This is due to the combination of low species diversity and climatic amelioration.
2.
Birch forests were advancing across former herb tundra in Beringia by 14.3ka 14 C years BP ( 17k cal years BP ) in response to climatic amelioration, indicating increased productivity of the landscape.
3.
To date, nine intact, well preserved burials have been recovered from stratigraphic layers dating from ca . 18, 000 to 11, 000 BP, the majority of burials corresponding to a period of climatic amelioration from ca . 15, 000 to 13, 000 cal BP ( Final Epigravettian ).