Brian Lazzaro


3134 Comstock Hall
(607) 255-3254

My research program is focused on the evolutionary and quantitative genetics of insect-pathogen interactions.

Research Focus

Our research is focused on the evolutionary genomics of insect-pathogen interactions, emphasizing such questions as how natural selection operates on host immune systems and why individuals vary in susceptibility or resistance to infection. In my group, we like to think of the host as an assemblage of interacting physiological processes, where the immune system is embedded in the overall physiological context of the host. This motivates us to consider effects of abiotic environment on immune defense and means that genetic determination of variation in resistance may lie in genes outside of the canonical immune system. This thinking also extends directly to the evolution and mechanism of life history constraints. Importantly, the host is itself the "environment" in which an infecting pathogen lives, and differences in host physiological state or abiotic environment can alter microbial behavior and therefore ultimate outcomes of infection. Our overarching goal is to consider host and pathogen as interacting components of a single system, shaped by the environment. We primarily use bacterial infection in Drosophila melanogaster as an experimental model to deconstruct elements of the unified system, studying components in tractable modular pieces. Understanding the dynamics of unified host-pathogen-environment systems is crucial because these dynamics determine the ecology and evolution of disease in natural settings with consequence at higher biological scales. More detail can be found on our lab’s research website at

Teaching Focus

My teaching effort has been primarily directed toward two major courses over the past five years: Ecological Genetics and Introduction to Evolution and Diversity. In addition, I previously co-instructed a January intersession field course in Kenya for four years (Tropical Field Ecology and Behavior) and Population Genetics for two years. I have also taught in a number of smaller courses on and off campus. The off-campus courses have included an intensive one-week graduate course offered at the Gulbenkian Institute in Oerias, Portugal on the “Evolutionary Ecology of Infection,” co-taught with Sylvain Gandon (University of Montpellier), and a variant of the Introductory Evolution course taught to 13 Cornell freshman in the Galapagos Islands (co-taught with Irby Lovette). On the Cornell campus, I have led graduate seminar courses in Ecology and Evolution of Infectious Disease, Topics in Entomology, and Graduate Fellowship Preparation for students in Genetics, Genomics and Development. I enjoy teaching and value informal interactions with my students outside of the classroom. I am very open to student questions and dialog when teaching, whether in my advanced Ecological Genetics class of 20 students or in the Introduction to Evolution class of 300 students.

Ecological Genetics (Entom 4700/BioEE 4800) course is an advanced course in evolutionary genetics that is targeted to senior undergraduates and entering graduate students. Enrollment is approximately 15-20 students per offering and I am solely responsible for teaching it. The small class size permits a conversational classroom dynamic, allowing group learning as the students with more practical research experience push a deeper, thoughtful discussion that draws in the students who may have less personal experience. I find it particularly gratifying when I can see students applying concepts that we are covering in class to their own research projects.

Introduction to Evolutionary Biology and Diversity (BioEE 1780) is part of the core biology curriculum at Cornell and is one of the few courses that is absolutely required for all Biology majors. Enrollment is 270-320 students per semester, and I have been one of five faculty members who shares major responsibility for the class since 2009. The course covers basic principles of evolutionary biology and provides an overview of the Tree of Life.

Awards and Honors

  • Liberty Hyde Bailey Professorship (2016) Cornell University
  • Early Career Achievement Award (2012) College of Agriculture and Life Sciences, Cornell
  • Provost's Award for Distinguished Scholarship (2009) Cornell University

Selected Publications

Journal Publications