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Cryogenic Bank Of The Earth

November 06, 2003

The littoral plains of north-eastern Eurasia are covered with a thick layer of permafrost. This layer preserves seeds, spores and microorganisms. Some of them that are thousands and hundreds of thousands years old are still alive. The study of fossil life was supported by the Russian Foundation for Basic Research.

Conditions of the glacial epoch were favourable to cryogenic conservation of life. Roots, stems and seeds of higher plants, green algae, yeast and funguses, as well as spores of anophytes, falgellates protozoa and amoebas had stayed in the cold thickness for tens of thousands of years and still managed to preserve viability. Russian scientists from the Institute of Physicochemical and Biological Problems of Soil Science (Russian Academy of Sciences), the north-eastern research station of the Pacific Institute of Geography, Far East Branch, Russian Academy of Sciences (Yakutia) and the Institute of Cell Biophysics, Russian Academy of Sciences (Pushchino) are convinced that flora and microorganisms of the glacial epoch are quite able to get re-activated and to live under contemporary conditions. Moreover, the process is actually under way now.

Glaciers are always clad with dust. As it is blown by the wind, the surrounding areas are covered with a thick layer of dust, thus everything lying on the surface quickly becomes hidden deeply below. During the glaciation period, vegetative remains, spores and microorganisms sank into the ground at a speed of 1-2 mm per year. It was not only very cold but also dry at that time, therefore a great number of biological objects got into an ideal deep-freezer before they could rot. They could be preserved in the 'freezer' for tens or even hundreds of thousands of years. Besides, gophers also made their contribution. These rodents dug deep burrows and accumulated seeds and fetus of various plants there. Being sintered with ice, they were well-preserved. A large fossil burrow may contain from 400 to 600 thousand of seeds complimented with spores, protozoa, grubs of parasites, and concomitant microorganisms brought there by the rodents.

In the laboratory environment of common humidity and room temperature, spores of fossil anophytes and lichens, and sometimes seeds of higher plants - especially those preserved by gophers - extracted from the thawed soils manage to sprout. Funguses and bacteria that may be hundreds of thousands years old, come to life. These events taking place in a laboratory may happen - and obviously do happen - in the natural environment. The scientists observed the damaged spots of tundra overgrowing in the far north-east of Asia. First, there appear local plants and weeds that always accompany land erosion. As the frozen ground gets warmer, thaws and dries, local fauna is replaced with steppe plants. Forest-tundra lies far away, so the seeds of steppe weeds could not be brought there by the wind. In the researches' opinion, local flora is enriched due to the seeds that come out as the frozen earth thaws (there used to be cold steppe here during the glaciation period).

The active erosion process is currently under way on the seacoasts and the banks of rivers and lakes. Huge amounts of frozen earth come to the surface and start thawing, and ancient seeds, funguses and spores start to grow. In addition, global warming has been promised, which will also heat the permafrost up. Having studied a large amount of the facts, Russian researches evaluated the period during which various groups of organisms retain viability. For the seeds of higher plants, spores of anophytes, some species of protozoa this period slightly exceeds 30,000 years; funguses, yeast, green algae, bacteria and cyanic-bacteria maintain viability for hundreds of thousands of years or longer. Thus, many species that existed during the glaciation or even much earlier take part in the formation of contemporary biologic diversity of the permafrost zone, and even determine the structure of some vegetative communities.

Informnauka (Informscience) Agency