Ancient DNA can be a powerful tool for helping us reconstruct the long-dead past. Most surviving genetic material comes from the bones and teeth of animals that lived in cold environments, where freezing temperatures help prevent decay. While hotter climates are seen as hostile to preservation, researchers have recently extracted DNA from a tooth found in South Africa that may date to around 50,000 years ago—the oldest yet retrieved from sub-Saharan Africa.

Despite many fossil-rich sites across the continent, such as South Africa’s coastal caves, few ancient DNA projects have been carried out because of the expectation of poor preservation. But that didn’t stop an international team of researchers who wanted to see whether it was possible to extract viable DNA from ancient skeletons across different time periods and sites in South Africa.

The results of their work are published in the journal Quaternary Science Reviews.