Million-year-old mammoth genomes shatter record for oldest ancient DNA

Mammoth teeth preserved in eastern Siberian permafrost have produced the oldest DNA on record. The DNA was extracted from tooth specimens that are up to 1.6 million years old. The DNA identifies a new kind of mammoth that gave rise to a later North American species. The research pushes the technology close to its limits. Once an organism dies, its chromosomes shatter into pieces that get shorter over time. Eventually, the DNA strands become so small that — even if they can be extracted — they lose their information content. The mammoth teeth were preserved in the constant cold of permafrost, which slows DNA fragmentation.