Preserved fossil DNA in the ice
Before the drilling of deep ice cores took place, fossil finds from ice-free areas supplied material to describe past warm climatic periods. Ice cores drilled in Greenland and Antarctica now provide access to frozen molecular remnants – “fossil” DNA – from the basal ice, which can be dated hundreds of thousands of years back in time.
By applying genetic methods to the basal ice from the deep ice cores it is possible, through “fossil” DNA from prehistoric organisms, to gain insight into the ecosystems of previous warm periods. These warm period ecosystems are interesting as it gives researchers the opportunity to compare current climate change with changes that occurred more than 100,000 years ago.
”Fossil” DNA should not be seen as a statically preserved molecule. From the moment an organism dies, its DNA decays and fragments. In frozen conditions the decomposition process goes slowly, while DNA-decomposing enzymes and chemical processes work much faster in warm conditions. If the DNA is bound to soil particles in dry or cold ice, or permafrost, the decomposing effect of enzymes will be lessened because the charges of the soil particles may have a stabilizing and protectingeffect on the DNA.
The ”fossil” preserved DNA consists of remains of the genomes of dead organisms, which can be propagated and studied for both prehistoric climatic conditions, biodiversity and the composition of ecosystems.
Ice Core Drilling Projects
For more information on the topic please contact Astrid Schmidt