Evolution of Mammalian Diving Capacity Traced by Myoglobin Net Surface Charge

This article in Science examines the molecular evolution of myoglobin and in particular changes that result in differences in the net surface charge of the protein.  Increases in net surface charge allow for increased oxygen storage while protecting protein stability.  This is an example of convergent evolution as this is a common them in different lineages of diving mammals.

Evolution of Mammalian Diving Capacity Traced by Myoglobin Net Surface Charge.