The first 3 paragraphs actually sent a shiver through my spine....a shiver of fear at the possibilities of some disease spreading....a new pandemic.
By Roger Highfield, Science Editor
Last Updated: 1:42am BST 08/08/2007
Creatures that once lived eight million years ago have been successfully thawed from the ice of an Antarctic glacier, in an experiment that sounds like a scene from a science fiction film.
Scientists found the microorganisms in ice samples from ancient Antartic glaciers
The feat of revival was managed with as yet unidentified single-celled microbes and should pose no health issues, say the scientists
However, it does show that evolution of simpler organisms is complicated by thawing glaciers which allow ancient bugs to contribute their old genes to modern populations.
The finding is significant, said Kay Bidle, assistant professor of marine and coastal sciences at Rutgers University, The State University of New Jersey, because scientists didn’t know until now whether such ancient, frozen organisms and their DNA could be revived at all or for how long cells are viable after they’ve been frozen.
Working with Prof Paul Falkowski, Prof Dave Marchant of Boston University and Prof SangHoon Lee of the South Korea Polar Research Institute, Dr Bidle melted five samples of ice from the Transantarctic Mountains ranging in age from 100,000 to eight million years old to find the microorganisms trapped inside.
The results are reported in the Proceedings of the National Academy of Sciences.
"The young stuff grew really fast. We recovered them [the microorganisms] easily; we could plate them and isolate colonies. They doubled every couple of days."
By contrast, Dr Bidle said, the microorganisms from the oldest ice samples grew very slowly, doubling only every 70 days.
"I do not think the readership need worry about the reappearance of ancient bugs in the environment," said Dr Falkowski.
"But as Antarctic ice melts, ancient genes from these organisms almost certainly will find their way to the ocean and may be incorporated with modern microbes. This 'horizontal' gene transfer process has probably occurred many times in Earth’s history and almost certainly has influenced the evolution of microbes."
Not only were the microorganisms in the eight million year old ice slow to grow, the researchers were unable to identify them as they grew, because their DNA had deteriorated, as a result of cosmic rays that bombard the ice.
This decline was rapid so that every million years or so half the DNA remained and this find undermines suggestions that icy bodies - comets - that bombarded the Early earth could have imported genetic material from outside our Solar System.
In this way, the work limits the idea of panspermia, that life spread through the cosmos as seeds of genetic material moved about.
"The preservation of microbes and their genes in icy comets may have allowed transfer of genetic material among planets," they wrote.
"However, given the extremely high cosmic radiation flux in space, our results suggest it is highly unlikely that life on Earth could have been seeded by genetic material external to this solar system."
Dr Bidle said the finds were also relevant to the quest to find the remains of life on Mars: "Years of detailed work on geology and formation of the debris-covered glaciers in the Transantarctic Mountains in Antarctica by Dave Marchant and others have revealed similarities to what has been observed for sub-surface ice on parts of Mars. So, currently, it is the best proxy we have here on Earth for potentially similar environments."