No evidence that polyploids arise during periods of environmental upheaval. A reply to Chen et al. (2026)

Abstract

Ancient whole-genome duplications (WGDs) are thought to have played a major role in plant evolution, but robust inference of the patterns and drivers of polyploid establishment through deep time remains challenging. We re-evaluate the recent large-scale study by Chen et al. (2026), which linked polyploid establishment throughout angiosperm evolution to periods of climatic instability and low species richness. We identify five conceptual and methodological issues that substantially affect these conclusions and collectively undermine the proposed temporal and ecological associations. We hope that clarifying these issues will support future efforts to understand the evolutionary role of polyploidy in plant evolution.