Ancient horse bone yields oldest DNA sequence

Ancient horse bone yields oldest DNA sequence

A fragment of a fossilised bone thought to be more than 700,000 years old has yielded the genome of an ancient relative of modern-day horses.

This predates all previous ancient DNA sequences by more than 500,000 years.

The study in the journal Nature was made possible because the bone was found preserved in Canadian permafrost following the animal's demise.

The study also suggested that the ancestor of all equines existed around four million years ago.

A remnant of the long bone of an ancient horse was recovered from the Thistle Creek site, located in the west-central Yukon Territory of Canada.

Palaeontologists estimated that the horse had last roamed the region sometime between a half to three-quarters of a million years ago.

An initial analysis of the bone showed that despite previous periods of thawing during inter-glacial warm periods, it still harboured biological materials - connective tissue and blood-clotting proteins - that are normally absent from this type of ancient material.

http://www.bbc.co.uk/news/science-environment-23060993