CLIMATE CHANGE AND ITS IMPACT ON GENETIC DIVERSITY, MOLECULAR ADAPTATION, AND ECOSYSTEM RESILIENCE: A COMPREHENSIVE REVIEW

Abstract

Climate change is increasingly altering biological systems across genetic, population, and ecosystem levels, with important consequences for biodiversity persistence and adaptive capacity. This comprehensive review examines how climate-related environmental stressors influence genetic diversity, molecular adaptation, and ecosystem resilience across terrestrial, freshwater, and marine environments. Genetic diversity provides the heritable variation required for populations to respond to changing environmental conditions, whereas genetic erosion, population bottlenecks, and habitat fragmentation can restrict adaptive potential. Climate-driven selection can alter allele frequencies and promote adaptive responses, while gene flow and population connectivity contribute to the maintenance of evolutionary potential. Advances in genomics, transcriptomics, epigenetics, and multi-omics have improved understanding of adaptive genetic variation, gene-expression responses, phenotypic plasticity, and molecular mechanisms associated with environmental stress. Ecosystem resilience is further shaped by functional diversity, species interactions, genetic variation, and landscape connectivity. Climate-smart conservation, assisted gene flow, ecological restoration, and genomics-informed management provide important approaches for maintaining adaptive capacity and biodiversity. Greater integration of molecular, ecological, and environmental information with long-term monitoring is needed to strengthen conservation planning and ecosystem resilience under accelerating climate change.