DISSERTATION RESEARCH: Urbanization and Avian Biodiversity

大多数人类现在生活在城市环境中。尽管有城市化的趋势，但人们对城市环境对许多动物的进化和生态的影响知之甚少。在欧洲，已发现一种基因在城市鸟类和乡村鸟类之间存在差异。这种基因编码一种蛋白质，负责将一种重要的荷尔蒙运入和运出细胞。这种变化被认为通过影响情绪和行为来帮助鸟类在城市环境中以不同的方式应对压力。然而，一个主要的问题仍然是，这种基因变异是否与跨物种和世界各地的城市化一致？这项研究将探索这种基因在美国太平洋沿岸和秘鲁亚马逊西部城市内外不同鸟类中的差异。研究不同地区不同鸟类的遗传差异将使我们对城市化如何影响鸟类进化有大致的了解。这项以城市为重点的研究将使生物科学与人类居民更相关，并将通过认识到我们与野生动物共享这些景观来指导城市的发展方式。此外，这项国际研究将促进秘鲁和美国之间的科学交流。这项研究将集中在与5-羟色胺转运体相关的遗传标记上。为了了解这些标记的背景遗传多样性，研究人员将首先在生物地理范围内表征这种变异。他们将从自然历史博物馆的收藏品中提取代表六个重点物种的全部组织样本，并对相关标记区域的DNA进行测序。然后，研究人员将与秘鲁当地科学家一起，在两个大城市、两个小城市和两个农村/自然地区捕获相同六种鸟类。将对相同的遗传标记进行测序，并评估研究地点和更大的生物地理模式之间的差异。由于以前没有进行过多物种、多环境、比较的方法，结果中的任何模式都有助于我们理解热带地区的遗传多样性及其在抵御城市化方面的作用。如果精细空间尺度上的模式与大空间尺度上的模式一致，这将表明，与欧洲不同，城市化并未对这些物种中该基因的等位基因分布产生重要影响。如果5-羟色胺转运体的遗传多样性在细空间尺度上不同于大空间尺度，而中性遗传标记在细空间尺度和大空间尺度上表现出相同的多样性模式，则表明该基因可能与城市化有关。如果所有的遗传标记都显示出从大空间尺度到精细空间尺度上的差异，将需要进一步的研究来梳理城市地区生态和物种选择的作用，使该项目成为在新环境中快速适应进化的一个有价值的首次尝试。

Most humans now live in urban environments. Despite the trend towards urbanization, little is known about the influence of urban environments on the evolution and ecology of many animals. In Europe, a gene has been found to vary between urban and rural birds. This gene encodes a protein that transports an important hormone in and out of cells. This variation is thought to help birds cope differently with stress in urban settings by influencing mood and behavior. However, a major question remains, does this genetic variation consistently correspond to urbanization across species and around the world? This research will explore how this gene varies in different bird species inside and outside cities in the Pacific coast of the US and western Amazon of Peru. Examining the genetic differences in a diversity of birds in different locations will give us general insight into how urbanization affects bird evolution. This urban focused research will make biological science more relevant to human residents and will inform the way cities grow by recognizing that we share these landscapes with wildlife. In addition, this international research will promote scientific exchange between Peru and the US. This research will focus on genetic markers associated with a serotonin transporter. To understand the background genetic diversity in these markers, the researchers will first characterize the variation at a biogeographic scale. They will do this by taking tissue samples from natural history museum collections representing the full range of six focal species and sequencing the DNA in the relevant marker regions. Then, along with local scientists in Peru, the researchers will catch birds of the same six species in two large cities, two small cities, and two rural/natural areas. The same genetic markers will be sequenced and variation between the study sites and the larger biogeographic patterns will be assessed. Because a multi-species, multi-environment, comparative approach has not been carried out before, any pattern in the results with inform our understanding of genetic diversity in the tropics and its role in resilience against urbanization. If the patterns at a fine spatial scale are consistent with those at a large spatial scale, it will show that, unlike in Europe, urbanization has not had an important effect on the distribution of alleles of this gene in these species. If the serotonin transporter genetic diversity is different at a fine spatial scale rather than a large spatial scale, while neutral genetic markers show the same patterns of diversity at fine and large spatial scales, it will indicate that this gene has perhaps been under selection associated with urbanization. If all genetic markers show differences at fine spatial scales from large spatial scales, further investigation will be needed to tease apart the roles of ecology and species selection in urban areas, making this project a valuable first foray into a case of rapid adaptive evolution in a novel environment.