Assistant Professor, Anatomy/EEOB
My field of study is Ecological and Evolutionary Physiology, or how organisms adjust their physiological phenotype in a given environmental context. Animals have to assign energy and resources to maximize their lifetime reproductive success. However, physiological limits constraint energy and resource allocation to offspring, although the nature and extent to which these limits operate are poorly understood.
I am currently working on three research projects:
Phenotypic plasticity and its influence on reproductive success in consecutive reproductive cycles in the viviparous cockroach Diploptera punctata. Surprisingly, researchers have not found significant associations between resting metabolic rate (RMR, a proxy for energy expenditure) and life history traits, perhaps because studies do not follow the entire reproductive history of individuals, but usually a unique reproductive event. I propose that the regulation of the degree of phenotypic plasticity in organ size will be the physiological mechanism by which animals adjust spare capacity and determine the allocation of energy and resources to reproduction during their lifetime. Since plasticity of organ size is apparently not fully reversible, energy allocation to offspring in the first reproductive event might condition future reproductive events. In this study I directly evaluate the correlation between RMR and the allocation of resources from females to offspring in the viviparous cockroach Diploptera punctata, quantified as the turnover rate of stable isotopes of carbon in their bodies. I also assess the impact of changing environmental conditions on the adjustment of those physiological mechanisms that regulate the allocation of energy and resources to reproduction during the lifetime of organisms.
Water balance in desert-dwelling bats of the Negev desert, Israel. In this project, I assessed the association between cutaneous water loss and the lipid composition of the skin of several species of bats from desert and mesic environments in Israel. We found that desert bats had lower rates of evaporation and lower energy expenditures than those of mesic bats. The reduction in cutaneous water loss was associated with a combination of lipids in the skin that has been shown to reduce water loss in other terrestrial vertebrates. I use high performance liquid chromatography coupled with mass spectrometry to analyze the lipid composition of the epidermis of bats and how changes in the structure of the epidermis determine cutaneous water loss rates.
Resting metabolic rate and its relationship with muscle maturation in Japanese quail selected for different rates of growth. This project examines the relationship between metabolic rate, growth rate and muscle development in three lines of quail selected for different growth rates (fast, slow and randomly bred). Birds from the three lines of growth reach adult body mass at 45 days of age, but animals of the fast growth line have a significantly higher adult body mass than animals from the slow growth rate line, whereas animals from the control line have an intermediate adult body mass. Since body mass determines many life history traits in animals, it is important to know what are the factors that shape evolution of body mass.
Students interested in doing research on Ecophysiology can contact me at email@example.com.