Down on the bayou, gators earn a lot of respect; they can sneak up on you with hardly a ripple in the water.
But without fins or flippers, how do they do it? By using their internal muscles to shift their lungs, according to researchers at the University of Utah. They change buoyancy by using their internal muscles to move their lungs fore and aft or port and starboard of their center of gravity. Lungs forward brings the gator to the surface; lungs astern helps them dive.
Scientists have focused on one muscle in particular, which some thought was an evolutionary holdover from the days when early crocodile-like reptiles were cat-sized and skittered around the countryside. It was just put to a new use. But the new study suggests an alternative: that the muscles in question evolved after these creatures took to the water. The results are set to appear in the April issue of the Journal of Experimental Biology.