Mediterranean great white sharks found to have 3.2 million-year-old origins

FEBRUARY 11, 2020

by University of Bologna

The great white shark has been in the Mediterranean for 3.2 million years, way longer than researchers have hypothesized until now. The white sharks currently living in the Mediterranean are genetically closer to those of the Pacific Ocean than to their neighbors inhabiting the Atlantic.

Starting from the analysis of artifacts and ancient trophies kept in museums, a research group led by the University of Bologna managed to sequence the DNA of Mediterranean white sharks. Their approach combines genetics and mathematical models and proved to be effective in tracing back their peculiar evolutionary history. However, researchers also warn that they might become extinct. Their study will be published on the Journal of Biogeography.

"White sharks have a complex evolutionary history, they are unusual. They evolved into sedentary populations scattered around the globe. Among these, there are the Mare Nostrum white sharks, which are really unique," explains Agostino Leone, researcher at the University of Bologna and first author of the study. "White sharks in the Mediterranean have a very low genetic variability, which may hint at a very small and endangered group of sharks."

DNA and historical artifacts

The great white shark (Carcharodon carcharias) is the largest predatory fish on earth, with larger individuals growing over six meters in length and one ton in weight. They're found off the shores of South Africa, Australia, New Zealand, Japan and North and South America, and, of course, of the Mediterranean. Despite being VIPs in the animal realm, starring in blockbuster movies like Spielberg's "Jaws" and in many documentaries, scientists know little about their history.

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