As previously reported (here), the collection of African art of Richard Scheller (a leading biochemist and an executive vice-president at the biotech corporation Genentech) is currently on view at the de Young museum. The exhibition catalogue features an interesting essay about DNA analysis (pp. 288-289): a number of objects of Scheller’s collection has been tested to identify the species of tree used to create the works. The goal was to develop a process that could be used to authenticate pieces and to provide scholars with more information about their creation. “There is a constant issue around authenticity in African art, if the species of tree didn’t grow on the continent of Africa, then you might wonder if your object was authentic or not”, Scheller said to The Art Newspaper.
Working first with modern objects, Scheller and his team at Genentech, which funded the research, discovered that they could chemically extract and sequence DNA from dead wood. By comparing it with a public database of chloroplast (organelles found in plant cells) DNA, they were able to identify the species of tree. They then turned to the works in Scheller’s collection, removing just enough sawdust from the bottom of three sculptures to repeat the process used with the newer wood. The results were extraordinary: the team was able to extract DNA that was 100 to 200 years old, proving that it could still be found in materials that had been dead for many years. This was probably the first time that this process has been applied to a work of art made from wood.
Finding a species DNA match in the database presented a challenge, however. “When we made the DNA from the art objects, we found that we were only able to establish distant relatives,” Scheller says. “There are 300,000 species of plants on earth and only around 400 have been deposited in the database so far.” The team was unable to find exact species matches for any of the works, but a Jonga sculpture from the Democratic Republic of Congo returned the highest number of database matches; these pointed to the Madagascar rosy periwinkle, many species in this family can be found in Central Africa. The nearest relatives identified in the other two works, although more distant, were also from families of trees commonly found in Africa.
For Scheller, the process was a success. “That it’s possible to do this is the question that we were asking,” he says. “It is possible to take wood, make DNA and determine the species.” Although the database needs to expand before this process can be fully utilized. Once the database catches up, the possibilities for research are endless.
“In ten years, this could become a very powerful tool,” says Lesley Bone (chief curator at the De Young), who believes that it holds the promise of great discoveries for curators, from establishing material trade routes to understanding how materials shifted with tribal migration. Scheller agrees, citing reports of tribes that created certain sacred objects using particular species of trees. Comparing the DNA of these objects would make it possible to determine if they came from the same species, so confirming their shared provenance.
Does this signal a change in the way African art is authenticated? “In the future, yes,” Scheller says. “For now, no. It’s too new and it’s too sophisticated scientifically. I think it will take a while.”
Obviously, this is a very interesting scientific development – stimulated by somebody who has the technology at his disposal; kudos to him. But, as Scheller correctly states, it is all a bit ‘too new’. Without a database containing the DNA of all trees that grow in Africa, the technique is not very helpful (yet). Even if DNA analysis would find out the species of wood that was used for making a specific object, it would tell us not much about its authenticity – except, in a negative way, if the wood did not exist in the area the object is reportedly from. Furthermore, specialists at the Belgian Royal Museum for Central Africa are already able to identify Congolese wood species. They are, however, impossible to consult as a private researcher. But, as is noted in the catalogue, the tremendous biodiversity in Africa can make distinguishing specific species rather difficult (reference is made to the approximately 1,300 species in the Acacia genus). Personally, I think, for now, connoisseurship will remain the first and foremost way to appraise African art, although science will definitely come to play a more important role in the not so far future (an example here).
UPDATE: learn more in this lecture given at the de Young by Richard H. Scheller (introduced by Christina Hellmich) called Identification of Tree Species through the Analysis of DNA