Mediterranean sharks closer to the Pacific than to the Atlantic
While previous studies had traced the presence of the great white in the Mediterranean to 450,000 years, its DNA reveals a completely different story: it has actually been 3.2 million years since this shark crossed the doors of the Strait of Gibraltar and s is installed! To determine this, researchers extracted and analyzed the mitochondrial DNA of several "trophies" (teeth, jaws and vertebrae) recovered from museums and private collections and dating from the 19th and 20th century. This material has made it possible to obtain the greatest genetic resource relating to the Mediterranean white shark. And compare it with those of other shark populations in the world which occupy almost all temperate waters.
The large genomic study that is published in the also examines the links that unite all of these populations. It thus reveals that Mediterranean sharks are related to sharks in the Pacific Ocean rather than those in the Atlantic Ocean. To understand this proximity, it was necessary to retrace the route of the first individuals who colonized and then populated it.
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A small population at risk
These first sharks crossed the passage between the two oceans at the level of Central America, before the formation of the isthmus of Panama, more than 3.5 million years ago. After reaching the Atlantic, they settled, 300 million years later, in the Mediterranean. During this period(…)
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