Position of the duplication events in the tree of life. (A) Phylogenetic relationships between the analyzed plant species. The arrow marks the probable position of the recent large-scale duplication event identified in this analysis. (B) Distribution of Ks values obtained from sets of orthologous sequences betweenArabidopsis and selected plant species and between paralogous sequences in recent and old Arabidopsis blocks. The numbers of sequences orthologous to Arabidopsis are 252 for Brassica rapa, 1358 for cotton, 1741 for Medicago, 1465 for tomato, and 1026 for rice. The paralog Ks distributions are for 2617 and 576 gene pairs occurring in recent duplicated blocks, and blocks identified in the pseudo ancestral genome, respectively. The vertical lines depict the positions of the modes of the distributions obtained fromArabidopsis paralogous genes.
