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Teeth belonging to members of an extinct branch of the human family tree were discovered in a cave.
BEACON TRANSCRIPT – Ancient teeth shed light on human relatives after they were discovered in southern Siberia. The teeth were discovered alongside a finger bone back in 2008 in the Denisova cave located in the Altai Mountains of Siberia and they have been identified by scientists as the remains of a caveman known as a Denisovan.
The Denisovans belong to an extinct branch of the human family tree that shared a common origin with the Neanderthals but were found to be very genetically distinct from them. In fact they were as different from the Neanderthals genetically as the Neanderthals were from modern man.
Modern man and the Denisovan obviously share some common ancestry but little was known about this mysterious extinct branch of the human family tree. After the discovery of the molars and the bone fragment, DNA analysis was used to examine the genetic specificities of the Denisovan. This helped scientists figure out if and how the ancient cavemen contributed genetically to the evolution of modern man.
Using DNA analysis of the Denisovan genome they found that the Denisovans contributed with roughly 5 percent of their DNA to the genomes of modern day people in Oceania and with about 0.2 percent of their DNA to the genomes of Native Americans and of people living on mainland Asia.
It is not clear as of yet whether Denisovans were a completely different species but the DNA evidence shows that they interbred with the Neanderthals and helps explain the origins of some of the traits humans have today. For example the adaptability that Tibetans have developed in order to live at high altitudes where the oxygen in the air is limited has been proven to come from the Denisovans.
Analyzing the two molars found in the Siberian cave also give scientists other important clues about the cavemen. Unlike the molars of Neanderthals and modern humans, the teeth found in the cave were significantly larger and lacked certain traits such as raised points on the crowns of molars, which would indicate that they in fact came from a different group.
Both the molars and the bone fragment have been tested and seem to belong to three different individuals of the same species. The DNA samples differed enough from one another to give scientists enough reason to believe that they came from different cavemen. This now gives the scientists the first opportunity to study Denisovan genomes from different individuals.
Image source: www.wikimedia.org
