SYDNEY, July 5 (Xinhua) -- Aussie scientists have uncovered a mystery surrounding tiger sharks on Wednesday, in a new study that revealed the species is one large single population right across the Indo-Pacific Ocean Basin, with very little genetic differentiation.
The University of Queensland Study found the tiger shark population extends through the South Pacific, to Hawaii and the Central Pacific and also as far west as the Indian Ocean, with minimal "genetic divergence."
"The finding is particularly important for the species itself, because when we discover these kinds of things we try to promote some form of cross jurisdictional management," author of the Study Dr Bonnie Holmes told Xinhua on Wednesday."
"Although they're afforded some level of protection here in Australia, as soon as they swim out to international waters they are targeted quite heavily."
To unlock the population structure of the tiger shark, Holmes conducted a number of biological and ecological tracking studies as part of her PhD research project.
"During my encounters tagging them, I would collect a small tissue sample," Holmes said.
"We would take a little nick out of the dorsal fin, preserve that tissue and then take it back to the laboratory to extract the DNA."
"The method we used to find how related each of the animals are related to one and another, was by examining microsatellites or the nuclear DNA, which is DNA inherited from both parents."
Researchers are now looking at employing similar methods to uncover more genetic secrets about the past.
Last year the Holmes' team published a paper that found shark jaws, preserved in museums across the world, could be analysed to find historical DNA.
"We could retrieve DNA even from quite degraded jaws from the 1900's and even 1800's, to find how old-world tiger sharks compare with the contemporary population structure and whether there was any divergence in genetic terms," Holmes said.
