Old goats: 3,000 years of genetic connectivity of the domestic goat in Ireland

The domestic goat likely first arrived to the island of Ireland as part of the introduction of agriculture approximately 5900 years ago, and remains a part of the island's biocultural heritage. However, due to the challenges of differentiating goat remains from that of sheep using traditional archaeozoological approaches, there are few specimens specifically identified as goat. To address this, we employed genetic, proteomics, and archaeozoological techniques to assess faunal remains from the Late Bronze Age assemblage of Haughey's Fort (Armagh) and medieval assemblage of Carrickfergus (Antrim). We identify these specimens as goats using archaeozoology, proteomics and genetics, and additionally determine their molecular sex. Genomic data recovered from a Haughey's Fort goat reveals a three-millennia genetic connection between the Late Bronze Age (Haughey's Fort), medieval period (Carrickfergus), and the indigenous Irish breed extant today, the Old Irish Goat. We additionally find varying levels of inbreeding within goats from the settlement of Carrickfergus, suggesting possible mixed use of herds within medieval Irish society. While based on a limited sample size, our results demonstrate the continuing potential of combining archaeological and biomolecular techniques to clarify existing ambiguities and at the same time reveal new facets of the past.