DISSERTATION RESEARCH: Urbanization and Avian Biodiversity

University Of Chicago, Chicago IL

Investigators

Abstract

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.