This study investigates the prevalence of paleopolyploidy in model plant species by analyzing the age distribution of duplicated genes. Researchers Guillaume Blanc and Kenneth H. Wolfe analyzed 14 model plant species, including wheat, maize, cotton, tomato, potato, soybean, and Arabidopsis, to determine the timing of gene duplication events. They used EST contigs (unigenes) to identify paralogous gene pairs and estimated the relative ages of gene duplication using synonymous nucleotide substitution levels. The results showed that nine species exhibited peaks in the age distribution of duplicated genes, suggesting large-scale duplication events such as polyploidy or aneuploidy. However, the unusual age profile of tandem gene duplications in Arabidopsis indicated that other factors, such as variation in the rate of gene deletion, may also be involved. The study highlights that genome duplication is common in flowering plants, with estimates ranging from 30 to 80% of angiosperms having undergone polyploidy. However, detecting ancient polyploidy is challenging due to the long-term evolution of polyploids, which involves extensive genome reorganization. The researchers found that the age distribution of duplicated genes in species like maize, cotton, and wheat showed secondary peaks, indicating ancient large-scale duplication events. For example, in maize, the secondary peak at Ks = 0.15 to 0.20 was attributed to an ancestral tetraploidy event. In cotton, the secondary peak at Ks = 0.40 to 0.45 was likely due to an older duplication event. Similarly, in Arabidopsis, the secondary peak at Ks = 0.75 to 0.80 was attributed to a recent polyploidy event. The study also found that the age distribution of duplicated genes in species like tomato and potato showed a secondary peak at Ks = 0.60, suggesting a common ancestor with a large-scale duplication event. In soybean and Medicago truncatula, the age distribution showed two secondary peaks, indicating multiple large-scale duplication events. The researchers concluded that nine of the 14 species studied had age distributions of paralogous genes that were incompatible with a null model of gradual gene duplication and loss but similar to what is expected from large-scale duplications such as polyploidy or aneuploidy. These events are summarized in Figure 4, and the researchers estimate that all these large-scale duplications occurred within the past 30 million years. The study underscores the prevalence of polyploidy in angiosperms and reaffirms the general consensus that many flowering plants are in fact paleopolyploids.This study investigates the prevalence of paleopolyploidy in model plant species by analyzing the age distribution of duplicated genes. Researchers Guillaume Blanc and Kenneth H. Wolfe analyzed 14 model plant species, including wheat, maize, cotton, tomato, potato, soybean, and Arabidopsis, to determine the timing of gene duplication events. They used EST contigs (unigenes) to identify paralogous gene pairs and estimated the relative ages of gene duplication using synonymous nucleotide substitution levels. The results showed that nine species exhibited peaks in the age distribution of duplicated genes, suggesting large-scale duplication events such as polyploidy or aneuploidy. However, the unusual age profile of tandem gene duplications in Arabidopsis indicated that other factors, such as variation in the rate of gene deletion, may also be involved. The study highlights that genome duplication is common in flowering plants, with estimates ranging from 30 to 80% of angiosperms having undergone polyploidy. However, detecting ancient polyploidy is challenging due to the long-term evolution of polyploids, which involves extensive genome reorganization. The researchers found that the age distribution of duplicated genes in species like maize, cotton, and wheat showed secondary peaks, indicating ancient large-scale duplication events. For example, in maize, the secondary peak at Ks = 0.15 to 0.20 was attributed to an ancestral tetraploidy event. In cotton, the secondary peak at Ks = 0.40 to 0.45 was likely due to an older duplication event. Similarly, in Arabidopsis, the secondary peak at Ks = 0.75 to 0.80 was attributed to a recent polyploidy event. The study also found that the age distribution of duplicated genes in species like tomato and potato showed a secondary peak at Ks = 0.60, suggesting a common ancestor with a large-scale duplication event. In soybean and Medicago truncatula, the age distribution showed two secondary peaks, indicating multiple large-scale duplication events. The researchers concluded that nine of the 14 species studied had age distributions of paralogous genes that were incompatible with a null model of gradual gene duplication and loss but similar to what is expected from large-scale duplications such as polyploidy or aneuploidy. These events are summarized in Figure 4, and the researchers estimate that all these large-scale duplications occurred within the past 30 million years. The study underscores the prevalence of polyploidy in angiosperms and reaffirms the general consensus that many flowering plants are in fact paleopolyploids.