Conducting impactful research at primarily undergraduate institutions.

Primarily Undergraduate Institutions (PUIs) are significant academic employers of Ph.D. recipients.

Relaxing life of the city? Allostatic load in yellow-bellied marmots along a rural-urban continuum.

Urban environments are expanding. As rural areas are urbanized, animals living in those environments must respond. Examinations of ecological responses to urbanization are abundant, but much less work has focused on the physiological responses driving those ecological patterns, particularly in mammals.

Merging the "Morphology-Performance-Fitness" Paradigm and Life-History Theory in the Eagle Lake Garter Snake Research Project.

The morphology-performance-fitness paradigm for testing selection on morphological traits has seen decades of successful application. At the same time, life-history approaches using matrix methods and perturbation studies have also allowed the direct estimate of selection acting on vital rates and the traits that comprise them. Both methodologies have been successfully applied to the garter snakes of the long-term Eagle Lake research project to reveal selection on morphology, such as color pattern, number of vertebrae, and gape size; and life-history traits such as birth size, growth rates, and juvenile survival.

Insulin-like signaling (IIS) responses to temperature, genetic background, and growth variation in garter snakes with divergent life histories.

The insulin/insulin-like signaling pathway (IIS) has been shown to mediate life history trade-offs in mammalian model organisms, but the function of this pathway in wild and non-mammalian organisms is understudied. Populations of western terrestrial garter snakes (Thamnophis elegans) around Eagle Lake, California, have evolved variation in growth and maturation rates, mortality senescence rates, and annual reproductive output that partition into two ecotypes: "fast-living" and "slow-living". Thus, genes associated with the IIS network are good candidates for investigating the mechanisms underlying ecological divergence in this system.

Rapid molecular evolution across amniotes of the IIS/TOR network.

The insulin/insulin-like signaling and target of rapamycin (IIS/TOR) network regulates lifespan and reproduction, as well as metabolic diseases, cancer, and aging. Despite its vital role in health, comparative analyses of IIS/TOR have been limited to invertebrates and mammals. We conducted an extensive evolutionary analysis of the IIS/TOR network across 66 amniotes with 18 newly generated transcriptomes from nonavian reptiles and additional available genomes/transcriptomes.

Temperature has species-specific effects on corticosterone in alligator lizards.

In response to conditions that threaten homeostasis and/or life, vertebrates generally increase production of glucocorticoid hormones, such as corticosterone (CORT), which induces an emergency physiological state referred to as the stress response. Given that extreme temperatures pose a threat to performance and survival, glucocorticoid upregulation might be an important component of a vertebrate ectotherm's response to extreme thermal conditions. To address this hypothesis, we experimentally examined the effects of body temperature (10, 20, 28, and 35°C; 5-h exposure) on CORT in two congeneric species of lizard naturally exposed to different thermal environments, northern and southern alligator lizards (Elgaria coerulea and Elgaria multicarinata, respectively).

Seasonal modulation of testosterone during breeding of the rufous-collared sparrow (Zonotrichia capensis australis) in Southern Patagonia.

The roles of testosterone (T) during reproduction are often complex and vary among and within vertebrate taxa and locations, making general hypotheses relating T to breeding behavior and success difficult to integrate. In birds, T is thought to influence degrees of territoriality and associated aggression in males to maximize breeding success. Importantly, most work supporting these ideas has been conducted in the Northern Hemisphere.

Modulation of androgens in southern hemisphere temperate breeding sparrows (Zonotrichia capensis): an altitudinal comparison.

Most work investigating modulation of testosterone (T) levels in birds has focused on northern temperate and Arctic species, and to a lesser degree, tropical species. Studies exploring modulation of T in birds in temperate regions of the Southern Hemisphere are lacking. Here we explore patterns of T secretion across the breeding season in two populations of temperate Zonotrichia capensis in Chile, located only 130 km apart, but separated by 2000 m in elevation.

Variation in circulating corticosterone levels is associated with altitudinal range expansion in a passerine bird.

Organisms frequently need to adjust physiological mechanisms to successfully breed in novel habitats. To explore how some populations physiologically acclimate to novel environmental conditions while others do not, we examine three subspecies of the white-crowned sparrow, Zonotrichia leucophrys. Of these subspecies, Z.

Seasonal and social modulation of testosterone in Costa Rican rufous-collared sparrows (Zonotrichia capensis costaricensis).

Previous work shows that most birds breeding in northern temperate regions adjust production of testosterone in response to stage of the breeding cycle and in some cases following social interactions. In contrast, prior research suggests that tropical breeding birds are less likely to modulate testosterone in response to social interactions (the propensity to increase testosterone in response to social instability is known as the challenge hypothesis). To further test the challenge hypothesis in tropical birds, we investigated whether variation in season affects reproductive condition, aggressive behavior, and social modulation of testosterone in two populations of Costa Rican rufous-collared sparrow, Zonotrichia capensis costaricensis.

Disentangling the effects of environment and life-history stage on corticosterone modulation in Costa Rican rufous-collared sparrows, Zonotrichia capensis costaricensis.

This study explores the factors that influence modulation of baseline corticosterone levels and the hypothalamo-pituitary-adrenal cortex (HPA) axis response to stress in Costa Rican rufous-collared sparrows (Zonotrichia capensis costaricensis). Individuals in our study population vary in their timing of breeding and molt. Thus, at multiple times of the year, we were able to investigate how the HPA axis changes with life-history stage (breeding, molt) and the interaction of season and life-history stage.