Sixty-six million years ago, an asteroid the size of Mount Everest struck the Earth, "erasing" all non-avian dinosaurs from the map. However, plants managed to survive. Scientists have now discovered why.
Their study was published in the journal *Cell*. In it, they detailed that many flowering plant species survived the planet's worst catastrophes because, by chance, they had duplicated their entire genome.
The research was led by investigators from the University of Ghent in Belgium, and it analyzed the genomes of 470 species of flowering plants.
They were able to identify 132 ancient events of complete genome duplication—a phenomenon known as polyploidy—and dated them using 44 plant fossils.
The results were clear: these duplications did not occur randomly. They clustered together, repeatedly, precisely during the periods of greatest environmental upheaval in Earth's history.
Having twice the number of genes can be an advantage.
Most organisms have two sets of chromosomes, one from each parent. However, in flowering plants, many species have accumulated extra sets by mistake. Cultivated wheat can have up to six, and the bananas sold in supermarkets typically have three.
Under normal circumstances, this is a problem. A larger genome consumes more nutrients, increases the risk of harmful mutations, and complicates reproduction. Therefore, during stable periods, most of these duplications disappear without a trace...
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An asteroid caused the extinction of the dinosaurs 66 million years ago, but many flowering plants survived thanks to the complete duplication of their genome. 66 million years ago, an asteroid the size of Mount Everest struck the Earth, "wiping out" all non-avian dinosaurs. Plants, however, persevered. Scientists discovered why. They published their study in the journal *Cell*. There, they detailed that many flowering plant species survived the worst catastrophes on the planet because, by chance, they completely duplicated their genes. The research was led by investigators from the University of Ghent, in Belgium, and analyzed the genomes of 470 species of flowering plants. They identified 132 ancient events of complete genome duplication—a phenomenon known as polyploidy—and dated them using 44 plant fossils. The result was clear: these duplications did not occur randomly. They clustered, again and again, precisely during the periods of greatest environmental upheaval in Earth's history. Scientists from Belgium, South Africa, and China identified 132 genetic duplication events in flowering plants, crucial for their survival in the face of environmental catastrophes. (Illustrative Image Infobae) Most organisms have two sets of chromosomes, one from each parent. But in flowering plants, many species have accumulated extra sets by mistake. Cultivated wheat can have up to six, and bananas sold in supermarkets usually have three. Under normal conditions, this is a problem. A larger genome consumes more nutrients, increases the risk of harmful mutations, and complicates reproduction. Therefore, during stable periods, most of these duplications disappear without a trace. However, when the environment collapses—due to an asteroid, extreme warming, or a sudden cooling of the planet—the rules change. Plants with duplicated genomes showed greater tolerance to heat, drought, and stress in general. The study published in the journal *Cell* analyzed the genomes of 470 species of flowering plants and dated them with the support of 44 plant fossils (Illustrative Image Infobae) "Complete genome duplication is often seen as an evolutionary dead end in stable environments," said Yves Van de Peer, one of the scientists who conducted the study. "But in extreme situations, it can provide unexpected advantages," he noted. According to this finding, the peaks of polyploidy detected coincide with specific events: the Cretaceous-Paleogene extinction 66 million years ago, several episodes of oceanic anoxia in the Cretaceous, the Eocene-Oligocene transition about 33.5 million years ago—when the planet cooled abruptly—and the Paleocene-Eocene Thermal Maximum (PETM), approximately 55.8 million years ago. Polyploid plants showed greater tolerance to heat, drought, and stress during episodes such as the Paleocene-Eocene Thermal Maximum and other global crises (Illustrative Image Infobae) The PETM is the episode that generates the most attention among researchers in relation to the present. During that period, the global temperature rose by 5 to 8 °C in about 100,000 years, a rate that scientists compare to the current warming. According to the authors, the difference is that today the increase is much faster. Van de Peer himself warned bluntly: "What we see in the past suggests that polyploidy may help plants cope with these stressful conditions," although he acknowledged that the current rate of climate change is unprecedented in the studied records. At the same time, an old paradox in biology was resolved: if polyploidy is so frequent, why are there so few traces of it in modern genomes? The complete results and data of the genomic analysis are available on the AngioWGD platform, developed by the University of Ghent for researchers to consult (Illustrative Image Infobae) According to the researchers, the answer is that only events that occurred during times of crisis managed to become fixed and persist. During peaceful times, duplicated plants simply lost the competition to their relatives with normal genomes. The data from the study are available on the AngioWGD platform, developed by the Ghent team, where any researcher can explore the 132 dated duplication events in the 470 species analyzed. The team is composed of Hengchi Chen, Fabricio Almeida-Silva, Garben Logghe, Steven Maere, Dries Bonte, and Yves Van de Peer.