Collaborative Research: A mechanistic understanding of biogeographic patterns and life histories in benthic organisms in advective coastal environments

合作研究：平流沿海环境中底栖生物的生物地理模式和生活史的机械理解

• 批准号: 0961344
• 负责人: James Pringle
• 金额: $ 23.21万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-15 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0961344&HistoricalAwards=false
• 关键词: Collaborative; Research; mechanistic; understanding; biogeographic

The biological and physical mechanisms that establish and maintain species boundaries in the ocean are controversial. Contributing factors are offspring of species with planktonic larvae being physically transported outside their natal range, and adults thriving when transplanted into regions immediately beyond their natural distributions. It is unclear, however, why long-distance dispersal of a benthic organism's larva should persist on evolutionary timescales. There is more larval dispersal from natal habitat than would seem propitious. Furthermore, long larval duration is known to increase reproductive output for species persistence, makes population retention of favorable alleles less likely, and reduces the genetic diversity of the population.The Co-PIs have shown that maintenance of range boundaries for a species are governed by a function analogous to that derived for allelic frequency/genetic clines in the coastal ocean. As with other recent advances in biodiversity theory, this work suggests a convergence between conditions that maintain the distribution of alleles within species and those that maintain the distribution of species themselves. This confluence of theory provides substantial opportunity for development of inter- and intra-species competition in an advective environment. It potentially would unify genetic and population-level theory, and create a holistic view of life in advective environs. It is clear from preliminary work that a synthesis would depend critically on tradeoffs between dispersal mode and successful reproductive output. The theory would be developed both by pushing its analytical envelope, and by drawing upon extensive, existing databases to quantitatively constrain reproductive and dispersal tradeoffs. For example, although tradeoffs between larval quantity versus quality (i.e., many "energetically cheap" larvae versus few "highly provisioned" individuals) have long been the subject of qualitative models, they have not been quantitatively defined for life history characteristics of different benthic marine taxa. Combining analytical developments and observed life-history tradeoffs would provide 1) evolutionarily stable states for a range of dispersal strategies, 2) mechanisms that define species boundaries as a function of physical (e.g., temperature and alongshore variation in currents) and biological (like larval mortality) parameters and 3) quantitative origins of dispersal behaviors that would locally retain larvae, and result in relationships between inter- and intra-species fitness. Such findings would predict species boundary locations and the presence/absence of various dispersal strategies as a function of local circulation, environmental conditions and their gradients. Predictions would be tested against data on species ranges gathered as part of an extensive literature and database search. Broader impacts: This research would allow a better mechanistic understanding species' ranges that occur due to changes in the Earth's climate. For example, this study will test the hypothesis that warming favors species with longer larval planktonic duration. Therefore, high-latitude areas now dominated by species with direct development would shift to a mixture of planktonic dispersers and direct developers as the climate warms. The research would allow managers to understand how disruption to habitat can alter species ranges by changing alongshore sources and transport of planktonic larvae. A quantitative theory of species range will also help managers understand what sets the ultimate limits of recently introduced exotic species, allowing improvement of management strategies. This proposal includes the following education components. Two graduate students will be trained in cutting-edge techniques in the fields of quantitative phylogeography and biogeography. In addition, two undergraduate students each year will assist with all aspects of the project and will present their work at a national meeting. The students will be mentored to write REU proposals to NSF. Undergraduates will be recruited with the help of the Louis Stokes Alliance for Minority Participation, of which UGA is a flagship member. Undergraduates will also be recruited from the Research and Discovery Program at UNH, from colleges with limited opportunities for undergraduate research.

在海洋中建立和维持物种边界的生物和物理机制是有争议的。 促成因素是物种的后代，其幼虫被物理运输到其纳塔尔范围之外，而成虫在移植到其自然分布区域之外时蓬勃发展。然而，目前还不清楚为什么一个底栖生物的幼虫长距离传播应该坚持进化的时间尺度。从纳塔尔地扩散的幼虫比看起来的要多。 此外，幼虫的持续时间长是已知的，以增加繁殖输出的物种持久性，使人口保留有利的等位基因不太可能，并降低了遗传多样性的population.The Co-PI已表明，维护范围边界的一个物种是由一个类似的功能，在沿海海洋中的等位基因频率/遗传倾斜。与生物多样性理论的其他最新进展一样，这项工作表明维持物种内等位基因分布的条件与维持物种本身分布的条件之间存在趋同性。这种理论的融合为平流环境中物种间和物种内竞争的发展提供了重要的机会。它可能会统一遗传和种群水平的理论，并创造一个整体的平流环境中的生命观。从初步工作中可以清楚地看出，综合将严重依赖于分散模式和成功的生殖输出之间的权衡。该理论的发展既要推进其分析范围，又要利用广泛的现有数据库来定量限制繁殖和扩散的权衡。例如，虽然幼虫数量与质量之间的权衡（即，许多“精力充沛的廉价”幼体与少数“高度供应的”个体）长期以来一直是定性模型的主题，但尚未对不同底栖海洋生物分类群的生活史特征进行定量界定。结合分析发展和观察到的生活史权衡将提供1）一系列扩散策略的进化稳定状态，2）将物种边界定义为物理（例如，温度和沿岸变化的电流）和生物（如幼虫死亡率）参数和3）的扩散行为的定量起源，将本地保留幼虫，并导致种间和种内适合度之间的关系。这些研究结果将预测物种边界位置和存在/不存在的各种扩散策略作为当地流通，环境条件及其梯度的函数。预测将对照作为广泛文献和数据库搜索的一部分收集的物种分布范围数据进行检验。更广泛的影响：这项研究将使人们能够更好地从机制上理解地球气候变化造成的物种分布范围。例如，这项研究将检验这样一个假设，即气候变暖有利于幼虫生长持续时间较长的物种。因此，随着气候变暖，现在由直接发展的物种主导的高纬度地区将转变为混合的南极扩散者和直接发展者。这项研究将使管理人员了解栖息地的破坏如何通过改变沿岸来源和浮游幼虫的运输来改变物种范围。物种分布范围的定量理论也将帮助管理人员了解是什么设定了最近引进的外来物种的最终限制，从而改进管理策略。该建议包括以下教育内容。两名研究生将接受定量地理学和地理学领域尖端技术的培训。此外，每年有两名本科生将协助该项目的各个方面，并将在全国会议上介绍他们的工作。学生将被指导写REU建议NSF。本科生将在路易斯·斯托克斯少数民族参与联盟的帮助下招募，其中UGA是旗舰成员。本科生也将从UNH的研究和发现项目中招募，这些项目来自本科生研究机会有限的学院。