Dissertation Research: The Evolutionary Genetics of Sexual Dimorphism

论文研究：性别二态性的进化遗传学

• 批准号: 0104948
• 负责人: Timothy Mousseau
• 金额: $ 0.82万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-15 至 2003-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0104948&HistoricalAwards=false
• 关键词: Dissertation; Research; Evolutionary; Genetics; Sexual

One of the great mysteries of the natural world concerns why males and females of the same species often differ in many morphological characters. Sexual size dimorphism (SSD), or the difference in mean body size between the sexes, is of particular interest since body size plays a central role in the fitness of an individual. With the advent of new statistical tools and conceptual advances, investigations into the evolution of SSD have moved from the traditional temporally static, single pressure, single sex perspective, to the more robust view of multiple selective forces interacting in both sexes across many generations. However, to fully interpret the evolutionary implications of these selective pressures, one must also know the underlying genetic architecture of male and female body size. This is true since genetic architecture may alter or constrain a dimorphic response to selection. Unfortunately, few studies have expanded their investigation of SSD beyond the scope of the selective pressures involved, creating a dearth of information regarding the evolutionary genetics of dimorphism. The objectives set forth in this proposal will investigate the underlying genetic structure of a sexually dimorphic trait that is known to be under selection from multiple sources. This study will employ an empirical quantitative genetic approach to generate for both sexes the variance covariance matrices (G-matrices) for body size and two other important correlated traits under selection. This will permit comparison between the sexes for differences in genetic architecture and tests for significant correlations between the sexes for homologous traits that may constrain dimorphic evolution. In addition, when G-matrices are coupled with selection gradients that describe the direction and intensity of selection, one can predict if genetic covariances will have a significant effect on trait evolution, if this effect constrains or reinforces trait evolution, and if dimorphism is still evolving. The results of this study will be of general interest as they will likely have bearing on gender-based differences for many other traits in many other systems.

自然界最大的谜团之一是为什么同一物种的雄性和雌性在许多形态特征上往往不同。性别大小二态性（SSD），或性别之间的平均身体大小的差异，是特别感兴趣的，因为身体大小在个体的健康中起着核心作用。随着新的统计工具和概念的进步，SSD的演变调查已经从传统的时间静态，单一的压力，单一性别的角度来看，更强大的观点，多个选择力在两性之间相互作用，跨越许多代。然而，为了充分解释这些选择压力的进化含义，我们还必须知道男性和女性身体大小的潜在遗传结构。这是真的，因为遗传结构可能会改变或限制选择的二型反应。不幸的是，很少有研究将他们对SSD的研究扩展到所涉及的选择压力的范围之外，从而缺乏关于二型性进化遗传学的信息。本提案中提出的目标将调查已知从多个来源进行选择的性二型性状的潜在遗传结构。本研究将采用经验定量遗传方法，以产生两种性别的方差协方差矩阵（G矩阵）的身体大小和其他两个重要的相关性状的选择。这将允许性别之间的遗传结构的差异进行比较，并测试性别之间的同源性状，可能会限制二型进化的显着相关性。此外，当G-矩阵与描述选择方向和强度的选择梯度相结合时，可以预测遗传协方差是否会对性状进化产生显著影响，这种影响是否会限制或加强性状进化，以及二型性是否仍在进化。这项研究的结果将是普遍感兴趣的，因为它们可能会对许多其他系统中许多其他特征的性别差异产生影响。