|1/2. Large fossil steppe bison skull with both horn cores recovered at Quartz Creek. Photograph: Government of Yukon|
University of California - Santa Cruz. Scientists using evidence from bison fossils have determined when an ice-free corridor opened up along the Rocky Mountains during the late Pleistocene. The corridor has been considered a potential route for human and animal migrations between the far north (Alaska and Yukon) and the rest of North America, but when and how it was used has long been uncertain.
The researchers combined radiocarbon dating and DNA analysis to track the movements of bison into the corridor, showing that it was fully open by about 13,000 years ago. Their findings, published June 6 in Proceedings of the National Academy of Sciences, indicate that the corridor could not account for the initial dispersal of humans south of the ice sheets, but could have been used for later movements of people and animals, both northward and southward. [...] phys.org / Link 2