After death, DNA begins to degrade.

The molecular chains that encode genetic information break down under the influence of bacterial action, water, oxygen, and time.

In most burial environments, DNA is effectively destroyed within a few thousand years.

The remarkable preservation that allows ancient DNA research to succeed requires specific conditions: cold temperatures, low humidity, or particular chemical environments that slow or prevent the degradation process.

The permafrost of Siberia — the permanently frozen ground that underlies vast areas of the region — is among the best environments in the world for ancient DNA preservation.