A study by researchers from the University of Aberdeen suggest that the presence of sharks in the Mediterranean may be the result of an off the course migration of some pregnant Australian sharks 450,000 years ago.

According to the researchers, high sea levels, climate change or strong currents might have caused their forced deviation from the actual migration path. Researchers have studied the mitochondrial DNA of the sharks to find its antecedent. Till now scientists believed them to be originated from the Atlantic or Indian Ocean shark family and were surprised to find their DNA sequence matching with the Australian great white sharks. “That was a time of interglacials, when you would've had all kinds of changes in the currents going down the east and up the western coast of Africa," Dr. Les Noble of the University of Aberdeen, the leading researcher said.

Some of the female sharks might have made the navigational error and given birth to shark pups in the Mediterranean. It may explain why the sharks stayed on in the Mediterranean as they like salmons like to return to their birthplace.

The peninsulas and the narrow channels in the Mediterranean might also have made these sharks journey back home difficult. "The reason we still have a genetic signature of that with the great whites is because they're like salmon - where the pups are dropped, they recognize as their home - that's where they always return to," said Dr Noble.

But, this new study is not conclusive as the samples analyzed are small. Scientists are trying to analyze the DNA samples of 50 more sharks to arrive at a definite inference. They feel that these findings will help draw attention to the plight of the existing Mediterranean shark population as these sharks are crucial for the sustenance of marine ecosystems of the Mediterranean.