DNA and genealogy for identification purposes

We devoted our two previous articles to the search to identify the skeleton found on 22 November 2003 in the Vanikoro fault. We recall that it lay buried in a mass of coral, on the ship La Boussole, commanded by Lapérouse. A thesis submitted in 2007 by Coranie Lutton for her state diploma as a doctor of dental surgery, which shows the extent of the work carried out on the skeleton, is a very interesting read.

The unknown man’s magnificent teeth: no cavities or fillings. A tooth lost post mortem.

The examinations carried out by the IRCGN (Institut de Recherche Criminelle de la Gendarmerie Nationale – National Gendarmerie Criminal Research Institute) point to a Caucasian male aged between 29 and 40, between 165 and 170 cm tall, with an old fracture of the left humeral diaphysis and a slight prognathism. The skeleton shows little musculature and remarkable dentition, which rules out the possibility that it was a sailor. The man could only be a scientist from a high social status who knew the rules of hygiene (he looked after his teeth) and sailed on La Boussole. The following candidates can be considered: Duché de Vancy, draughtsman, aged 32 (but we have seen that he was sent from La Boussole to the Astrolabe), Le Corre, surgeon, aged 29, Rollin, surgeon, aged 37, Mongez, entomologist, mineralogist, physicist, aged 36-37, Lepaute Dagelet, astronomer, aged 36. Two families, that of Lepaute Dagelet and that of Mongez, came forward to provide information about their ancestor.

The first point of comparison concerns facial morphology.

Jean André Mongez
Joseph Lepaute Dagelet
Reconstruction of the unknown by Elizabeth Daynes

Dr Yves Schuliar, forensic pathologist at the IRCGN, interviewed by Alain Conan, examined the measurements of the skeleton’s skull and the portraits of Mongez (both with large faces) and concluded that there was no incompatibility, but nothing more. Elizabeth Daynes, the sculptor responsible for the facial reconstruction, replied: “It’s true that there are similarities, but that doesn’t allow us to say that it’s him. Lepaute’s face looks finer.

Only a DNA comparison could identify the unknown.

Mitochondrial DNA (transmitted only by females) was extracted from the femur of the skeleton. The Lepaute and Mongez families then set about finding a descendant passed down only by women who would carry this famous DNA.

– Given the difficulty of carrying out these investigations and after having considered exhuming a descendant, the search for Lepaute was voluntarily abandoned. He was considered to be the last survivor, according to what were considered to be fanciful accounts. He is said to have been seen in several places after the shipwreck and to have died in 1794. There is nothing to give them any credence.

– As for the Mongez family, in 2006, Fabien Cler, president of the Sine Dolo Association, encouraged by Alain Conan of the Salomon Association, drew up a very complete family tree (more than five hundred descendants of the Mongez family) and submitted it to Dr Cathala of the University of Montpellier in order to identify the carriers of this DNA among them. Etienne Beaumont, forensic pathologist, coordinated the research.

Victor Diday (Grenoble 1841-1924), mayor and district councillor

Mongez had no descendants and in any case, being male, he could not pass on this DNA to his children. Fabien therefore started with Anne, a sister of Abbé Mongez, and worked his way down from woman to woman until a male child led to this line being abandoned. This led to Victor Diday, who died in Grenoble in 1924. All that remained was to find a descendant of Victor who might have kept a personal object that belonged to him. Michel Brun, his great-grandson, was contacted. He remembered an old family trunk containing an envelope bearing the title “Beard hair from my beloved father”. Once the envelope had been found, Michel Laffont (then Secretary General of the Lapérouse Albi France Association and a member of the Salomon Association) went to Mr Brun’s home in Bizanos (Pyrénées Atlantiques) on 4 February 2006 and handed over the beard hairs, which were then sent to Professor Eric Baccino and then to Professor Cathala, who had to extract mitochondrial DNA from them and compare it with the DNA on the skeleton.

But Mr Cathala went abroad and the study was entrusted to a replacement. We then learned that “there was no incompatibility” between Victor Diday’s DNA and that of the unknown person, but that the hairs had been contaminated by other DNA.

Fabien Cler resumed his research, and again using Anne Mongez as a starting point, found Albert Delabeye, born in 1892, who carried Mongez’s mitochondrial DNA. When Albert died in 1981, he left behind his razor.

