Chernobyl as a natural laboratory: Genetic instability, adaptation, and ecological recovery in flora and fauna under chronic radiation

Abstract

The Chernobyl nuclear accident of April 1986 remains the most severe nuclear disaster in human history, with long-lasting consequences for ecosystems exposed to chronic ionizing radiation. In the decades since the event, the Chernobyl Exclusion Zone has become an unintended but invaluable natural laboratory for investigating the genetic and ecological effects of persistent radiation exposure. This review synthesizes current knowledge on both immediate and long-term biological consequences observed in plants and animals inhabiting contaminated areas. Initial impacts included acute mortality, reproductive failure, and ecosystem collapse, most notably exemplified by the “Red Forest.” Over subsequent years, studies revealed elevated mutation rates, chromosomal aberrations, genomic instability, and heritable genetic damage across diverse taxa. At the same time, evidence of adaptive responses has emerged, including increased antioxidant defenses, epigenetic modifications, and phenotypic changes such as melanism in amphibians. Flora and fauna within the exclusion zone illustrate the dual narrative of vulnerability to mutagenic stress and resilience through evolutionary adaptation. Comparisons with the Fukushima accident demonstrate convergent biological responses across ecosystems while highlighting the importance of context, such as terrestrial versus marine contamination and remediation strategies. Future research must integrate advanced genomic and epigenomic tools, accurate dosimetry, and long-term monitoring to clarify thresholds for harmful versus adaptive outcomes. Chernobyl thus continues to provide critical insights into radiation biology, ecological recovery, and evolutionary toxicology under conditions of chronic environmental stress.