bison-1581895_640

(Pexels CC0)

The bison’s arrival in North America from Asia was an ecologically significant event, but its timeline remained a mystery—until now. The mystery started to unravel when researchers found a bison fossil dating about 130,000 years old in northern Yukon—the oldest known fossil of the large mammal in North America. They compared the genomes of the Yukon fossil and another fossil from Colorado, USA, to DNA samples from 44 other Siberian and North American bison specimen. Their findings showed a common maternal ancestor for the North American bison dating 195,000 to 135,000 years ago, coincident with a period of low sea level and the emergence of the Bering Land Bridge, suggesting that bison first arrived in North America during this time.

Authors:

Duane Froese, Mathias Stiller, Peter D. Heintzman, Alberto V. Reyes, Grant D. Zazula, André E. R. Soares, Matthias Meyer, Elizabeth Hall, Britta J. L. Jensen, Lee J. Arnold, Ross D. E. MacPhee, and Beth Shapiro

Corresponding author:

Duane Froese, Earth and Atmospheric Sciences, University of Alberta, Edmonton, Email: duane@ualberta.ca

Original paper published in PNAS on March 13, 2017.