Dissertation Research: Using Genealogical Portraits of Speciation to Understand Diversity Patterns

论文研究：利用物种形成的谱系肖像来理解多样性模式

• 批准号: 9801284
• 负责人: Douglas Futuyma
• 金额: $ 0.99万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-01 至 2000-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9801284&HistoricalAwards=false
• 关键词: Dissertation; Research; Using; Genealogical; Portraits

Futuyma 9801284 The proposed research uses molecular analyses to gain insight into the origin of species in the relatively recent geological past, and into the biological consequences of major changes in climate. The mountains of western North America constitute an unusual archipelago of sky islands for high-altitude species. Closely related species, including Melanoplus grasshoppers as well as other animals and plants, occupy different mountain ranges and peaks, in a pattern that suggests recent evolutionary diversification. It as often been suggested that such species originated by isolation and colonization during the Pleistocene glaciations that ended about 10,000 years ago. However, it is not certain which regions remained free of ice, or how habitats such as grasslands were distributed during the alternating glacial and interglacial periods. Thus the exact history by which organisms came to occupy different mountain ranges and differentiated into distinct species is very uncertain. For instance, species may have colonized progressively more northern areas from southern refuges as the glaciers retreated. Alternatively, ancestral species may have persisted at low altitudes, and have given rise to new species, as their habitats became restricted to isolated mountaintops when the climate became warmer. The proposed research uses Melanoplus grasshoppers to determine more fully the history by which biodiversity has originated in the western mountains. Comparisons of DNA sequences among populations and species from different mountain ranges can provide dates for divergence, and thus test the hypothesis that many species formed during or since the Pleistocene glaciations. Evolutionary relationships among species as reconstructed from DNA sequences, will be used to determine whether species formed by fragmentation or by progressive northward colonization. This research will provide one of the few comprehensive views of an evolutionary radiation. Using modern phylogenetic techniques and population genetic models, it will test hypotheses about species formation, and thus provide insights into the origin of diversity. And it will cast light on how past changes in climate have affected the distribution and diversity of organisms - information that may help to predict effects of future global changes in climate.

拟议的研究使用分子分析来深入了解相对较近的地质历史中的物种起源，以及气候重大变化的生物学后果。北美西部的山脉为高海拔物种组成了一个不寻常的天空岛屿群岛。密切相关的物种，包括黑蝗以及其他动物和植物，占据着不同的山脉和山峰，这种模式表明了最近的进化多样化。人们经常认为，这些物种起源于大约1万年前结束的更新世冰川时期的隔离和殖民。然而，目前还不能确定哪些地区没有冰，或者在冰期和间冰期交替期间，草原等栖息地是如何分布的。因此，生物是如何占据不同山脉并分化成不同物种的确切历史是非常不确定的。例如，随着冰川的消退，物种可能逐渐从南方的避难所移居到更北部的地区。另一种可能是，当气候变暖时，祖先物种可能在低海拔地区生存下来，并产生了新物种，因为它们的栖息地被限制在孤立的山顶上。拟议中的研究使用Melanoplus蚱蜢来更全面地确定生物多样性起源于西部山区的历史。比较来自不同山脉的种群和物种之间的DNA序列可以提供分化的日期，从而验证在更新世冰期期间或之后形成许多物种的假设。从DNA序列重建的物种之间的进化关系将用于确定物种是由碎片化形成还是由逐渐向北殖民化形成。这项研究将为进化辐射提供为数不多的全面观点之一。利用现代系统发育技术和种群遗传模型，它将测试关于物种形成的假设，从而提供对多样性起源的见解。它还将揭示过去的气候变化是如何影响生物的分布和多样性的——这些信息可能有助于预测未来全球气候变化的影响。