Evolutionary ecology and conservation biology of fishes

我的研究重点是自然种群内部和种群之间生殖策略的巨大差异。这种生活史上的差异反映在与适合度相关的特征上，如成熟时的年龄和大小、每只雌性的卵数和后代的大小。这种可变性的来源在多大程度上是遗传的、环境的，还是它们的某种组合？这是进化生态学和保护生物学的一个基本问题。首先，这种变化的来源决定了生命史对环境扰动（如栖息地改变和采伐）的反应是快速的还是缓慢的，或者它们是否会发生。其次，生活史反应的性质可以影响种群从崩溃中恢复的能力，持续存在的时间，并维持开发。使用几种鱼类作为研究生物，我的总体目标是：1)确定如何在可变环境中维持可选择的繁殖策略；2)评估性别偏向扩散和迁移的适应意义；3)研究影响种群在崩溃后恢复到历史上前所未有的丰度水平的能力的因素；4)评价渔业诱导的进化对表型可塑性的影响。具体来说，我的第一项研究是关于大西洋鲑鱼种群中不同的雄性繁殖策略是如何持续存在的。第二项研究基于20年的数据集，试图理解为什么在溪流种群中，雄性鳟鱼比雌性鳟鱼分散得更远，流动性更强。第三项研究探讨了与交配和繁殖有关的因素，这些因素可能会阻碍海洋鱼类的恢复，比如大西洋鳕鱼，自1992年以来，纽芬兰的大西洋鳕鱼数量减少了99%。第四个项目以斑马鱼为研究对象，研究大小差异的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，从而可能导致个体对环境变化的反应能力下降。该研究对进化生态学和保护生物学的重要意义在于，它有可能预测生命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.