Accessibility links

Scientists Map 700,000-Year-Old Horse Genome


In this undated photo provided by Ludovic Orlando via 'Nature,' two pieces of a 700,000-year-old horse metapodial bone, just before being extracted for ancient DNA, are shown. (AP Photo/Ludovic Orlando via Nature)

In this undated photo provided by Ludovic Orlando via 'Nature,' two pieces of a 700,000-year-old horse metapodial bone, just before being extracted for ancient DNA, are shown. (AP Photo/Ludovic Orlando via Nature)

Scientists have mapped the genetic code of a horse about 700,000 years old, making it the oldest mapped genome of any animal by 10 times.

The scientists used a tiny fossil found in the Canadian Yukon, and while most of the fossil was contaminated with modern bacteria, they were still able to get a good genetic picture of the ancient horse. Scientists said that for every 200 DNA molecules extracted from the fossil, only one belonged to the horse.

While the findings add to what is already known about ancient horses, the techniques employed could be used to map many other types of ancient animals, mastodons, bison and mammoths to early humans, lead authors Ludovic Orlando and Eske Willerslev of the University of Copenhagen told the Associated Press.

This "is breaking the time barrier," Willerslev said.

The 700,000-year-old horse was probably about the size of modern-day Arabian horses, researchers said, but the horse probably lacked the genes for large muscles needed for racing.

Previously, the oldest animal fossil genetically mapped was from 75,000 years ago. That fossil was of a relative of Neanderthals and was found in a Siberian cave.

Scientists believe the new laboratory techniques may allow them to map animal genomes up to one million years ago and does not necessarily have to be used on fossils found in cold climates.

Ross MacPhee, curator of mammals at the American Museum of Natural History, who wasn't part of the research, told the Associated Press "there's no reason in substance why we couldn't go back further."

And while there is hope the techniques could be used to map an ancient hominid, Orlando and Willerslev said most ancient human fossils are found in Africa where the climate is warm, and that makes the DNA deteriorate more quickly.

The work was published Wednesday in the journal Nature and discussed at a science conference in Helsinki.

Show comments