Where did the ivory come from from the 500 year old wreck of the Portuguese merchant ship “Bom Jesus”? An analysis of the material now provides insights into the trade in the “white gold” at the time and into the history of the tragic relationship between humans and elephants. According to this, the ivory of the shipload of forest elephants came from West Africa and thus probably from the area around the Portuguese bases there. The genetic analyzes show that most of the elephant groups to which the animals belonged no longer have any present-day descendants. Apparently, hunting and habitat loss have wiped these lines out over the past 500 years.
The destination of the Portuguese caravel was India – but the journey of the Bom Jesus was to end before the southwest coast of Africa: The merchant ship sank in 1533 with its precious cargo and then slumbered for centuries on the seabed off the coast of what is now Namibia. The wreck was discovered in 2008 and initially large amounts of gold and silver coins were recovered. But later it turned out that more than 100 elephant tusks were part of the ship’s precious cargo. As the researchers working with Alida de Flamingh from the University of Illinois in Urbana-Champaign report, ivory was already a central component of the transcontinental trading system that connected Europe, Africa and Asia by sea.
On the trail of 500 year old tusks
“The ivory of the Bom Jesus was stowed on a lower floor of the ship under a heavy load of copper and lead ingots,” says de Flamingh. “When the ship sank, the ingots pressed the tusks into the seabed, which led to the good conservation status, which also includes the DNA of the animals from which the ivory came,” explains the scientist. In order to learn more about the finds, Flamingh and her colleagues have now dedicated a study to them that combined paleogenomic, isotopic, archaeological and historical methods. “To fully understand where those elephant tusks came from, we needed several lines of evidence,” says co-author Ashley Coutu University of Oxford. However, the central method was genetic and isotopic analyzes of sample material from the tusks. The researchers were able to compare the results with information on elephant populations living today.
It turned out that the tusks were not of savannah elephants (Loxodonta africana), but from their smaller cousins, the forest elephants (Loxodonta cyclotis), originated. The scientists were able to trace the animals back to 17 groups that lived exclusively in West Africa. As the researchers explain, this finding came as a surprise. “We had expected that the ivory would come from different regions thanks to the extensive trading network at the time – from West, but also from Central Africa,” says co-author Shadreck Chirikure from the University of Cape Town. According to historical sources, the Portuguese had already established trade relations with the Congo Kingdom in Central Africa in the 16th century. The elephants of the wreck ivory lived exclusively in a region of what is now Guinea. There were bases of the Portuguese at that time, from whose surroundings the ivory of the Bom Jesus apparently came.
References to the history of elephant populations
The genetic comparisons showed that of the total of 17 different elephant groups that supplied the ivory 500 years ago, only four have left offspring to this day. The others were apparently later lost due to the increasing intensity of hunting for the ivory trade or the destruction of the habitat, the scientists explain. As for the history of forest elephants in the age of hunting, the isotope analyzes also provided interesting information, the researchers report. This procedure allows conclusions to be drawn about the diet and the characteristics of the habitat of the animals.
Today forest elephants not only live in dense vegetation, but are also on the move in savannah areas. “There were speculations that the forest elephants only spread in steppe areas after almost all savannah elephants in West Africa were exterminated,” says co-author Alfred Roca of the University of Illinois. “However, our study showed that this was not the case. Because according to the results of the isotope analyzes, forest elephants lived in savannah habitats even in the early 16th century, long before the extensive decimation of savannah elephants by the ivory trade ”, says Roca.
The researchers now hope to initiate further studies of ivory in order to gain historical and biological information. In conclusion, Coutu says: “The investigation of historical ivory from other archaeological contexts also has great potential to provide information on the history of the global ivory trade and the hunt for elephants and the associated development of elephant populations,” says the scientist.
Source: Cell Press, University of Illinois, Article: Current Biology, doi: 10.1016 / j.cub.2020.10.086