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College of Arts & Sciences
Department of Biological Sciences

Graduate Student Directory

Rachel Steward

Degree Program: Integrative Biology
Room: EWS 707
Major Professor: Dr. Carol Boggs
Current Research
The goal of my dissertation research is to understand how herbivorous insects respond to evolutionary traps imposed by invasive nonnative plants. Many insects, especially butterflies, have evolved to recognize a very small range of potential host plants. Recognition and feeding are often mediated through secondary chemicals produced by the plants. Invasive plants can interrupt these relationships, and evolutionary traps arise when plants possess chemicals that cue recognition for adult insects, while also possessing novel defenses to which the offspring are na├»ve and therefore vulnerable.The fitness costs imposed by evolutionary traps should represent strong selective pressures for local adaptation to the trap.
 For insects, this may favor better discrimination between potential host plants or incorporation of the novel plant into the larval diet. However, these selection pressures can vary greatly between populations with different levels of exposure to the novel plant. Evolutionary traps present a unique opportunity to study local adaptation to geographically heterogeneous selection pressures. The evolutionary trap that I am studying occurs in areas where the European mustard Thlaspi arvense has invaded the habitat of the North American butterfly Pieris macdunnoughii. This system offers the additional opportunity to understand the limitations of recognition and the role of gene flow in constraining adaptive responses to evolutionary traps.
BS Biology Summa Cum Laude (2011) Tufts University, Medford MA
Leadership Positions 
President, Graduate Association of Biological Sciences (2016-2017)
Vice President, Graduate Association of Biological Sciences (2015 - 2016)
Coordinator, EEOB Journal Club (2015 - present)
Coordinator, RMBL Grad Seminar (2015 - present)
Awards & Honors
NSF Graduate Research Fellowship (2014-2017)
University of South Carolina Presidential Fellows (2013-2017)
Class of 1942 Scholarship Prize, Tufts Universiy (2011)
Phi Beta Kappa Academic Honor Society (2011)
Summer Scholars Research Scholarship, Tufts University (2010)
Research Experience for Undergraduates, Tufts University (2009)