Neandertal DNA recovered from cave mud reveals that these ancient humans spread across Eurasia in two different waves.
Analysis of genetic material from three caves in two countries suggests an early wave of Neandertals about 135,000 years ago may have been replaced by genetically and potentially anatomically distinct successors 30,000 years later, researchers report April 15 in Science. The timing of this later wave suggests potential links to climate and environmental shifts.
By extracting genetic material from mud, “we can get human DNA from people who lived in a cave without having to find their remains, and we can learn interesting things about those people from that DNA,” says Benjamin Vernot, a population geneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
A few years ago, scientists showed that it’s possible to extract prehistoric human DNA from dirt, which contains genetic material left behind by our ancestors from skin flakes, hair or dried excrement or bodily fluids such as sweat or blood. Genetic analysis of ancient sediments could therefore yield valuable insights on human evolution, given that ancient human fossils with enough DNA suitable for analysis are exceedingly rare (SN: 6/26/19).