Evolution Following Establishment in a Novel Environment

种群对新栖息地的入侵会引起种群内部的变化，而这些变化可能是物种形成初始阶段的基础。城市地区代表着新的栖息地。黑眼睛的Junco是一种雀鸟，最近入侵了加利福尼亚州圣地亚哥的一个城市栖息地。首先，将城市juncos与其自然栖息地针叶林中的juncos进行比较，以确定城市juncos是否以及如何在形态，羽毛，行为和遗传方面发生变化。其次，由于城市人口是孤立的，每只junco都可以被独特的彩色条纹和全年监测，以确定个体的繁殖和生存命运。这使得一项彻底的研究能够确定哪些个体具有更高的存活率和繁殖率，哪些特征导致了差异率，以及某些特征的变化如何影响其他特征。这项研究将揭示物种形成的初始阶段，这是生物学的核心问题，但目前还没有得到很好的理解。这项研究还将提供具有实际重要性的知识——增加我们对城市化如何影响物种的理解，以及物种因城市化而变化的原因、方式和速度。这项工作还有一个重要的教育组成部分：每年大约有15名本科生和研究生参与研究的各个方面。

The invasion of novel habitats by populations can cause changes within the populations, and these changes can be the basis for the initial stages of speciation. Urban areas represent novel habitats. The Dark-eyed Junco, a passerine bird, recently invaded an urban habitat in San Diego, California. First, urban juncos are compared with juncos in their natural habitat, coniferous-mixed forest, to determine if and how urban juncos have changed in morphology, plumage, behavior, and genetics. Second, because the urban population is isolated, each junco can be uniquely color-banded and monitored throughout the year to determine individual reproductive and survival fates. This enables a thorough study to determine which individuals have higher survival and reproductive rates, which traits are responsible for the differential rates, and how changes in certain traits affect other traits. This research will shed light on the initial stages of speciation, a question central to biology but currently not well understood. The research will also provide knowledge of practical importance - increasing our understanding of how urbanization affects species, and why, how, and at what rate species change as a result of urbanization. There is also an important educational component to this work: each year approximately fifteen undergraduate and graduate students are involved in all aspects of the research.