Nuclear DNA from sediments unlock human history

The department of ancient Nuclear DNA has revealed important aspects of human history. It includes the relationships with our distant cousins, Denisovans and Neandertals.These studies have dependent on the DNA from bones and teeth, which store and protect it from the environment. The skeletal remains are exceedingly rare, leaving large parts of human history inaccessible to genetic analysis.

Researchers at the Max Planck Institute for Evolutionary Anthropology developed new methods for enriching and researching the human Nuclear DNA from sediments, which are abundant at almost every archaeological site. Recently the mitochondrial DNA has been restored from archaeological sediments which are of limited value for studying population relationships. The advent of Nuclear DNA analyses of sediments provides new opportunities to investigate the deep human past.

They extracted the ancient human DNA from the sediments, the scientists had to be careful to avoid the considerable amount of DNA from other mammals, such as bears and hyenas. Benjamin Vernot, the first author of the study said that there are lots of places in the human genome that are very similar to a bear’s DNA. They targeted regions in the genome where they could be confident of isolating only human DNA, and they also designed methods to measure their success in removing non-human DNA. They also wanted to be confident that we weren’t looking at some unknown species of hyena.

The scientists used more than 150 sediment samples from three caves. Two of these are Chagyrskaya and Denisova Caves in the Altai Mountains of southern Siberia which previous studies had analyzed DNA from bones. The authors were able to compare the DNA from sediments to the DNA from bones. Matthias Meyer, the senior author of the study said that the techniques developed are very new, and they wanted to be able to test them in places where we knew what to expect. DNA from the sediments are closely related to genomes retrieved from bones from those sites, giving them confidence in the robustness of their methods.