Academic Degrees
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Ph.D. Zoology (Vertebrate Morphology), University of California at
Davis (1980)
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M.S. Biology, Northern Arizona University (1974)
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B.S. Zoology, Northern Arizona University (1973)
Courses Taught
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BIOL 3233
Vertebrate Zoology w/Lab
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BIOL 4111 Evolution (offered for graduate credit)
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BIOL 4235 Mammalogy w/Lab (offered for graduate credit as Biol 5235)
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BIOL 4293 Comparative Vertebrate Anatomy w/Lab (offered for graduate
credit)
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BIOL 4600 Senior Seminar
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BIOL 6070 Graduate Topics in Anatomy (offered for graduate credit
only)
Vertebrate Skeletal Muscle Structure and Function
 Research in my lab focuses on understanding the evolution
of structure and function in skeletal muscles. Have you ever wondered
how some animals are able to move so fast while others seem limited to
very slow movements (e.g. cheetah versus sloth)? How do some
frogs hop 20X body length, while toads plop along at only 2X body length?
What kinds of cellular, structural and biomechanical differences produce
these differences in function? And, how different do muscle properties
have to be in order to allow adaptation for different functions?
The primary emphasis in my lab is on describing the range of contractile
properties present in muscles: we measure force properties,
contraction and relaxation speed and fatigability by direct stimulation
techniques. In addition, we characterize the muscle fiber
types and their distribution within and between muscles using histological
techniques. Measurement of the activities of important oxidative and
glycolytic enzymes also allows us to see how strong a correlation exists between
the fiber type populations and the actual contractile functions of the
muscles. I am interested in understanding the relationship between
the functional properties of muscle and the behaviors that they produce.
Therefore, we always film the animals during their natural behaviors
so we can estimate the range of movement over which a muscle acts.
In the past, my students and I have worked with mammals (cat, opossum),
birds (pigeon, owl, hawk), and, most recently, with amphibians - primarily
with frogs. We have found that the hopping muscles in frogs are
exceptionally powerful, but that even those muscles that we think are
primarily used for posture have unusually large motor units.
We discovered that hopping and swimming behaviors require
very similar input from the muscles and that the behaviors are derived
by modifying a typical quadrupedal gait pattern in almost identical ways,
i.e., hopping and swimming evolved together as frogs developed their specialized anatomy and behaviors.
Recently, we compared forelimb muscles between males and females in two
different species of frogs. Males have exceptionally enlarged
forelimb flexors which maintain the mating embrace, amplexus.
These sexually dimorphic muscles are also much less fatigable in males.
So far we have found higher oxidative capacity in males without much
difference in fiber type populations from females. We are
currently looking at the expression of androgen receptor genes to
quantify differences between males and females. We have also
done studies on the tongue and jaw muscles in species of
frogs that feed differently. These comparative studies should
help us to better understand the diversity of structure and function that
skeletal muscles exhibit, and how different their properties are which
produce the vast diversity of behaviors that we see among the vertebrates.
Selected Publications
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Crockett, C.J. and S.E. Peters 2008. Hindlimb muscle
fiber types in two frogs (Rana catesbeiana and Litoria
caerulea) with different locomotor behaviors: histochemical and
enzymatic comparison. J. Morphol.
269:365-374
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Clark, D.L. and S.E. Peters 2006. Isometric contractile
properties of sexually dimorphic forelimb muscles in the marine toad,
Bufo marinus: functional analysis and implications for amplexus.
J. Exp. Biol. 209:3448-3456.
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Corvidae, E.L., R.O. Bierregaard and S.E. Peters 2006.
Comparison of wing morphology in three birds of prey: Correlations
with differences in flight behavior. J. Morphol. 267:612-622.
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Chadwell, B.A., H.J. Hartwell and S.E. Peters 2002. Comparison
of isometric contractile properties in hindlimb extensor muscles of
the frogs Rana pipiens and Bufo marinus: Functional
correlations with differences in hopping performance. J. Morphol.
251:309-322.
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Peters, S.E. and D.A. Aulner 2000. Sexual dimorphism in
forelimb muscles of the bullfrog, Rana catesbeiana: A functional
analysis of isometric contractile properties. J. Exp. Biol. 203:3639-3654.
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Peters, S.E. and K.C. Nishikawa 1999. Comparison of isometric
contractile properties of the tongue muscles in three species of frogs,
Litoria caerulea, Dyscophus guinetti and Bufo
marinus. J. Morphol. 242: 107-124.
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Peters, S.E., L.T. Kamel and D.P. Bashor 1996. Hopping
and swimming in the leopard frog, Rana pipiens: I. Step cycles
and kinematics. J. Morphol. 230:1-16.
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Kamel, L.T., S.E. Peters and D.P. Bashor 1996. Hopping
and swimming in the leopard frog, Rana pipiens: II. A comparison
of muscle activities. J. Morphol. 230:17-31.
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Peters, S.E. 1994. Properties of the twitch motor units
of the ankle extensor muscles in the bullfrog Rana catesbeiana.
J. Morphol. 221:121-131.
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Peters, S.E. 1989. Structure and function in vertebrate
skeletal muscle. Amer. Zool. 29:221-234.
Current Graduate Students
Past Graduate Students
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Lee Clark. MS, 2005. Thesis title: A Comparison of
Isometric Contractile Properties of Sexually Dimorphic Forelimb Muscles
in the Marine Toad, Bufo marinus
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Elaine Corvidae. MS, 2005. Thesis title: A
Comparison of Wing Morphology in Three Birds of Prey: Correlations with
differences in flight behavior. Currently on rehabilitation staff
at Carolina Raptor Center, Charlotte, NC.
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Brad Chadwell. MS, 1999. Thesis title: A Comparison of
Hindlimb Muscles in Two Anurans: Contractile Properties and Fiber Types.
Currently PhD student in the Biology Department at Wake Forest University.
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Dwane Aulner. MS 1996. Thesis title: Sexual Dimorphism in the Forelimb
of the North American Bullfrog: A Functional Comparison. Currently
on biology faculty at Community College of Southern Nevada in Las Vegas.
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Patricia Boland. MS 1996. Thesis title: Comparison of Motor Pools
in Two Amphibians: A Test of Neuroanatomical Conservatism.
Currently teaches human anatomy & physiology, and general zoology at
Medaille College, NY.
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Charles Dobbins. MS 1993. Thesis title: A Comparative Study of the
Mechanics of the Pectoralis Muscle of the Red-tailed Hawk and the
Barred Owl.
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Lynn Kamel. MS 1992. Thesis title: Frog Hindlimb Muscle Activity in
Hopping and Swimming: An Electromyographic Analysis.
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Robert Jones. MS 1992. Thesis title: A Model for the Evolution
of the Phylum Cnidaria, Evaluated Cladistically. I was a
co-Advisor on his thesis with our Cell Biologist.
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Terry Chapman. MS 1989. Thesis title: Evolution of the Carnivora:
An Immunological Comparison of the families Mustelidae and Viverridae.
I was co-Advisor with our Immunologist.
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Greg Cornwell. MS 1985. Thesis title: Sonographic Analysis of
Pine Warbler Vocalizations. I took over completion of this thesis
from another faculty member who left UNCC.
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