The Role of Epigenetic Mechanisms in Animal Adaptation to Environmental Stressors in Polar Bears in the Arctic

Abstract

Polar bears (Ursus maritimus) live in one of the fastest-changing regions on the planet, where accelerating global warming, the loss of sea ice, and increased exposure to toxins subject them to critical physiological and ecological pressures. Although genetic adaptation is a necessary process that may take a long time over evolutionary time, epigenetic modifications enable polar bears to adapt more quickly to environmental stressors. The present paper focuses on how epigenetic activities, including DNA methylation, histone modifications, and non-coding RNA regulation, contribute to phenotypic plasticity and stress resistance in polar bears. These processes can regulate gene expression involved in metabolism, immune responses, reproduction, and stress responses without necessarily altering the underlying DNA sequences. Additionally, new evidence on arctic mammals indicates that exposure to pollutants, severe temperatures, and nutritional stress might result in epigenetic modifications that may enhance short-term adaptive capacity. Nevertheless, the changes can also affect the lives of individuals across generations. Through a review of the existing literature on epigenetics and Arctic animals, the present study finds that epigenetic regulation is an essential but under-researched area of polar bear adaptation. Understanding these processes is important for anticipating species behavior under current environmental change and for conservation policy to safeguard Arctic biodiversity as climatic stress intensifies.