Evolutionary ecology and conservation biology of fishes

我的研究重点是自然种群内和自然种群之间生殖策略的巨大差异。这种生活史的差异反映在与健康相关的特征上的个体差异，如年龄和成熟时的大小，每只雌性的卵子数量，以及后代的大小。这种可变性的来源在多大程度上是遗传的、环境的或它们的某种组合？这是进化生态学和保护生物学的一个基本问题。首先，这种变异的来源决定了生活史对环境扰动(如栖息地改变和收获)的反应是快速还是缓慢，甚至根本不会发生。其次，生活史反应的性质可能会影响种群从崩溃中恢复、在时间中坚持和维持剥削的能力。使用几种鱼类作为研究生物，我的总体目标是：1)确定在变化的环境中如何保持替代的繁殖策略；2)评估性别偏见的扩散和流动性的适应意义；3)研究影响种群在崩溃到历史上前所未有的丰度水平后恢复能力的因素；以及4)评估渔业诱导的进化对表型可塑性的影响。具体地说，我的第一项研究是问不同的雄性繁殖策略如何在大西洋鲑鱼种群中持续存在。第二个是基于20年的数据集，试图了解为什么在溪流鲑鱼种群中，雄性比雌性分散得更远，流动性更大。第三项研究探讨了可能阻碍海洋鱼类恢复的与交配和繁殖有关的因素，例如大西洋鳕鱼，自1992年以来，纽芬兰的大西洋鳕鱼数量下降了99%。利用斑马鱼，第四个项目研究了个体大小差异死亡率是否会在几代人的生活史反应规范中产生选择反应，从而潜在地导致个体对环境变化的反应能力降低。这项拟议的研究对进化生态学和保护生物学的意义在于它有可能预测生命历史对短期和长期环境变化的反应。

My research focuses on the tremendous variability in reproductive strategies within and among natural populations. Such life-history variation is reflected by individual differences in fitness-related characters, such as age & size at maturity, number of eggs per female, and offspring size. To what extent is the source of this variability genetic, environmental, or some combination thereof? This is a fundamental question to evolutionary ecology and conservation biology. Firstly, the source of this variation determines whether life-history responses to environmental perturbations, such as habitat alteration and harvesting, will be rapid, slow, or indeed whether they will occur at all. Secondly, the nature of the life-history response can affect a population's ability to recover from collapse, persist through time, and sustain exploitation. Using several species of fish as study organisms, my general objectives are: 1) to determine how alternative reproductive tactics are maintained in variable environments; 2) to assess the adaptive significance of sex-biased dispersal and mobility; 3) to study factors that affect the ability of populations to recover following collapse to historically unprecedented levels of abundance; and 4) to evaluate the influence of fisheries-induced evolution on phenotypic plasticity. Specifically, my first study asks how different male reproductive tactics persist within populations of Atlantic salmon. The second, building upon a 20-year data set, seeks to understand why males disperse further, and have greater mobility, than females within a stream population of brook trout. The third study explores factors related to mating and reproduction that may hinder the recovery of marine fish, such as the Atlantic cod which has declined 99% off Newfoundland since 1992. Using zebrafish, the fourth project examines whether size-differential mortality can generate a selection response in life-history reaction norms over several generations, potentially leading to a reduced individual capacity to respond to environmental change. The significance of the proposed research to evolutionary ecology and conservation biology lies in its potential to predict life-history responses to short- and long-term environmental change.