Scientists Recover Ancient DNA From Caves
Researchers used bones or tissues to trace ancient DNA. Today, however, no bones are required. Scientists can sift through clay and sand to isolate human DNA.
The new technique was described in a study published in the journal Science. It promised to open new research avenues regarding human prehistory. Adam Spiel, a population genticist from the Cold Spring Harbor Laboratory, said that the process was similar to "discovering that you can extract gold dust from the air." Other scientists were equally as excited about the prospect. David Reich, a genetics professor from Harvard, said that the paper was "absolutely amazing and exciting."
The New York Times noted that studying the genes of ancient humans like the Neanderthals needed scientists to recover DNA from fossils. These fossils can be very hard to find. Because of this limitation, research on human ancestry has been very difficult.
However, recent developments in technology made it possible for researchers to look for genetic signposts from sediments. For the most part, DNA does stick to minerals in decayed plants in soil. It was not until recently that scientists were able to fish out gene fragments from the debris. After all, bits of ancient human genes make up just a minute part of the DNA floating around soils and caves, where most ancient people were believed to have lived.
Palm Beach Post reported that to extract ancient human DNA, scientists had to refine a method previously used to find plant and animal DNAs. They focused instead on mitochondrial DNA, which is passed down the maternal line. This is particularly important as it tells them how closely related species are. By analyzing damaged molecules, they were able to separate ancient genetic material.
By enriching samples of human-like DNA, scientists were able to detect Denisovan traces. This mysterious lineage was first discovered in a Siberian cave. In a crucial turn of events, scientists also discovered Neanderthal DNA in the Trou Al'Wesse cave in Belgium. No human bones were ever found in this area before. Stone artifacts and animal bones with cut marks, however, strongly suggested that people visited it.
The new method of recovering DNA could help scientists expand their knowledge of Denisovans. In the long run, it will also help them learn more about ancient human civilizations.