NSF Award
1840987
The endocrine system is a collection of diverse glands that secrete hormones, which are often essential regulators of physiological and developmental processes. The actions of hormones can range from the control of blood glucose levels to the transformation of a tadpole into a frog. The fundamental biological roles of hormones in diverse processes suggest that they have been important in shaping animal form and function. However, the dynamic nature of hormones and their varying responses has presented challenges to understanding how alterations to the endocrine system have impacted animal evolution. This study utilizes a group of salamanders that vary in sensitivity to thyroid hormone to test how changes to the endocrine system influence patterns of evolution at different levels of organization. Mechanisms of hormone action are a fundamental part of animal systems, and are important at many levels of science education. This project will include curriculum development in organismal biology and evolution for secondary education, as well as undergraduate and graduate-level training in conducting integrative biology research. This research will fund two professional development workshops in comparative and molecular endocrinology for Oklahoma educators. <br/><br/>This research will provide a compelling test of the consequences of endocrine system evolution on phenotypic, transcriptomic, and genomic diversification. It will also serve as a model for analyzing the evolution of dynamic traits. Even though all salamanders utilize thyroid hormone for at least some functions, in some paedomorphic species thyroid hormone has become dysregulated from metamorphosis. This research will use the multiple independent losses of thyroid hormone controlled metamorphosis in salamanders to test how hormone dysregulation influences patterns of morphological, transcriptomic, and genomic diversification. Experimental treatment with thyroid hormone will be used to test for differences in tissue sensitivity among the larvae of biphasic and larval form paedomorphic salamanders. Morphological and transcriptomic data from the experiment, as well as genomic data, will be used to evaluate rates of evolution across different levels of organization. The prediction is that thyroid hormone regulation should constrain evolution, while dysregulation of this endocrine signal should promote diversification.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
