Lauren Lucas
Graduate
Student (M.S.)
Population
and Conservation Biology Program
Department
of Biology
Texas State
University
San Marcos, TX
78666
Email:
lucas@txstate.edu
Research
Interests
Biogeography
& Phylogeography
Population
Genetics
Natural
History
Conservation
Current
Research
Advisor:
Dr. Chris Nice
Committee:
Dr. Jim Ott, Dr. Caitlin Gabor, Joe Fries (USFWS)
Population Genetics and Conservation
of Texas Hill Country Salamanders (Plethodontidea: Eurycea)
There
are many salamander populations of the genus Eurycea found in springs scattered throughout
the Texas Hill Country. Many of these populations belong to taxa that are federally
listed as threatened or endangered due to their restricted ranges and the
threats to their habitats by human usage. Phylogenetic relationships among most
of these Texas Hill Country Eurycea populations are uncertain, as divergences are shallow and many
springs are currently unsampled. Some of Texas Hill Country springs are known
to dry up during drought years or even seasonally. There is anecdotal evidence
for population persistence, but it is unknown how these salamander populations
persist under such conditions. Two scenarios postulated for how these
populations persist are: populations go extinct and re-colonize from
connections within river drainage systems, or populations may persist in
subterranean habitats
within the aquifers.
I
am using data from genetic markers (mtDNA sequence, nuclear DNA sequence, and
AFLPs) to test hypotheses about potential hydrogeological systems responsible
for phylogeographic structure in this system. My hypotheses are: A) Genetic
variation is organized along aquifer boundaries, and B) Genetic variation is
organized along river boundaries. Testing these hypotheses will make it
possible to: 1) Detect boundaries of units for conservation, and 2) Elucidate
the means by which Eurycea persist through periods of drought. I am also using these
genetic data to calculate effective population size estimates for each
population to compare to available census estimates. Such estimates will help
me determine the proportion of a population in subterranean habitats and/or detect
bottlenecks if present.
I
am also assessing extant genetic diversity and population structure of the wild
and captive populations of the federally-threatened E. nana to determine if the diversity of the
wild population is represented in the captive population.
Scientific
Presentations
Talks
Lucas, L.K. 2006. The Phylogeography of Texas Hill
Country Salamanders: Implications for Conservation and Population Persistence.
Southwestern Association of Naturalists 53rd Annual Meeting, Colima,
Mexico.
Lucas, L.K. 2006. Rivers and Aquifers: What
structures genetic variation in Texas Hill Country salamanders? 11th
annual Student Colloquium. Texas State University-San Marcos, Department of
Biology.
Lucas, L.K., C.R. Gabor, J.N. Fries and C.C. Nice.
2005. Conservation genetics of salamander populations in the Texas Hill
Country. East Texas Herpetology Society Annual Meeting, Austin, TX.
Lucas, L.K., C.R. Gabor, J.N. Fries and C.C. Nice.
2005. Population genetics of a threatened plethodontid salamander. Evolution
Annual Meeting, Fairbanks, AK.
Posters
A. M. Graves, L.K. Lucas and M.C. Swift. 2004. Phylogenetic
relationships among Chaoborus species. 52nd Annual Meeting. North American
Benthological Society. Vancouver, BC, Canada.
Graves, A. and L. Lucas. 2004. Phylogenetic relationships
among Chaoborus
species. 72nd Minnesota Academy of Science Annual Meeting. 18th
Winchell Undergraduate Research Symposium. St. JohnÕs University, Collegeville,
MN.
Publications
Wende, F., L.K. Lucas, A.M. Graves, M.C. Swift and T.U.
Berendonk. Steps between lakes?
Initial genetic data on the planktonic predator Chaoborus flavicans. In press: Archives of Hydrobiology
Lucas, L.K., J.A. Fordyce and C.C. Nice. Patterns
of Genitalic Morphology Around Suture Zones in North American Lycaeides (Lepidoptera: Lycaenidae): Implications
for Taxonomy and Historical Biogeography. In review.
Links
San Marcos National Fish Hatchery & Technology
Center (Home of captive Eurycea nana)
Spring
Lake, Aquarena
Center (Home of Eurycea nana)