From remains to relatives: aDNA reveals family groups in a Roman cemetery
- DATE WRITTEN:
- READING TIME: 2 minutes
- AUTHORS: Caz Adams (Community Engagement Officer) and Sharon Clough (Human Remains Specialist)
Excavations at Childrey Warren, Oxfordshire, revealed an ancient settlement containing an array of historical artefacts, alongside more than 30 human burials dating to the Iron Age and Roman periods. Ancient DNA analysis, conducted on eight individuals from the cemetery, revealed the presence of two distinct family groups.
Individuals buried in the small Late Roman rural cemetery, which dates to the 4th century AD, ranged from newborn to older adults (45 years and older). Burial practice included one decapitated individual with the skull placed below his feet.
Ancient DNA, or aDNA, is genetic material extracted from archaeological specimens. It can be preserved in bones, teeth, hair, sediments, ice and other organic archaeological materials. In humans, it confirms genetic ancestry and direct family relationships – blood relatives! For example, sequencing aDNA has revealed interbreeding between Neanderthals and modern humans, reshaping our understanding of human evolution.
The preservation of aDNA in human bone depends on environmental conditions such as temperature, humidity and soil chemistry. When preparing samples, a small piece of human bone (commonly an ear bone) is crushed into powder, which is then cleaned to remove any contaminants, including dirt, bacteria and other microbes. This is done using a special enzyme that breaks down the cell walls of the cells, releasing the aDNA for genetic testing.
When analysis of genetic relations and ancestry was conducted on the eight individuals from this cemetery, we identified two family clusters involving six closely-related individuals, one of which possibly spanned four generations. Within one family cluster, study of the aDNA revealed sisters, paternal first cousins, and paternal and maternal uncles. Two further individuals were also found to share some genetic links with one of these family groups.
The majority of the individuals carried ancestry broadly consistent with that found in Iron Age Britain, indicating a continuation of genetic ancestry into the Roman period. One adult male had genetic ancestry which included a contribution consistent with continental sources, suggesting his lineage had European origins.
The genetic results point to a Late Roman community burying their relatives in this small cemetery, but nevertheless in contact with communities elsewhere. By combining aDNA with osteology and stratigraphy, studies such as this one provide insights into different aspects of life and death during the Late Roman period in Britain.
Ancient DNA is revolutionising our knowledge and understanding of the people of the past, helping us to answer poignant questions about who was buried and how they were related to one another.
