Urbanization dramatically alters AbMole Nodakenin natural habitats, and its speed and intensity will increase as over two-thirds of the world’s human population is predicted to live in urban areas by 2050. Understanding how natural populations adapt to ecologically divergent urban habitats is thus an important and immediate goal for urban ecologists and evolutionary biologists. Few ecological and evolutionary studies are conducted in urban environments, but recent attitude shifts and technological advancements have removed many of the obstacles to working on urban wildlife. Multiple studies have demonstrated that urban areas are biologically diverse, productive, and viable, and the development of next generation sequencing has facilitated the generation of genomic resources for uncharacterized species in natural environments. Understanding the genetic basis of adaptation in successful urban species will aid in future conservation efforts and provide insights into the effects of other anthropogenic factors, such as global climate change and evolutionary trajectories in human-dominated environments. Cities typically experience a substantial AbMole Tulathromycin B decrease in biodiversity of many taxonomic groups as urban ‘avoiders’ disappear, accompanied by a rise in urban ‘exploiters’ that are primarily non-native human commensals such as pigeons or rats. Urban ‘adapters’ are native species that favor disturbed edge habitats such as urban forest fragments, relying on a combination of wild-growing and human-derived resources. Severe habitat fragmentation is one of the primary impacts of urbanization and often leads to genetic differentiation between populations. Introductions of new predators and competitors alter ecological interactions, and new or more abundant parasites or pathogens influence immune system processes. Air, water, and soil pollution typically increase in local urban ecosystems, and selection may favor previously-rare genetic variants that more efficiently process these toxins. Recent studies provide some evidence of local adaptation and rapid evolution in urban patches. Using a candidate gene approach, Mueller et al. found consistent genetic divergence between behavioral genes for circadian behavior, harm avoidance, migratory behavior and exploratory behavior in multiple urban�Crural population pairs of the common blackbird, Turdus merula. Examining phenotypes, Brady found rapid adaptation to roadside breeding pond conditions in the salamander, Ambystoma maculatum, and Cheptou et al. reported a heritable increase in production of non-dispersing seeds in the weed, Crepis sancta, over 5-12 generations in fragmented urban tree pits. The genetic architecture of the phenotypes under selection has not been described for either of these urban ‘adapters’, but outlier scans of transcriptome sequence datasets are one promising approach. Peromyscus spp. are an emerging model system for examining evolution in wild populations, but large-scale genomic resources are not yet widely available. The genus contains the most widespread and abundant small mammals in North America, and Peromyscus research on population ecology, adaptation, aging, and disease has a long, productive history. An increasing number of studies have demonstrated that Peromyscus spp. rapidly adapt to divergent environments. These examples include adaptation to hypoxia in high altitude environments and adaptive variation in pelage color on light-colored soil substrates. Presently, P. leucopus is the sole Peromyscus spp. in New York City and searches of the Mammal Networked Information System database indicate that P. maniculatus has not occurred in NYC for several decades.