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Full-Text Articles in Life Sciences
Species-Specific Means And Within-Species Variance In Glucocorticoid Hormones And Speciation Rates In Birds, L. Z. Garamszegi, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams
Species-Specific Means And Within-Species Variance In Glucocorticoid Hormones And Speciation Rates In Birds, L. Z. Garamszegi, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams
Biology Faculty Research
At macroevolutionary scales, stress physiology may have consequences for species diversification and subspecies richness. Populations that exploit new resources or undergo range expansion should cope with new environmental challenges, which could favor higher mean stress responses. Within-species variation in the stress response may also play a role in mediating the speciation process: in species with broad variation, there will always be some individuals that can tolerate an unpredictable environment, whereas in species with narrow variation there will be fewer individuals that are able to thrive in a new ecological niche. We tested for the evolutionary relationship between stress response, speciation …
Standing Variation And The Capacity For Change: Are Endocrine Phenotypes More Variable That Other Traits?, M. C. Miles, Maren N. Vitousek, Jerry F. Husak, Michele A. Johnson, L. B. Martin, C. C. Taff, C. Zimmer, M. B. Lovern, M. J. Fuxjager
Standing Variation And The Capacity For Change: Are Endocrine Phenotypes More Variable That Other Traits?, M. C. Miles, Maren N. Vitousek, Jerry F. Husak, Michele A. Johnson, L. B. Martin, C. C. Taff, C. Zimmer, M. B. Lovern, M. J. Fuxjager
Biology Faculty Research
Circulating steroid hormone levels exhibit high variation both within and between individuals, leading some to hypothesize that these phenotypes are more variable than other morphological, physiological, and behavioral traits. This should have profound implications for the evolution of steroid signaling systems, but few studies have examined how endocrine variation compares to that of other traits or differs among populations. Here we provide such an analysis by first exploring how variation in three measures of corticosterone (CORT)—baseline, stress-induced, and post-dexamethasone injection—compares to variation in key traits characterizing morphology (wing length, mass), physiology (reactive oxygen metabolite concentration [d-ROMs] and antioxidant capacity), and …
Hormonebase, A Population-Level Database Of Steroid Hormone Levels Across Vertebrates, Maren N. Vitousek, Michele A. Johnson, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, J. J. Uehling, T. D. Williams
Hormonebase, A Population-Level Database Of Steroid Hormone Levels Across Vertebrates, Maren N. Vitousek, Michele A. Johnson, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, J. J. Uehling, T. D. Williams
Biology Faculty Research
Hormones are central regulators of organismal function and flexibility that mediate a diversity of phenotypic traits from early development through senescence. Yet despite these important roles, basic questions about how and why hormone systems vary within and across species remain unanswered. Here we describe HormoneBase, a database of circulating steroid hormone levels and their variation across vertebrates. This database aims to provide all available data on the mean, variation, and range of plasma glucocorticoids (both baseline and stress-induced) and androgens in free-living and un-manipulated adult vertebrates. HormoneBase (www.HormoneBase.org) currently includes >6,580 entries from 476 species, reported in 648 publications from …
Do Seasonal Glucocorticoid Changes Depend On Reproductive Investment? A Comparative Approach In Birds, S. Casagrande, L. Z. Garamszegi, W. Goymann, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams, M. Hau
Do Seasonal Glucocorticoid Changes Depend On Reproductive Investment? A Comparative Approach In Birds, S. Casagrande, L. Z. Garamszegi, W. Goymann, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams, M. Hau
Biology Faculty Research
Animals go through different life history stages such as reproduction, moult, or migration, of which some are more energy-demanding than others. Baseline concentrations of glucocorticoid hormones increase during moderate, predictable challenges and thus are expected to be higher when seasonal energy demands increase, such as during reproduction. By contrast, stress-induced glucocorticoids prioritize a survival mode that includes reproductive inhibition. Thus, many species down-regulate stress-induced glucocorticoid concentrations during the breeding season. Interspecific variation in glucocorticoid levels during reproduction has been successfully mapped onto reproductive investment, with species investing strongly in current reproduction (fast pace of life) showing higher baseline and lower …
Iucn Conservation Status Does Not Predict Glucocortoid Concentrations In Reptiles And Birds, L. B. Martin, Maren N. Vitousek, Jeremy W. Donald, T. Flock, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, E. T. Miller, L. A. Schoenle, T. D. Williams, C. D. Francis
Iucn Conservation Status Does Not Predict Glucocortoid Concentrations In Reptiles And Birds, L. B. Martin, Maren N. Vitousek, Jeremy W. Donald, T. Flock, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, E. T. Miller, L. A. Schoenle, T. D. Williams, C. D. Francis
Biology Faculty Research
Circulating glucocorticoids (GCs) are the most commonly used biomarkers of stress in wildlife. However, their utility as a tool for identifying and/or managing at-risk species has varied. Here, we took a very broad approach to conservation physiology, asking whether International Union for the Conservation of Nature (IUCN) listing status (concern versus no obvious concern) and/or location within a geographic range (edge versus non-edge) predicted baseline and post-restraint concentrations of corticosterone (CORT) among many species of birds and reptiles. Even though such an approach can be viewed as coarse, we asked in this analysis whether CORT concentrations might be useful to …
Detecting Bias In Large-Scale Comparative Analyses: Methods For Expanding The Scope Of Hypothesis-Testing With Hormonebase, Michele A. Johnson, C. D. Francis, E. T. Miller, C. J. Downs, Maren N. Vitousek
Detecting Bias In Large-Scale Comparative Analyses: Methods For Expanding The Scope Of Hypothesis-Testing With Hormonebase, Michele A. Johnson, C. D. Francis, E. T. Miller, C. J. Downs, Maren N. Vitousek
Biology Faculty Research
To address large-scale questions in evolutionary biology, the compilation of data from a variety of sources is often required. This is a major challenge in the development of databases in organismal biology. Here, we describe the procedure we used to reconstruct the phylogeny of the 474 species represented in HormoneBase, including fish, amphibians, mammals, birds, and reptiles. We also provide the methodology used to compile vertebrate environmental, life history, and metabolic rate data for use in conjunction with the HormoneBase database to test hypotheses of the evolution of steroid hormone traits. We then report a series of analyses using these …
Behavioural Display Systems Across Nine Anolis Lizard Species: Sexual Dimorphisms In Structure And Function, Michele A. Johnson, J. Wade
Behavioural Display Systems Across Nine Anolis Lizard Species: Sexual Dimorphisms In Structure And Function, Michele A. Johnson, J. Wade
Biology Faculty Research
Relationships between structure and function are a primary focus in biology, yet they are most often considered within individual species. Sexually dimorphic communication behaviours and the morphology of associated structures can vary widely, even among closely related species, and these traits provide an ideal opportunity to investigate the evolution of structure-function patterns. Using nine Anolis lizard species, we addressed a series of questions regarding sex differences in and the evolution of relationships between extension of the throat fan (dewlap) and morphology of the muscles and cartilage controlling it. The main results indicated that within species, males displayed the dewlap more …