Department of Integrative Biology, UC Berkeley

Diversity is our strength

In the Department of Integrative Biology, we embrace the diversity of life to study fundamental problems in biology, using techniques from ecology, biochemistry, physiology, and evolutionary biology. The strength in diversity extends to the people doing science – we maximize our potential when we have a diverse set of perspectives and experiences. We are committed to transforming academia to welcome and support all scientists, broadening the picture of what a scientist looks like so that we can benefit from the full pool of talent that a diverse community brings.  We denounce racism in all its forms, and welcome and commit to supporting people who have been historically excluded from science on the basis of their race, ethnicity, gender, ability, or any other aspects of identity.

Key research themes:

Evolutionary impacts of seasonality

How do organisms adapt to seasonal variations in temperature and food availability? As our seasons shift and change, how can organisms keep up with the rate of change? Who will be the “winners and losers” of changing winter climate?  We are currently studying the physiological and genetic impacts of changing snow cover on montane willow leaf beetles, in collaboration with Nathan Rank, Elizabeth Dahlhoff, and Jonathon Stillman.

Cold and energy stress in winter

A second key theme of my research has been mechanisms underlying stress responses. For overwintering ectotherms (cold-blooded animals), the key stresses in winter are those of cold and energy stress. They can deal with those stresses through phenotypic plasticity in their cold hardiness and energy metabolism. My research investigates the connections between responses to cold and energetics.

Life history evolution

The third major research direction in the lab seeks to understand biochemical and metabolic origin of resource-based trade-offs. Why do we see such striking variation in the capacity for energy generation across individuals and species with divergent life history demands? What constrains evolution of metabolic systems? We use field crickets with flight-capable and incapable morphs to study the impacts of flight on life history strategies, and responses to environmental variation.

 

Research approaches in the lab

Research in the lab combines field-based natural history and experiments with laboratory-based biochemistry and physiology. We use the UC Natural Reserves extensively for fieldwork (mostly Sedgwick Reserve, SNARL, and White Mountain Research station, see Photos). One of the hallmarks of research in my lab is a focus on linking detailed biochemical and physiological measurements to their life history and fitness consequences. Biochemical and physiological techniques are often low-throughput, limiting their application in ecological and evolutionary studies that frequently require large sample sizes and multiple treatment groups. We overcome this challenge by first doing the careful and slow biochemistry and physiology across multiple levels of the biological hierarchy (from molecules, cells and organs to tissues and whole organisms), and then using the results to develop and validate high-throughput assays that recapitulate the phenotype of interest. This approach has enabled us to discover links between genotype and physiological phenotype, and understand how those links are mediated through the biochemistry of metabolic pathways. Another hallmark of my research approach is the analysis of evolutionary change in the plasticity of physiological traits. Unlike morphological traits that are frequently fixed during development, physiological traits are labile over the entire lifetime of an organism, responding almost instantly to changes in environmental conditions with changes in their rates and intensities. Thus, most physiological traits are best described as curves or functions that describe their environmental sensitivity. Joel Kingsolver and Ray Huey, among others, have pioneered this “curve-thinking”, and this approach is revealing that much of physiological evolution occurs in the shape of these curves. My research incorporates these powerful theoretical advances to understand how environmental variability on a range of timescales, ranging from a fraction of an organism’s lifetime to multiple generations, reshapes the sensitivity of physiological traits to environmental variation.