Figure 6

Molecular properties of ancestral and extant Mbs. The values of aMbWp, aMbWb’, aMbWb, and swMb are indicated by diamonds (light brown), squares (light green), triangles (light blue), and circles (blue). The horizontal axis shows the evolutionary distance (d) of each Mb sequence from that of extant swMb, and the data points are those of aMbWp, aMbWb’, aMbWb, and swMb from left to right. (a) Isoelectric point (pI), (b) positive net charge (Z_Mb), (c) log of solubility (log S₀), (d) solubility slope against precipitant (β), (e) solvation free energy (ΔG_solv), (f) relative molecular mass (Mr), (g) second virial coefficient (A₂), (h) mutational folding energy changes (ΔΔG_mut), (i) folding free energy (ΔG_fold), and (j) half-saturation oxygen pressure (P₅₀). (k) Correlation coefficients between the values shown in panels (a–j) and evolutional distance. The highly positive (>0.9) and negative (<−0.9) coefficients are meshed in magenta and blue, respectively. The two clusters of molecular properties correspond to the early (from terrestrial to ancestral whale) and late (from ancestral whale to extant whale) evolutionary phases. The illustrations of animals are not covered by the CC BY license. Credit to Satoshi Kawasaki. All rights reserved, used with permission.