1.2 Million Year Old DNA Resequenced

[SelfSim]

Mammoth molars yield the oldest DNA ever sequenced:

A genetic analysis of long-extinct Siberian mammoths has nearly doubled the record for the oldest DNA yet sequenced. The genetic material, from a creature that roamed frozen lands some 1.2 million years ago, pushes the study of ancient DNA closer to its theoretical limit—and reveals a new lineage of mammoth.

First estimate:

In the 1970s, Russian paleontologist Andrei Sher discovered a trove of frozen remains at several sites in northeastern Siberia, including a trio of mammoths. Based on the orientation of magnetic materials in the surrounding rocks and the types of rodents found buried alongside them, the researchers estimated that the mammoths had lived about 1.2 million, 1 million, and 700,000 years ago.

Verified using new method:

.. The ravages of time had degraded the DNA into many billions of short, fragmented sequences ..
To put those pieces together, researchers used the previously sequenced genomes of elephants and of much younger mammoth remains as a reference. It was a bit like “looking at the picture on the puzzle box,” says Love Dalén, an evolutionary geneticist at the Centre for Palaeogenetics in Stockholm and study co-author. When the researchers plotted the relationships between the older mammoths and the elephants and estimated how long it would have taken for their genes to diverge, the dates matched those provided by the earlier methods.

Hybridization with woolly mammoths to produce new subspecies:

The second mammoth, dated to about 1 million years old, was a steppe mammoth, the direct ancestor to woolly mammoths, the researchers report today in Nature. The third and oldest specimen, at about 1.2 million years old, belongs to a previously unknown lineage, which the researchers named Krestovka after a village near where it was found.
...
The researchers suspect the Krestovka mammoth entered North America about 1.5 million years ago, then hybridized with woolly mammoths about 1 million years later to produce the continent’s distinct subspecies.

 

[AV1611VET]

Crunch them numbers.

DNA Mutation Clock Proves Tough To Set

 

[jayem]

The article says that the DNA was fragmented and had to be, in effect, reassembled.But it shouldn’t be surprising that genetic material can withstand prolonged freezing. Just last year, a healthy girl was born from an in-vitro fertilized embryo, that had been frozen for 24 years. With modern cryoprotectant techniques, (and reliable deep-freeze equipment) frozen DNA should remain viable indefinitely.