Understanding variation in fitness conferring traits

遗传变异如何维持在增强适应性的性状中，仍然是进化生物学中的一个基本难题。已经提出了几个主要的理论来解释遗传变异的持久性。这些理论包括基因捕获、波动选择、基因型与环境的相互作用、基因型与基因型的相互作用、杂种优势和拮抗多效性。我和我的学生们正在用一种结合了统计遗传学和生态生理学工具的动物行为方法来检验其中的一些理论。我们的实验室和实地实证研究量化了表型和遗传变异的条件、生活史和性选择特征，并确定了这种变异如何受到饮食和社会环境的影响。具体来说，我们的研究考察了(1)基本元素和有限元素（氮和磷）的饮食变化如何影响条件的遗传（包括生长速度、发育时间、成年体型、体脂含量和体内营养保留），以及(2)饮食和条件如何相互作用影响性选择和生活史特征（雄性远距离配偶广告信号的吸引力、雌性交配偏好、终生生殖成功、雄性和雌性之间的关系）。反掠食行为，以及父母和后代的生存)。我们的短期研究目标是确定这些性状之间的相互作用是否维持高遗传变异。我们还将进行人工选择实验，以确定暂时波动的选择是否可以维持性别限制和性选择性状的遗传变异。总的来说，我们的研究将明确地检验上述两种理论，以维持高遗传变异——基因捕获和暂时波动的性别限制选择。从长远来看，我的研究计划的首要目标是有助于更全面地了解如何在提高适应性的性状中保持高遗传变异。

How genetic variation is maintained in traits that enhance fitness remains a fundamental dilemma in evolutionary biology. Several major theories have been put forth to explain the persistence of genetic variance. These theories include genic capture, fluctuating selection, genotype-by-environment interactions, genotype-by-genotype interactions, heterosis, and antagonistic pleiotropy. My students and I are testing some of these theories using an animal behaviour approach that incorporates tools from statistical genetics and ecological physiology. Our laboratory and field based empirical research quantifies the phenotypic and genetically based variation in condition, life-history, and sexually selected traits and determines how this variation is influenced by diet and the social environment. Specifically, our research examines (1) how dietary variation in essential and limited elements (nitrogen and phosphorus) influences the genetics of condition (including growth rate, development time, adult size, body fat content, and nutrient retention in the body), and (2) how diet and condition interact to influence sexually selected and life-history traits (attractiveness of male long-distance mate advertisement signals, female mating preferences, lifetime reproductive success, anti-predatory behaviours, and survival of both parents and their offspring). Our short-term research goals are to determine whether the interactions between these traits act to maintain high genetic variance. We will also conduct an artificial selection experiment with the short-term goal of ascertaining whether temporally fluctuating selection can maintained the genetic variance in sex-limited and sexually selected traits. Overall, our research will explicitly test two of the above theories for the maintenance of high genetic variance - genic capture and temporally fluctuating sex-limited selection. Long-term, the overarching goal of my research program is to contribute to a more complete understanding of how high genetic variance is maintained in traits that enhance fitness.