Researchers Find Human DNA in Cave Floor Sediments

BEACON TRANSCRIPT – A team of scientists succeeded in extracting DNA from Neanderthals and Denisovans from caves which contained no remains of our extinct ancestors. The DNA was found in the sediment floors of the caves in which these ancient populations lived.

Gathering DNA information from sites with no skeletal remains

Researchers have always been struggling with the challenge of finding out more about our history as a species. This has been tough as they needed bones and remains from our ancestors which could provide the DNA needed to gather information about their way of life and their history.

Now, researchers retrieved Neanderthal and Denisovan DNA from caves which contained no fossils or skeletons of these two populations. Between 14,000 and 550,000 ago, the hominins lived in these caves, and they left DNA in the sediments gathered in these shelters.

Thus, they were able to detect the presence of these specimens in the caves even though they did not leave any physical trace. Thus, researchers think that sediment analysis should become widely used from now on, as it might contain DNA which signals the presence of different life forms.

Scientists knew that sediments have this ability to absorb DNA from bones or fossils and keep it even after decomposition. However, it is not so easy to extract the desired genetic information from them. Sediments absorb any kind of DNA.

Thus, Neanderthal and Denisovan gene are captured in the cave floor together with many other samples of genetic information. Sometimes, the amount of such information might be overwhelming. Thus, researchers decided to investigate and see what they can find in such deposits.

Scanning sediments in cave floors for human DNA

For the study, they chose seven archaeological sites in Europe with no records of hominin remains. The sites are situated in several countries, which include Spain, Croatia, Belgium, France, and Russia. Initially, researchers extracted DNA from mammal species such as the woolly mammoth, the cave hyena, the cave bear, and the woolly rhino.

The amount of animal DNA was quite abundant but, when they started looking specifically for ancient human DNA, their attempts were successful. Thus, they discovered nine instances of hominin DNA in sediments from four archaeological sites. Eight of these samples belonged to Neanderthals, while the last one belonged to Denisovans.

This is a great discovery. Now, archaeologists might find traces of ancient humans in places with no skeletal remains if they just look for human DNA in the sediments. They gathered all their findings in a study which can be found here.
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