I received my Ph.D. in Ecology and Evolution from the State University of New York at Stony Brook in 1999. I was a Postdoctoral Fellow in the Department of Ecology and Evolutionary Biology at the University of Arizona in 1999-2002.
My research focuses on speciation and the processes that initiate or contribute to population divergence, and spans a wide range of temporal and spatial scales that have both ecological and evolutionary implications. My primary research interests include the relative contributions of selection and drift to speciation, the evolution of reproductive isolation, and the processes generating macroevolutionary patterns of diversity.
One major area of my research addresses what factors have driven the evolutionary radiation of a group of montane grasshoppers in the genus Melanoplus. Part of this work tests how the Pleistocene glaciations have affected rates of speciation and the divergence process. Patterns of genetic variation are studied in a predictive framework where alternative historical scenarios can be distinguished statistically using coalescent simulations.
Another component of this research addresses whether sexual selection has played a role in Melanoplus diversification. This work uses a comparative phylogenetic approach and geometric morphometrics to test for an association between the strength of sexual selection and clade diversity.
In a separate project on the role of sexual selection in speciation, I am studying the role of antagonistic-coevolutionary interactions between males and females in driving reproductive isolation in cactophilic Drosophila. This research examines the rapid divergence of postmating-prezygotic reproductive characters in Sonoran endemic flies using a combination of experimental and genomic approaches. In addition to identifying the selective basis for divergence in these characters, this research also examines these coevolutionary interactions between males and females at the molecular level. Comparisons of gene expression patterns under different mating conditions with microarray data, as well as tests of selection at the nucleotide level on specific candidate loci, are used to study the genes and processes involved in postmating-prezygotic reproductive interactions.
See a comic featuring the research of Dr. Knowles "Grasshoppers and the Ice Age" by Jennifer Zee, a Ph.D. art student.
EEB 516 Evolution
EEB 442 Insect Biology
Diego Alvarado Serrano, Qixin He, Tristan McKnight, Carlos Munoz, Andrea Thomaz, Lucy Tran, Jen-Pan Huang, Rob Massatti, Marcelo José Sturaro (visiting research scholar)
Hayley Lanier, Pavel Klimov (assistant research scientist), Anna Papadopoulou
Mark Christie; Dr.Guo-Fang Jiang, professor, Jiangsu Key Laboratory for Biodiversity and Biotechnology and Institute of Genetic Resources, College of Life Sciences, Nanjing Normal University; Joaquin Ortego
Jason Brown, Postdoctoral Fellow, 2010 - 2013
Bryan Carstens, Postdoctoral Fellow 2004-07, now Assistant Professor, Louisiana State University
Tim Connallon, Ph.D. 2009, now Postdoctoral Fellow, Cornell Unviversity, email@example.com
Dan Edwards, Postdoctoral Fellow, Yale University
Huateng Huang, Postdoctoral Fellow in systems biology, Nephrology/ Internal Medicine, University of Michigan
John McCormack, Postdoctoral Fellow 2008-10, now Assistant Professor at Occidental College
Elen Oneal, Ph.D. 2009, now Postdoctoral Fellow, Duke University, firstname.lastname@example.org
Corrine Richards, Ph.D. 2008, Postdoctoral Fellow 2008-09, University of California Berkeley, now Assistant Professor, Tulane University, email@example.com
Amanda Zellmer, Ph.D. 2010, now Postdoctoral Fellow, Louisiana State University