Genetic characterization of Pompeii and Herculaneum Equidae buried by Vesuvius in 79 AD.

This research uses DNA analysis to identify the species and ancestry of six horse-like animals that perished in the eruption of Mount Vesuvius in 79 AD. The results show that the animals from Pompeii were horses and mules, with one potentially representing an ancient, previously unknown lineage.

Investigation and Methodology

• The researchers began by extracting DNA from the skeletal remains of five equids (a family of mammals that includes horses, donkeys, and zebras) from Pompeii and one horse from Herculaneum. These were animals that had been buried during the eruption of Vesuvius in 79 AD.
• Amino acid racemization, a process that often occurs after death and can indicate the presence of DNA, was found in the samples.
• The team then focused on post-mortem base modifications to the DNA, which were ruled out by sequencing a 146 base pair fragment of the 16S rRNA mitochondrial gene. This is a gene that is often used in evolutionary biology to identify species and trace lineage because it is present in all species and changes slowly over time.

Results

• The researchers then sequenced a 370 base pair fragment of the mitochondrial DNA control region. This facilitated the construction of a phylogenetic tree, or diagram showing the hypothesized relationships and evolutionary paths of the animals.
• Additional DNA analysis of the nuclear genes (epsilon globin, gamma interferon, and p53) provided deeper insights into the lineage and relationships of the specimens.
• Through this analysis, the researchers determined that the bones belonged to horses and mules rather than donkeys or crossbreeds.
• Interestingly, one sample (CAV5) appeared to belong to a haplotype (a set of DNA variations) that is either not present in the GenBank database or that has disappeared over time. This sample showed closer resemblance to donkeys, suggesting that it might represent a lineage that evolved within the Equidae family much earlier than horses.