Abstract Detail

Biogeography

Kontur, Sophie [1], Schenk, John [1].

Speciation in response to novel habitats in Paronychia (Caryophyllaceae).

Paronychia (Caryophyllaceae) is a polyphyletic genus of approximately 110 species that occur in temperate regions of North and South America, the Caribbean, Eurasia, and Africa. In North America, species are abundant especially in the west and in Florida. The Florida populations are associated with particular sand ridges that were created at different times by varying sea levels formed during climate fluctuations. We tested the hypothesis that the seven Floridian Paronychia species underwent speciation as new, adjacent coastal habitats became available. We conducted preliminary analyses to determine (1) how many times Paronychia colonized peninsular Florida, (2) from what regions Paronychia colonized Florida, (3) the level of endemicity on Florida's sand ridges, and (4) whether speciation was associated with sand ridge formation. To answer the above questions, we took a historical biogeographic approach. Sequences were generated from six chloroplast (matK, nadhF, psbA-trnH, psbZ, trnL, and trnQ-rps16) and one nuclear ribosomal gene (ITS) for all seven of Florida's species and 18 putative relatives. To determine the level of sand ridge endemism, locality data were gathered from personal and herbarium collections. At least two colonizations of North America were inferred, both likely from the Mediterranean region. We estimated at least two independent colonizations of Florida from western United States. The first colonization involved P. herniarioides, which did not lead to further diversity in Florida. The second colonization substantially diversified following its dispersal from western North America, further leading to at least two northward range expansions into southeastern continental North America. Although species show affinity to particular sand ridges in the southern portion of their ranges, this relationship becomes obscured at the northern limits in some species (e.g., P. herniarioides). Closely related species tended to not co-occur on ridges, suggesting competitive exclusion and/or allopatric speciation. Phylogenetic and geographic structure suggests movement from older to younger ridges in at least one clade that includes P. erecta, P. rugelii, and P. patula, although more detailed genetic analyses are needed at the population-level to determine how species moved across these ridges.

1 - Tulane University, Department of Ecology and Evolutionary Biology, 400 Lindy Boggs Center, New Orleans, LA, 70118-5698, USA

Keywords:
Paronychia
Caryophyllaceae
Speciation
historical biogeography
Florida
sand hill habitat.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Eyrie/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PBG009
Abstract ID:75
Candidate for Awards:None