Fig. 2. The evolution of genome size in the grasses inferred using Wagner's linear parsimony criterion. Ancestral genome sizes (in pg DNA per 2C nucleus) were reconstructed as continuous-valued characters on a cladogram of diploid grass species using linear parsimony with minimum equally parsimonious values. The phylogeny of the grasses was rooted using phylogenetic information derived from RNA structure. Closed and open circles indicate nodes with more than twofold increases or decreases in genome size, respectively.