Andrew Stewart

Co-Chair/Associate Professor

Director, Science Scholars Program

BS Biology; University of Texas, Arlington
MS Biology; University of Texas, Arlington
PhD Population Biology, Ecology, & Evolution; Emory University

HS 304A

Dr. Stewart is interested in all things genetics, ranging from the small scale (molecular) to the large scale (populations). Additionally, Dr. Stewart is fascinated by evolutionary conflicts between competing species (host vs. parasite), or individuals of the same species (sexual conflict). Dr. Stewart teaches Introductory Biology I (BIO 111), Genetics (BIO 404), Population Genetics (BIO 406), Evolution (BIO 357), Zoology (BIO 364), Parasitology (BIO 308), and Senior Seminar II (BIO 353), and is the director of the Canisius Science Scholars program.

Dr. Stewart’s research area focuses on sexual conflict, where the evolutionary interests of one sex differs from that of the other. Sexual conflict is manifested in two forms: intralocus & interlocus. Intralocus conflict is a tug of war over the expression of sexually antagonistic alleles: those that increase fitness when expressed in one sex, but decrease fitness when expressed in the other. Interlocus conflict is a ‘Red Queen’ process, where an allele at one locus increases one sex’s success in sexual selection, but harms the other sex. To explore both forms of sexual conflict Dr. Stewart utilizes the Drosophila melanogaster (fruit fly) model system.

Currently, research in the Stewart lab is focused on how intralocus conflict over life-history traits affects the fitness of males & females, specifically how phenotypic changes one sex may constrain the response in the other. Students, however, are invited to speak with Dr. Stewart about any and all research interests. Drosophila lends itself to a wide range of research projects, and many collaboration opportunities exist within the department for those interested in exploring interactions between flies and microbes, biochemistry, climate change, etc.


Hjelmen, C.E., Parrott, J.J., Srivastav, S., McGuane, A.S., Ellis, L.L., Stewart, A.D., Johnston, J.S., & Tarone, A.M. (2020). Effect of phenotype selection on genome size variation in two species of Diptera. Genes 11, 218; doi:10.3390/genes11020218.

Stewart, A.D. and Rice, W.R. (2018). Arrest of sex specific adaptation during the evolution of sexual dimorphism in Drosophila. Nature Ecology & Evolution 2: 1507-1513;

Stewart, A.D. and Pischedda, A (2016). Intraspecific coevolutionary arm races. In: Kliman, R.M. (ed.), The Encyclopedia of Evolutionary Biology. vol. 2, pp. 270-276. Oxford: Academic Press.

Turner, T. L., Stewart, A. D., Fields, A. N., Rice, W. R., and Tarone, A. M. (2011). Population-based resequencing of experimentally evolved populations reveals the genetic basis of body size variation in Drosophila melanogaster. PLoS Genetics 7: e1001336

Stewart, A. D., Morrow, E. H. & Rice, W. R. (2005). Assessing putative interlocus sexual conflict in Drosophila melanogaster using experimental evolution. Proc. R. Soc. B. 272: 2029-2035.

Stewart, A. D., Logsdon, J. M., & Kelley, S. E. (2005). An empirical study of the evolution of virulence under both horizontal and vertical transmission. Evolution 59: 730-739.

Stewart, A. D. & Phillips, P. C. (2002). Selection and maintenance of androdioecy in Caenorhabditis elegans. Genetics 160: 975-982.