Dean of the College and Biology Program Present
Linking Mechanism and Function Through Ecophysiology:
Lessons From Mice and Elk
Thursday, November 20, 2014
Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
A lecture by Cynthia Downs, University of Nevada, Reno
Evolution and ecology influence physiological traits and physiology in turn, influences ecology and even evolutionary trajectories. Although an organism is more than the sum of its phenotypic traits, the question of how different physiological systems interact is often ignored. I seek to understand how complex interactions between immune and metabolic traits affect physiological function at the organismal level, and study the consequences of individual variation in physiology on ecological and evolutionary timescales. For example, trade-offs among physiological systems can constrain phenotypes, and trade-offs with other ecologically relevant traits can hinder local adaptation and act as evolutionary constraints. In recent work I explored trade-offs among ecologically important traits using mice artificially selected for high maximal metabolic rates (MMR); I found that selection for high MMR, but not corresponding evolved changes in basal metabolic rate suppressed innate immune function and altered growth trajectories. These findings revealed connections among physiological systems with consequences for individual variation in life history traits. I am also interested in understanding how environmental variation affects expression of functional traits. To test the hypothesis that the strength of immune function correlates with resource availability, I experimentally manipulated the population density of free-ranging North American elk and found that levels of constitutive immunity are inversely related to nutritional state. This surprising result informs our understanding of the complicated interactions between resource availability, animal physiology, and disease dynamics. As a whole, these experiments demonstrate the connectivity of physiological systems and the need for a systems approach to fully understand how natural selection acts on organisms.
For more information, call 845-752-2331, or e-mail [email protected].
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium