Looking for human relatives
Human-made tools and other artifacts are abundant enough in prehistoric sites, scientists say that human skeletal remains are scarce. So researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, decided to go hunting for human DNA instead. They collected the ancient mud from seven archaeological sites in Europe and Asia, finding DNA fragments that belonged to a variety of mammals, including woolly mammoths and cave bears, as well as some DNA from extinct human lineages. Their work is detailed in the April 27, 2017, issue of the journal Science. [Read the full story on the search for human DNA]
Here, the view of the valley from the Caune de l'Arago archaeological site in France.
Svante Pääbo points to the location of a sediment sample collected at the site of Caune de l'Arago, France, from a layer dated to 450,000 years ago.
Svante Pääbo shows the location of a sediment sample collected at the site of Caune de l'Arago, France, from a layer where a 560,000-year-old tooth from an extinct human relative was discovered in 2015.
The entrance to the archaeological site of Chagyrskaya Cave in Russia, where the researchers took sediment samples for DNA analysis. They found DNA linked to Neanderthals in their samples.
View of the valley from the Chagyrskaya Cave archaeological site, Russia.
A stratigraphic profile of Chagyrskaya Cave, Russia, from which sediment samples were collected for genetic analyses.
Across the world
View of the archaeological site of Trou Al'Wesse, Belgium. The scientists found DNA linked to Neanderthals in samples collected from this cave, though no actual skeletal remains from hominins have been found in those layers.
Layers of time
Over time, layers of sediment and any remains from human or other activity form on top of the ground only to be covered up by the next round of activity. In that way, when scientists take cores or other vertical samples of sediments, they can view a window back in time. Here, the geological layers of Trou Al'Wesse, a large cave in Belgium. The study scientists collected samples from the different layers, or strata, in order to run genetic analysis.
Becky Miller samples sediment for genetic analyses at the archaeological site of Trou Al'Wesse, Belgium. [Read the full story on the search for human DNA]
Marie Soressi samples sediment for genetic analyses at the archaeological site of Les Cottés, France. DNA from several mammals was found at this site: woolly mammoths, woolly rhinoceroses, cave bears, cave hyenas and others.
The archaeological site of Les Cottés, France.
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Jeanna served as editor-in-chief of Live Science. Previously, she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species. She also received an ocean sciences journalism fellowship from Woods Hole Oceanographic Institution.