Department of Biology

Lab

Biology Bldg. 116/121

Awards

• Fellow, American Academy of Arts and Sciences, 2022
• Fulbright Specialist Grant, 2016
• Fellow, American Association for the Advancement of Science, 2010
• Guggenheim Fellowship, 2005
• Trustees’ Teaching Award, 2005
• Teaching Excellence Recognition Award, 2000
• Senior Class Award for Teaching Excellence in Biology and Dedication to Undergraduates, 1995
• Outstanding Junior Faculty Award, 1994-95

Research

I am generally interested in evolutionarily based questions concerning various aspects of flowering plant reproduction from both ecological and genetic perspectives. At a more general level, my research focuses on understanding selective forces in natural populations and the extent to which adaptation is slowed or prevented by genetic constraints. I am also interested in speciation from the perspective of how/which traits lead to reproductive isolation.

My recent and current research revolves around the dioecious plant species Silene latifolia. It’s basically a look at how sex-specific selection can drive sexual dimorphism and sex-chromosome evolution, and how genetic correlations can constrain adaptive evolution. My collaborators and I have taken a variety of approaches including: artificial selection to change the means of traits as well as the genetic correlations between traits, quantitative-genetic breeding designs, experimental arrays planted in the field, QTL analysis, pool-seq analysis, and within- and among-population studies involving both work in natural populations and the greenhouse.

Past research includes: (1) an investigation of the forces that select for unisexuality rather than hermaphroditism, and how this affects other plant traits, (2) the evolution of sexual dimorphism given underlying genetic correlations, (3) pollen competition, (4) how flower size and number can affect plant fitness, (5) inbreeding and inbreeding depression, (6) a multitude of questions on gynodioecious species, including the maintenance of females and the cost of restoration, and (7) reproductive isolation.

Students in my lab don’t necessarily work on my system. In fact, most of them work on species and questions that are related, but separate from my own. For example, my past students have worked on gynodioecious and dioecious species, inbreeding depression, adaptive phenotypic plasticity, pollen competition, the maintenance of flower color polymorphism, and negative-frequency dependent selection. Visit The Delph Lab website for more information.

Research areas

Ecology
Evolution
Plant Molecular Biology