Archeology and science always go together to discover our real origins, how the world used to be, what its vegetation was like, how, why and when species came to an end, among other things. And it seems that whenever you think you know “with certainty” something, a new discovery emerges and changes everything.
It is known that the modern human being had several ancestors to reach where he is today. However, it appears that not all of these ancestors were discovered. An example of this is the handful of mud that was buried under the ground of a cave for millennia. He produced the genome of an ancient human.
The analysis revealed that the genome was from a woman who lived 25,000 years ago during the last ice age. And as much as researchers don’t know much about it, it represents a pretty big scientific achievement. In other words, being able to identify ancient human populations even when there are no bones to be recovered.
In addition to this woman, the sample also gave DNA from species of wolves and bison. And an international team of scientists managed to put them in context of their population histories.
“Our results provide new insights into the Late Pleistocene genetic histories of these three species and demonstrate that direct DNA sequencing of sediments, without target enrichment methods, can yield informative ancestor data and phylogenetic relationships across the genome,” they said. The researchers.
Usually, the discovery of ancient DNA is based on bones, and a little luck. First, you need bones that have survived intact long enough to have preserved the DNA for several million years.
After that, it is necessary to find them and recover enough genetic material for the sequencing to be done. This is a very thorough job. Ancient DNA is able to fill more gaps in evolutionary history and not only of humans, but of other animals as well.
However, several archaeological sites have more evidence of the use of hominids than bones. For example, the Satsurblia cave in Georgia, USA. In it, artifacts like stone tools have survived time better than bones. This cave was used by ancient humans for thousands of years, and yet, only the genome of a single person at the site had been sequenced. It was from a human who had lived 15,000 years ago.
But environmental DNA, which can be found preserved in sediment, is increasingly proving to be an optimal way for researchers to learn about the past. It is deposited in feces or bone fragments that have been ground up.
So the team led by evolutionary biologist Pere Gelabert and archaeologist Ron Pinhasi from the University of Vienna, Austria, went looking for environmental DNA in the cave of Satsurbila. And they got six soil samples where they carefully found traces of genetic material.
Only a small fraction of a woman’s genome has been recovered. However, from this, researchers were able to infer that she was a member of a group of modern humans that until then was unknown.
The group in question is now extinct. But he contributed to current populations in Europe and Asia. This was discovered when the ancient genome was compared to modern human genomes.
“Our results demonstrate that sequencing ancient DNA from sediments can yield genome-wide data that is informative about ancestry. The genome-wide DNA of ancient sediments can open up new approaches to the study of entire ecosystems, including interactions between different species and aspects of human practices linked to the use of animals or plants”, concluded the researchers.