To the FWGNA group:
I'm pleased to report that Amy Wethington's excellent 2004 dissertation
has, at long last, found its way to publication (1). "A molecular
phylogeny of Physidae (Gastropoda: Basommatophora) based on
mitochondrial DNA sequences" is now available as a PDF download from the FWGNA site. Our congratulations go to Amy and to her advisor, Chuck Lydeard, for a job well done!
Amy sequenced fragments from both the CO1 and 16S mitochondrial genes
(summing to 1,200 bp) from a sample of 65 individual physids,
representing 28 nominal taxa (2). The results of her phylogenetic
analyses dovetail nicely with her anatomical observations, as well as
with the growing body of experimental evidence demonstrating little
reproductive isolation among many physid populations formerly
considered specifically distinct. Amy and Chuck propose a return
to the simple two-genus classification system favored by Thiele and
Zilch - Physa and Aplexa - the former with about ten species and the latter with but one.
Although their sample size within any single physid population was kept
small by the exigencies of scale, Amy and Chuck demonstrate in their
analysis the appreciation for interpopulation variation that
characterizes all good evolutionary science. Amy has published at
least 14 papers on the genetics, ecology, behavior, and reproductive
biology of Physa over the
last 15 years. She first familiarized herself thoroughly with her
organism, then sequenced its genes and cranked out her phylogenetic
trees. It shows.
Amy is currently an assistant professor at Chowan University in Murfreesboro, North Carolina (3). We'll look forward to many additional contributions from her in the future!
And keep in touch,
Rob
Notes
(1) Wethington, A.R. & C. Lydeard (2007) Journal of Molluscan Studies 73: 241 - 257.
(2) Amy's sample of taxa was primarily North American, but did include
fontinalis from The Netherlands, marmorata from Guadeloupe, and acuta
from several spots around the world.
(3) Email Amy at <wethia@chowan.edu>
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