg, Gabriel [1], Douglas, Norman [2], Brockington, Samuel [3].

The age of gypsum endemism and arid-adapted plants within Nyctaginaceae inferred using extensive taxon sampling in Caryophyllales.

Morphological, distributional, and genetic evidence suggests that gypsum endemic plant clades in southwestern North America predate the Pleistocene, and consequently survived the climatic fluctuations of the last two million years. We test this hypothesis in Nyctaginaceae tribe Nyctagineae, which contains multiple clades of gypsum endemics, using a molecular dating approach. Sequences were generated for the three most variable plastid protein-coding genes (ycf1, ndhF, and matK) for an extensive sampling of Nyctaginaceae and surrounding families, as well as exemplar taxa throughout Caryophyllales. In addition, all available Caryophyllales sequences of these genes were downloaded from GenBank and included in gene-specific analyses to examine the influence of taxon and gene sampling on age estimates. Molecular dating analyses include constraints based on the best available fossils for Caryophyllales, including Eocene and late Cretaceous pollen of Amaranthaceae s.l. We address the implications of our results for the origins of both gypsum endemism and arid adaptations within Nyctagineae, in light of other recent studies.

Broader Impacts:

1 - Oberlin College, Department of Biology, 119 Woodland St., Oberlin, OH, 44074, USA
2 - North Carolina State University, Department Of Biology, Campus Box 7612, Raleigh, NC, 27695, USA
3 - University of Cambridge, Department of Plant Sciences, Downing Street, Cambridge, CB2 3EA, UK

Keywords:
Nyctaginaceae
Caryophyllales
molecular dating
gypsum endemism
arid-adapted plants.

Presentation Type: Oral Paper:Papers for Sections
Session: 19
Location: Lindell B/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 1:45 PM
Number: 19002
Abstract ID:319