Doctoral Dissertation Research: Androgyny & Androgens in Females: Relating Hormones to the Evolution of Sexual Dimorphism

博士论文研究：雌雄同体

• 批准号: 0910036
• 负责人: Ellen Ketterson
• 金额: $ 1.47万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0910036&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Androgyny; &amp

When the optimal phenotype differs by sex, the evolution of sex differences, or sexual dimorphism, is expected. In many species, however, the degree of dimorphism is mild, and numerous individuals express traits, e.g. body size or behavior, that fall between male and female norms. Females in this group, known as androgynous females, are of interest because they offer a natural experiment for understanding the sources and consequences of sexual dimorphism. Variation in hormone exposure, especially androgens like testosterone, is a primary mechanism for the development of sex differences in vertebrates. This variation may also mediate the expression of androgynous traits within a sex, leading to covariation among male-like traits, e.g. big females may also be aggressive females. If male-like females differ from typical females in survival or reproduction, the degree of sexual dimorphism may reduced or enhanced. This project seeks to determine whether the degree androgyny expressed in one trait (morphology or behavior) is related to the level of androgyny in other traits, which would indicate a common mechanism controlling trait expression. Additionally this project will strive to determine whether androgen exposure during development or in adulthood is driving this covariation, and also whether androgynous females vary from typical females in survival or reproductive success. Answers to these questions will inform our understanding of the potential links between social behavior, morphology and hormone exposure levels in females as well as the evolution of complex traits that are mediated by hormones. This work will be done with free-living songbirds and serve to train undergraduates to conduct research as part of training programs such as NSF's Research Experience for Undergraduates (REU) and Indiana University's Student Achievement in Research and Scholarship (STARS) programs.

当最理想的表型因性别不同而不同时，性别差异或性别二型性的进化是可以预料的。然而，在许多物种中，二型性的程度是温和的，许多个体表现出介于男性和女性标准之间的特征，例如身体大小或行为。这一群体中的雌性，也就是所谓的雌雄同体的雌性，之所以令人感兴趣，是因为她们为理解性别二态的来源和后果提供了一个自然的实验。激素暴露的变化，特别是雄激素，如睾酮，是脊椎动物性别差异发展的主要机制。这种变异也可能调节雌雄同体的特征在性别中的表达，导致类似雄性的特征之间的协变，例如，大的雌性也可能是攻击性的雌性。如果类似雄性的雌性在生存或繁殖方面与典型的雌性不同，性二型性的程度可能会降低或增强。这个项目试图确定一个性状(形态或行为)的双性同体程度是否与其他性状的双性同体水平有关，这将表明一种共同的控制特质表达的机制。此外，该项目将努力确定雄激素暴露是否在发育期间或成年期是导致这种共同变异的原因，以及雌雄同体的雌性在存活或生殖成功方面是否与典型的雌性不同。对这些问题的回答将使我们了解女性的社会行为、形态和激素暴露水平之间的潜在联系，以及由激素调节的复杂特征的进化。这项工作将使用自由生活的鸣禽来完成，并作为培训计划的一部分，用于培训本科生进行研究，这些计划包括NSF的本科生研究体验(REU)和印第安纳大学的学生研究成就和奖学金(STARS)计划。