Van de Peer, YvesAshman, Tia-LynnSoltis, Pamela S.Soltis, Douglas E.2021-02-252021-02-252021-01Van de Peer, Y., Ashman, T.-L., Soltis, P.S. et al. 2021, 'Polyploidy : a biological force from cells to ecosystems', Plant Cell, vol. 33, no.1, pp. 11-26.1040-4651 (print)1532-298X (online)10.1093/plcell/koaa015http://hdl.handle.net/2263/78843Polyploidy has been hypothesized to be both an evolutionary dead-end and a source for evolutionary innovation and species diversification. Although polyploid organisms, especially plants, abound, the apparent nonrandom long-term establishment of genome duplications suggests a link with environmental conditions. Whole-genome duplications seem to correlate with periods of extinction or global change, while polyploids often thrive in harsh or disturbed environments. Evidence is also accumulating that biotic interactions, for instance, with pathogens or mutualists, affect polyploids differently than nonpolyploids. Here, we review recent findings and insights on the effect of both abiotic and biotic stress on polyploids versus nonpolyploids and propose that stress response in general is an important and even determining factor in the establishment and success of polyploidy. Polyploidy can be an evolutionary and ecological force in stressful times.en© The Author(s) 2020. Published by Oxford University Press on behalf of American Society of Plant Biologists. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence.PolyploidyPlantsGlobal changeEnvironmental conditionsPolyploidy : an evolutionary and ecological force in stressful timesArticle