A widely reported hominin jawbone, found in a Tibetan cave and dated to 160,000 years ago, was announced this week. The fossil jawbone was identified as" Dennisovan", according to the investigative team. The dating of the jawbone was ascertained by the UT (uranium-thorium) method.
This fossil is significant in a number of respects:
Method of attribution. The Denisovan lineage to date has been identified only genetically, through DNA via an intricate process. There was no usable DNA remaining on this fossil but the attribution was made buy an analysis of collagen protein from the two teeth found in the jawbone. The collagen protein was determined to be similar to that found in the previously discovered remains of individuals attributed to the Denisovan lineage.
Denisovan dispersal. The Denisova Cave in Siberia lies at an altitude of 700 meters or approximately 2275 feet. The Tibetan cave in which the jawbone was found has an altitude of 3280 meters or more than 10,000 feet. The distance between these two locations and the considerable difference in altitude indicate a far wider dispersal of these people than was known before.
Adaptation to high altitude. It has been found that contemporary Tibetans, living at altitudes in excess of a mile, have a gene mutation permitting lower levels of oxygenated blood and able to exist comfortably at high altitudes. It is hypothesized the Tibetan Homo sapiens of today inherited this mutation from Denisovan ancestors.
Both the New York Times and the journal Nature have well illustrated articles on this significant find. The Times story is headlined " Denisoan jawbone found in Tibetan Cave" and the commentary in Nature is headlined "Biggest Denisovan fossil yet spills ancient human’s secrets".