Historical and Contemporary Drivers of Macroalgal Reproductive System Variation along the Western Antarctic Peninsula

南极西部半岛巨藻繁殖系统变化的历史和当代驱动因素

• 批准号: 2301026
• 负责人: Charles Amsler
• 金额: $ 38.8万
• 依托单位: University of Alabama at Birmingham
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2301026&HistoricalAwards=false
• 关键词: Historical; Contemporary; Drivers; Macroalgal; Reproductive

General abstractMost organisms alternate between life stages that vary in the number and arrangement of their chromosomes, in the number of cells they possess, and in the environmental conditions in which they are best adapted to live. Much of what we understand about these alternations comes from organisms like animals and land plants in which one of the two stages dominates the life cycle with the other small and short-lived. However, across the tree of life there are countless examples of organisms in which both stages are of long duration, multicellular, or both. These life cycles challenge common ideas used to explain ecological and evolutionary patterns we see in nature. Macroalgae (seaweeds) display a wide range of life cycle types and consequently are excellent models to test and expand ideas about how life cycles evolve. Undersea forests of seaweeds with a variety of life cycle types dominate the shallow waters of the western Antarctic Peninsula where they are ecologically important and, for most of the species, at the southern end of their geographic range. Using existing samples from previous expeditions to Antarctica, the investigators are uniquely positioned to test and expand knowledge of life cycle evolution and how this intersects with reproductive mode variation. This project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the public. The project will support a postdoctoral scholar as well as a faculty member new to US Antarctic research. The investigators will take advantage of an existing program to include high school or undergraduate students in the work which will also expand mentorship experience for the postdoc. All team members will contribute by writing for blogs produced by professional societies for the public. Technical abstractExisting macroalgal taxa samples from across a latitudinal gradient in the western Antarctic Peninsula will be used to explore patterns of genetic diversity from the center to the southern latitudinal limits of their range. Not only will genetic diversity be documented for an understudied and critical group of Antarctic organisms, but how it changes with latitude, compounded by high levels of endemism, will be explored. This will be accomplished by (i) characterization of latitudinal gradients in genetic diversity of many species and (ii) determination of the reproductive system of five focal foundation species. At present, there are few genetic data for macroalgae, dominant primary producers in coastal ecosystems around the world. This gap is particularly acute along Antarctic coastlines that are experiencing rapid climate change. Furthermore, Antarctica is isolated by the Southern Ocean, decreasing the likelihood of regular migration from other land masses. Latitudinal reproductive system patterns are predicted to be largely driven by recolonization events that increase with latitude due to changes in iceberg scour and sea ice coverage. Thus, Antarctica is the best place to understand what processes underlie reproductive mode variation in populations that are isolated, including many endemic taxa, while simultaneously extending our knowledge about how marginal environments converge with complex life cycles.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

一般的抽象最大生物在生命阶段之间交替，在其染色体的数量和排列，它们所拥有的细胞数量以及最适合生存的环境条件下，其数量和排列各不相同。我们对这些交替的理解中的大部分内容来自动物和陆地植物等生物，其中两个阶段之一与另一个小小的和短暂的生命周期主导着生命周期。但是，在整个生命之树中，有无数的生物例子，其中两个阶段都是持续时间，多细胞或两者兼有的。这些生命周期挑战了用于解释我们在自然界中看到的生态和进化模式的共同思想。大型藻类（海藻）展示了广泛的生命周期类型，因此是测试和扩展有关生命周期如何发展的想法的绝佳模型。具有多种生命周期类型的海藻的海底森林主导着南极半岛的浅水，在那里它们在生态上很重要，对于大多数物种而言，在其地理范围的南端。使用从以前的探险到南极洲的现有样本，研究人员的定位是为了测试和扩展生命周期演变知识的知识，以及如何与生殖模式变化相交。该项目还将进一步培训新一代科学家的目标，并为公众提供科学发现。该项目将支持博士后学者以及美国南极研究的新任教职员工。调查人员将利用现有计划，包括高中或本科生，这也将扩大博士后的指导经验。所有团队成员都将通过为专业社会为公众制作的博客写作而做出贡献。 来自南极半岛西部纬度梯度的技术抽象兴趣升级的大藻类分类单元样品将用于探索从中心到其范围南部纬度限制的遗传多样性模式。将探索遗传多样性的遗传多样性，这些遗传多样性将用于研究的南极生物群体，而且将探索它如何随纬度的变化而变化，并探索高水平的特征主义。这将通过（i）表征许多物种遗传多样性的纬度梯度以及（ii）确定五个焦点基础物种的生殖系统。目前，大藻类的遗传数据很少，这是世界各地沿海生态系统中主要的主要生产者。沿南极海岸线尤其急剧，正经历着快速的气候变化。此外，南极通过南大洋隔离，降低了定期从其他土地群落迁移的可能性。预计纬度生殖系统模式在很大程度上是由重新殖民事件驱动的，这些事件随着冰山冲刷和海冰覆盖率的变化而增加的纬度。因此，南极是了解孤立人群中的生殖模式差异基础的最佳场所，包括许多地方性分类群，同时扩展了我们对边际环境如何与复杂生活周期融合的知识。该奖项反映了NSF的法定任务，反映了通过评估基金会的智力效果，并通过评估了基金会的范围。