Wild bison, climb up a ledge on the Rocky Mountain Arsenal National Wildlife Refuge August 6, 2009.
(REUTERS/U. S. Forest Service)
The term for bison – the most successful mammals in the colonization of North America after the people came to the continent of Asia has long been a topic of discussion.
But a group of Canadian scientists, using genetic and geological information, recently were able to pinpoint a time frame of when these beasts came over the Bering land bridge.
According to a new study published in the Proceedings of the National Academy of Sciences, the Bison came to North America between 135,000 and 195,000 years ago – much earlier than the 640,000 years ago, is determined in the previous estimates.
More about this…
Bison, cars is threatened by the deep snow in Wyoming, Grand Teton
Hundreds of bison sent to slaughter than are the objections of the
Environmentalists protest against the hunting of bison plan in Poland
Bison apparently also did very well in their new home, multiply quickly in their number, the diversification and the dominant grazers on the plains of North America. They moved mammoths, Pleistocene horses, and other mammals that arrived on the continent earlier.
“They became very successful very quickly,” Duane Froese of the University of Alberta, lead author of the study, told the Alaska Dispatch News. “Outside man, it is pretty much the most successful mammals invasion in North America.”
The findings are highly dependent on DNA extracted from the oldest known bison fossil, which was discovered almost a decade ago in the vicinity of the Gwich’in native village of Old Crow in the canadian Yukon Territory.
The fossil was discovered under a layer of ash from a huge eruption that occurred about 130,000 years ago in the southwest of Alaska. The ash is, in principle, acted as a marker in the earth that allowed scientists to determine the age of the Yukon bison fossil and confirm it as the oldest known bison fossil in North America.
Expand / Contract
In this Feb. 4, 2017 photo provided by Grand Teton National Park, three bison hang on a plowed area of Antelope Flats Road, Grand Teton National Park, Wyo.
(Grand Teton National Park via AP)
Because radiocarbon dating doesn’t work past the age of about 40,000 to 50,000 years old, the DNA analysis was necessary. The use of new technology, researchers compared the DNA of the Yukon fossil with that of a younger fossil found near Snowmass, Colorado. Both fossils were then compared with dozens of young bison fossils.
From their research, the scientists were able to determine that all bison is a common ancestor of 135,000 195,000 years ago – during a period when the Bering land bridge was exposed. The scientists were also able to determine that bison migrated across the bridge in a second wave of 21,000 to 45,000 years ago.
“It’s kind of a long puzzle in the world of paleontology and paleobiology,” Froese said.