Hybrid
sharks have been discovered swimming in the waters off Australia's east
coast. The finding may be driven by climate change, a research team
says, suggesting such discoveries could be more common in the future.
The
hybridization is between the Australian black tip shark which favors
tropical waters and the larger, common black tip shark, which favors
sub-tropical and temperate waters.
While the distribution for the
genetically distinct species overlaps along the northern and eastern
Australian coastline, the finding that they mated and produced offspring
is unprecedented, according to the discovery team from the University
of Queensland.
"To actually find something like this and prove it
genetically is unprecedented," Bob Hueter, director of the Center for
Shark Research at the Mote Marine Laboratory in Sarasota, Florida, told
me Tuesday.
Hueter was not involved with the research, though one
of the scientists responsible for the discovery used to work in his
lab, which he said lends the finding credibility. The finding is based
on genetic testing and body measurements and reported December 2011 in
the journal Conservation Genetics.
The team identified 57 of the hybrids from five locations spanning 1,250 miles along the Australian coast.
"Wild
hybrids are usually hard to find, so detecting hybrids and their
offspring is extraordinary," Jennifer Ovenden, an expert in genetics of
fisheries species and team member, said in a news release.
The
hybridization could be an adaptation to climate change, the team noted,
allowing the tropical Australian black tip shark to live in the cooler,
sub-tropical waters.
It could also be a technique to survive in
over-fished waters, speculated Hueter. As fisheries are depleted,
hybridization is a way to keep reproducing.
"In a sense, it is catching evolution in action," he told me.
http://futureoftech.msnbc.msn.com/_news/2012/01/03/9921974-australias-hybrid-shark-reveals-evolution-in-action
