The article discusses the evolutionary significance of polyploidy, a process where entire genomes are duplicated. Polyploidy has been observed in both prokaryotic and eukaryotic organisms, and while its consequences are complex and vary across systems, there is growing evidence that it correlates with environmental change or stress. Despite often being considered an evolutionary dead end, the short-term adaptive potential of polyploidy is increasingly recognized. The unique retention profile of duplicated genes following whole-genome duplication (WGD) may explain important long-term evolutionary transitions and increases in biological complexity. The authors review significant WGD events throughout the last 500 million years of evolution, focusing on the short-term survival and establishment of polyploids, as well as their long-term evolutionary potential. They discuss neutral and adaptive processes that might associate WGD with survival and invasiveness, and highlight the importance of polyploidy and WGD in non-germline and clonal systems such as prokaryotes and cancer. Short-term effects of WGDs include increased genetic variation, which can affect morphology, physiology, and ecology, leading to interspecies interactions and increased resistance to pathogens. Ancient WGDs seem to occur at specific times, such as during major ecological or environmental changes, and may have played a role in avoiding extinction. For example, a wave of WGDs around the Cretaceous-Paleogene boundary coincided with mass extinctions, and polyploidy in plants and amphibians may have facilitated survival and speciation. Long-term effects of WGDs include the biased retention of regulatory and developmental genes, which can lead to novel gene functions and increased biological complexity. In clonal systems, transient polyploidy can increase genetic variation and adaptive potential, contributing to tumorigenesis and drug resistance. In prokaryotes, polyploidy is more common than previously thought and may provide resistance against severe conditions and gene dosage regulation. The authors conclude that the impact of WGD on evolutionary events and adaptations is more widespread than initially thought, and a better understanding of polyploidy and WGD is crucial for addressing future challenges in areas such as global warming, agriculture, and cancer research.The article discusses the evolutionary significance of polyploidy, a process where entire genomes are duplicated. Polyploidy has been observed in both prokaryotic and eukaryotic organisms, and while its consequences are complex and vary across systems, there is growing evidence that it correlates with environmental change or stress. Despite often being considered an evolutionary dead end, the short-term adaptive potential of polyploidy is increasingly recognized. The unique retention profile of duplicated genes following whole-genome duplication (WGD) may explain important long-term evolutionary transitions and increases in biological complexity. The authors review significant WGD events throughout the last 500 million years of evolution, focusing on the short-term survival and establishment of polyploids, as well as their long-term evolutionary potential. They discuss neutral and adaptive processes that might associate WGD with survival and invasiveness, and highlight the importance of polyploidy and WGD in non-germline and clonal systems such as prokaryotes and cancer. Short-term effects of WGDs include increased genetic variation, which can affect morphology, physiology, and ecology, leading to interspecies interactions and increased resistance to pathogens. Ancient WGDs seem to occur at specific times, such as during major ecological or environmental changes, and may have played a role in avoiding extinction. For example, a wave of WGDs around the Cretaceous-Paleogene boundary coincided with mass extinctions, and polyploidy in plants and amphibians may have facilitated survival and speciation. Long-term effects of WGDs include the biased retention of regulatory and developmental genes, which can lead to novel gene functions and increased biological complexity. In clonal systems, transient polyploidy can increase genetic variation and adaptive potential, contributing to tumorigenesis and drug resistance. In prokaryotes, polyploidy is more common than previously thought and may provide resistance against severe conditions and gene dosage regulation. The authors conclude that the impact of WGD on evolutionary events and adaptations is more widespread than initially thought, and a better understanding of polyploidy and WGD is crucial for addressing future challenges in areas such as global warming, agriculture, and cancer research.