<\/a>Courtesy Photo \/ Ned Rozell \n Elizabeth Hall holds the leg bone of a horse that is 765,000 years old. A paleontologist for the Yukon government, Hall helped extract the fossil from a Yukon gold mine during her first far-north field experience in 2003.<\/p><\/div>\n\t\t\t\t
In summer 2003, she was a student at Simon Fraser University in Vancouver when she applied for the Yukon Student Training Employment Program.<\/p>\n\t\t\t\t
That led her to step onto a small plane on a remote airstrip a few hundred miles northwest of Whitehorse. Thistle Creek is not far from Dawson City, the epicenter of the Gold Rush in the late 1800s that drew so many prospectors to northwestern Canada. The same stampede was responsible for much of the white settling of Alaska.<\/p>\n\t\t\t\t
On that summer day 19 years ago at Thistle Creek, Hall watched a scientist pry a rich brown bone fragment from between two lines of ash deposited by prehistoric volcanic eruptions. A researcher identified the bone as the metacarpal bone of a horse, which is sort of like one of our fingers.<\/p>\n\t\t\t\t
The geneticist handed the bone to Hall. The hard-as-ivory fragment was still cold with the memory of being frozen in place for who-knew-how many thousands of years.<\/p>\n\t\t\t\t
The scientists there at Thistle Creek were excited because they knew the fossil bones they had gathered that day — a few from horses and some from mammoth and mastodon — were quite old.<\/p>\n\t\t\t\t
The researchers had to wait a long time before the picture of the horse became unusually clear.<\/p>\n\t\t\t\t
Nine years later, a sample sawed out of the horse bone yielded the world’s oldest, most completely sequenced DNA genome.<\/p>\n\t\t\t\t
That meant that the scientists suddenly knew that horse was munching grasses and sedge at Thistle Creek 765,000 years ago. They also knew the horse was a male that galloped the frigid grasslands alongside mastodons, camels and lions.<\/p>\n\t\t\t\t
Hall compared extracting the exquisite DNA from the bone to finding a film of the horse’s life with no scenes missing.<\/p>\n\t\t\t\t
“You now know everything about this one particular creature,” she said.<\/p>\n\t\t\t\t