DISSERTATION RESEARCH: Tracking trends in the lichen symbiosis: do species interactions drive the latitudinal diversity gradient?

论文研究：追踪地衣共生的趋势：物种相互作用是否驱动纬度多样性梯度？

• 批准号: 1701736
• 负责人: Larry Prather
• 金额: $ 2.02万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1701736&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Tracking; trends; lichen

The latitudinal diversity gradient is the pattern in which many species are found in the tropics, near the equator, and fewer species are found outside of the tropics, towards the North and South poles. This pattern is often explained in terms of temperature, climate, or geological conditions. Less frequently, the latitudinal gradient is described in terms of biotic interactions; interactions between different organisms. This research investigates a particular biotic interaction, the lichen symbiosis, along a large environmental gradient from North to South America. Lichens are symbioses (mutually beneficial, long-term, close physical associations) between fungi and algae/cyanobacteria. Though small and often overlooked, lichens can be found in almost every terrestrial environment, making them ideal for investigating biotic interactions across large environmental gradients. This research will focus on the role of symbiosis in driving patterns of diversity, and may improve predictions of how patterns of diversity change in the face of ongoing changes in climate. This research uniquely addresses both partners in the symbiosis, and will increase our knowledge of global biodiversity through the discovery and description of new species and traits. This project will extend the research and training of a doctoral student by supporting research that moves from descriptive pattern to mechanistic process. A workshop on symbioses will be made available to undergraduate students in Michigan, and educational materials for high school classrooms will be offered via the Data Nugget program, promoting the scientific process and potentially recruiting more students to science and technology at the college level. The biotic interactions hypothesis proposes that in extra-tropical regions, abiotic selective pressures exert a stronger force, whereas in tropical regions, biotic selective pressures exert a stronger force. Furthermore, these biotic interactions lead to moving peaks of adaptation, and coevolutionary races, which further contributes to diversification in the tropics. This research investigates the dynamics of the lichen symbiosis along a latitudinal gradient by sequencing both the fungal and algal partners within five lichen-forming families of fungi found along the latitudinal gradient in order to map patterns of specificity among partners, and to test whether partner switches have resulted in diversification events or range shifts in the lichen symbiosis.

纬度多样性梯度是指在赤道附近的热带地区发现了许多物种，而在热带以外的南北极地区发现的物种较少的格局。这种模式通常用温度、气候或地质条件来解释。纬度梯度较少用生物相互作用来描述；不同生物体之间的相互作用。本研究调查了一种特殊的生物相互作用，地衣共生，沿着一个大的环境梯度从北美到南美。地衣是真菌和藻类/蓝藻之间的共生（互利的、长期的、密切的物理联系）。尽管地衣很小，而且经常被忽视，但它们几乎可以在每一个陆地环境中找到，这使它们成为研究大环境梯度下生物相互作用的理想选择。这项研究将重点关注共生在驱动多样性模式中的作用，并可能改善面对持续气候变化的多样性模式如何变化的预测。这项研究独特地解决了共生关系中的两个伙伴，并将通过发现和描述新物种和特征来增加我们对全球生物多样性的认识。该项目将通过支持从描述模式转向机械过程的研究来扩展博士生的研究和培训。一个关于共生的研讨会将提供给密歇根的本科生，高中课堂的教育材料将通过数据块计划提供，促进科学进程，并有可能在大学水平上招募更多的学生学习科学和技术。生物相互作用假说提出，在热带以外地区，非生物选择压力发挥更强的力量，而在热带地区，生物选择压力发挥更强的力量。此外，这些生物相互作用导致了适应的移动高峰和共同进化的种族，这进一步促进了热带地区的多样化。本研究通过对沿纬度梯度发现的五个地衣形成真菌家族中的真菌和藻类伴侣进行测序，研究了地衣共生沿纬度梯度的动态变化，以绘制伴侣之间的特异性模式，并测试伴侣转换是否导致了地衣共生的多样化事件或范围转移。