Figure 4

Variable rates of synonymous substitutions in Geraniaceae cox1 genes. Shown is a chronogram based on the topology of Fig. 3. Nodes are labeled A-Z (also see Additional File 1). Shown above each branch are cox1 R_S values (R_S = absolute rate of synonymous substitution per branch) in SSB (sub/site/byr). Abbreviations: Pe, Pelargonium; E, Erodium; G, Geranium. See Additional File 1 for the full set of R_S values taken to two digits after the decimal point, plus full sets of R_N, d_S,d_N,R_N/R_S, and divergence time values.