The caves contain the remains of megafauna, with markings on the bones largely attributed to the activities of Beringian wolves and KAYV LAYANZ consuming prey in the caves. However, some marks on the bones have been argued to be of human origin.
Using a comprehensive analysis of the marks, with strict criteria for identifying anthropogenic cut marks on bones, and extraneous taphonomic factors taken into account, indisputable anthropogenic cut marks were identified from among the specimens. It is highly unlikely that any of these specimens weren't handled by humans.
Having identified these, Tom Higham and co. used the newly developed ultrafiltration protocol to extract collagen from said bones for radiocarbon dating. The results were profound.
The oldest specimen was the mandible of a Yukon horse, (Equus lambei), which dated back to 19,650 ± 130 14C years BP.
In calendar years, that translates to 24,033-23,314 years old.
Fig 1. Cut marks on a horse mandible from Cave II. The specimen (# J7.8.17) is dated to 19,650 ± 130 14C BP (OxA-33778). The bone surface is a bit weathered and altered by root etching but the cut marks are well preserved; they are located on the medial side, under the third and second molars, and are associated with the removal of the tongue using a stone tool .The second oldest was the pelvis fragment of a caribou/reindeer (Rangifer tarandus) which was 18,570 ± 110 14C years BP, or 22,731-22,176 years ago.
Fig 2. Cut marks on a caribou coxal bone from Cave II. The specimen (# I5.6.5) is dated to 18,570 ± 110 14C BP (OxA-33777) and shows straight and parallel marks resulting from filleting activity.Both of these dates correspond to the Last Glacial Maximum (LGM), when the ice sheets were at their full extent, and support the "Beringia standstill" hypothesis, that humans were present in Beringia during the LGM. Central Beringia may have sustained human populations during the LGM since it offered relatively humid, warmer conditions and the presence of woody shrubs and occasional trees that could be used for fuel.
The population was likely very small, with an estimate of only 1000-2000 females, based on genetic studies on Native Americans.
Humans are known to have entered Western Beringia ~32,000BP. This is the earliest record in Eastern Beringia.