Dissertation Research: The roles of genetic variation and competition in resource niche expansion

研究人员先前的实验表明，遗传多样性和竞争分别提高了物种适应新资源的能力（生态位扩张）。目前的项目将测试遗传多样性和个体之间的竞争相互作用是否协同作用以实现这一目标。面粉甲虫种群的增长，开始不同程度的遗传多样性和竞争，并提供了祖先和新的资源，将监测八代。定期从每个种群中取样的甲虫的饮食将使用稳定碳同位素分析进行量化，这是一种量化饮食变化的有效方法。资源利用的时间变化率将被测量为实验操作的遗传多样性和竞争的函数。生态位扩展通常被用来解释物种的分布和范围。因此，加强对限制或促进生态位扩大的因素的了解的实验是了解生物多样性变化的原因和后果的窗口。该项目是对有性生物体中这一现象的首次实验研究。实验设计还模仿保护策略，寻求增加种群规模和受威胁物种的遗传变异。因此，这些结果也直接应用于保护生物学。

Previous experiments by the investigators have shown that genetic diversity and competition separately increase species' ability to adapt to novel resources (niche expansion). The current project will test whether genetic diversity and competitive interactions between individuals act synergistically to achieve this. Growth of flour beetle populations, initiated with varying degrees of genetic diversity and competition and supplied with ancestral and novel resources, will be monitored for eight generations. Diet of beetles sampled periodically from each population will be quantified using stable carbon isotope analysis, a powerful method of quantifying diet variation. The rate of temporal change in resource use will then be measured as a function of experimentally manipulated genetic diversity and competition.Niche expansion is commonly invoked to explain species distributions and ranges. Hence, experiments that enhance knowledge of factors that constrain or facilitate niche expansion are windows into the causes and consequences of changes in biodiversity. This project represents the first experimental study of this phenomenon in sexual organisms. The experimental design also mimics conservation strategies seeking to increase population size and genetic variation of threatened species. Therefore, results also have direct applications in conservation biology.