DNA Can Now be Extracted from Dirt! New Tech May Solve Many Mysteries of Human Origins
An amazing technological innovation in the study of DNA has been called a ‘game changer’ in the research into ancient humans and hominids. It may solve many of the mysteries that exist in relation to the origins of humans and could completely rewrite our family tree.
A new study published in the journal Science has revealed a technique that can extract human and hominid DNA from dirt – no bones needed! This means that by simply taking half a teaspoon of soil from a cave and running it through the new analysis, scientists will know if species of ancient hominids lived in that cave and who or what they were.
“This is pretty damn incredible,” said Rob Scott, an evolutionary anthropologist at Rutgers. Tom Higham, an Oxford professor who specializes in dating bones, called the discovery a “new era in Paleolithic archaeology.”
Paul Kozowyk, a PhD student working under the supervision of Marie Soressi, collecting sediment for genetic analyses at the archaeological site of Les Cottés, France. Credit: Marie Soressi.
Scientists have known for over a decade that DNA, which may have come from urine, feces, sweat, blood, semen or a decomposed body, can survive in ancient sediments, even for hundreds of thousands of years, but they had no way to analyze it. Just a teaspoon of dirt can contain trillions of fragments of DNA from dozens of different species.
However, research from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, discovered that they could cut through the clutter with a molecular ‘hook’ made from the mitochondrial DNA of modern humans. This means that essentially, they were able to pull out the fragments of DNA that specifically belonged to a human or hominid species.
The scientific team collected 85 sediment samples from seven archeological sites in Belgium, Croatia, France, Russia and Spain, covering a span of time from 550,000 to 14,000 years ago. With the new method, they were able to capture DNA fragments from Neanderthals and Denisovans, an enigmatic human ancestor that so far has only been found in single cave in Russia. They even identified Neanderthal DNA in a cave in Belgium where no bones had ever been found.
Denisova Cave in Russia, where the only trace of Denisovan DNA has been found (CC by SA 4.0)
“By isolating DNA directly from sediments, we can dramatically expand what we know about where people were, when they got there, and how long they stayed,” Beth Shapiro, an evolutionary biologist at the University of California, Santa Cruz, told ScienceMag.
It is expected that the new technique will now become a standard method of analysis in the field of archaeology, much like radiocarbon dating. The next step will be to examine archaeological sites that have stone tools but no evidence of who made them. Many mysteries can now be solved.
“It could also reveal even more hominid species that we have not found bones for,” reports SmithsonianMag, “creating an even more complete human family tree.”
Top image: Vindija Cave in Croatia where Neanderthal DNA was found in cave sediment (CC by SA 2.0)