Great White Sharks Share Surprising Genetic Similarity with Humans

Researchers have discovered surprising similarities in proteins found in the genetic code of humans and great white sharks. The find is remarkable because the great white proteins are more similar those found in humans than in zebrafish, the quintessential fish model.

The proteins, which play a role in regulating an array of functions, including metabolism, have a variety of similarities despite belonging to markedly different species.

"We were very surprised to find, that for many categories of proteins, sharks share more similarities with humans than zebrafish," said Michael Stanhope, a professor of evolutionary genomics at Cornell's College of Veterinary Medicine. "Although sharks and bony fishes are not closely related, they are nonetheless both fish ... while mammals have very different anatomies and physiologies. Nevertheless, our findings open the possibility that some aspects of white shark metabolism, as well as other aspects of its overall biochemistry, might be more similar to that of a mammal than to that of a bony fish."

Stanhope, along with his colleague Mahmood Shivji of the Save Our Seas Shark Research Center at Nova Southeastern University, published their work in the journal BMC Genomics.

Stanhope said the work lays the foundation for genomic exploration of sharks and "vastly expands" the genetic tools available for white shark conservation efforts.

One notable discovery in the similar genetic codes is that sharks have a close match to humans involving proteins involved in metabolism.

"Sharks have many fascinating characteristics," Stanhope said. "Some give live birth to fully formed young, while some lay eggs. In some species, the embryos eat the remaining eggs or even other embryos while still developing in the uterus. Some can dive very deep, others cannot. Some stay local; others migrate across the entire ocean basins. White sharks dive deep, migrate very long distances and give live birth. We will use what we've learned in this species in a broader comparative study of genes involved in these diverse behaviors."

Stanhope said their study has increased the number of genetic markers scientists can use to study the great white shark population by a thousandfold.