Evolutionary Rescue in Urban Fauna and Genomic Signatures of Adaptation to Chronic Environmental Stress

Abstract

Urbanization has resulted in chronic stressful conditions on wildlife, marked by constant stressors
such as pollution, habitat fragmentation, urban heat islands, noise, artificial light, and changed
resource supply. Although these conditions tend to reduce the population, there are still certain urban
fauna, which means that there are adaptive evolutionary mechanisms. This paper is a synthesis of
existing information on evolutionary rescue in the case of urban fauna, particularly looking at the
genomic signatures of adaptation that can help populations to endure the long-term stresses of the
urban environment. An organized literature review of evolutionary ecology and urban genomics was
carried out, incorporating conceptual frameworks, genomic and regulation-based information, and
exemplary case studies of larger animal groups. There was a focus on the connection between chronic
stressors in urban areas and adaptive genomic reactions and the population-scale outcomes. Synthesis
reveals that evolutionary rescue among the urban fauna is assisted by coordinated genomic adaptations
of genomic stress response, detoxification, immune regulation, metabolism, behavior, and gene
regulation. The genomic signatures of allele frequency changes, regulatory changes, and adaptive
divergence are always related to the characteristics that can be seen to make individuals become
tolerant of urban stress. Theoretical studies have shown that in the event of sustained moderate
selection, evolutionary rescue is most probable when the standing genetic variation is sufficient and
there is demographic stability. Urban setting functions as a selective filter, which causes the adaptation
of heredity, not only acclimation in the short term. The contribution of genomic evidence to urban
ecological studies enhances the ability to predict species resilience and conservation interventions that
increase the adaptive capacity and long-term survival of species in more urbanized environments.