Nuclear Test Sites as Natural Experiments: Conceptual Perspectives on Plant Evolution from the New Mexico Desert

The detonation of nuclear weapons, beginning with the Trinity test in New Mexico and followed by the bombings of Hiroshima and Nagasaki, created distinct environments of ionizing radiation exposure. While the ecological consequences of reactor accidents at Chernobyl and Fukushima have been extensively investigated, the potential evolutionary implications of historical weapons testing for plant communities remain comparatively underexplored, particularly in arid ecosystems. This review synthesizes available, yet fragmented, evidence to examine the hypothesis that residual radionuclides in arid test-site environments may have acted as potential selective pressures influencing plant persistence and stress-associated traits in native populations. We propose a comparative conceptual framework contrasting the exposure regimes of nuclear weapons testing with those of reactor accidents and acute detonations. Particular attention is given to the combined effects of initial high-dose exposure and subsequent chronic low-dose contamination, including the long-term persistence of high-linear energy transfer alpha-emitting radionuclides such as 239Pu in desert ecosystems. The analysis integrates current knowledge of radionuclide persistence, exposure pathways, and documented and inferred biological responses in local flora, including site-specific evidence of cytogenetic alterations in taxa such as Machaeranthera spp. alongside broader, largely indirect indications of physiological stress responses derived from comparable plant systems. Current evidence remains limited and uneven across taxa, with only a small number of species investigated directly under site-specific conditions. Given uncertainties in long-term dose reconstruction and environmental heterogeneity, adaptive evolution is considered here as a testable hypothesis rather than a demonstrated outcome. By situating New Mexico test sites within the broader context of radioecological research, this review outlines methodological approaches, including targeted field studies and multi-omics strategies, that may clarify whether sustained radiological exposure contributes to distinguishable ecological, physiological, and potentially evolutionary responses in plant populations.