Reconstruction of past ecosystems and climate using fossil DNA

The largest and coldest ice sheets on Earth are found in Greenland and Antarctica. Smaller ice caps are found on almost all continents, for example, in the Himalayas in Asia or the Andes in South America. It is only in connection with the drilling of ice cores in Greenland and Antarctica that researchers have gained access to the biology below the ice sheets, or the ecosystems that existed before the ice sheets were formed and grew large due to changes in the climate.

The ice core drilling provides access to the basal ice – the oldest ice near the bottom of the ice sheets – and thus provides access to genetic remnants of plants and animals that existed in these areas before the ice was formed.

Ancient biomolecules are preserved and adsorbed to the soil particles in the basal ice. When extracting and sequencing these molecules it is possible to describe the past ecosystems and their biodiversity.

By examining soil particles in the basal ice for DNA, it is possible to gain insight into which organisms lived in these places in prehistoric times. In this way, researchers can reconstruct past ecosystems from genetic remnants in the basal ice. The ice cores thus provide unique access to so-called molecular “fossils”, also called “fossil” DNA.

- Preserved fossil DNA in the ice
- Fossil DNA's potential and limitations
- Paleo-ecosystems and climate
- Combining biodiversity and climate parameters