Saturday, July 21, 2007

My summer research

Well, my poster revision has been excepted by the AOU for the 125 meeting in Wyoming this August. So here's the official abstract, Poster #312 from the meeting abstract pdf:

312 Sly, Townsend, Rimmer & Lovette
Species limits and phylogeography of Hispaniolan palm-tanagers (Phaenicophilus). NICHOLAS D. SLY, Lab. Ornithol., Cornell Univ., Ithaca, NY, ANDREA K. TOWNSEND, Dept. Ecol. & Evol. Biol., Cornell Univ., CHRISTOPHER C. RIMMER, Vermont Inst. Nat. Sci., Woodstock, VT, and IRBY J. LOVETTE, Dept. Ecol. & Evol. Biol., Cornell Univ.

Avian speciation within medium-sized islands is unusual, yet Hispaniola supports several species pairs, including the palm-tanagers, Phaenicophilus palmarum and P. poliocephalus. These sister species have ranges that meet along a former sea channel in southwestern Haiti. Their respective species status has been questioned after the discovery of a hybrid zone in this region, but the only previous molecular work on this system relied on isozymes. We use sequence data to explore the level of differentiation between the 2 forms, to access if the timing of their divergence dates to the ancient sea channel, and to examine potential cryptic divergence within the genus. Analysis of an mtDNA-based haplotype network indicates a deep split (mean 5.51%; range: 5.27% - 5.86% uncorrected divergence) between P. palmarum and P. poliocephalus. The mtDNA networks apparently have no further phylogeographic structure within either species, indicating recent gene flow between many conspecific populations. These data support species status for both palm-tanagers, point toward within-island speciation that corresponds to the timing of the sea channel, as well as confirm P. poliocephalus as Haiti’s only endemic bird.

Disclaimer: As the abstract book says, "The abstracts in this work are not issued for the permanent scientific record." These are preliminary data, and I won't post any final results here, because they will ultimately be used as my Honor's Thesis and (hopefully) published in a Journal.

I suppose I should back up a little and explain a little about what I'm up to. This summer I am a Hughes Scholar at Cornell, doing research at Irby Lovette's Evolutionary Biology Program at the Lab of Ornithology (the website is rather out of date). I'm working with Andrea Townsend on the comparative phylogeography of Hispaniolan endemics. The first of this work has already been completed by Andrea:

Townsend, AK, CC Rimmer, SC Latta, and IJ Lovette. Ancient differentiation in the single-island avian radiation of endemic Hispaniolan chat-tanagers (Aves: Calyptophilus). In press.

She compared mitochondrial and nuclear sequences for chat-tanagers across Hispaniola to examine the phylogeographic structure and species limits. I am doing the same with the Palm-tanagers, Phaenicophilus palmarum and Phaenicophilus poliocephalus. It's exciting work and I am happy to be presenting the first round of results for Hughes and for the conference.

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