RUI: Generating the Entangled Bank: Biogeography and Host Use in a Hawaiian Herbivore Radiation

摘要浏览器DEB 0445086。生物学家长期以来一直在研究岛屿辐射，以了解适应和地理隔离是如何相互作用产生生态多样性的。夏威夷群岛一直是进行这类物种形成研究的富有成效的地方，因为它与大陆移民来源地极端隔绝，环境高度可变，促使少数几个血统的壮观辐射成功地殖民了它。这个项目调查了26种以上夏威夷粉蝇的多样化机制和速度，这些苍蝇可能是在不到300万年的时间里从单一的殖民祖先那里辐射出来的。这些昆虫以仅在夏威夷发现的植物物种为食，包括夏威夷银剑联盟的大多数成员，这是适应辐射的经典模式；许多昆虫以种子为食，因此直接影响其宿主植物的繁殖，其中一些是联邦濒危物种。乔纳森·布朗博士将与有才华的本科生合作，进行实地和实验室研究，以(1)调查群岛各地可能的植物宿主，以确定所有物种利用宿主的地理范围和模式；(2)基于来自多个基因序列的信息，确定所有物种之间的进化关系。这些进化关系随后将被用来检验地理隔离与不同寄主植物在物种形成过程中的适应性变化所起的作用。这些结果将为未来研究行为和形态特征的进化提供一个框架，例如黑色素翅膀图案，这是用于识别粉蝶和其他一些苍蝇群体的关键特征。了解这些特征的进化将有助于更好地了解这一多样化的昆虫家族，其中包括许多具有重要经济意义的害虫物种。了解夏威夷等岛屿群岛的进化过程对于了解它们的保护价值很重要，特别是考虑到它们独特的本土物种目前面临的威胁。这项研究项目还将为几名本科生提供暑期研究经验，以展示在生物、分子和保护生物学方面跨学科研究的力量。学生们将通过国家科学基金会支持的格林内尔学院的核心生物学课程为这些经历做好准备，该课程强调基于研究的学习和跨生物子学科的整合。布朗博士致力于招募参加格林内尔新科学项目的研究生，这是一个旨在鼓励代表性不足的群体追求科学事业的创新项目。与他以前的工作一样，学生将成为收集、分析和传播研究结果的完全合作伙伴。通过在以探究技能为中心的生物课程中提供独立的研究机会，该项目将延续布朗博士和格林内尔学院成熟的传统，即将科学研究整合到广泛而有意义的文科教育中。

AbstractBrownDEB 0445086. Biologists have long studied island radiations to understand how both adaptation and geographic isolation have interacted to generate ecological diversity. The Hawaiian archipelago has been a productive place to undertake such speciation studies, because its extreme isolation from continental sources of immigrants and its highly variable environments have spurred spectacular radiations of the few lineages to have successfully colonized it. This project investigates the mechanisms and tempo of diversification of the 26+ species of Hawaiian tephritid flies, which have likely radiated from a single colonizing ancestor in less than 3 million years. These insects feed on plant species found only in Hawaii, including most members of the Hawaiian silversword alliance, a classic model of adaptive radiation; many feed on the seeds and thus have a direct impact on reproduction of their host plants, some of which are federally endangered species. In collaboration with talented undergraduate research students, Dr. Jonathan Brown will undertake field and laboratory studies to (1) survey likely plant hosts from across the archipelago to determine the geographic range and mode of host use for all species; and (2) determine the evolutionary relationships among all the species, based on information from multiple gene sequences. These evolutionary relationships will then be used examine the role of geographic isolation vs. adaptive changes to different host-plants in the speciation process. The results will provide a framework for future studies of the evolution of behavioral and morphological traits, e.g., melanin wing patterns, a key trait used to identify tephritids and some other groups of flies. Understanding the evolution of these traits will contribute to a better understanding of this diverse family of insects, which includes many pest species of economic importance. Knowledge of the evolutionary processes that play out on island archipelagos like Hawaii is important for understanding their conservation value, especially given current threats to their unique native species. This research project will also provide several undergraduate students with summer research experiences that demonstrate the strength of interdisciplinary research in organismal, molecular, and conservation biology. Students will be well prepared for these experiences via an NSF-supported core biology curriculum at Grinnell College that emphasizes research-based learning and integration across biological subdisciplines. Dr. Brown is committed to recruiting research students who have participated in Grinnell's New Science Project, an innovative program designed to encourage under-represented groups to pursue scientific careers. As in his previous work, students will be full partners in the gathering, analysis and dissemination of the results of the study. By providing independent research opportunities within a biology curriculum centered on skills of inquiry, this project will continue both the Dr. Brown's and Grinnell College's proven tradition of integrating scientific research into a broad and meaningful liberal arts education.