We can understand the prehistoric past only by interpreting the things people left behind. Finds don’t come with words to explain how an object arrived at a site or why people decorated a pot a certain way. So there’s a lot of detail about prehistoric people’s lives, cultures, and interactions that these objects can only hint at. In recent years, however, the DNA of ancient people has added depth and detail to the information gleaned from artifacts. Genomic studies, it turns out, can tell us who the people using those artifacts were and where they came from.

Most of the genomic work so far has been relatively small-scale due to the massive effort involved in sampling and processing ancient DNA, but two new studies add several hundred prehistoric genomes to the existing data.

“The two studies published this week approximately double the size of the entire ancient DNA literature and are similar in their sample sizes to population genetic studies of people living today,” Harvard Medical School geneticist David Reich, who coordinated the studies, told Ars. “We can pick out subtleties in ancient demographic process that were more difficult to appreciate using the small sample size studies available before.”