Oldest Genome From a Living Creature Sequenced: A 700,000-Year-Old Canadian Horse

Researchers from the Center of GeoGenetics at the Natural History Museum of Denmark and the University of Copenhagen have officially sequenced the oldest genome from any living creature. The subject of interest? A horse. 

Before this study, the oldest DNA sequence belonged to a polar bear aging somewhere between 110,000 years and 130,000 years old.

The genome was sequenced from little bits of DNA saved in the bones from a horse in Yukon, Canada that lived between 780,000 and 560,000 years ago. Despite the luxury of having permafrost store the DNA and bones relatively well, team members did not get their hopes up until amino acids, peptides, and proteins were found. Only then did it seem hopeful that the necessary DNA needed for a sequence existed.

"Sequencing the first genome from the Middle Pleistocene was by no means straightforward," says Dr. Ludovic Orlando, a member of the research team responsible for the findings.

"Because 700,000 years of evolution and damage, it is not something that does come without any modification to the DNA sequence itself. We had to improve our ability to identify modified and divergent ancient horse sequences by aligning them to the genome of present day horses," says professor Eske Willerslev.

The genome sequence allows the scientists to compare the evolution of DNA mutations within horses. According to results stemming from this genome, Przewalski's horses, radical horses from the Mongolian steppes that once dwindled in population, are genetically viable and tend to grow in between periods of extreme cold when there is plenty of grass. Essentially, they need not be condemned so soon.

"This kind of study is giving us novel views that show us the nuts and bolts of how evolution is working," says Alan Cooper, director of the University of Adelaide's Australian Center for Ancient DNA. 

"The results of the studies and the applied techniques open up new doors for the exploration of prehistoric living creatures. Now with genomics and proteomics, we can reach ten times further back in time compared to before." said Willerslev. 

You can read the full published study detailing the genome sequence of the 700,000-year-old horse online in the journal Nature.