Meeting Abstract
S8.3-2 Monday, Jan. 6 14:00 Physiological mediation of integrated phenotypes: From plasticity to evolution SWANSON, E.M.*; SNELL-ROOD, E.C.; Univ. of Minnesota, Twin Cities; Univ. of Minnesota, Twin Cities eliswanson@gmail.com
Hormones are important mediators of phenotypic responses to environmental variation at both the developmental and the population level. In addition, hormones commonly influence multiple traits simultaneously; this pleiotropy is thought to generate correlations among phenotypic traits and play an important role in phenotypic integration. Nevertheless, many questions persist regarding the role of hormonal pleiotropy in evolution and development. For example, it is unclear whether hormonal pleiotropy stems from a limited number of hormones or represents an adaptation. If pleiotropy results due to a compromise among a limited number of physiological mediators, it suggests that limitations in the extent of physiological variation could constrain the evolution of individual traits. Alternatively, if specific correlations among traits are commonly beneficial, hormonal pleiotropy could potentially facilitate appropriate correlated responses to the environment. Furthermore, we don’t know if this hormonal pleiotropy facilitates or constrains developmental responses to environmental variation differently than population-level responses. Is selection for appropriate plastic responses generally at odds with selection for appropriate population-level responses? Here, we develop a framework for a broader approach to studying the evolution of neuroendocrine-regulated plasticity. We first review the current state of knowledge about how hormones hierarchically influence patterns of variation within individuals, within populations and across species. After discussing the gaps in our knowledge, we introduce a developmental model-based approach to help address these questions. Finally, we attempt to bridge and integrate the roles of neuroendocrine variation within individuals, within species, and among species.
