Figure 5
From: Tracing whale myoglobin evolution by resurrecting ancient proteins

Oxygen equilibrium curves of ancient and sperm whale Mbs. The logarithmic ratios of oxy-myoglobin to deoxy-myoglobin are plotted against the logarithmic oxygen partial pressure (pO2) for (a) aMbWp, (b) aMbWb’, (c) aMbWb, and (d) swMb.