By IANS,
Washington : DNA from extinct sub-species of tiger has revealed they migrated through the heart of China, what is now popularly known as the ‘Silk Road’, according to an international study.
A team of scientists from Oxford University and NCI Laboratory of Genomic Diversity in the US have shown that the Caspian tiger from Central Asia, which became extinct in 1970, was identical to the living Siberian tigers found in the Russian Far East today.
The discovery not only sheds new light on how the animals reached Central Asia and Russia but also opens up the intriguing possibility that conservationists might repopulate tiger-less Central Asia with Siberian tigers from Russia or China.
“What these striking results indicate is that extinct Caspian tigers and modern Siberian tigers are molecular nearest neighbours,” said Carlos Driscoll, doctoral student at Oxford University’s Wildlife Research Conservation Unit (the WildCRU), who led the study.
“In a sense it means that Caspian tigers never became extinct, it’s just that there never was any such thing as a ‘Siberian’ tiger.” The relationship is so close that the mitochondrial DNA of the two sub-species differs by just a single nucleotide.
Because Caspian tigers were not well studied before they became extinct almost 40 years ago the team had to retrieve DNA from specimens held in the region’s museums.
“We had to travel through Russia and Central Asia taking tiny bone samples from Caspian tiger specimens in natural history collections,” said co-author Nobby Yamaguchi of Oxford’s WildCRU.
“We then compared the mitochondrial DNA from these samples with those taken from living animals, especially Siberian and Indian tigers.”
The route that Caspian tigers took to get to Central Asia has always been a puzzle because Central Asian tigers seemed isolated from other populations by the massive Tibetan plateau, said an Oxford release.
The new research suggests that rather than skirting around the plateau, via India to the south or Siberia to the north, perhaps about 10,000 years ago ancient tigers went through it along China’s narrow Gansu Corridor – which would thousands of years later form part of ‘the Silk Road’ trading route.
These findings were published in the Public Library of Science.