Oldest DNA exposes ancient ecosystems <newscientist.com>

DNA from the animals and plants that populated Siberia and Alaska up to 395,000 years ago has been recovered from specks of permafrost.....

Eske Willerslev and his team at the University of Copenhagen in Denmark sampled permafrost along 1200 kilometres of Siberia's Arctic coast. They drilled to depths of 31 metres, removed cores of soil, and then extracted any DNA remaining in the frozen earth......

The permafrost contained DNA from eight species of mammals including woolly mammoth, steppe bison and musk ox, dating back 30,000 years, as well as 28 families of trees, shrubs, mosses and herbs, some of which lived 300,000 to 400,000 years ago.

By drilling at widely spaced locations, and at different depths, the team could recreate ancient landscapes and watch them evolve. "From just two grams of soil, you can obtain a meaningful sample of the ecosystem," says Willerslev.