DNA Barcoding of Commercial Myrrh

DNA barcoding identifies a biological sample by sequencing a short standard stretch of its genome and matching it against reference sequences. This investigation applied the method, using the psbA-trnH region, to twenty five samples of myrrh bought as a commercial commodity, in order to find out which species of Commiphora the modern trade is actually selling.

The samples resolved to three species, Commiphora gileadensis, Commiphora myrrha and Commiphora edulis. Only about eight per cent matched the species named in the pharmacopoeia. In other words the traded material is neither uniform nor reliably the plant the standards specify, and a purchaser of myrrh is buying a category rather than a species.

That result is worth stating on its own terms before any historical question is raised. A resin harvested from related trees across a wide arid region, traded through many hands and sold by appearance and smell, turns out under genetic testing to be a mixture. The finding is about the present day supply chain, it is methodologically straightforward, and it is checkable by anyone willing to repeat the sequencing.

The pharmacopoeia figure is the part with practical consequence beyond the historical question. Where a standard names a species and the traded material largely does not match it, work resting on the assumption that a labelled sample is what it says, in pharmacology, in chemistry or in comparison with ancient descriptions, is resting on less than it appears to. The authors present the barcoding of samples at point of sale as the check that closes that gap.

The atlas holds this study because of a question it does not answer. Myrrh appears throughout the religious literature of the ancient Near East and the Mediterranean, in temple incense, in anointing oil, in burial preparation and in trade records, and the ancient sources name it as a single commodity. Which species that commodity was has never been established.

This investigation does not establish it either, and its own account is careful on the point: the result stands for the modern trade and does not reach the ancient question. No securely dated archaeological myrrh from any trade period has been analysed the same way, and until some is, the species behind the myrrh of antiquity is unestablished.

What the study does is remove an assumption. Because the modern commodity is demonstrably not one species, there is no longer any warrant for supposing that the ancient one was. That changes the status of the question rather than answering it. It is why the atlas records the ancient identification as unknown, meaning that nobody holds a position that could be argued against, rather than as debated, which would imply camps and a live dispute. The study is what the unknown points at, and what would close it is plain: sequencing of residue from a securely dated ritual or funerary vessel.