Abstract Detail

Population Genetics

Prunier, Rachel E. [1], Holsinger, Kent E. [2], Borevitz, Justin [3].

Why hasn't Protea repens (Proteaceae L.) speciated? Genetic structure and patterns of selection in an atypically widespread Cape Floristic Region species.

What evolutionary processes give rise to high botanical diversity? Some regions of the world have exceptionally high diversity, while others do not.  For example, the Cape Floristic Region (CFR) of southwestern South Africa is home to >9,000 plant species, many more than other temperate regions. Intriguingly, most of the species endemic to the region have narrow and non-overlapping ranges, causing high beta diversity. However, there are a few species that are exceptions to the rule, and range across the CFR.  By studying the micro evolutionary processes that keep these species unified, the evolutionary processes underlying the patterns of diversity in the CFR can be further elucidated. Protea repens (Proteaceae L.) is one of those exceptional species.  Previous work has shown that there is very low gene flow between populations of more narrowly ranged Protea species (Protea section Exsertae), suggesting that isolation has lead to speciation in this group.  We hypothesize that there will be higher levels of population connectivity in P. repens than in these narrowly ranged species.  We identified hundreds of SNPs in Protea repens using high throughput DNA sequencing techniques and the UNEAK pipeline. We then estimated genetic boundaries using STRUCTURE and patterns of genetic structure using Arlequin to address this hypothesis. Low levels of differential selection might also be helping P. repens to continue to be a cohesive species.  We identified SNPs that are likely associated genomic regions undergoing natural using a Bayesian FST-outlier analysis.  If there is strong differential selection among populations in P. repens, we can infer that divergent selection on those loci alone may be insufficient to cause diversification.  By using population genetics to study micro-evolutionary processes, we can gain insight in the causes of the remarkable diversity of the CFR as well as other high diversity regions.

1 - Western Connecticut State University, 181 White Street, Danbury, CT, 06810, USA
2 - University of Connecticut, Ecology & Evolutionary Biology, 75 North Eagleville Rd., U-3043, Storrs, CT, 06269, USA
3 - The Australian National University , Center of Excellence in Plant Energy Biology, Research School of Biology, ANU College of Medicine, Biology and Environment , Canberra, ACT, 0200, Australia

Keywords:
population genomics
popiulation genetics
phylogeography
Proteaceae
Protea repens
natural selection
genetic drift.

Presentation Type: Oral Paper:Papers for Topics
Session: 6
Location: Pines South/Boise Centre
Date: Monday, July 28th, 2014
Time: 10:15 AM
Number: 6007
Abstract ID:359
Candidate for Awards:Margaret Menzel Award