Fig. 1

Gene conversion events of homologous gene quartets and changes in phylogenetic tree topology. a Colinear chromosomal segments from two genomes (O and S), represented by rectangles of different colours. Arrows show genes, and homologous genes are indicated by the same colours. Homologous gene quartets are formed by paralogous genes O1 and O2 in one genome and their respective orthologues S1 and S2 in the other genome. (b-e) Squares symbolize a WGD event in the common ancestral genome; circles symbolize species divergence. b The expected phylogenetic relationship of the homologous genes if no conversion occurs. c O2 (an acceptor) is converted by O1 (a donor). d S1 is converted by S2. e Both of the above conversions occur