Polar research: Reports and findings

Dead for 32,000 years, an Arctic plant is revived

(Nicholas Wade/New York Times, 20 February 2012) -- Living plants have been generated from the fruit of a little arctic flower, the narrow-leafed campion, that died 32,000 years ago, a team of Russian scientists reports. The fruit was stored by an arctic ground squirrel in its burrow on the tundra of northeastern Siberia and lay permanently frozen until excavated by scientists a few years ago. This would be the oldest plant by far that has ever been grown from ancient tissue. The present record is held by a date palm grown from a seed some 2,000 years old that was recovered from the ancient fortress of Masada in Israel.

The new report is by a team led by Svetlana Yashina and David Gilichinsky of the Russian Academy of Sciences research center at Pushchino, near Moscow, and appears in Tuesday’s issue of The Proceedings of the National Academy of Sciences of the United States of America. “This is an amazing breakthrough,” said Grant Zazula of the Yukon Paleontology Program at Whitehorse in Yukon Territory, Canada. “I have no doubt in my mind that this is a legitimate claim.” It was Dr. Zazula who showed that the apparently ancient lupine seeds found by the Yukon gold miner were in fact modern. ...

The Russian researchers excavated ancient squirrel burrows exposed on the bank of the lower Kolyma River, an area thronged with mammoth and woolly rhinoceroses during the last ice age. Soon after being dug, the burrows were sealed with windblown earth, buried under 125 feet of sediment and permanently frozen at minus 7 degrees Celsius. Some of the storage chambers in the burrows contain more than 600,000 seeds and fruits. Many are from a species that most closely resembles a plant found today, the narrow-leafed campion (Silene stenophylla).

Working with a burrow from the site called Duvanny Yar, the Russian researchers tried to germinate the campion seeds, but failed. They then took cells from the placenta, the organ in the fruit that produces the seeds. They thawed out the cells and grew them in culture dishes into whole plants. ... They grew 36 ancient plants, which appeared identical to the present day narrow-leafed campion until they flowered, when they produced narrower and more splayed-out petals. ... The Russian team says it obtained a radiocarbon date of 31,800 years from seeds attached to the same placenta from which the living plants were propagated. ...

Eske Willerslev, an expert on ancient DNA at the University of Copenhagen, said the finding was “plausible in principle,” given the conditions in permafrost. But the claim depends on the radiocarbon date being correct: “It’s all resting on that — if there’s something wrong there it can all fall part.” ...


Posted by Amanda Graham – 20 February 2012; 8:38:40 PM – Permalink