Find Out How Marine Mammals Can Hold Their Breath For So Long [Video]

Mammals such as whales and seals can hold their breaths for incredibly long periods of time, and it's not due to large lungs. Instead, scientists found that an oxygen-binding protein is responsible for the impressive dive times these creatures post.

Myoglobin is the protein that gives meat its reddish tint, but elite mammalian divers have it in such droves that it can actually turn the muscle black. Proteins, however, don't function very well in incredibly high concentrations. Instead they clump up and impair each other. Luckily it seems that the myoglobin in mammalian divers has found a way around that by adopting an electrical charge.

"Our study suggests that the increased electrical charge of myoglobin in mammals that have high concentrations of this protein causes electro-repulsion, like similar poles of two magnets. This should prevent the proteins from sticking together and allow much higher concentrations of the oxygen-storing myoglobin in the muscles of these divers," explained Dr. Scott Mirceta, a PhD student who was one of the researchers involved in the study.

"We are really excited by this new find, because it allows us to align the anatomical changes that occurred during the land-to-water transitions of mammals with their actual physiological diving capacity. This is important for understanding the prey items that were available to these extinct animals and their overall importance for past aquatic ecosystems."

The scientists took these findings and were able to apply them backwards in time, mapping out the muscle oxygen stores for over a 100 mammalian divers, including fossilized ancestors.

"By mapping this molecular signature onto the family tree of mammals, we were able to reconstruct the muscle oxygen stores in extinct ancestors of today's diving mammals," said team leader Dr. Michael Berenbrink from the University's Institute of Integrative Biology. "We were even able to report the first evidence of a common amphibious ancestor of modern sea cows, hyraxes and elephants that lived in shallow African waters some 65 million years ago."

You can read the full published study in the journal Science.