Recent Topics Posters
Kates, Heather Rose , Charboneau, Joseph , Moore, Michael .
Phylogeny and biogeography in a Chihuahuan Desert gypsophilic plant group: Nerisyrenia (Brassicaceae).
Nerisyrenia Greene (Brassicaceae) is a small genus of 11 arid-adapted species that are endemic to the Chihuahuan Desert of southwestern North America. With the exception of the widespread species N. camporum (A. Gray) Greene, all taxa within Nerisyrenia are restricted to gypsum deposits and soils, which are scattered in an island-like fashion throughout the Chihuahuan Desert. This phenomenon is referred to as gypsophily. Patterns of morphology, phylogeny, and biogeography within other Chihuahuan Desert gypsophilic plant groups suggests that gypsophily may be several million years old in these groups. As part of a larger effort to understand the age, origins, and phylogeography of gypsophily in the Chihuahuan Desert, we have initiated a phylogenetic and phylogeographic study of Nerisyrenia to answer the following questions: (1) How many times has gypsophily evolved within the genus?; (2) Is the widespread species N. camporum derived from gypsophilic ancestors?; and (3) Is there a strong correlation between biogeographic distribution and genetic diversity within gypsophilic Nerisyrenia, both within and between species? To address these questions, we reconstructed the phylogeny of Nerisyrenia by generating and analyzing DNA sequences for ITS and five chloroplast spacer regions (ndhF/rpl32, rpl32/ccsA, ndhC/trnV, rps16/trnQ, and petA/psbJ). We sampled all but one species in the genus, including numerous populations of the two most widespread species, N. camporum and N. linearifolia (S. Wats.) Greene, from across their geographic ranges. Preliminary results indicate that the widespread gypsophile N. linearifolia has a significant amount of geographically-correlated sequence variation, and that N. camporum shares chloroplast haplotypes with several other species, suggesting a complex evolutionary history.
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The Origins and Biogeography of Gypsophily in the Chihuahuan Desert
1 - Oberlin College, Biology Department, Science Center K123, 119 Woodland Street, Oberlin, OH, 44074, U.S.A
2 - Oberlin College, Biology Department, 119 Woodland Street, Science Center K111, Oberlin, Ohio, 44074-1097, USA
Presentation Type: Recent Topics Poster
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM