Friday, November 19, 2010

Mediterranean Sharks Resulted from Wrong Turn

A new study involving Mediterranean great white sharks suggests that they are more closely related to sharks from Australia and New Zealand, and less similar to those of the Atlantic Ocean as previously thought.  It is believed that the group of Mediterranean sharks arrived about 450,000 years ago after making a "wrong turn" on their return to the location of their birth.  This period of time was an interglacial period, in which extreme current variations were occurring.  The change in warm and cold currents may have been significant enough to alter the course of the migrating sharks.  If only a few shark pups were born in the Mediterranean waters, the study indicates that this would be all that was needed to begin a new cycle of migration to the same location for future generations.  This is an interesting study which may have implications for other species migrations during interglacial periods.