Will DNA swabs launch CSI: cargo scene investigation ?
By Traci Watson - Science Mag
Ceramic jugs known as amphorae were the cardboard boxes of ancient Greece. Produced in the millions, they contained goods that were shipped across the Mediterranean and beyond.
But what was in them ? In a new study that uses a DNA-based method inspired by crime-scene protocols, scientists say they've uncovered a cornucopia of cargoes, but other researchers are skeptical of the technique.
Shipwrecks and other sites have yielded plenty of intact amphorae. Maddeningly, nearly all are empty, devoid of obvious clues to what they once held. Researchers have scraped bits of ceramic from the vessel's interior to look for leftover genetic material.
In the new study, however, they also turned to a less destructive method straight from television'sCSI: swiping the amphorae with a swab.
The idea came from the Massachusetts State Police, whom the investigators called for leads.
A team led by maritime archaeologist Brendan Foley of the Woods Hole Oceanographic Institution tested the new protocol on nine 5th to 3rd century B.C.E. amphorae that had been languishing in a government storage room in Athens for more than a decade.
All had been hauled up in fishermen's nets before being handed over to the Greek government in the 1990s.
To reveal what the vessels once held, the researchers collected DNA from the amphorae and mixed it with snippets of DNA from a selection of plants. When amphora DNA stuck to one of these genetic probes, the investigators knew they'd found a match.
The scientists also sequenced amphora DNA, then searched a DNA database for the same sequences.
The results, published online last week by the Journal of Archaeological Science, suggest that swabbing works better than shaving the ceramic. And the data seem to show something less surprising as well: The ancient Greeks really liked olive oil. The team found that olive oil, olives, or some combination of the two were even more common in the amphorae than grape products such as wine.
Many of the amphorae also had traces of DNA from oregano, thyme, or mint, which may have been used to flavor and preserve foods. Most common of all was DNA from the juniper bush, "not something you typically think of in the ancient Greek diet," Foley says.
"Maybe a whole lot of juniper berries were added to food and drink in the ancient world."