The year was 2014. This time, Alain Conan and Fabien Cler have an appointment with Professor Philippe Charlier from Garches, a forensic pathologist and palaeopathologist, renowned for his work in identifying famous historical figures. This first contact gives Fabien and Alain hope that the analyses will be carried out seriously.

Charlier asked Etienne Beaumont to retrieve the report on Professor Cathala’s analyses, as well as the piece of the unknown man’s femur and Victor Diday’s remaining beard polish.

Lawnmower by Albert Delabeye (1892-1981)

The clippers supplied still contain a beard hair, but Philippe Charlier is more interested in the cells it may contain. The analyses are to be carried out in Barcelona.

The conclusion is, as for the previous analysis, “there is no incompatibility with Mongez”. Charlier added: “If it’s not Mongez, I’ll tell you”. This does not close the Mongez page definitively, as such research could have led to the conclusion of an incompatibility, but this is not the case.

Fabien Cler recovered the razor, but not the shards of femur or the remaining hairs from Victor Diday’s beard. Fortunately, Michel Brun had been asked to keep half of them as a precaution.

Research is still possible by exhuming bodies in Vénissieux (Delabeye and Veyron-Lacroix branches) and Grenoble (Marine Mongenet and her mother née Perrard). But before any bones can be removed, a number of conditions must be met: the remains must not be mixed with other bodies, which happens when several people are buried in the same plot. This also presupposes well-maintained funeral archives to obtain this information. Secondly, the agreement of descendants. In many cases, the first condition is met. For the second, Sine Dolo comes up against legal or administrative difficulties: agreement from the curators, authorisation from the public prosecutor.

The skeleton now rests in Brest

After being exhibited at the Musée de la Marine in Paris, the skeleton was forgotten for several years in the storerooms of a major Parisian museum. Alain Boulaire, a historian from Brest, urged the authorities to give it a burial in Brest, the expedition’s port of departure.

On 29 June 2011, the Ministry of the Navy buried the body in the Préfecture Maritime, with military honours, near the château-musée, under a compass rose created in several shades of marble by sculptor Joël Kerhervé. The coffin contains Vanikoro sand and glass beads from the Compass, entrusted to us by Alain Conan, as well as the skeleton’s DNA formula. Since 2018, visitors to the Museum have been able to approach the tomb. “This unknown sailor represents all the explorers who left Brest to discover our world and the ocean that we love so much,” says Alain Boulaire, comparing him to the unknown soldier who lies under the Arc de Triomphe.

Headstone (photo A.M. Guillot)

Will he remain unknown?

Fabien Cler recently discovered an astonishing bust of Jean André Mongez in the family of one of his descendants.

An astonishing bust of Jean André Mongez recently discovered by Fabien Cler in the family of a descendant Bringing back a skeleton, preserved for more than two hundred years in a marine environment, is a rare event in marine archaeology, and you can imagine the emotion of the divers faced with such an unexpected sight. For Alain Conan, after the discovery of the two ships, this discovery is a culmination and a kind of reward after thirty-five years of research. He was able to unite a whole team of enthusiasts around him and defied all the administrative and financial obstacles. Many thanks are due to him, as well as to the people mentioned in this article and all those who took part in the research on the Vanikoro site. Thanks also to the TV programme Thalassa and Georges Pernoud, who left us some magnificent images.

The presence of the skeleton in Brest, Lapérouse’s port of departure, is symbolic. Its stele represents the memory of this expedition, so dear to Louis XVI, and that of the sailors and scientists who set off on a crazy epic that was both humanitarian and scientific, braving the oceans in extreme conditions, culminating in this dramatic shipwreck.

Alain Conan’s last involvement before his tragic death, carried out with as much passion as ever, was the search for the identity of the skeleton. His personal conviction, given the many clues, was that it was Mongez.

Science is making steady progress in the field of DNA. Perhaps one day we will know his identity. His magnificent tomb will remain as a tribute to the sailors who died.

Anne Marie GUILLOT
Member of the ALAF Board of Directors
Secretary of the Sine Dolo association
Professor at the University of Bordeaux

Fabien Cler recently discovered an astonishing bust of Jean André Mongez in the family of one of his descendants.

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