Newly Discovered Hybrid Shark is a Model of Rapid Evolution

A never before-seen breed of shark has been spotted off the Australian coast, and scientists now say it is a hybrid of the Australian black-tip and part common black-tip species. Researchers published their findings in December in the journal Conservation Genetics, and they say the never-before-seen crossbreeding could be an attempt by the fish to adapt to global warming, French news wire AFP reported.

"It's very surprising because no one's ever seen shark hybrids before, this is not a common occurrence by any stretch of the imagination," lead researcher Jess Morgan, from the University of Queensland, said to AFP.

"This is evolution in action."

The research team was cataloging sharks when they made the discovery. They found the sharks to be genetically one species despite the fact they looked like another species. Australian black-tip sharks is smaller than the common black-tip, and live only in tropical seas. The team found the hybrid sharks living 2,000 kilometers further south, where the water is cooler. This is just the type of adaptation the sharks might need to make if the oceans keep getting warmer. By becoming more like the common black-tip, the Australian black-tip may extend its range and avoid being wiped out.

There seems to be an abundance of evidence for the claims because the hybrid sharks were found to be around 20 percent of the specimens found. Morgan added that this large number did not mean there were necessarily fewer of the single-breed sharks, and that doesn't help explain the situation.

"We thought we understood how species of sharks have separated, but what this is telling us is that in reality we probably don't fully understand the mechanisms that keep species of shark separate," he said.

"And in fact, this may be happening in more species than these two."