DISSERTATION RESEARCH: Integrating Fossils and Molecules to Trace Ecological Divergence and Convergence in Marine Bivalves

论文研究：整合化石和分子来追踪海洋双壳类动物的生态分歧和趋同

• 批准号: 1501880
• 负责人: David Jablonski
• 金额: $ 1.08万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501880&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Integrating; Fossils; Molecules

Closely related biological species are thought to exclude one another from a particular habitat because they compete for similar food and habitat resources. Yet, many closely related species inhabit the same geographic space. This research dissects the tension between 1) the ecological pressure on closely related, co-occurring species to use different resources, and 2) the evolutionary tendency for closely related species to play similar ecological roles. By studying ecologically important traits in pairs of closely related species in the fossil record, the researchers will study the ecology of each species when it is, first, isolated from, and then co-occurs with its near relative, giving a direct window into the nature of evolutionary divergence or convergence of those species as they interact. Thus, the balance of pressures pushing species closer in form (as they enter the same environment) and pushing them apart (as they come into ecological competition) can be assessed directly. This research will collaborate with members of the ongoing Bivalve Tree of Life effort and give one of the first examples of ecological evolution over time among closely related bivalve species. Finally, this project will train one graduate student and contribute course material to the researchers? interactive Science Café on the role of ecology in evolution for middle school students at the Chicago Museum of Science and Industry.The researchers will investigate two prominent ecological hypotheses that suggest co-occurring, closely related species should differ in their ecological traits to ease direct competition for resources. ?Character displacement? predicts that competition between species after they co-occur drives their ecological divergence whereas ?species sorting? involves the co-occurrence of species that already differed ecologically before coming into sympatry. Character displacement and species sorting will be tracked in pairs of related species by using the fossil record to trace shifts from allopatry to sympatry and any corresponding change in ecological traits through time. This project will construct a molecular phylogeny for a genus of marine bivalves along the American coasts, Chione (9 extant species plus 3 extinct species fitted into the molecular tree via analysis of character matrices), which coupled with spatially explicit fossil data will provide unique access to the relation between character displacement, species sorting, and phylogenetic relatedness. Given the tendency for ecological similarity to correlate with relatedness, the researchers expect character displacement and species sorting to operate along a continuum, where character displacement predominates between more closely related species and species sorting predominates between more distantly related species. However, ecological selection imposed by the environment may trump selection mediated by competition. In that case, species will express similar ecological traits where they co-occur.

密切相关的生物物种被认为将彼此排除在特定的栖息地之外，因为它们争夺相似的食物和栖息地资源，然而，许多密切相关的物种栖息在同一地理空间中，这一研究剖析了 1）密切相关的生态压力之间的紧张关系。 ，共存物种利用不同的资源，以及2）密切相关物种发挥相似生态作用的进化趋势通过研究化石记录中密切相关物种的生态重要特征，研究人员将研究每个物种的生态。当它是物种时，首先，与其近亲分离，然后与其共同发生，为了解这些物种在相互作用时进化分歧或趋同的本质提供了一个直接的窗口。因此，压力的平衡推动物种在形式上更加接近（当它们进入物种时）。这项研究将与正在进行的双壳类生命之树项目的成员合作，并给出密切相关的双壳类随着时间的推移生态进化的第一个例子。最后，这个项目将。培训一名研究生并向芝加哥科学与工业博物馆的中学生提供关于生态在进化中的作用的互动科学咖啡馆的课程材料。研究人员将研究两个重要的生态假设，这些假设同时发生，密切相关相关物种的生态特征应该有所不同，以缓解对资源的直接竞争。“特征位移”预测物种共存后的竞争会导致其生态分歧，而“物种分类”则涉及生态上已经不同的物种的共存。在进入同源性之前，将通过使用化石记录追踪从异源性到同源性的转变以及随时间变化的生态特征的任何相应变化，以成对的方式跟踪相关物种的特征位移和物种分类。沿美国海岸的海洋双壳类动物 Chione（通过特征矩阵分析将 9 个现存物种加上 3 个灭绝物种安装到分子树中），与空间明确的化石数据相结合将提供对关系的独特访问考虑到生态相似性与相关性相关的趋势，研究人员预计字符位移和物种排序将沿着一个连续体进行，其中字符位移在更密切相关的物种之间占主导地位，而物种排序在更密切相关的物种之间占主导地位。然而，环境带来的生态选择可能胜过竞争介导的选择，在这种情况下，物种在共存的地方会表现出相似的生态特征。