By Sharon Kingman
BioWorld International Correspondent
LONDON ¿ Relics of innumerable saints are spread far and wide throughout the Catholic churches and cathedrals of Europe, and venerated by the faithful. Exactly whom these skulls, ribs, finger bones and other body parts once belonged to is frequently a matter of debate among historians ¿ and now, the techniques of modern molecular biology are helping the church substantiate or disprove the oral and written histories associated with them.
The body said to be that of the evangelist Luke was recently subjected to this type of scrutiny. A team of scientists from Italy and Switzerland carried out tests to try to establish whether a body said to be that of Luke, which rests in Padua, Italy, had genetic similarities with people from Syria, where Luke was said to have been born.
Their results appear in a paper titled ¿Genetic characterization of the body attributed to the evangelist Luke¿ in the Proceedings of the National Academy of Sciences.
According to historical accounts, Luke was born in Antioch, in the Roman province of Syria, and died in Thebes, Greece, in A.D. 150, probably at age 85. In 338, his body was transferred to Constantinople (now Istanbul, Turkey) and by 1177 it had been taken to Padua.
In September 1998, a committee headed by Vito Terribile Wiel Marin, of the Institute of Pathological Anatomy at the University of Padua, opened the marble tomb where the body lay to obtain tissue samples for study. The tomb contained a lead coffin, which apparently fits exactly into the tomb in Thebes said to have been where Luke¿s body was originally placed.
The tomb in Padua contained the skeleton of a male, complete except for the skull. Although the skull was missing, some teeth lay loose in the coffin, and the scientific team removed two of these for analysis.
According to the web site www.traces-cl.com, the skull was taken in 1354 from the skeleton in Padua to Prague, the Czech Republic, where it is still on display in the Cathedral of St. Vitus. While the skeleton was exposed, the deacon of Prague Cathedral, together with a paleontologist, brought the skull from Prague to see if it articulated well with the atlas (the first vertebra). It did. Furthermore, the teeth that were later used for the genetic analysis also fitted sockets in the skull.
Guido Barbujani, professor of genetics at the University of Ferrara in Ferrara, Italy, and last author of the PNAS paper, told BioWorld International that his team became involved because it had experience with studying DNA in ancient tissue samples.
He said: ¿The problem is, in order to be sure that a body belongs to a certain person, you need some direct descendants of that person. That was evidently impossible in this case. So we studied mitochondrial DNA, to try to find out whether the genetic features of the body were compatible with someone of Syrian origin.¿
Mitochondrial DNA is also easier to recover and amplify from ancient samples because while there are only two copies of each gene in nuclear DNA, there are many copies of the mitochondrial DNA. Some types of contamination also can be ruled out, because mitochondrial DNA is highly variable. It can be compared with that of the scientists working on the project, although there is still the possibility that DNA from people who previously had handled the body could contaminate the samples.
A third reason for studying mitochondrial DNA, said Barbujani, is that, historically, men would have been the ones involved in going off to fight in campaigns ¿ while mitochondrial DNA is transmitted along the female line. ¿This therefore minimizes the impact of certain types of historical events ¿ migrations associated with military invasions ¿ and means that the population you study has a greater chance of resembling the past population that you would really like to be able to compare with the specimen,¿ Barbujani said.
As well as the mitochondrial DNA from the Padua body, the team collected and analyzed modern samples from Syria and Greece. Sequences from modern Turkish samples were also available. Barbujani said, ¿We then asked whether the body had a higher chance of belonging to the Syrian gene pool rather than the Greek gene pool, and to the Syrian gene pool rather than the Turkish gene pool. Statistical tests showed that a Greek origin was very unlikely, and statistically we were able to reject that hypothesis. On the contrary, because the Turkish and Syrian gene pools were more similar to each other, we were only able to say that there was a higher chance that the body came from Syria rather than the area that is now Turkey, but this difference was not statistically significant.¿
The results lead to two possible conclusions, Barbujani said. Either the body belonged to someone of Syrian origin, or the body may have been replaced ¿ either deliberately or by chance ¿ while it was in Constantinople.
¿The possibility that it is a replacement should be taken seriously, because the most likely radiocarbon date of the body is around A.D. 300. But there is a broad confidence interval around this date, so the body is still compatible with someone who died around A.D. 150, and this would accord with the official story of St. Luke.¿