Figure 6.

Species-species networks for AT2G37040, an Arabidopsis gene. In these networks, nodes represent species and are connected to other species based on the ratio of genes homologous to each other at a threshold of 0.56, because in networks with this threshold, species belonging to single families are well grouped such as Brassicaceae, Leguminosae, and Poaceae. Blue and gray nodes represent species with and without genes homologous to a gene of interest, respectively. A–C, The networks, in which nodes are colored, are depicted using different thresholds of 0.6 (A), 0.8 (B), and 0.9 (C). In (A), all land plants are in blue and, in (C), only plants of the Brassicaceae are in blue.