I am primarily interested in disease ecology and host-parasite coevolution. Though
parasites are often thought of as highly virulent pathogens that quickly overrun their host,
parasites that kill their hosts too rapidly or cause the population to go extinct will not
enjoy long-term reproductive success. In response to the risk of disease, the host mounts
defenses against infection (resistance) or controlling infections (tolerance), both of which
effectively lessen a parasite’s success. In this sense, many host-parasite systems are
embroiled in a constant arms race: the parasite adapting to evade its host’s immune
system, and the host adapting to escape the parasite’s new offensive tactics. The “Red
Queen hypothesis” addresses this very scenario, where the host is “running” from the
pathogen that is “chasing” it.
My PhD research proposes to examine the coevolution of host and parasite in large
aquatic salamanders, chiefly the two-toed amphiuma, Amphiuma means, and the greater
siren, Siren lacertina. These amphibians are common in the southeast United States and
can be found throughout Florida. Both species, though only distantly related, undergo
aestivation in periods of drought. I plan on examining the parasite fauna of these
salamanders and determining whether infection with parasites affects aestivation success;
these animals exhaust their fat reserves while aestivating and pathogens could consume
even more resources. I am also interested in whether aestivation is an immune adaptation
whereby they can clear infections while in a dormant state. Many intestinal parasites
simply absorb nutrients from their hosts’ meals, so a parasite in an empty intestine would
most likely starve. Finally, have the parasites adapted to cope with their hosts’ behavior?
Parasites often have dormant states (like the metacercariae of trematodes) that can remain
inert for long periods of time, or eggs that can remain infective for years (like those of
Ascaris). I am always excited to work on parasites, and especially excited to work on
those of four-foot-long salamanders!
Brittany F. Sears
Curriculum Vitae
Tel: (813) 215-1346
Email: bsears@mail.usf.edu
Education
2007: B.S. in Zoology, summa cum laude from the University of Florida.
2008: Ph.D. student, Department of Integrative Biology, University of South Florida
Academic Positions
Aug 2008-present: Teaching Assistant, University of South Florida
Fall 2008: Parasitology
Spring 2009: Ecology
Aug 2005 – May 2007: Undergraduate Research Assistant. Laboratory of Dr. Marta L. Wayne,
Department of Zoology, University of Florida
Academic Benchmarks
President’s Honor Roll Fall 2005, Spring 2007
Undergraduate GPA: 3.53 cumulative, 3.42 science
GRE General Test Score: 1470
B.S. in Zoology, summa cum laude, 2007
Scholarships and Certification
2008: Presidential Fellow, University of South Florida
2006: University Scholar, Department of Infectious Disease and Pathology, University of Florida
2003-2007: University of Florida National Merit Scholarship
2004: Rescue scuba diving certification (YMCA)
2004: Advanced scuba diving certification (YMCA)
2003: Open water scuba diving certification (NAUI)
2002: National Merit Scholar
Work Experience
July 2007-Aug 2008: Canine Heartworm Project Coordinator. Department of Infectious Disease
and Pathology, College of Veterinary Medicine, University of Florida.
May 2006-Aug 2008: Parasitology Research Assistant. Department of Infectious Disease and
Pathology, University of Florida.
Grant Funded
2006-2007. University Scholars Grant. Department of Infectious Disease and Pathology.
University of Florida. . $2500
The "Red Queen" hypothesis suggests that organisms employing sexual reproduction
can evolve to escape parasites by constantly recombining their DNA while asexuals cannot
because their genomes are not recombined and thus, evolve much more slowly. I tested this
hypothesis by examining the trematode parasites of Campeloma limum, quantifying prevalence
and describing the morphologies of the heretofore undescribed flatworms.
Talks
August 4 – 8 2008: “Parasites in cold stunned green turtles in Florida” by E. Greiner, B. Stacy, T.
McIntosh, A. Foley, B. Sears, J. Miller and E. Jacobson.” Wildlife Disease Association,
Edmonton, Canada. Presented by E. Greiner.
April 19, 2007: Zoology Undergraduate Research Symposium. “Sex, lies, and trematodes.”
February 17, 2007: University Scholars Program Undergraduate Research Symposium.
“Parthenogenesis and parasitism in Campeloma limum.”
Anticipated Publications
As a result of ongoing research with the viviparid snail Campeloma limum, I anticipate be
included as an author in three papers. One will stem from my work on trematode parasites of C.
limum it will address the morphology of various undescribed species and their correlation with
specific populations of C. limum; it will address the implications of the snail-trematode relationship
for the Red Queen Hypothesis, which proposes parasite-mediated evolutionary advantages to
parthenogenesis. A second publication will address the correlation between water quality
indicators (dissolved oxygen, pH) and sexual or parthenogenic populations of C. limum. A third
publication will describe embryo size, brood size, and egg capsule resorption in sexual vs.
parthenogenic populations of C. limum. I anticipate being second author on the first publication
and third on the other publications.
References:
Dr. Jason Rohr, University of South Florida, Integrative Biology Department.
Email: jrohr@cas.usf.edu
Dr. Lynn Martin, University of South Florida, Integrative Biology Department.
Email: lmartin@cas.usf.edu.
Dr. Ellis Greiner, University of Florida College of Veterinary Medicine: (352) 392-4700 x5861
Email: greinere@mail.vetmed.ufl.edu