NSF Postdoctoral Fellowship in Biology FY 2014

美国国家科学基金会生物学博士后奖学金将研究和培训相结合，为年轻科学家在生物学领域的职业生涯做好准备，并要求制定计划，扩大在科学和工程领域代表性不足的群体的参与。这些奖学金加强了美国国家科学基金会在现在和未来多样化STEM劳动力方面的努力。梅塞德斯·伯恩斯获得的奖学金支持研究昆虫的繁殖以及不同环境下不同的繁殖策略是如何进化的。这项奖学金的主办机构是圣地亚哥州立大学，赞助科学家是马歇尔·赫丁博士。该研究员还通过与日本科学家的研究合作拓宽了她的科学视野。主要训练目标是掌握基因组测序技术，用于识别种群水平的遗传变异。这项研究调查了两种收割机（通常被称为长腿爸爸）在交配系统进化中的雌雄比例。有效的雌雄比例可能通过改变对两性交配率控制的选择，推动物种生殖结构和交配系统的进化变化。在这些物种中，雄性受精或不受精都可以进行繁殖，在高纬度和高海拔边缘生境中，这些物种的雌性偏向种群很常见。研究目标是：1)利用分子标记重建边缘生境的定殖，阐明雌性偏倚种群地理分布的机制；2)利用比较方法研究长期的雌性偏倚比例对雌性繁殖力、雄性形态和父系卵群多样性的影响。主办机构是一个为少数民族服务的机构，提供节肢动物生物学的两门课程，为作为有效榜样的研究员提供了一个机会，让他们在学习功能形态学和分子测序程序后，找到积极主动的学生来指导和协助研究。

NSF Postdoctoral Fellowships in Biology combine research and training components to prepare young scientists for careers in biology and require a plan to broaden participation of groups under-represented in science and engineering. The fellowships enhance NSF efforts to diversify the STEM workforce now and in the future. This fellowship to Mercedes Burns supports research on reproduction in insects and how different reproduction strategies evolve in different environments. The host institution for this fellowship is San Diego State University, and the sponsoring scientist is Dr. Marshal Hedin. The Fellow is broadening her scientific horizons also through a research collaboration with scientists in Japan. The main training goal is to achieve mastery of genomic sequencing techniques to be used in identifying population-level genetic variation.The research investigates the role of the ratio of males to females in evolution of mating systems in two species of harvestmen, the insects commonly known as daddy-longlegs. Effective male/female ratios may drive evolutionary change in the reproductive structures and mating systems of species by altering selection over the control of mating rate of each gender. In these species, reproduction proceeds with or without male fertilization and female-biased populations of these species are common in high-latitude and altitude marginal habitats. The research goals are to 1) elucidate mechanisms producing the geographic distribution of female-biased populations by reconstructing the colonization of marginal habitats using molecular markers and 2) examine the effects of a long-term female-biased ratio on female fecundity, male morphology, and paternal diversity of egg clutches using a comparative approach.The host institution is a Minority-serving institution that offers two courses in arthropod biology, providing the Fellow who serves as an effective role model an opportunity to identify highly motivated students for mentoring and assisting in the research once they learn functional morphology and molecular sequencing procedures.