A research team has discovered DNA from living bacteria that are more than half a million years old. This is the oldest example of a still-living organism. The discovery was made by Professor Eske Willerslev from the University of Copenhagen and his international research team.

All cells decompose with time but some cells are better than others at delay the aging process. Some organisms are capable of regenerating and thereby repairing damaged cells. These cells – their DNA – are important to the understanding of the process of how cells break down with age.

The research team have found ancient bacteria that still contain living DNA and it is the oldest finding of organisms containing active DNA on earth. The discovery was made after excavations of layers of permafrost in the north-western Canada, the north-eastern Sibiria and Antarctica.

The project is about examining how bacteria can live after being frozen for millions of years. Other researchers have tried to follow evolutionary development by focusing on cells that are in a state of deadlike lethargy. The new method that makes is possible to extract and isolate DNA-traces from cells that are still active. It gives a more precise picture of past life and evolution because they are dealing with cells that still have a metabolistic function – unlike “dead” cells where that function has ceased, says Eske Wilerslev.

After the fieldwork and the isolation of the DNA, the researchers compared the DNA to DNA from a worldwide gene-bank in the US to identify the ancient material. The researchers were able to place the DNA more precisely and to place it in a context.

There is a very long way from basic research to understanding why some cells can become that old but it is interesting to look at how cells break down and are restored and thus are kept over a very long period.

"These methods and results can be used to determine if there was ever life on Mars the way we perceive life on earth. Then there is the grand perspective in relation to Darwin’s evolution theory. It predicts that life never returnms to the same genetic level. But our findings allows us to post the question: are we dealing with a circular evolution where development, so to speak, bites its own tail if and when ancient DNA are mixed with new", says Eske Willerslev.

The researchers behind the discovery are: Professor Eske Willerslev, Sarah Stewart Johnson - Massachusetts Institute of Technology, Martin B. Hebsgaard - University of Copenhagen, Torben R. Christensen Lund University, Mikhail Mastepanov - Lund University, Rasmus Nielsen - University of Copenhagen, Kasper Munch - University of Copenhagen, Tina B. Brand - University of Copenhagen, M. Thomas P. Gilbert - University of Copenhagen, Maria T. Zuber - Massachusetts Institute of Technology, Michael Bunce - Murdoch University, Regin Rønn - University of Copenhagen, David Gilichinsky - Russian Academy of Sciences, Duane Froese - University of Alberta