An international team of scientists has identified DNA from the soil in a Georgian cave. Thanks to this, the researchers were able to restore the human genome at the age of 25 thousand years, without having any skeletal remains.
The Satsurblia cave in the west of Georgia was inhabited by people in different periods of the Paleolithic. However, the remains of only one human individual were found in it, dating back 15 thousand years. No human bones were found in other layers of the cave.
An international team of scientists led by Professors Ron Pinhazi, Pere Gelabert and Susanna Sawyer from the University of Vienna (Austria), as well as their colleagues from the Francis Crick Institute (Great Britain) used an innovative method that allowed identifying DNA from environmental samples and reconstructing the human genome from the Satsurblia cave layer dating back 25 thousand years.
Ancient DNA has already been extracted from the soil, but in the described case, the researchers were able to obtain not only the genome of an ancient cave inhabitant, but also to establish the environment in which he lived. It was also shown that this person contributed to modern Western Eurasian populations.
To confirm the results, the researchers compared the reconstructed genome with genetic sequences from the bone remains of the nearby Dzuzuang cave, obtaining definitive evidence of genetic similarity. This fact, according to scientists, confirms the reliability of the results and excludes the possibility of modern contamination of samples.
The researchers also managed to restore the wolf genome, which can be called the basic one for existing Eurasian wolves and dogs. It represents a previously unknown representative of these animals, probably belonging to the extinct Caucasian population.
The bison genome has also been reconstructed, which is also the basic one for modern populations. In the future, the team intends to learn more about the interaction between the extinct fauna and people who lived in the cave, as well as to study the impact of climate change on mammal populations.
The article was published in the journal Current Biology